Name: coronary angiography during ex-situ heart perfusion in a porcine model
Uploaded: 2024-07-12T13:30:00.000+00:00
Duration: 6 min 25 s
Description: Heart transplantation is the gold standard treatment for advanced heart failure. The procurement of extended criteria donors (ECD) increases due to the ...

We gratefully acknowledge the Fondation C&#339;ur Recherche and ADETEC for their financial support. We would also like to express our gratitude to Marie Lannelongue&#39;s lab team for their contributions to this project: Antoine Agathon, Laure Aubr&#232;ge, Aim&#233;e Alm&#233;ras, Catarina Bastos Dias, Antoine Gruss&#233;, Anselme Limousin, and Slimane Idir.

All pigs received humane care in compliance with the &#39;Principles of Laboratory Animal Care&#39; formulated by the National Society for Medical Research and the &#39;Guide for the Care and Use of Laboratory Animals&#39; prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (Eighth Edition, 12910. National Academies Press, Washington, D.C., 2011). This study design was approved by the French Ministry of Research for the use of animals for scientific purposes (protocol APAFiS#23716-2020012112432923v1). Eight large-white male pigs (60 kg, 6 months) were used for the present study. The animals were housed for one week before surgery with congeners at room temperature with a day-night light shift. Food and water were freely available. The reagents and equipment used for this study are listed in the Table of Materials.
1. Animal preparation
<ol>
	<li>Premedicate animals with an intramuscular injection of Tiletamine and Zolazepam (2 mg/kg).</li>
	<li>Complete anesthesia with an intravenous injection of propofol (3 mg/kg).</li>
	<li>After mask ventilation using 100% FiO2, perform oro-tracheal intubation with a 7.5 mm probe using a laryngoscope dedicated to large animals.</li>
	<li>Maintain general anesthesia by inhalation of 2% isoflurane, continuous infusion of sufentanil (10 &#181;g/kg/h), and intermittent injections of cisatracurium (0.3 mg/kg every 30 min).</li>
	<li>Perform a transthoracic echocardiogram to look for any cardiac disease that may contraindicate ex-situ perfusion of the heart. Significant aortic regurgitation does not allow for efficient NESP in Langendorff mode since coronary flow will be impaired. Retrograde aortic flow will mainly go to the left ventricle in this condition. 
	NOTE: Animals presenting with cardiac abnormalities, including significant aortic regurgitation, should be excluded from the protocol (the anesthesia is stopped for excluded animals to allow transfer to the animal facility).</li>
</ol>
2. Heart retrieval
<ol>
	<li>Perform a midline sternotomy. Use a scalpel (No. 23) to open the skin. Open the subcutaneous tissues using a monopolar cautery. Open the sternum using a semilunar sternal saw and complete the sternotomy using Mayo scissors.
	<ol>
		<li>Dissect the thymus, open it, and expose the pericardium with Metzenbaum scissors to avoid ventricular fibrillation induced by the electric field of the monopolar cautery.</li>
	</ol>
	</li>
	<li>Inject Heparin (300 IU/kg) directly into the right atrium.</li>
	<li>Perform purse-string stitches using 4/0 polypropylene sutures on the right atrium and aortic root to prepare for cannulation.</li>
	<li>Carefully detach the aorta from the main pulmonary artery to prepare for clamping of the aorta.</li>
	<li>Control the superior and inferior vena cava with a surgical loop.</li>
	<li>Introduce a 9-French antegrade long cannula into the aortic root 3 min after heparin administration.</li>
	<li>Purge the cardioplegia line and connect it to the aortic cannula, then clamp the cardioplegia line before blood collection. 
	NOTE: Blood collection results in a significant volume drop that may impair appropriate cannulation of the ascending aorta. Therefore, it is easier to do it before blood collection.</li>
	<li>Canulate the right atrium with a 32-French two-stage venous cannula.</li>
	<li>Connect a sterilized bag previously heparinized (10,000 IU) to the right atrium cannula and collect 1500 mL of blood. 
	NOTE: The collected blood is leukodepleted by another operator using a leukocyte filter and then placed directly in the machine perfusion circuit.</li>
	<li>Clamp the aorta and infuse 1000 mL of cold (4 &#176;C) cardioplegia solution (Table 1).</li>
	<li>Secure the superior and inferior vena cava with a surgical loop.</li>
	<li>Stop mechanical ventilation. Open the inferior vena cava and the left superior pulmonary vein to unload the heart. Place a cold saline solution in the pericardium.</li>
	<li>Remove the aortic and venous cannulas. Explant the heart by sectioning the left azygos vein, the two vena cavae, the distal ascending aorta, the pulmonary artery trunk, and the four pulmonary veins. 
	NOTE: The left azygos vein is specific to porcine anatomy. This vein goes directly to the coronary sinus. The left azygos vein must be transected between two ligatures before the heart is harvested.</li>
</ol>
3. Heart preparation for NESP
<ol>
	<li>Place the heart in 4 &#176;C saline solution.</li>
	<li>Investigate the aortic valve to confirm normal coaptation and close a patent foramen ovale if present using a 4-0 polypropylene suture.</li>
	<li>Complete the separation between the aorta and the pulmonary artery.</li>
	<li>Place four pledgeted sutures (4/0 polypropylene) around the distal section of the ascending aorta.</li>
	<li>Insert the appropriate aortic cannula and fix it with a hose clamp. Four sizes of aortic cannula are available: 3/4 inch, 7/8 inch, 1 inch, and 5/4 inch.</li>
	<li>Insert the 30 Fr pulmonary artery cannula and secure it with a 4/0 purse-string suture.</li>
	<li>Place a 20-French intracardiac sump through the mitral orifice to vent the left ventricle.</li>
</ol>
4. Normothermic ex-situ heart perfusion
NOTE: A detailed composition of the cardioplegia solution, priming solution, epinephrine, and adenosine infusions is provided in Table 1.
<ol>
	<li>Prime the machine perfusion (MP) with the collected blood (1500 mL) and add the priming solution (500 mL).</li>
	<li>Oxygenate with a membrane oxygenator and warm the blood to 34 &#176;C using a heater-cooler.</li>
	<li>Place a pressure probe on the aortic line above the aorta.</li>
	<li>Place a flowmeter around the pulmonary artery cannula. 
	NOTE: Continuous infusion of epinephrine (0.5 mL/h) is initiated after connection to the aortic line. Adenosine infusion will be adjusted to maintain mean aortic pressure between 65 mmHg and 80 mmHg.</li>
	<li>Increase the pump speed to reach a flow rate of 2500 mL/min.</li>
	<li>Collect an initial blood sample for blood gas analysis, ionogram, and lactate level. Adjust potassium, calcium, glycemia, and pH if necessary. 
	NOTE: All these steps are performed simultaneously with heart retrieval.</li>
	<li>Before positioning the heart in the MP, reduce the pump flow to 1000 mL/min and remove the shunt between the aortic and venous lines.</li>
	<li>De-air the aorta and connect the aortic cannula to the aortic line.</li>
	<li>Place the heart for optimal NESP (following the manufacturer&#39;s instructions). The postero-inferior ventricular wall will be in front of the operator, and the pulmonary artery cannula will be placed behind the aortic cannula.</li>
	<li>Perform gentle cardiac massage until the heart is warmed.</li>
	<li>Deliver a 20 J shock in case of ventricular fibrillation.</li>
	<li>Pace the heart at 80 beats per minute with an external pacemaker.</li>
	<li>Slowly increase pump flow to reach an aortic pressure of 65 mmHg.</li>
	<li>Close the inferior vena cava with a 4/0 polypropylene running suture.</li>
	<li>Purge and connect the pulmonary artery cannula to the venous line to continuously assess coronary flow. 
	NOTE: The coronary flow should be between 650 mL/min and 850 mL/min. The mean aortic pressure should be maintained between 70 mL/min and 85 mmHg. Assess blood gas and ionogram every hour and lactates every 30 min. If venous lactate is higher than arterial lactate, the first step is to ensure the normality of the ionogram and correct any biochemical abnormality. If pressure and coronary flow are low, increase the pump speed. If the pressure is high and the coronary flow is low, increase adenosine to vasodilate the coronary arteries. Stop adenosine infusion if aortic pressure is below 70 mmHg.</li>
</ol>
5. Coronary angiography during NESP
<ol>
	<li>Experimental setup 
	NOTE: The setup is depicted in Figure 1.
	<ol>
		<li>Ensure sufficient space is available for the machine perfusion (MP) system.</li>
		<li>Elevate the MP by approximately 25 cm using a platform. Rotate the MP 90&#176; to the left from the initial position.</li>
	</ol>
	</li>
	<li>Perform coronary angiography (Figure 2).
	<ol>
		<li>Flush the 5 French introducer and the 5 French Judkins right 3.5 coronary angiography catheter with serum.</li>
		<li>Insert a 5 French introducer through the valved orifice of the MP. 
		NOTE: The distal part of the introducer has to be placed just above the aorta.</li>
		<li>Advance the guide wire into the coronary angiography catheter up to the distal orifice. Insert the catheter and guide wire into the introducer up to the aortic root.</li>
		<li>Perform catheterization of the right coronary artery (RCA) using the following views: RAO 35/ CAU 44 or RAO 135/ CAU 62. Capture images of the RCA network using the views described in Table 2.</li>
		<li>Perform catheterization of the left coronary artery with the following view: RAO 135/ CAU 62. Capture images of the left coronary artery network using the views described in Table 2.</li>
		<li>Remove the coronary angiography catheter and the introducer. 
		NOTE: Use approximately 50 mL of Iomeprol without exceeding 100 mL.</li>
	</ol>
	</li>
</ol>

