Does third generation left ventricular assist device alter heart failure-related microvascular dysfunction?

Background Left ventricular assist device (LVAD) is a promising new therapy in patients with advanced heart failure. Previous studies suggested that continuous blood flow impairs endothelial function. Whether the third-generation LVAD (HeartWare®, HeartWare Inc. Framingham, MA, USA) system affects endothelial regulation of microvascular flow, endothelial nitric oxide (NO) bioavailability and endothelial production of vWF is not known. Methods Fifteen LVAD-supported heart failure patients and 13 age/body mass index matched heart failure patients (HF) were included. The microvascular endothelial function of skin vessels was assessed with laser Doppler imager (LDI) using 3 different hyperaemic challenges: acetylcholine (Ach) iontophoresis, sodium nitroprusside (SNP) iontophoresis and local heating to 44°C. NO-mediated vasodilation was further evaluated by comparing heating hyperaemic response in skin area pretreated either by a saline solution (control) or a specific NO-synthase inhibitor (L-N-arginine-methyl-ester, L-NAME). vWF antigen was also measured in LVAD and HF patients. Results SNP-induced vasodilation did not differ between LVAD and HF patients, and we observed a trend towards an increased vasodilator response to Ach in LVAD patients (P = 0.06). Compared to HF patients, skin thermal hyperaemia was increased in LVAD patients in both control and L-NAME pretreated skin (all P < 0.001). The hyperaemic reaction attributable to NO-mediated vasodilation correlated negatively with HF duration (r = –0.50, P < 0.01, n = 28), but did not differ between LVAD and HF patients. Both groups disclosed also similar vWF antigen serum levels. Conclusion This case-control study indicates that third-generation LVAD therapy does not alter skin microvascular endothelial function and vWF production of patients with HF.SCOPUS: ar.j