INTRODUCTION A common limitation to normothermic ex situ heart perfusion (ESHP) is functional decline. We previously designed a cardioprotective normothermic perfusion protocol, incorporating adenosine-lidocaine cardioplegia, subnormothermic reperfusion, pyruvate and methylprednisolone supplementation, and hemofiltration to prevent myocardial functional decline over 4 hours. In this study, we added continuous catecholamine infusion and protective loading conditions to assess the effectiveness of this enhanced cardioprotective perfusion protocol in preventing functional decline during extended normothermic perfusion in marginal porcine hearts. MATERIALS & METHODS Six slaughterhouse pig hearts underwent 9 hours of normothermic ESHP using the enhanced cardioprotective protocol. Cardiac function was assessed at 90, 120, 240, 360, 480 and 540 minutes of ESHP. Subsequently, a preload-challenge was conducted after 9 hours to assess preload-responsiveness (mimicking the Frank-Starling principle) and suitability for transplantation. RESULTS During perfusion, myocardial function remained stable, indicated by consistent mean cardiac index (9.2 L/min/kg at 90; 9.3 L/min/kg at 540 minutes of ESHP), left ventricular stroke work index (6258 mmHg*ml/kg at 90; 6707 mmHg*ml/kg at 540 minutes) and rate of ventricular pressure change over time. In response to a preload-challenge, there was a notable increase of 34% in mean cardiac index and 58% in mean stroke work. CONCLUSION Our study demonstrates that the implementation of a cardioprotective protocol enables (very) marginal porcine slaughterhouse hearts, subjected to both a warm and cold ischemic insult prior to ESHP, to sustain satisfactory cardiac function without notable decline during 9 hours of normothermic ESHP, while also preserving their preload-responsiveness. The latter finding might indicate suitability for transplantation. This study provides a groundwork for further extending normothermic ESHP, unlocking the full potential of this promising technology.

中文翻译：

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一种新的心脏保护性灌注方案可防止猪心脏延长正常离位心脏灌注期间的功能下降。


引言 正常体温异位心脏灌注 （ESHP） 的一个常见限制是功能下降。我们之前设计了一种心脏保护常温灌注方案，包括腺苷-利多卡因心脏麻痹、亚常温再灌注、丙酮酸和甲泼尼龙补充剂以及血液滤过，以防止心肌功能在 4 小时内下降。在这项研究中，我们增加了连续儿茶酚胺输注和保护性负荷条件，以评估这种增强的心脏保护性灌注方案在防止边缘猪心脏延长正常灌注期间功能下降的有效性。材料和方法 六只屠宰场猪心脏接受了9小时的正常体温ESHP使用增强的心脏保护方案。在 ESHP 的 90 、 120 、 240 、 360 、 480 和 540 分钟评估心脏功能。随后，在 9 小时后进行前负荷激发试验，以评估前负荷反应性（模拟 Frank-Starling 原理）和移植适宜性。结果 灌注期间心肌功能保持稳定，表现为一致的平均心脏指数 （90 时 9.2 L/min/kg;ESHP 540 分钟时 9.3 L/min/kg）、左心室卒中工作指数 （90 时 6258 mmHg*ml/kg;540 分钟时 6707 mmHg*ml/kg）和心室压力随时间变化的速率。作为对前负荷挑战的响应，平均心脏指数显着增加 34%，平均中风功显着增加 58%。 结论 我们的研究表明，心脏保护方案的实施使 （非常） 边缘猪屠宰场心脏在 ESHP 之前受到热缺血和冷缺血损伤，能够在正常体温 ESHP 的 9 小时内维持令人满意的心脏功能，而不会显着下降，同时还保持其前负荷反应性。后一项发现可能表明适合移植。这项研究为进一步扩展常温 ESHP 提供了基础，释放了这项有前途的技术的全部潜力。