Exercise capacity in patients implanted with left ventricular assist devices for end-stage heart failure treatment

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Left ventricular assist device (LVAD) is an expanding therapy in end-stage heart failure today. Although LVAD therapy bears the potential to normalize cardiac output, a majority of patients show a severely impaired physical condition at the time of LVAD implantation. To date, no validated standardized training protocol is available, and established practices to effectively improve LVAD patients’ exercise tolerance is lacking. This study sought to investigate exercise capacity quantified by cardiopulmonary exercise testing (CPX) and a standardized six-minute walk test (6MWT) in patients after LVAD implantation. Methods We enrolled 30 end-stage heart failure patients who had received an LVAD implantation 20.7 ± 7.6 days prior to examination, mean age 54.9 ± 7.8 years, 26 males (87 %). Exercise tolerance was assessed using cardiopulmonary exercise testing (CPX) for maximal and submaximal exercise capacity, followed by a standardized (6MWT). Results Patients showed peak oxygen uptake values of 8.3 ± 2.4 ml/min/kg at a mean workload of 46.7 ± 11.3 watts and a mean anaerobic threshold of 6.7 ± 1.7 ml/min/kg at a workload of 32.6 ± 6.9 watts. Mean standardized 6-minute walking distance was at 183.8 ± 71.4 meters. There were no adverse events during exercise testing. Conclusions Cardiopulmonary exercise testing (CPX) and standardized 6MWT show severely impaired cardiopulmonary exercise capacity in patients after LVAD implantation, warranting further studies for dedicated training protocols, specifically focusing on LVAD patients to improve exercise tolerance at an acceptable safety profile.