Association of right ventricular functional parameters with adverse cardiopulmonary outcomes: A meta-analysis

We aimed to confirm that three-dimensional echocardiography (3DE)-derived right ventricular (RV) ejection fraction (EF) is better associated with adverse cardiopulmonary outcomes than the conventional echocardiographic parameters.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) were rescaled by the within-study standard deviations (SD) to represent standardized changes. Within each study, we calculated the ratio of HRs related to 1 SD reduction in RVEF versus TAPSE, or FAC, or FWLS, to quantify the association of RVEF with adverse outcomes relative to the other metrics. These ratios of HRs were pooled using random-effects models.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, head-to-head comparison revealed that RVEF showed significantly stronger association with adverse outcomes per SD reduction versus the other three parameters (vs.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).Reduction in 3DE-derived RVEF shows stronger association with adverse clinical outcomes than conventional RV functional indices, therefore, it might further refine the risk stratification of patients with cardiopulmonary diseases.