Coronary Artery Assessment During Ex-Situ Heart Perfusion

<ol>
	<li>Khush, K. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+International+Thoracic+Organ+Transplant+Registry+of+the+International+Society+for+Heart+and+Lung+Transplantation:+37th+adult+heart+transplantation+report-2020;+focus+on+deceased+donor+characteristics.">The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: 37th adult heart transplantation report-2020; focus on deceased donor characteristics.</a> J Heart Lung Transplant. 39 (10), 1003-1015 (2020).</li><li>Khush, K. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+International+Thoracic+Organ+Transplant+Registry+of+the+International+Society+for+Heart+and+Lung+Transplantation:+Thirty-fifth+Adult+Heart+Transplantation+Report-2018;+Focus+Theme:+Multiorgan+Transplantation.">The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-fifth Adult Heart Transplantation Report-2018; Focus Theme: Multiorgan Transplantation.</a> J Heart Lung Transplant. 37 (10), 1155-1168 (2018).</li><li>Dorent, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+potential+heart+donors:+A+statement+from+the+French+heart+transplant+community.">Assessment of potential heart donors: A statement from the French heart transplant community.</a> Arch Cardiovasc Dis. 111 (2), 126-139 (2018).</li><li>Ivanes, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performing+diagnostic+coronary+angiography+to+evaluate+high-risk+cardiac+donors:+A+French+nationwide+cohort+study.">Performing diagnostic coronary angiography to evaluate high-risk cardiac donors: A French nationwide cohort study.</a> Int J Cardiol. 277, 71-78 (2019).</li><li>Hassanein, W. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+perfusion+of+donor+hearts+in+the+beating+state+extends+preservation+time+and+improves+recovery+of+function.">Continuous perfusion of donor hearts in the beating state extends preservation time and improves recovery of function.</a> J Thorac Cardiovasc Surg. 116 (5), 821-830 (1998).</li><li>Ardehali, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=et+al.Ex-vivo+perfusion+of+donor+hearts+for+human+heart+transplantation+(PROCEED+II):+a+prospective,+open-label,+multicentre,+randomised+non-inferiority+trial.">et al.Ex-vivo perfusion of donor hearts for human heart transplantation (PROCEED II): a prospective, open-label, multicentre, randomised non-inferiority trial.</a> Lancet. 385 (9987), 2577-2584 (2015).</li><li>McCurry, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=294:+Prospective+Multi-Center+Safety+and+Effectiveness+Evaluation+of+the+Organ+Care+System+Device+for+Cardiac+Use+(PROCEED).">294: Prospective Multi-Center Safety and Effectiveness Evaluation of the Organ Care System Device for Cardiac Use (PROCEED).</a> J Heart Lung Transplant. 27 (2), S166 (2008).</li><li>Langmuur, S. J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normothermic+ex-situ+heart+perfusion+with+the+organ+care+system+for+cardiac+transplantation:+A+Meta-analysis.">Normothermic ex-situ heart perfusion with the organ care system for cardiac transplantation: A Meta-analysis.</a> Transplantation. 106 (9), 1745-1753 (2022).</li><li>Anthony, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ex+vivo+coronary+angiographic+evaluation+of+a+beating+donor+heart.">Ex vivo coronary angiographic evaluation of a beating donor heart.</a> Circulation. 130 (25), e341-e343 (2014).</li><li>Nadel, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Successful+transplantation+of+high-risk+cardiac+allografts+from+DCD+donors+following+ex+vivo+coronary+angiography.">Successful transplantation of high-risk cardiac allografts from DCD donors following ex vivo coronary angiography.</a> J Heart Lung Transplant. 39 (12), 1496-1499 (2020).</li><li>Dang Van, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=et+al.Ex+vivo+perfusion+of+the+donor+heart:+Preliminary+experience+in+high-risk+transplantations.">et al.Ex vivo perfusion of the donor heart: Preliminary experience in high-risk transplantations.</a> Arch Cardiovasc Dis. 114 (11), 715-726 (2021).</li><li>Mendirichaga, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ex+vivo+coronary+angiography+and+intravascular+ultrasound+of+a+donor+heart+in+the+organ+care+system.">Ex vivo coronary angiography and intravascular ultrasound of a donor heart in the organ care system.</a> JSCAI. 1 (4), 100342 (2022).</li><li>Schibilsky, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+angiography+and+intravascular+ultrasound+in+an+ex-vivo+perfused+heart+using+the+Organ+Care+System+(OCS).">Coronary angiography and intravascular ultrasound in an ex-vivo perfused heart using the Organ Care System (OCS).</a> J Heart Lung Transplant. 38 (4), 271 (2019).</li><li>Davis, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+angiography+of+older+donor+hearts+during+evaluation+for+transplantation.">Coronary angiography of older donor hearts during evaluation for transplantation.</a> J Heart Lung Transplant. 33 (4), S161-S162 (2014).</li><li>Grauhan, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+atherosclerosis+of+the+donor+heart+-+impact+on+early+graft+failure.">Coronary atherosclerosis of the donor heart - impact on early graft failure.</a> Eur J Cardiothorac Surg. 32 (4), 634-638 (2007).</li><li>Abid, Q., Parry, G., Forty, J., Dark, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concurrent+coronary+grafting+of+the+donor+heart+with+left+internal+mammary+artery:+10-year+experience.">Concurrent coronary grafting of the donor heart with left internal mammary artery: 10-year experience.</a> J Heart Lung Transplant. 21 (7), 812-814 (2002).</li><li>Pinto, C. S., Prieto, D., Antunes, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+artery+bypass+graft+surgery+during+heart+transplantation.">Coronary artery bypass graft surgery during heart transplantation.</a> Interact Cardiovasc Thorac Surg. 16 (2), 224-225 (2013).</li><li>Plyer, A., Colin, E., Orlik, X., Akamkam, A., Guihaire, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+vasculature+of+a+beating+heart+by+dynamic+speckle:+the+challenge+of+a+quasiperiodic+motion.">Imaging the vasculature of a beating heart by dynamic speckle: the challenge of a quasiperiodic motion.</a> J Biomed Opt. 28 (04), 046007 (2023).</li><li>Dang Van, S., Brunet, D., Akamkam, A., Decante, B., Guihaire, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+assessment+of+the+donor+heart+during+ex+situ+perfusion:+Insights+from+pressure-volume+loops+and+surface+echocardiography.">Functional assessment of the donor heart during ex situ perfusion: Insights from pressure-volume loops and surface echocardiography.</a> J Vis Exp. (188), e63945 (2022).</li></ol>

