Exercise capacity in left ventricular assist device patients with full and partial support

In the present work, we investigated the exercise capacities of patients with partial flow left ventricular assist devices and its evolution over time. We then compared the exercise capacities of these patients with those of full support ventricular assist device patients.

We retrospectively analysed the data of maximal cardiopulmonary exercise tests of ten partial support patients (CircuLite Synergy® Micropump) collected before (PS0), at 3 (PS3) and 6 months (PS6) after implantation. The data were then compared with those of 17 patients (FS6) treated with a full support device (HeartMate II, Thoratec©). For this analysis, we considered the exercise tests performed at 6 months after pump implantation for both groups.

Peak oxygen uptake evolved in the PS0, PS3 and PS6 groups from 11.5 ± 2.3 to 12.6 ± 2.8 and 12.0 ± 2.7 mL/kg/min, respectively. Heart rate peak increased from PS0 to PS6 (100 ± 17 bpm and 107 ± 22 bpm, p = 0.05). The comparative analysis between PS6 and FS6 groups showed no difference in terms of exercise performance (12.0 ± 2.7 and 13.5 ± 3.0 mL/kg/min, respectively), fatigue perception, ventilation efficiency slope, anaerobic threshold and oxygen uptake efficiency slope. The chronotropic response was also similar in both PS6 and FS6 groups. However, PS6 patients were more often treated with β-blockers and therefore had lower heart rates at rest and at peak exercise than FS6 patients.

Exercise performance does not change after partial support implantation and stays stable over time. Partial and full support patients show similar exercise performances that attain 41% and 46% of the expected values, respectively.