Determinants of Functional Capacity and Quality of Life After Implantation of a Durable Left Ventricular Assist Device

Abstract

Continuous-flow left ventricular assist devices (LVAD) are increasingly used as destination therapy in patients with end-stage heart failure and, with recent improvements in pump design, adverse event rates are decreasing. Implanted patients experience improved survival, quality of life (QoL) and functional capacity (FC). However, improvement in FC and QoL after implantation is not unequivocal, and this has implications for patient selection and preimplantation discussions with patients and relatives. This article identifies preimplantation predictors of lack of improvement in FC and QoL after continuous-flow LVAD implantation and discusses potential mechanisms, allowing for the identification of potential factors that can be modified. In particular, the pathophysiology behind insufficient improvement in peak oxygen uptake is discussed. Data are included from 40 studies, resulting in analysis of >700 exercise tests. Mean peak oxygen uptake was 13.4 ml/kg/min (equivalent to 48% of predicted value; 259 days after implantation, range 31–1,017 days) and mean 6-minute walk test distance was 370 m (182 days after implantation, range 43–543 days). Finally, the interplay between improvement in FC and QoL is discussed.

Oxygen Uptake During Activities of Daily Life in Patients Treated With a Left Ventricular Assist Device

“…As expected, the study confirmed that the mean peak exercise capacity of LVAD recipients was less than half of that of the controls, and the reduced pVO 2 observed in LVAD recipients the current study is well in line with earlier reports 10,19,20 as is the ventilatory inefficiency. 9 The patient population in the current study is generally comparable to the HF patients with moderate HF as described in the study by Mapelli 11 (pVO 2 between 12 to 16 ml/kg/min), but the VE/VCO 2 of in LVAD recipients in the current study was somewhat lower (i.e., ventilatory efficiency was better) compared with the unsupported HF patients.…”

Prognostic Value of Peak Oxygen Uptake in Patients Supported With Left Ventricular Assist Devices (PRO-VAD)

“…Several studies (7) have reported pVO 2 in LVAD recipients with values ranging from 9.9 (34) to 20.3 STUDY LIMITATIONS. Although the current study is strengthened by its multicenter design and the large sample size, some limitations remain.…”

“…A retrospective multicenter study was designed to collect data for pVO 2 in LVAD recipients. Based on earlier published reports (described elsewhere [7]), 34 centers performing CPET in LVAD recipients, either as part of research projects or as standard of care, were identified and invited to participate in this study.…”

“…In fact, recent studies have shown that short-term and intermediate term survival after LVAD implantation parallels that of cardiac transplantation (4). Furthermore, most LVAD recipients experience significant improvement in heart failure (HF) symptoms and quality of life (QOL) (5)(6)(7).…”

“…Recently, pVO 2 has been studied extensively in LVAD recipients and has been reported to remain reduced even in patients with significant symptomatic improvement (7). However, it is unknown whether pVO 2 maintains its prognostic power in patients with HF once they are supported with an LVAD.…”