Authors have no conflicts of interest to declare.

This study describes, for the first time, a protocol for coronary angiography on an isolated beating heart without compromising myocardial metabolic viability during Normothermic Ex-situ Heart Perfusion (NESP). The views were reproducible, allowing for a comprehensive anatomical analysis of the coronary network. The required contrast agent volume was approximately 50 mL and rarely exceeded 100 mL. In comparison, the average volume used for in vivo coronary angiography is twice as much, ranging between 100 mL and 150 mL. The volume of the contrast agent was associated with the duration of the procedure. The experience gained by interventional cardiologists led to a reduction in exposure to X-rays as well as the volumes of the contrast agent.
Coronary angiographies showed that artifacts related to machine perfusion (MP) did not impair imaging interpretation. The unusual cardiac position during NESP led to anatomical views different from those observed in clinical practice during in vivo coronary angiography. The RAO 135/CAU 62 view was appropriate for catheterizing both the right and left coronary arteries. However, the RAO 35/CAU 44 incidence also facilitated easy catheterization of the RCA. This view is usually the first to be observed in our experience. Thus, catheterizing the RCA using RAO 35/CAU 44 as the first option is recommended. In case of technical difficulty, the RAO 135/CAU 62 view can be used as a secondary option. The 25 cm elevation of the MP requires meticulous care to prevent inclinations exceeding 45&#176;, as this may introduce air into the perfusion circuit. Sterility during the procedure is mandatory. An appropriate sterile field and disinfection of the valve orifice of the aortic line are highly recommended. Additionally, the operator is very close to the fluoroscopic arm in this configuration. Protection against X-ray exposure has to be adapted.
Limited literature exists on coronary angiography during Normothermic Ex-situ Heart Perfusion (NESP). The first description was reported in 2014 by Anthony et al. at St. Vincent Hospital in Australia9. Ex-situ coronary angiography identified coronary artery disease in the three main arteries, and the graft was not transplanted. A second description by the same team in 2020 reported the success of two donations after circulatory death (DCD) heart transplantations, including coronary angiography during NESP10. In both publications, the authors did not describe the volume and nature of the contrast agent they used or the imaging views. Another case of NESP coronary angiography on a DCD heart was reported by Mendirichaga et al. in San Diego in April 202212,13.
To the best of our knowledge, this study is the first to investigate the reproducibility of coronary angiography during NESP. A detailed protocol for coronary angiography during NESP is provided that could be applied for clinical use. These results obtained in a porcine model are reproducible in clinical practice, as porcine hearts share anatomical and physiological similarities with the human heart. Additionally, instrumentation and resuscitation of porcine hearts on machine perfusion are similar to clinical practice on the human heart.
This protocol could enhance the assessment of extended criteria donors (ECD), particularly within the European population, since donors are older and thus more exposed to coronary artery disease (CAD) compared to North America. This demographic difference underscores the importance of considering all available donor hearts, including those without coronary angiography, before organ procurement1. In France, Ivanes et al. showed that coronary angiography was not performed in 55% of ECDs. Among these hearts without coronary angiography, 88% were offered, and 57% were accepted4. In the US, 30% of ECD hearts are accepted without coronary angiography since the donor pool is younger with fewer donors at risk for CAD14.
This procedure has some limitations. It only allows for the investigation of the main coronary vessels. However, distal stenosis or single-vessel stenosis does not necessarily rule out heart transplantation. Hearts with mild stenosis can be accepted for unstable patients (such as those requiring VA-ECMO, Bi-VAD, etc.) in urgent need of heart transplantation15. Currently, no coronary artery revascularization has been performed on the Organ Care System (OCS) to date, and coronary artery bypass grafting is not a conventional procedure during heart transplantation16,17. The current gold standard approach remains to perform coronary angiography before organ procurement due to its cost-effectiveness and more sensitive analysis of the coronary network. Ex-situ coronary angiography represents an interesting alternative option if coronary angiography cannot be performed in extended criteria donors (ECD) at high risk for CAD while the recipient needs urgent transplantation.
Other less invasive methods for coronary assessment are currently under development, such as dynamic speckle laser imaging18. This technology employs low-energy laser illumination to achieve high-resolution real-time imaging of coronary microvascularization. However, this method still requires validation in isolated ex-situ perfused hearts. Previous work has described cardiac echography during Normothermic Ex-situ Heart Perfusion (NESP), requiring heart perfusion in a working mode state19. Screening for CAD in ECD could expand the pool of donor hearts. This protocol would also allow for the assessment of the coronary network in donation after circulatory death (DCD) donors. In this category of donors, coronary angiography cannot be performed before organ retrieval due to ethical considerations. Performing coronary angiography during NESP in this setting could enhance the safety of these transplantations. NESP is a major technological advancement in the field of heart transplantation. This technology paves the way for a better assessment of donor hearts prior to transplantation.

