Background: Vascular function is further attenuated in chronic heart failure patients implanted with a continuous-flow left ventricular assist device (LVAD), likely due to decreased arterial pulsatility, and this may contribute to LVAD-associated cardiovascular complications. However, the impact of increasing pulsatility on vascular function in this population is unknown. Methods: Therefore, fifteen LVAD recipients and fifteen well-matched controls, underwent a 45-minute, unilateral, arm pulsatility treatment, evoked by intermittent cuff inflation/deflation (2-second duty cycle), distal to the elbow. Vascular function was assessed by percent brachial artery flow mediated dilation (%FMD) and reactive hyperemia (RH) (Doppler ultrasound). Results: Pre-treatment, %FMD (LVAD: 4.0±0.4; Controls: 4.2±0.4 %) and RH (LVAD: 340±26; Controls: 308±24 ml) were not different between LVAD recipients and controls; however, %FMD/Shear rate was attenuated (LVAD: 0.10±0.01; Controls: 0.17±0.02 %/s^-1, p<0.05). The LVAD recipients exhibited a significantly attenuated pulsatility index (PI) compared to controls prior to treatment (LVAD: 2±1; Controls: 15±2 AU, p<0.05), however, during the treatment PI was no longer different (LVAD: 37±10; Controls: 36±4 AU). Although time to peak dilation and RH were not altered by the pulsatility treatment, %FMD (LVAD: 7.0±0.5; Controls 7.4±0.7 %) and %FMD/Shear rate (LVAD: 0.19±0.02; Controls 0.33±0.04 %/s^-1) increased significantly in both groups with, importantly, %FMD/Shear rate in the LVAD recipients being restored to that of the controls pre-treatment. Conclusion: This study documents that a localized pulsatility treatment in LVAD recipients can recover local vascular function, an important precursor to the development of approaches to increase systemic pulsatility and reduce systemic vascular complications in LVAD recipients.

中文翻译：

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连续流左心室辅助装置接受者的血管功能：单次搏动治疗的效果

背景：慢性心力衰竭患者植入连续流左心室辅助装置 (LVAD) 后，血管功能进一步减弱，这可能是由于动脉搏动降低所致，这可能导致 LVAD 相关的心血管并发症。然而，增加搏动对这一人群血管功能的影响尚不清楚。方法：因此，15 名 LVAD 接受者和 15 名匹配良好的对照接受了 45 分钟的单侧手臂搏动治疗，由肘部远端的间歇性袖带充气/放气（2 秒占空比）诱发。通过肱动脉血流介导的扩张百分比 (%FMD) 和反应性充血 (RH)（多普勒超声）评估血管功能。结果：治疗前，%FMD（LVAD：4.0±0.4；对照：4.2±0.4 %）和 RH（LVAD：340±26；对照：308±24 ml) 在 LVAD 接受者和对照组之间没有差异；然而，%FMD/剪切率减弱（LVAD：0.10±0.01；对照：0.17±0.02%/s^-1，p<0.05)。与治疗前的对照相比，LVAD 接受者表现出显着减弱的搏动指数 (PI)（LVAD：2±1；对照：15±2 AU，p<0.05），然而，在治疗期间 PI 不再不同（LVAD： 37±10；对照：36±4 AU）。尽管达峰时间和 RH 未因搏动治疗而改变，但 %FMD（LVAD：7.0±0.5；对照 7.4±0.7 %）和 %FMD/剪切率（LVAD：0.19±0.02；对照 0.33±0.04 %/s ^-1) 在两组中都显着增加，重要的是，LVAD 接受者的 %FMD/剪切率恢复到对照组治疗前的水平。结论：本研究证明 LVAD 接受者的局部搏动治疗可以恢复局部血管功能，这是开发增加全身搏动和减少 LVAD 接受者全身血管并发症的方法的重要先导。