Pre-implant Right Ventricular dP/dt Can Predict Severe Right Ventricular Failure After Left Ventricular Assist Device Implantation.

Background: Right ventricular (RV) failure remains a major cause of morbidity and mortality after continuous flow left ventricular assist device (CF-LVAD) implantation. Previous risk assessment tools using pre-operative data to predict RV failure have performed only modestly well. We retrospectively evaluated the potential of a non-invasive measure of right ventricular contractility - RV dP/dt, derived from the echocardiographic Doppler signal of tricuspid regurgitation (TR) both without and with inotropes - to predict RV failure post-CF-LVAD. Methods: We studied 65 consecutive CF-LVAD recipients at Vanderbilt University Medical Center from 2013-2019 who had a baseline off inotrope echocardiogram with an evaluable TR signal within 3 months prior to LVAD implantation. Of the 65 patients, 40 were started on inotropes before LVAD implantation, 32 of whom had an evaluable TR signal on a repeat echocardiogram prior to LVAD. RV dP/dt was evaluated using spectral Doppler recordings from the TR and calculated by obtaining the time required from the TR velocity to increase from 0.5 m/s to 2 m/s. Off inotrope RV dP/dt of the 65 patients and on inotrope RV dP/dt of the 32 patients were collected. Post-CF-LVAD RV failure was defined by Interagency Registry for Mechanically Assisted Circulatory Support criteria. Overall survival was estimated by Kaplan-Meier curves and compared by log-rank test among different subgroups. Receiver operative characteristic curves were constructed to determine the optimal thresholds for prediction of severe RV failure post-LVAD. Results: Of the 65 patients, 30 had no/mild RV failure; RV failure was moderate in 17 and severe in 18 patients after LVAD. Subjects with severe RV failure had worse survival than patients with no/mild and moderate RV failure. Either a baseline off inotrope, or on inotrope RV dP/dt of greater than or equal to 300 mmHg/s predicted a low risk of severe RV failure with high sensitivity (89% and 80%, respectively) and negative predictive value (91% and 88% respectively). Persistently low RV dP/dt <300 mmHg/s despite being on inotrope was associated with a high likelihood of post-LVAD RV failure (OR 10.5; 95% CI [1.8-59.4]) compared with the rest of the cohort on inotropic therapy. Conclusion: Echocardiographic RV dP/dt may be a valuable adjunct tool for predicting post-operative RV failure in patients undergoing evaluation for CF-LVAD implantation.