Heart transplantation is the gold standard therapy for advanced heart failure1,2. However, this treatment is limited by the current organ shortage, leading to increased allocation of extended criteria donors (ECD), who are more frequently exposed to coronary artery disease (CAD). Coronary angiography is recommended in France to prevent the risk of primary graft failure related to CAD if the donor&#39;s age is greater than 55 years or 45 years with two cardiovascular risk factors3. Even though coronary angiography increases the chances of graft acceptance by 9%, this procedure is performed in only 33% of cases in France4. Hearts from ECD at risk for CAD are therefore either declined for transplant or procured without screening for coronary artery disease.
The Organ Care System (OCS) is the only clinically available machine perfusion (MP) for Normothermic Ex-situ heart perfusion (NESP). This technology allows for longer preservation before transplantation by perfusing the donor heart with warm, oxygenated blood. Continuous metabolic assessment is performed during NESP by monitoring the lactate profile5. The efficacy and safety of NESP are now demonstrated by several studies, including a recent meta-analysis6,7,8. Performing coronary angiography during NESP would be of major interest to increase the probability of transplanting hearts from ECDs at risk for CAD.
Previously published experiences of ex-situ coronary angiography9,10,11 suggest that conventional views are not suitable due to the inverted position of the heart in the perfusion module. In addition, OCS components visible with X-rays may impair imaging findings. Lastly, the toxicity of contrast agents on the myocardium during isolated heart perfusion remains questionable. The present report aims to provide a safe and reproducible approach to performing coronary angiography during NESP.

<table><tbody><tr><td>3T Heater Cooler System</td><td>Liva Nova, Ch&amp;acirc;tillon, France</td><td>IM-00727 A</td><td>Extracorporeal Heater Cooler device</td></tr><tr><td>4-0 polypropylene suture</td><td>Peters, bobigny, France&amp;nbsp;</td><td>20S15B</td><td>sutures</td></tr><tr><td>5-0 polypropylene suture</td><td>Peters, bobigny, France&amp;nbsp;</td><td>20S10B</td><td>sutures</td></tr><tr><td>Adenosine</td><td>Efisciens BV, Rotterdam, Netherlands&amp;nbsp;</td><td>9088309</td><td>Drugs for the ex-vivo perfusion</td></tr><tr><td>Adrenaline</td><td>Aguettant, Lyon, France&amp;nbsp;</td><td>600040</td><td>Drugs for the ex-vivo perfusion</td></tr><tr><td>ADW software</td><td>General Electric Healthcare, Chicago, Ill, USA</td><td>ADW_IGS730/ M5173653</td><td>Software used for the coronary angiography visualization</td></tr><tr><td>Atracurium</td><td>Pfizer Holding France, Paris, France&amp;nbsp;</td><td>582547</td><td>Drugs for the induction of the anesthesia</td></tr><tr><td>CG4 +</td><td>Abbott, Chicago, Ill, USA</td><td>03P85-25</td><td>Lactates and blood gas cartridge for the blood analyzer machine&amp;nbsp;</td></tr><tr><td>CG8 +</td><td>Abbott, Chicago, Ill, USA</td><td>03P88-25</td><td>Ionogram cartridge for the blood analyzer machine&amp;nbsp;</td></tr><tr><td>DeltaStream&amp;nbsp;</td><td>Fresenius Medical Care, L&amp;rsquo;Arbresle, France</td><td>MEH2C4024</td><td>Extracorporeal blood pump</td></tr><tr><td>Discovery IGS 7</td><td>General Electric Healthcare, Chicago, Ill, USA</td><td>Discovery IGS7.3 / M5173652</td><td>Angiography system for hybrid operating room&amp;nbsp;</td></tr><tr><td>DLP Aortic Root Cannula</td><td>Medtronic Inc. Minneapolis, Minneapolis, USA</td><td>ref. 11012, 12.5 inch</td><td>Aortic Root Cannula</td></tr><tr><td>External pacemaker</td><td>Medtronic Inc. Minneapolis, Minneapolis, USA</td><td>5392</td><td>Pacemaker device</td></tr><tr><td>Fresinus Agilia injectomat</td><td>Fresenius vial , Brezins, France</td><td>018010/20640320</td><td>Syringe driver&amp;nbsp;</td></tr><tr><td>Glucose 5%</td><td>B.Braun Melsungen AG, Melsungen, Germany</td><td>3400891780017</td><td>Drugs for the priming solution</td></tr><tr><td>Haemonetics leukocyte filter</td><td>Haemonetics, Boston, Massachusetts, USA</td><td>RS1VAE</td><td>Leukocyte Filter&amp;nbsp;</td></tr><tr><td>Heart Perfusion Set, Organ Care System</td><td>Transmedics, Andover, MA, USA</td><td>Ref#1200</td><td>Normothermic ex-vivo heart perfusion device, including, the perfusion module, pulmonary artery and aortic cannula</td></tr><tr><td>Intellivue MX550</td><td>Philips Healthcare, Suresnes, France</td><td>NA</td><td>Permanent monitoring system&amp;nbsp;</td></tr><tr><td>Iomeron 350</td><td>Bracco imaging, Massy, France</td><td>3400933794606.00</td><td>Iomeprol contrast agent product</td></tr><tr><td>istat 1</td><td>Abbott, Chicago, Ill, USA</td><td>714336-03O</td><td>Blood Analyzer machine&amp;nbsp;</td></tr><tr><td>Judkins Right 3.5</td><td>Boston Scientific,&amp;nbsp; Marlborough, Massachusetts, USA</td><td>H74934358202&amp;nbsp;</td><td>Coronary angiography catheterization probe&amp;nbsp;</td></tr><tr><td>Magnesium</td><td>Aguettant, Lyon, France&amp;nbsp;</td><td>564 780-6</td><td>Drugs for the cardioplegia</td></tr><tr><td>Magnesium Sulfate</td><td>Aguettant, Lyon, France&amp;nbsp;</td><td>600111</td><td>Drugs for the cardioplegia</td></tr><tr><td>Mannitol 20%</td><td>Macopharma, Mouvoux, France</td><td>3400891694567.00</td><td>Drugs for the cardioplegia</td></tr><tr><td>Methylprednisolone&amp;nbsp;</td><td>Mylan S.A.S, Saint Priest, France&amp;nbsp;</td><td>400005623</td><td>Drugs for the priming solution</td></tr><tr><td>MWI software&amp;nbsp;</td><td>General Electric Healthcare, Chicago, Ill, USA</td><td>NA</td><td>software used for the Ultrasound echocardiographic machine</td></tr><tr><td>Orotracheal probe</td><td>Smiths medical ASD, Inc., Minneapolis, Minneapolis, USA</td><td>100/199/070</td><td>probe for the intubation during anesthesia&amp;nbsp;</td></tr><tr><td>Potassium chloride 10%&amp;nbsp;</td><td>B.Braun Melsungen AG, Melsungen, Germany</td><td>3400892691527.00</td><td>Drugs for the cardioplegia</td></tr><tr><td>Propofol</td><td>Zoetis France, Malakoff, France&amp;nbsp;</td><td>8083511</td><td>Drugs for the induction of the anesthesia</td></tr><tr><td>Quadrox-I small Adult Oxygenator</td><td>Getinge, G&amp;ouml;teborg, Sweden</td><td>BE-HMO 50000</td><td>Extracorporeal blood oxygenator</td></tr><tr><td>Ringer solution</td><td>B.Braun Melsungen AG, Melsungen, Germany</td><td>DKE2323</td><td>Drugs for the cardioplegia</td></tr><tr><td>Sodium Bicarbonate</td><td>Laboratoire Renaudin, itxassou, France</td><td>3701447</td><td>Drugs for the cardioplegia</td></tr><tr><td>Sodium chloride</td><td>Aguettant, Lyon, France&amp;nbsp;</td><td>606726</td><td>Drugs for the priming solution</td></tr><tr><td>Swan Ganz Catheter</td><td>Merit Medical, south jordan, utah, USA&amp;nbsp;&amp;nbsp;</td><td>5041856</td><td>Right pressure and cardiac output probe&amp;nbsp;</td></tr><tr><td>Tiletamine&amp;nbsp;</td><td>Virbac France, Carros, France&amp;nbsp;</td><td>3597132126021.00</td><td>Drugs for the induction of the anesthesia</td></tr><tr><td>Two staged Venous Cannula&amp;nbsp;</td><td>Medtronic Inc. Minneapolis, Minneapolis, USA</td><td>91240, 32 french</td><td>Venous Cannula</td></tr><tr><td>Vivid E95 ultraSound Machine</td><td>General Electric Healthcare, Chicago, Ill, USA</td><td>NA</td><td>Ultrasound echocardiographic machine</td></tr><tr><td>Xyloca&amp;iuml;ne 2%</td><td>Aspen, Reuil-malmaison, France&amp;nbsp;</td><td>600550</td><td>Drugs for the cardioplegia</td></tr><tr><td>Zolazepam</td><td>Cardinal Health LLC, Waukegan, Illinois, USA</td><td>31050522</td><td>EKG detection electrodes&amp;nbsp;</td></tr><tr><td>Zolazepam</td><td>Virbac France, Carros, France&amp;nbsp;</td><td>3597132126021.00</td><td>Drugs for the induction of the anesthesia</td></tr></tbody></table>

