Load Dependency of Right Ventricular Performance Is a Major Factor to be Considered in Decision Making Before Ventricular Assist Device Implantation

Abstract

Left ventricular assist devices (LVADs) provide better outcome than biventricular devices, but it is a challenge to predict the impact of LV mechanical unloading on postoperative right ventricular (RV) function preoperatively. We assessed the load dependency in RV performance before and after LVAD implantation aiming to improve preoperative decision making. Laboratory, echocardiography, and right heart catheterization data collected from 205 patients before LVAD implantation were tested for relationship with postoperative RV function. Comparing patients with different time-course of RV function after LVAD implantation, we found significant differences (P<0.01) in preoperative RV end-diastolic short-/long-axis and long-axis/length-area ratios, tricuspid annulus peak systolic velocity, RV peak longitudinal global systolic strain rate, systolic pressure gradient between RV and right atrium (ΔPRV-RA), tricuspid regurgitation velocity-time integral, and pulmonary arterial pressure between patients with and without postoperative RV failure. High predictive values for postoperative RV failure were found for end-diastolic short-/long-axis ratio ≥ 0.6, tricuspid annulus peak systolic velocity <8 cm/s, and peak systolic longitudinal strain rate <0.6/s in patients with maximum ΔPRV-RA <35 mm Hg. These parameters also seemed predictive for RV failure in patients with tricuspid regurgitation grade >2 and pulmonary arterial pressure <50 mm Hg. End-diastolic short-/long-axis ratio <0.6, tricuspid annulus peak systolic velocity ≥ 8 cm/s, and peak systolic longitudinal strain rate ≥ 0.6 in patients with maximum ΔPRV-RA ≥ 35 mm Hg showed high predictive values for postoperative freedom from RV failure. The RV load adaptation index seemed particularly predictive for RV function after LVAD implantation. RV geometry and velocity of contraction before LVAD implantation become more predictive for postoperative RV function and can improve decision making before VAD implantation if preoperative RV pressure load and tricuspid regurgitation are also considered.