Comparing the Effectiveness of an Axial and a Centrifugal Left Ventricular Assist Device in Ventricular Unloading.

Centrifugal (CFG) and axial flow (AX) left ventricular assist devices have different hydrodynamic properties that may impact the effectiveness of left ventricular unloading. We sought to determine whether patients implanted with the HeartWare HVAD (CFG) and HeartMate II (AX) had a similar degree of hemodynamic support by comparing parameters measured using echocardiography and right heart catheterization. Using our prospectively collected database, we identified 268 patients implanted with the AX and 93 with the CFG. Demographic characteristics were similar between groups. AX patients had a significantly lower INTERMACS score. Baseline ventricular dimension, mitral regurgitation, right ventricular systolic pressure, right atrial pressure, mean pulmonary artery pressure, cardiac output, and pulmonary vascular resistance were similar. Wedge pressure was higher, and left ventricular ejection fraction was lower at baseline in the AX. After implantation, there was a greater reduction of right atrial pressure, pulmonary capillary wedge pressure, mean pulmonary artery pressure, and left ventricular internal diameter during diastole in the AX cohort. After implantation, cardiac output by Fick calculation showed a greater improvement in the AX group. These results demonstrate that both AX and CFG devices resulted in left ventricular unloading; however, AX devices may offer advantages in the magnitude of left ventricular unloading, which could have implications in myocardial recovery or reduction in pulmonary vascular resistance before transplantation.