coronary angiography during ex-situ heart perfusion in a porcine model

Heart transplantation is the gold standard treatment for advanced heart failure. The procurement of extended criteria donors (ECD) increases due to the current organ shortage. Coronary angiography is recommended in ECD at risk for coronary artery disease but is not systematically performed. These hearts are, therefore, either declined for transplant or procured without screening for coronary artery disease. Coronary angiography during normothermic ex-situ heart perfusion (NESP) could be an interesting approach to enhance the rate of ECD procurement and to reduce the risk of primary graft failure in the absence of coronary angiography in ECD. The present protocol aims to provide material details along with optimal imaging views for coronary angiography during NESP. Reproducible angiographic views were observed, including one dedicated to the right coronary artery, two for the left anterior descending artery, two for the circumflex artery, and a spider view. Continuous lactate extraction was observed in all procedures with a final median concentration of 1.10 mmol/L (0.61-1.75 mmol/L) two hours after coronary angiography, consistent with myocardial viability. The median contrast agent volume used for ex-situ imaging of the isolated perfused heart was 48 mL (38-108 mL). This protocol was reproducible for coronary artery imaging and did not impair myocardial viability during NESP.

The outlined protocol was designed for easy reproducibility in clinical practice. Minimal modifications were made to the available module for Normothermic Ex-situ Heart Perfusion (NESP). The only adjustments were made to connect the module to an extracorporeal life support pump, an oxygenator, and a heater-cooler unit to replace the machine perfusion (MP).
Two test procedures were initially conducted to assess the coronary angiography views used in this protocol. Six coronary angiographies were then performed on ex-situ perfused porcine hearts. Hearts were perfused for 240 min, and coronary angiography was performed after 120 min. The initial 120-min period was defined to replicate the average time observed in clinical practice between the beginning of NESP and the return to the transplant center where coronary angiography will be performed; the last two hours represented the duration needed for coronary angiography and preparation of the receiver in the operating room. Coronary angiography procedures were performed by two experienced interventional cardiologists. Mean aortic pressure and coronary flow were continuously monitored. Lactate levels were measured every 30 min to assess myocardial viability. Iomeprol volume and exposure to radiation were also recorded.
Baseline parameters are presented in Table 3. All hearts showed a favorable metabolic profile with preserved lactate extraction and were successfully preserved for 4 h on NESP. There were no premature endings due to perfusion failure. There was a failure in catheterizing the left coronary artery during the second procedure. In the third case, the views between the left and right coronary arteries were switched. The median volume of the contrast agent was 48 mL (min 38 mL-max 108 mL). The median dose of ionizing radiation was 3.30 mGy (min 1.0 mGy-max 17 mGy), with a median Dose-Area Product (DAP) of 0.55 Gy/cm2 (min 0.18 Gy/cm2-max 2.05 Gy/cm2). The median exposure time to ionizing radiation was 9.50 min (IQR: 6.75-12.75). The average procedure duration was 34.5 min (&#177; 21). Lactate profiles, coronary flow, aortic pressure, and metabolic results are shown in Table 4 and Figure 3.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/66567/66567fig01.jpg" /> 
Figure 1: MP and fluoroscopic arm setup. (A) The MP is elevated by a platform so that the heart is within the X-ray field of the fluoroscopic arm to access the coronary angiography images. (B) After a 10 cm elevation, the MP is within the X-ray field, and coronary angiography images can be captured. (C) Operators performing coronary angiography through the valved orifice. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/66567/66567fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/66567/66567fig02.jpg" /> 
Figure 2: Coronary angiography during normothermic ex-situ heart perfusion. (A) Right coronary artery. (B) Left anterior descending artery. (C) Circumflex artery. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/66567/66567fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/66567/66567fig03.jpg" /> 
Figure 3: Median lactate levels, coronary flow, and aortic pressure trends during the 240 min of normothermic ex-situ heart perfusion. The red diagram bars represent the median lactate concentration in mmol/L. The blue line with dots represents the median coronary flow in mL/min. The green line with triangles represents the median aortic pressure in mmHg. The error bars represent 95% CI. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/66567/66567fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Solution</td>
			<td>Components</td>
		</tr>
		<tr>
			<td rowspan="6">Cardioplegia</td>
			<td>500 mL of Ringer solution</td>
		</tr>
		<tr>
			<td>10 mL of 10% KCl</td>
		</tr>
		<tr>
			<td>3 mL of 2% Xyloca&#239;ne</td>
		</tr>
		<tr>
			<td>6 mL of 20% Mannitol</td>
		</tr>
		<tr>
			<td>6 mL of 8.4% Sodium Bicarbonate</td>
		</tr>
		<tr>
			<td>7 mL of 15% Magnesium Sulfate</td>
		</tr>
		<tr>
			<td rowspan="6">Priming</td>
			<td>500 mL NaCl solution</td>
		</tr>
		<tr>
