Independent and incremental role of quantitative right ventricular evaluation for the prediction of right ventricular failure after left ventricular assist device implantation.

OBJECTIVES: This study sought to determine the utility of quantitation of right ventricular (RV) function in predicting RV failure in patients undergoing left ventricular assist device (LVAD) implantation.
BACKGROUND: Clinical evaluation alone seems insufficient for predicting RV failure, an important cause of morbidity and mortality after LVAD implantation.
METHODS: Clinical, hemodynamic, and echocardiographic data were collected on 117 patients undergoing LVAD implantation. Standard pre-procedural echocardiographic RV measurements were supplemented by velocity vector imaging of RV free wall longitudinal strain. RV failure was defined as the need for placement of an RV assist device, or the use of inotropic agents for >14 days. Receiver operating characteristic curves were derived, with resampling to generate valid estimates of prediction accuracy. A net reclassification index was calculated for comparison of risk scores.
RESULTS: RV failure occurred in 47 of 117 patients (40%). There was a significant difference in peak strain between patients with and without RV failure (-9.0% vs. -12.2%; p < 0.01). A peak strain cutoff of -9.6% predicted RV failure with 76% specificity and 68% sensitivity. In a multivariate logistic regression analysis including variables from the established Michigan RV risk score, peak strain remained an independent predictor of RV failure. RV strain was incremental to the Michigan risk score as a predictor of RV failure (area under the receiver operating characteristic curve: 0.77 vs. 0.66; p < 0.01). The net reclassification index with strain was +10.4%.
CONCLUSIONS: Reduced RV free wall peak longitudinal strain was associated with an increased risk for RV failure among patients undergoing LVAD implantation.