Vascular Function in Continuous-Flow Left Ventricular Assist Device Recipients: Effect of a Single Pulsatility Treatment Session.

Abstract

BACKGROUND\nVascular 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.\n\n\nMETHODS\nTherefore, 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).\n\n\nRESULTS\nPre-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.\n\n\nCONCLUSION\nThis 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.