Superior prognostic value of three-dimensional echocardiography-derived right ventricular ejection fraction: a meta-analysis

Abstract

Objective: Due to the complexity of right ventricular (RV) geometry and mechanics, conventional echocardiographic parameters may fail to capture the prognostic significance of RV systolic dysfunction. We hypothesized that three-dimensional (3D) echocardiography-derived RV ejection fraction (EF) is a more robust predictor of adverse cardiopulmonary outcomes than the conventional echocardiographic parameters of RV function. Methods: We performed a meta-analysis of studies reporting the impact of unit change of RVEF, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and free-wall longitudinal strain (FWLS) on clinical outcomes (all-cause mortality and/or adverse cardiopulmonary outcomes). Hazard ratios (HR) of RV metrics were rescaled by the within-study standard deviations (SD) to represent standardized changes. Within each study, we then calculated the ratio of HRs related to 1 SD reduction in RVEF versus TAPSE, or FAC, or FWLS, to quantify the predictive value of RVEF relative to the other metrics. These ratios of HRs were pooled using random-effects models. Heterogeneity resulting from different study designs was assessed through mixed-effects meta-regression. Results: Ten independent studies were identified as suitable, including data on 1,928 patients with various cardiopulmonary conditions. Overall, 1 SD reduction in RVEF was robustly associated with adverse outcomes (HR: 2.64 [95% CI: 2.18 to 3.20], p<0.001; heterogeneity: I2=65%, p=0.002). In studies reporting HRs for RVEF and TAPSE, FAC, or FWLS in the same cohort, RVEF had superior predictive value per SD reduction versus the other three parameters (vs. TAPSE, HR: 1.54 [95% CI: 1.04 to 2.28], p=0.031; vs. FAC, HR: 1.45 [95% CI: 1.15 to 1.81], p=0.001; vs. FWLS, HR: 1.44 [95% CI: 1.07 to 1.95], p=0.018). Differences in study designs did not contribute to heterogeneity. Conclusions: 3D echocardiography-derived RVEF has superior prognostic value compared with conventional RV function indices, therefore, it might further refine the risk stratification of patients with cardiopulmonary diseases.