Abstract 3377: Right Ventricular Dysfunction in Recipients of Destination Therapy Left Ventricular Assist Devices versus Marginal-Donor Cardiac Allografts
Introduction: Right ventricular (RV) systolic “dysfunction” or “afterload mismatch,” due to reduced RV contractility or elevated RV afterload, frequently occurs in patients either after left ventricular assist device (LVAD) implantation or orthotopic heart transplantation (OHT), and confers substantial morbidity and mortality. In patients ineligible for OHT based on standard criteria, LVAD implantation and marginal donor organ (MDO) OHT are the principal definitive surgical therapies. We sought to characterize and identify hemodynamic predictors of RV failure in both groups.
Methods: A review of all destination therapy (DT) LVAD implantations (n=60) and MDO OHT (n=79) performed at Duke University Medical Center between January 2000 and July 2008 was conducted. Available preoperative hemodynamic data were obtained from right-sided cardiac catheterization and transthoracic echocardiography (TTE). After DT LVAD implantation, RV failure was defined as inotrope dependence ≥7 days. After MDO OHT, to exclude hearts with isolated LV dysfunction, RV failure was defined as inotrope dependence with TTE evidence of RV systolic hypokinesis.
Results: DT LVAD patients, versus MDO OHT patients, had preoperative evidence of equivalent RV contractility based upon a load-independent index of systolic ventricular function [RV stroke work index (RVSWI) (553.5±286.2 mm Hg∝ml/m2 vs. 668.9±400.4 mm Hg∝ml/m2; p=0.2168)] but had elevated RV afterload [pulmonary artery occlusion pressure (PAOP) (24.8±8.6 mm Hg vs. 20.9±8.5 mm Hg; p=0.0216) and pulmonary vascular resistance index (PVRI) (1.90±1.29 Wood units/m2 vs. 1.58±1.21 Wood units/m2; p=0.0488)]. RV failure occurred more frequently after DT LVAD implantation (23/50=46%) than after MDO OHT (7/79=8.9%) [p <0.0001]. The only hemodynamic predictor of RV failure within the DT LVAD group was reduced RVSWI (p=0.0103). Although RV afterload was higher in the DT LVAD group in comparison to the MDO OHT group, its indices failed to predict RV failure within the DT LVAD group (PAOP: p=0.7077; PVRI: p=0.8895).
Conclusions: RV failure is more common after DT LVAD implantation than MDO OHT, and the risk of its occurrence can be ascertained based on RVSWI. These data may consequently guide surgical therapies.