			<td>150 mg of Magnesium</td>
		</tr>
		<tr>
			<td>250 mg of Methylprednisolone</td>
		</tr>
		<tr>
			<td>1 g of Cefotaxime</td>
		</tr>
		<tr>
			<td>50 UI of Insuline</td>
		</tr>
		<tr>
			<td>5 mL of 30% Glucose</td>
		</tr>
		<tr>
			<td rowspan="2">Epinephrine infusion</td>
			<td>500 mL of 5% Glucose</td>
		</tr>
		<tr>
			<td>0.25 mg of epinephrine</td>
		</tr>
		<tr>
			<td rowspan="2">Adenosine infusion</td>
			<td>60 mg of Adenosine</td>
		</tr>
		<tr>
			<td>40 mL of NaCl solution</td>
		</tr>
	</tbody>
</table>
Table 1: A detailed composition of the cardioplegia solution, priming solution, epinephrine, and adenosine infusions.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Coronary arteries</td>
			<td>Lateral rotation</td>
			<td>Supero-inferior rotation</td>
		</tr>
		<tr>
			<td>RCA</td>
			<td>RAO 35</td>
			<td>CAU 44</td>
		</tr>
		<tr>
			<td>Proximal RCA</td>
			<td>RAO 64</td>
			<td>CAU 38</td>
		</tr>
		<tr>
			<td>Distal RCA</td>
			<td>RAO 65</td>
			<td>CAU 66</td>
		</tr>
		<tr>
			<td>Spider</td>
			<td>RAO 70</td>
			<td>CAU 52</td>
		</tr>
		<tr>
			<td>LAD</td>
			<td>RAO 135</td>
			<td>CAU 62</td>
		</tr>
		<tr>
			<td>LAD</td>
			<td>RAO 167</td>
			<td>CAU 79</td>
		</tr>
		<tr>
			<td>Marginal artery</td>
			<td>RAO 44</td>
			<td>CAU 51</td>
		</tr>
		<tr>
			<td>Cx</td>
			<td>LAO 125</td>
			<td>CAU 83</td>
		</tr>
	</tbody>
</table>
Table 2: Coronary angiography views. RCA: Right Coronary Artery; LAD: Left Anterior Descending coronary artery; Cx: Circumflex artery; RAO: Right Anterior Oblique view; LAO: Left Anterior Oblique view; CAU: Caudal view.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>T0</td>
		</tr>
		<tr>
			<td>Weight&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Pigs (kg) &#8224;</td>
			<td>51.9 (50.1&#8212;53.9)</td>
		</tr>
		<tr>
			<td>Hearts (g) &#8225;</td>
			<td>228.5 (&#177; 30.1)</td>
		</tr>
		<tr>
			<td>Timing (min) &#8225;</td>
			<td></td>
		</tr>
		<tr>
			<td>Heart retrieval</td>
			<td>13.5 (&#177; 5.4)</td>
		</tr>
		<tr>
			<td>Cold ischemic time&#160;</td>
			<td>41.8 (&#177; 9.8)</td>
		</tr>
		<tr>
			<td>Back-table time&#160;</td>
			<td>29.3 (&#177; 8.2)</td>
		</tr>
		<tr>
			<td>Perfusion parameters &#8224;&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Aortic Pressure (mmHg)</td>
			<td>80.50 (75.25&#8212;83.50)</td>
		</tr>
		<tr>
			<td>Coronary flow (L/min)</td>
			<td>0.450 (0.375&#8211; 0.650)</td>
		</tr>
		<tr>
			<td>Biological results &#8224;&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactates (mmol/L)</td>
			<td>2.59 (2.87&#8212;2.32)</td>
		</tr>
		<tr>
			<td>pH &#160;&#8225;</td>
			<td>7.44 (&#177; 0.05)</td>
		</tr>
		<tr>
			<td>pO2 (mmHg)</td>
			<td>523 (466&#8211;631)</td>
		</tr>
		<tr>
			<td>pCO2 (mmHg)</td>
			<td>30.1 (26.2&#8211;35.8)</td>
		</tr>
		<tr>
			<td>HCO3- (mmol/L)</td>
			<td>22.10 (17.55&#8211;24.37)</td>
		</tr>
		<tr>
			<td>Natremia (mmol/L)</td>
			<td>143 (138.7&#8211;145.0)</td>
		</tr>
		<tr>
			<td>Kaliemia (mmol/L) &#8225;</td>
			<td>2.97 (&#177; 0.60)</td>
		</tr>
		<tr>
			<td>Calcemia (mmol/L)</td>
			<td>1.11 (1.09&#8211;1.16)</td>
		</tr>
		<tr>
			<td>Glycemia (mmol/L)</td>
			<td>1.17 (1.12&#8211;1.34)</td>
		</tr>
	</tbody>
</table>
Table 3: Baseline characteristics. &#8224;Data are expressed as medians (with IQR interquartile range).
&#8225;Data are expressed as means (with standard derivations). T0 = at the beginning of the normothermic ex-situ heart perfusion; pO2 = oxygen partial pressure; pCO2 = carbon dioxide partial pressure; HCO3- = Bicarbonates.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>T120</td>
			<td>T240</td>
		</tr>
		<tr>
			<td>Perfusion parameters</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Aortic Pressure (mmHg)</td>
			<td>79.00 (74.2 &#8211; 82.2)</td>
			<td>73.00 (69.50 &#8211; 76.25)</td>
		</tr>
		<tr>
			<td>Coronary flow (L/min)</td>
			<td>0.65 (0.60 &#8211; 0.70)</td>
			<td>0.85 (0.67 &#8211; 1.10)</td>
		</tr>
		<tr>
			<td>Biological results</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lactates (mmol/L)</td>
			<td>1.68 (0.92 &#8211; 2.08)</td>
			<td>1.10 (0.61 &#8211; 1.75)</td>
		</tr>
		<tr>
			<td>pH&#160;</td>
			<td>7.39 (7.35 &#8211; 7.42)</td>
			<td>7.36 (7.32 &#8211; 7.43)</td>
		</tr>
		<tr>
			<td>HCO3- (mmol/L)</td>
			<td>22.10 (20.10 &#8211; 23.12)</td>
			<td>21.20 (19.22 &#8211; 22.92)</td>
		</tr>
		<tr>
			<td>Natremia (mmol/L)</td>
			<td>144.5 (144.00 &#8211; 146.25)</td>
			<td>142.5 (137.50 &#8211; 145.25)</td>
		</tr>
		<tr>
			<td>Kaliemia (mmol/L)</td>
			<td>3.55 (3.12 &#8211; 3.82)</td>
			<td>3.10 (2.97 &#8211; 3.62)</td>
		</tr>
		<tr>
			<td>Calcemia (mmol/L)</td>
			<td>1.13 (1.11 &#8211; 1.16)</td>
			<td>1.10 (1.08 &#8211; 1.16)</td>
		</tr>
	</tbody>
</table>
Table 4: Perfusion parameters and biological results before and 2 h after coronary angiography.&#160;Data are expressed as medians (with IQR interquartile range). T120 = 120 min after the beginning of the normothermic ex-situ heart perfusion, just before coronary angiography; T240 = 240 min after the beginning of the normothermic ex-situ heart perfusion, 120 min after coronary angiography; HCO3- = Bicarbonates.

Author Spotlight: Innovative Technique for Coronary Angiography in Marginal Donors

Screening for coronary artery disease could increase the procurement of donor hearts with extended criteria. A protocol for performing reproducible coronary angiography during ex-situ heart perfusion is described herein in a porcine model.

