Prediction of right ventricular dysfunction after left ventricular assist device implantation

Abstract

Background: Right ventricular dysfunction (RVD) significantly affects mortality and morbidity after left ventricular assist device (LVAD) implantation, and its occurrence often is unpredictable. The aim of the present study was to identify predictors of RVD after LVAD implantation.

Methods and results: We studied right ventricular (RV) hemodynamics in 28 patients before and after LVAD implantation with a rapid-response thermistor pulmonary artery catheter. Measurements included mean right atrial pressure (RAP), mean pulmonary arterial pressure (PAP), cardiac index, transpulmonary gradient (TPG), pulmonary vascular resistance (PVR), RV end-diastolic and end-systolic volume indexes (EDVI and ESVI, respectively), and RV ejection fraction (RVEF). We regarded patients who had RAP > or = 15 mm Hg at LVAD explantation (n = 8) or who required an RV assist device (n = 3) as the RVD group (n = 11). The other patients were categorized as the RV nondysfunctional group (RVN, n = 17). Before LVAD implantation, the RVD group had larger RV volumes (200 +/- 107 versus 125 +/- 46 mL/m2 for EDVI; 177 +/- 109 versus 104 +/- 48 mL/m2 for ESVI) and higher preload (23 +/- 6 versus 17 +/- 6 mm Hg for RAP) and afterload (20 +/- 9 versus 13 +/- 6 mm Hg for TPG; 5.9 +/- 3.0 versus 3.8 +/- 2.0 Wood units for PVR) than the RVN group (P < .05 for all). RVEF and PAP did not differ significantly. LVAD implantation remarkably improved RV hemodynamics in both groups, decreasing RV volumes, preload, and afterload and increasing RVEF in all patients, but post-LVAD PAP tended to be higher in the RVD group. Multivariate logistic regression analysis revealed that RAP and TPG before LVAD implantation and an acute decrease (delta) in PAP by LVAD were significant predictors of RVD (P < .05). The sensitivity for predicting RVD by a combination of at least two of these three predictors (RAP > or = 20 mm Hg, TPG > or = 16 mm Hg, and delta PAP < or = 10 mm Hg) was 82%, and the specificity was 88%.

Conclusions: Dilated right ventricle with increased RV preload and afterload predisposes to RVD after LVAD implantation. Not only baseline parameters but also the immediate hemodynamic response to the LVAD are predictive, and a combination of these parameters may be useful in predictions of the occurrence of RVD after LVAD implantation.