Right ventricular function and cardiopulmonary performance among patients with heart failure supported by durable mechanical circulatory support devices

BACKGROUND: Patients with continuous-flow left ventricular assist devices (CF-LVADs) experience limitations in functional capacity and frequently, right ventricular (RV) dysfunction. We sought to characterize RV function in the context of global cardiopulmonary performance during exercise in this population. METHODS: A total of 26 patients with CF-LVAD (aged 58 +/- 11 years, 23 males) completed a hemodynamic assessment with either conductance catheters (Group 1, n = 13) inserted into the right ventricle to generate RV pressure.volume loops or traditional Swan. Ganz catheters (Group 2, n = 13) during invasive cardiopulmonary exercise testing. Hemodynamics were collected at rest, 2 sub-maximal levels of exercise, and peak effort. Breath-by-breath gas exchange parameters were collected by indirect calorimetry. Group 1 participants also completed an invasive ramp test during supine rest to determine the impact of varying levels of CF-LVAD support on RV function. RESULTS: In Group 1, pump speed modulations minimally influenced RV function. During upright exercise, there were modest increases in RV contractility during sub-maximal exercise, but there were no appreciable increases at peak effort. Ventricular. arterial coupling was preserved throughout the exercise. In Group 2, there were large increases in pulmonary arterial, left-sided filling, and right-sided filling pressures during sub-maximal and peak exercises. Among all participants, the cardiac output. oxygen uptake relationship was preserved at 5.8:1. Ventilatory efficiency was severely abnormal at 42.3 +/- 11.6. CONCLUSIONS: Patients with CF-LVAD suffer from limited RV contractile reserve; marked elevations in pulmonary, left-sided filling, and right-sided filling pressures during exercise; and severe ventilatory inefficiency. These findings explain mechanisms for persistent reductions in functional capacity in this patient population. (C) 2020 International Society for Heart and Lung Transplantation. All rights reserved.

Automated summary

The study showed that patients with CF-LVAD have limited right ventricular contractile reserve during exercise, marked elevations in pulmonary, left-sided filling, and right-sided filling pressures, and severe ventilatory inefficiency.