Further Peripheral Vascular Dysfunction in Heart Failure Patients With a Continuous-Flow Left Ventricular Assist Device

Abstract

Background Peripheral endothelial function is recognized to be impaired in patients with heart failure with reduced ejection fraction (HFrEF), but the peripheral vascular effects of continuous-flow left ventricular assist device (LVAD) implantation, now employed as either a bridge-to-transplantation or as a destination therapy, remain unclear. Using flow-mediated vasodilation (FMD) and reactive hyperemia (RH), this study aimed to provide greater insight into LVAD-induced changes in peripheral vascular function. Methods and Results Sixty-eight subjects (13 New York Heart Association (NYHA) Class II HFrEF patients, 19 NYHA Class III/IV HFrEF patients, 20 NYHA Class III/IV HFrEF patients post-LVAD implantation, and 16 healthy age-matched controls) underwent FMD and RH testing in the brachial artery with blood flow velocity, artery diameters, and pulsatility index (PI) assessed by ultrasound Doppler. PI was significantly lower in the LVAD group (2.0 ± 0.4) compared to both the HFrEF II, (8.6 ± 0.8) and HFrEF III/IV (8.1 ± 0.9) patients, who, in turn, were significantly lower than the controls (12.8 ± 0.9). Likewise, LVAD %FMD/shear rate (0.09 ± 0.01 %Δ/s−1) was significantly reduced compared to all other groups (controls, 0.24 ± 0.03; HFrEF II, 0.17 ± 0.02 and HFrEF III/IV, 0.13 ± 0.02 %Δ/s−1) and %FMD/shear rate was significantly correlated with PI (r=0.45). RH was unremarkable across groups. Conclusions Although central hemodynamics are improved in patients with HFrEF by a continuous-flow LVAD, peripheral vascular function is further compromised, likely due, at least in part, to the reduction in pulsatility that is a characteristic of such a mechanical assist device.

The study on hemodynamic effect of series type LVAD on aortic blood flow pattern: a primary numerical study

“…6), which means the series type LVAD may promote the benefit of swirling flow. These changes maybe improve the complications caused by conventional LVAD support, such as peripheral vascular dysfunction [33] and impaired vascular compliance [34]. In addition, from Fig.…”

Acute and chronic effects of continuous‐flow support and pulsatile‐flow support

“…This indicates that CF support is associated with increased peripheral vascular reactivity, which is caused by impaired reactivity of both the endothelial and smooth muscle cell layers due to a decrease in bioavailability and response to NO. Witman et al also used FMD and reactive hyperemia to evaluate the vascular function of subjects with heart failure ( n = 32), patients on CF LVAD support ( n = 20), or healthy controls ( n = 16). These authors showed that the %FMD/shear rate was significantly reduced in the CF LVAD group compared to all the other groups and that the %FMD/shear rate significantly correlated with pulsatility index.…”

Physiologic effects of continuous-flow left ventricular assist devices

“…HFrEF = Heart Failure with Reduced Ejection Fraction. Reproduced from Witman, et al, [41] with permission.…”

“…These changes do not appear to be manifest at the end-organ level, however, as evidenced by a lack of difference in the vasculature with regard to perivascular infiltrates, intravascular infiltrates, wall thickness, thrombosis, endothelial cell swelling, vessel wall necrosis, or perivascular fibrosis [40]. However, larger vessels, such as the brachial artery, have been shown to have reduced flow-mediated vasodilation in patients with continuous flow LVADs compared to control patients without LVADs [41]. These differences could also be observed with regard to changes in vessel diameter (Figure 2).…”