BACKGROUND The coronary vasculature encounters a reduction in pulsatility after implementing durable continuous-flow left ventricular assist device (CF-LVAD) circulatory support. Evidence exists that appropriate pulsatility is required to maintain endothelial cell homeostasis. We hypothesized that coronary artery endothelial function would be impaired after CF-LVAD intervention. METHODS AND RESULTS Coronary arteries from patients with end-stage heart failure caused by ischemic cardiomyopathy (ICM; n=16) or non-ICM (n=22) cardiomyopathy were isolated from the left ventricular apical core, which was removed for the CF-LVAD implantation. In 11 of these patients, paired coronary arteries were obtained from an adjacent region of myocardium after the CF-LVAD intervention (n=6 ICM, 5 non-ICM). Vascular function was assessed ex vivo using isometric tension procedures in these patients and in 7 nonfailing donor controls. Maximal endothelium-dependent vasorelaxation to BK (bradykinin; 10-6-10-10 M) was blunted (P<0.05) in arteries from patients with ICM compared with non-ICM and donor controls, whereas responses to sodium nitroprusside (10-4-10-9 M) were similar among the groups. Contrary to our hypothesis, vasorelaxation responses to BK and sodium nitroprusside were similar before and 219±37 days after CF-LVAD support. Of these patients, an exploratory subgroup analysis revealed that BK-induced coronary artery vasorelaxation was greater (P<0.05) after (87±6%) versus before (54±14%) CF-LVAD intervention in ICM patients, whereas sodium nitroprusside-evoked responses were similar. CONCLUSIONS Coronary artery endothelial function is not impaired by durable CF-LVAD support and in ICM patients appears to be improved. Investigating coronary endothelial function using in vivo approaches in a larger patient population is warranted.

中文翻译：

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持续流动左心室辅助装置支持对缺血性和非缺血性心肌病冠状动脉内皮功能的影响。

背景技术在实施持久的连续流动左心室辅助装置（CF-LVAD）循环支持后，冠状脉管系统的搏动性降低。有证据表明维持内皮细胞稳态需要适当的搏动。我们假设 CF-LVAD 干预后冠状动脉内皮功能会受损。方法和结果 由缺血性心肌病 (ICM; n=16) 或非 ICM (n=22) 心肌病引起的终末期心力衰竭患者的冠状动脉从左心室心尖核心分离出来，用于 CF- LVAD 植入。在这些患者中，有 11 名患者在 CF-LVAD 干预后从邻近的心肌区域获得了成对的冠状动脉（n = 6 个 ICM，5 个非 ICM）。在这些患者和 7 名非失败供体对照中使用等长张力程序离体评估血管功能。与非 ICM 和供体对照相比，ICM 患者的动脉对 BK（缓激肽；10-6-10-10 M）的最大内皮依赖性血管舒张减弱（P<0.05），而对硝普钠的反应（10-4 -10-9 M) 在各组之间相似。与我们的假设相反，对 BK 和硝普钠的血管舒张反应在 CF-LVAD 支持之前和之后 219±37 天相似。在这些患者中，探索性亚组分析显示，在 ICM 患者中，BK 诱导的冠状动脉血管舒张在 (87±6%) 与之前 (54±14%) CF-LVAD 干预之前相比更大（P<0.05），而硝普钠-诱发反应相似。结论 持久的 CF-LVAD 支持不会损害冠状动脉内皮功能，并且在 ICM 患者中似乎有所改善。有必要在更大的患者群体中使用体内方法研究冠状动脉内皮功能。