Background: Coronary artery fluid dynamics may be altered because of the nonphysiological flow seen in continuous-flow left ventricular assist devices (CF-LVADs). Our aim was to study the structure and composition of coronary vessels after CF-LVAD.

Methods and Results: Coronary arteries were collected from patients with heart failure (HF) at the time of transplantation, of whom 15 were supported with a CF-LVAD before transplant (HF+LVAD group) and 9 were not (HF non-LVAD group). In addition, coronary samples were obtained from 5 nonfailing age-matched donors (nonfailing group). Histological analysis was performed to quantify coronary morphology, composition, vascular fibrosis, and vasa vasorum density. The age and sex mix of the 3 groups were similar, and the mean duration of LVAD support was 213 days. Compared with patients with HF and nonfailing donors, the arteries from patients with HF+LVAD had expansion of the adventitia, breakdown of the internal elastic lamina, and increased adventitial collagen deposition and density of vasa vasorum.

Conclusions: Among patients supported with CF-LVADs, the coronary arteries develop marked remodeling with increased adventitial fibrosis. The physiological consequences of these structural changes are unknown, but it is possible that arterial contractility may be impaired, thus limiting coronary flow reserve and promoting myocardial ischemia. This may contribute to CF-LVAD complications, such as ventricular arrhythmias and right ventricular failure. As more patients receive CF-LVADs and new pump technology attempts to modulate flow profiles and pulsatility, further research is needed to understand the mechanisms and long-term sequela of these changes in coronary arteries and other vascular beds.

中文翻译：

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冠状动脉重塑和纤维化伴连续流左心室辅助装置支持

背景：由于连续流左心室辅助装置（CF-LVAD）中出现非生理流，因此冠状动脉流体动力学可能会改变。我们的目的是研究CF-LVAD后冠状动脉的结构和组成。

方法和结果：移植时从心力衰竭（HF）患者中收集冠状动脉，其中15例在移植前接受CF-LVAD支持（HF + LVAD组），而9例未接受（HF非LVAD组） ）。另外，从5名年龄相匹配的供体（不衰竭组）获得了冠状动脉样本。进行组织学分析以定量冠状动脉形态，组成，血管纤维化和脉管血管密度。3组的年龄和性别混合相似，LVAD支持的平均持续时间为213天。与HF和无衰竭供体的患者相比，HF + LVAD患者的动脉具有外膜扩张，内部弹性层破裂和血管外膜胶原沉积和血管密度的增加。

结论：在支持CF-LVADs的患者中，冠状动脉发生明显的重塑，并伴有外膜纤维化增加。这些结构变化的生理后果尚不清楚，但可能会损害动脉收缩力，从而限制冠状动脉血流储备并促进心肌缺血。这可能会导致CF-LVAD并发症，例如室性心律失常和右室衰竭。随着越来越多的患者接受CF-LVAD和新的泵技术尝试调节血流曲线和搏动性，需要进一步研究以了解冠状动脉和其他血管床这些改变的机制和长期后遗症。