The right ventricular failure risk score - A pre-operative tool for assessing the risk of right ventricular failure in left ventricular assist device candidates

Objectives This study sought to develop a model that estimates the post-operative risk of right ventricular (RV) failure in left ventricular assist device (LVAD) candidates. Background Right ventricular failure after LVAD surgery is associated with increased morbidity and mortality, but identifying LVAD candidates at risk for RV failure remains difficult. Methods A prospectively collected LVAD database was evaluated for pre-operative clinical, laboratory, echocardiographic, and hemodynamic predictors of RV failure. Right ventricular failure was defined as the need for post-operative intravenous inotrope support for > 14 days, inhaled nitric oxide for >= 48 h, right-sided circulatory support, or hospital discharge on an inotrope. An RV failure risk score (RVFRS) was created from multivariable logistic regression model coefficients, and a receiver-operating characteristic curve of the score was generated. Results Of 197 LVADs implanted, 68 (35%) were complicated by post-operative RV failure. A vasopressor requirement (4 points), aspartate aminotransferase >= 80 IU/ l (2 points), bilirubin >= 2.0 mg/dl (2.5 points), and creatinine >= 2.3 mg/dl (3 points) were independent predictors of RV failure. The odds ratio for RV failure for patients with an RVFRS <= 3.0, 4.0 to 5.0, and >= 5.5 were 0.49 (95% confidence interval [CI] 0.37 to 0.64), 2.8 (95% CI 1.4 to 5.9), and 7.6 (95% CI 3.4 to 17.1), respectively, and 180-day survivals were 90 +/- 3%, 80 +/- 8%, and 66 +/- 9%, respectively (log rank for linear trend p = 0.0045). The area under the receiver-operating characteristic curve for the RVFRS (0.73 +/- 0.04) was superior to that of other commonly used predictors of RV failure (all p < 0.05). Conclusions The RVFRS, composed of routinely collected, noninvasive pre-operative clinical data, effectively stratifies the risk of RV failure and death after LVAD implantation.