Coronary Angiography During Ex-Situ Heart Perfusion in a Porcine Model

Heart transplantation is the gold standard treatment for advanced heart failure. The procurement of extended criteria donors (ECD) increases due to the ...

coronary-angiography-during-ex-situ-heart-perfusion-in-a-porcine-model

Nanyang Technological University

Research

JoVE Journal

Medicine

302 Views.  Groupe Hospitalier Paris Saint Joseph. Screening op coronaire hartziekte wordt aanbevolen vóór de aanschaf van het hart bij marginale donoren, maar ontbreekt vaak. Het uitvoeren van een coronaire angiografische ex-situ hartperfusie zou een alternatief kunnen zijn. Deze video geeft een gedetailleerde beschrijving van deze methode.Niet-conventionele weergaven zijn nodig voor coronaire beeldvorming, aangezien het hart wordt omgekeerd in de perfusiemodule. Ten tweede kunnen de componenten van...

Video: Auteur in de schijnwerpers: innovatieve techniek voor coronaire angiografie bij marginale donoren

Intra-cardiac Side-Firing Light Catheter for Monitoring Cellular Metabolism using Transmural Absorbance Spectroscopy of Perfused Mammalian Hearts

Absorbance spectroscopy of cardiac muscle provides non-destructive assessment of cytosolic and mitochondrial oxygenation via myoglobin and cytochrome absorbance respectively. In addition, numerous aspects of the mitochondrial metabolic status such as membrane potential and substrate entry can also be estimated. To perform cardiac wall transmission optical spectroscopy, a commercially available side-firing optical fiber catheter is placed in the left ventricle of the isolated perfused heart as a light source. Light passing through the heart wall is collected with an external optical fiber to perform optical spectroscopy of the heart in near real- time. The transmission approach avoids numerous surface scattering interference occurring in widely used reflection approaches. Changes in transmural absorbance spectra were deconvolved using a library of chromophore reference spectra, providing quantitative measures of all the known cardiac chromophores simultaneously. This spectral deconvolution approach eliminated intrinsic errors that may result from using common dual wavelength methods applied to overlapping absorbance spectra, as well as provided a quantitative evaluation of the goodness of fit. A custom program was designed for data acquisition and analysis, which permitted the investigator to monitor the metabolic state of the preparation during the experiment. These relatively simple additions to the standard heart perfusion system provide a unique insight into the metabolic state of the heart wall in addition to conventional measures of contraction, perfusion, and substrate/oxygen extraction.

Here we introduce a method for using an intra-ventricle optical catheter in perfused hearts to perform absorbance spectroscopy across the heart wall. The data obtained provides robust information on tissue oxygen tension as well as substrate utilization and membrane potential simultaneously with cardiac performance measures in this ubiquitous preparation.

Absorbance spectroscopy of cardiac muscle provides non-destructive assessment of cytosolic and mitochondrial oxygenation via myoglobin and cytochrome ...

Bioengineering

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Improvement of a Closed Chest Porcine Myocardial Infarction Model by Standardization of Tissue and Blood Sampling Procedures

Myocardial ischemia reperfusion (I/R) injury contributes to almost half of the necrotic area after myocardial infarction. To date there is no approved drug to prevent or reduce myocardial I/R injury. The study and understanding of the pathophysiological mechanisms of myocardial I/R injury is essential to develop successful treatments. Large animal experiments are an important step in translational methods. The porcine model of acute myocardial infarction has been established and described by ourselves and others. We aimed to further improve the value of the model by focusing in detail on the sampling techniques for use in future experiments. Furthermore, we emphasize small but important steps that can affect the quality of the final results. To mimic the clinical situation of myocardial I/R injury, a percutaneous coronary intervention (PCI) catheter was inserted into the left anterior descending coronary artery (LAD) of an anesthetized pig. &#176;&#176;&#176;This model mimics acute myocardial infarction and PCI treatment in humans with the possibility of accurately determining the area at risk as well as the necrotic- and viable ischemic tissue. Here the model was used to investigate the effect of a bicyclic peptide inhibitor of FXIIa. The model can also be modified to allow longer reperfusion times to study later effects of myocardial infarction.

Here we demonstrate a protocol to standardize sampling procedures of an established porcine model of acute myocardial infarction in order to increase its translational value in the understanding of the pathophysiology of myocardial ischemia/reperfusion injury and to test novel drug candidates.

Myocardial ischemia reperfusion (I/R) injury contributes to almost half of the necrotic area after myocardial infarction. To date there is no approved ...

Normothermic Ex Situ Heart Perfusion in Working Mode: Assessment of Cardiac Function and Metabolism

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation time and increases the risk of adverse post-transplantation outcomes. Moreover, the static nature of CS does not allow for organ evaluation or intervention during the preservation interval. Normothermic ex situ heart perfusion (ESHP) is a novel method for preservation of the donated heart that minimizes cold ischemia by providing oxygenated, nutrient-rich perfusate to the heart. ESHP has been shown to be non-inferior to CS in the preservation of standard-criteria donor hearts and has also facilitated the clinical transplantation of the hearts donated after the circulatory determination of death. Currently, the only available clinical ESHP device perfuses the heart in an unloaded, non-working state, limiting assessments of myocardial performance. Conversely, ESHP in working mode provides the opportunity for comprehensive evaluation of cardiac performance by assessment of functional and metabolic parameters under physiologic conditions. Moreover, earlier experimental studies have suggested that ESHP in working mode may result in improved functional preservation. Here, we describe the protocol for ex situ perfusion of the heart in a large mammal (porcine) model, which is reproducible for different animal models and heart sizes. The software program in this ESHP apparatus allows for real-time and automated control of the pump speed to maintain desired aortic and left atrial pressure and evaluates a variety of functional and electrophysiological parameters with minimal need for supervision/manipulation.

Normothermic ex situ heart perfusion (ESHP), preserves the heart in a beating, semi-physiologic state. When performed in a working mode, ESHP provides the opportunity to perform sophisticated assessments of donor heart function and organ viability. Here, we describe our method for myocardial performance evaluation during ESHP.

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation ...

Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.

The objective of this study was to establish a method for investigating cardiac dynamics using a translational animal model. The described experimental approach incorporates dual-emission optocardiography in conjunction with an electrophysiological study to assess electrical activity in an isolated, intact porcine heart model.

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to ...

Novel Percutaneous Approach for Deployment of 3D Printed Coronary Stenosis Implants in Swine Models of Ischemic Heart Disease

Minimally invasive methods for creating models of focal coronary narrowing in large animals are challenging. Rapid prototyping using three-dimensionally (3D) printed coronary implants can be employed to percutaneously create a focal coronary stenosis. However, reliable delivery of the implants can be difficult without the use of ancillary equipment. We describe the use of a mother-and-child coronary guide catheter for stabilization of the implant and for effective delivery of the 3D printed implant to any desired location along the length of the coronary vessel. The focal coronary narrowing was confirmed under coronary cineangiography and the functional significance of the coronary stenosis was assessed using gadolinium-enhanced first-pass cardiac perfusion MRI. We showed that reliable delivery of 3D printed coronary implants in swine models (n = 11) of ischemic heart disease can be achieved through repurposing mother-and-child coronary guide catheters. Our technique simplifies the percutaneous delivery of coronary implants to create closed-chest swine models of focal coronary artery stenosis and can be performed expeditiously, with a low procedural failure rate.

