There is a dearth of information regarding the functional abilities of patients with the total artificial heart (TAH). Increased utilization of the TAH and patient discharge to home with the portable unit necessitates a shift in focus to quality of life, which includes quantifying and ultimately optimizing functional capacity. To date, only single-patient case studies have described the exercise response of the TAH patient. Fourteen patients with the TAH underwent cardiopulmonary exercise testing with concurrent analysis of TAH device function. All device settings remained fixed during testing. Peak oxygen consumption (VO2; 0.872 L/min [interquartile range (IQR) = 0.828–1.100 L/min]), percent predicted peak VO2 (36% [IQR = 32–42%]), and ventilatory anaerobic threshold (0.695 L/min [IQR = 0.542–0.845 L/min]) were markedly reduced in the TAH compared with predicted normal values. Determinants of VO2 using device-generated hemodynamics revealed a blunted cardiac output (+9% increase) and exaggerated oxygen extraction with exercise. Peak VO2 strongly correlated with resting (R = +0.548, p = 0.045), ventilatory anaerobic threshold (R = +0.780, p = 0.001), and peak exercise cardiac output (R = +0.672, p = 0.008). Patients with the TAH have significantly impaired exercise performance. The limitations to cardiopulmonary exercise testing performance appear to be related to limited ability of the pump to modulate output for activity and reduced oxygen carrying capacity.
From the *Department of Kinesiology & Health Sciences, Virginia Commonwealth University, Richmond, Virginia
†Division of Cardiology, VCU Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
‡Department of Physical Therapy at the University of Illinois Chicago, Chicago, Illinois
§Division of Cardiothoracic Surgery, VCU Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.
Submitted for consideration July 2017; accepted for publication in revised form December 2017.
Disclosures: The authors have no conflict of interest to report.
K.B.S. reports research grants from Thoratec Corporation, Institutional Grants from HeartWare Incorporated, Consulting for HeartWare/Medtronic. V.K. reports research grants from Syncardia Systems Incorporated, research grants from Thoratec Corporation. D.T. reports research grants from Syncardia Systems Incorporated, research grants from Thoratec Corporation, research grants from HeartWare International Incorporated, and research grants from Sunshine Heart Incorporated.
Correspondence: Justin M. Canada, 1200 East Broad Street, PO Box 980204, Richmond, VA 23298. Email: firstname.lastname@example.org.