Effects of the HeartMate II continuous-flow left ventricular assist device on right ventricular function.

BACKGROUND Continuous-flow devices have become the standard of care for mechanical circulatory support for end-stage heart failure patients because of improved survival and durability. The effects of these devices, such as the HeartMate II (HMII) left ventricular assist device (LVAD), on right ventricular (RV) function have not been evaluated in detail. This study evaluated the incidence of RV failure, alterations in RV function, severity of tricuspid regurgitation (TR), and cardiac hemodynamics after HMII implantation. METHODS Echocardiograms (n = 22) and right heart catheterizations (n = 40) were performed before and after 4 to 6 months of HMII support in 40 bridge-to-transplant patients. Right heart failure was defined as the requirement for inotropes and/or nitric oxide requirement after LVAD implantation for >14 days or the need for right-sided mechanical circulatory support. RESULTS Overall, RV failure after HMII implantation occurred in 2 of 40 patients (5%). Significant improvements occurred in cardiac index, with reductions in right atrial pressure, RV stroke work index, tricuspid annular motion, mean pulmonary artery pressure, and pulmonary vascular resistance after HMII support. There was a trend towards reduction in TR after LVAD support (p = 0.075). CONCLUSIONS The incidence of RV failure after support with continuous-flow devices such as the HMII is low. The favorable effects of the HMII on cardiac hemodynamics result in improved RV function, improved right- and left-sided hemodynamic profiles, and a reduction in TR severity. These findings may have important implications for LVAD patients needing longer-term support.