We describe a novel, cost-effective, and efficient technique for percutaneous delivery of three-dimensionally printed coronary implants to create closed-chest swine models of ischemic heart disease. The implants were fixed in place using a mother-and-child extension catheter with high success rate.

Minimally invasive methods for creating models of focal coronary narrowing in large animals are challenging. Rapid prototyping using three-dimensionally ...

Development of a Selective Aortic Arch Perfusion System in a Porcine Model of Exsanguination Cardiac Arrest

Hemorrhage constitutes the majority of potentially preventable deaths from trauma. There is growing interest in endovascular resuscitation techniques such as selective aortic arch perfusion (SAAP) for patients in cardiac arrest. This involves active perfusion of the coronary circulation via a thoracic aortic balloon catheter and is approaching clinical application. However, the technique is complex and requires refinement in animal models before human use can be considered. This paper describes a large animal model of exsanguination cardiac arrest treated with a bespoke SAAP system.
Swine were anesthetized, instrumented and a splenectomy was performed before a controlled, logarithmic exsanguination was initiated. Animals were heparinized and the shed blood collected in a reservoir. Once cardiac arrest was observed, the blood was pumped through an extra-corporeal circuit into an oxygenator and then delivered through a 10 Fr balloon catheter placed in the thoracic aorta.
This resulted in the return of a spontaneous circulation (ROSC) as demonstrated by ECG and aortic root pressure waveform. This model and accompanying SAAP system allow for standardized and reproducible recovery from exsanguination cardiac arrest.

The goal of this protocol is to demonstrate a porcine exsanguination cardiac arrest model and a specifically built selective aortic arch perfusion circuit for translational research.

Hemorrhage constitutes the majority of potentially preventable deaths from trauma. There is growing interest in endovascular resuscitation techniques such ...

Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in G&#246;ttingen Minipigs and Landrace Pigs

The development of heart failure is the most powerful predictor of long-term mortality in patients surviving acute myocardial infarction (MI). There is an unmet clinical need for prevention and therapy of post-myocardial infarction heart failure (post-MI HF). Clinically relevant pig models of post-MI HF are prerequisites for final proof-of-concept studies before entering into clinical trials in drug and medical device development.
Here we aimed to characterize a closed-chest porcine model of post-MI HF in adult G&#246;ttingen minipigs with long-term follow-up including serial cardiac magnetic resonance imaging (CMRI) and to compare it with the commonly used Landrace pig model.
MI was induced by intraluminal balloon occlusion of the left anterior descending coronary artery for 120 min in G&#246;ttingen minipigs and for 90 min in Landrace pigs, followed by reperfusion. CMRI was performed to assess cardiac morphology and function at baseline in both breeds and at 3 and 6 months in G&#246;ttingen minipigs and at 2 months in Landrace pigs, respectively.
Scar sizes were comparable in the two breeds, but MI resulted in a significant decrease of left ventricular ejection fraction (LVEF) only in G&#246;ttingen minipigs, while Landrace pigs did not show a reduction of LVEF. Right ventricular (RV) ejection fraction increased in both breeds despite the negligible RV scar sizes. In contrast to the significant increase of left ventricular end-diastolic (LVED) mass in Landrace pigs at 2 months, G&#246;ttingen minipigs showed a slight increase in LVED mass only at 6 months.
In summary, this is the first characterization of post-MI HF in G&#246;ttingen minipigs in comparison to Landrace pigs, showing that the G&#246;ttingen minipig model reflects post-MI HF parameters comparable to the human pathology. We conclude that the G&#246;ttingen minipig model is superior to the Landrace pig model to study the development of post-MI HF.

The overall goal of the current study is to present the techniques of induction of myocardial infarction (MI) and post-myocardial infarction heart failure (post-MI HF) in closed-chest, adult G&#246;ttingen minipigs and the characterization of post-MI HF model in G&#246;ttingen minipigs as compared to Landrace pigs.

The development of heart failure is the most powerful predictor of long-term mortality in patients surviving acute myocardial infarction (MI). There is an ...

Preclinical Evaluation of Coronary Artery Stents

Coronary artery disease is a major contributor to morbidity and mortality worldwide. While lifestyle changes and medication are the cornerstones of treatment, coronary artery balloon angioplasty and stenting are routinely performed on patients with acute coronary syndromes and chronic coronary artery disease who remain symptomatic with optical medical treatment. Several generations of coronary stents have been developed over recent decades. Balloon angioplasty and stenting are supported by the use of pharmaceutical agents applied onto balloons and the stent surface, either to advance the healing properties of the artery post-intervention or to prevent the formation of restenosis. New devices need to be rigorously tested for safety and efficacy before acceptance into clinical practice; thus, there is a continuing need for reliable and reproducible preclinical methods of stent evaluation. We describe here a pig coronary artery model as well as an atherosclerotic rabbit model for coronary artery stent research and describe basic steps in intravascular imaging and stent histology.

New coronary artery stent designs and materials must be tested before clinical use in relevant preclinical models. Here we describe an atherosclerotic rabbit aorta model and a pig coronary artery model for stent research with in vivo and histological analyses.

Coronary artery disease is a major contributor to morbidity and mortality worldwide. While lifestyle changes and medication are the cornerstones of ...

Surgical Technique for Jugular Vein Thermodilution Catheter Placement in Pigs

Determination of Cardiac Output in a Porcine Model for Ex Vivo Pulmonary Perfusion

Due to their physiological similarities to humans, pigs are used as experimental models for ex vivo lung perfusion (EVLP). EVLP is a technique that perfuses lungs that are not suitable for transplantation via an extracorporeal circulation pump to improve their function and increase their viability. Existing EVLP protocols are differentiated by the type of perfusion solution and perfusion flow, which varies from 40%-100% of the estimated cardiac output (CO) according to the body surface area (BSA). Devices for measuring CO use simple physical principles and other mathematical models. Thermodilution in animal models continues to be the reference standard for estimating CO because of its simplicity and ease of reproduction. Therefore, the objective of this study was to reproduce the measurement of CO by thermodilution in pigs and compare its precision and accuracy with those obtained by the BSA, weight, and Fick's method, to establish perfusion flow during EVLP. In 23 pigs, a thermodilution catheter was placed in the right jugular vein, and the carotid artery on the same side was cannulated. Blood samples were obtained for gasometry, and CO was estimated by thermodilution, adjusted body surface area, Fick's principle, and per body weight. The CO obtained by the BSA was greater (p = 0.0001, ANOVA, Tukey) than that obtained by the other methods. We conclude that although the methods used in this study to estimate CO are reliable, there are significant differences between them; therefore, each method must be evaluated by the investigator to determine which meets the needs of the protocol.

Author Spotlight: Assessment of Cardiac Output Calculation by Thermodilution in Pigs for Effective Perfusion Flow During EVLP

This protocol describes the surgical technique used for the placement of a thermodilution catheter through the jugular vein in pigs to estimate cardiac output and ensure adequate lung perfusion during ex vivo lung perfusion (EVLP).

Due to their physiological similarities to humans, pigs are used as experimental models for ex vivo lung perfusion (EVLP). EVLP is a technique that ...

Coronary Angiography During Ex-Situ Heart Perfusion in a Porcine Model

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