Combined use of right ventricular coupling and pulmonary arterial elastance as a comprehensive stratification approach for right ventricular function.

Right ventricular (RV)-pulmonary arterial uncoupling is the consequence of increased afterload and/or decreased RV contractility. However, the combination of arterial elastance (Ea) and end-systolic elastance (Ees)/Ea ratio to assess RV function is unclear. We hypothesized that the combination of both could comprehensively assess RV function and refine risk stratification. The median Ees/Ea ratio (0.80) and Ea (0.59mmHg/mL) were used to classify 124 advanced heart failure patients into four groups. RV systolic pressure differential was defined as end-systolic pressure (ESP) minus beginning-systolic pressure (BSP). Patients among different subsets showed dissimilar New York Heart Association functional class (V=0.303, P=0.010), distinct tricuspid annular plane systolic excursion/ pulmonary artery systolic pressure (mm/mmHg) (0.65 vs. 0.44 vs. 0.32 vs. 0.26, P<0.001), and diverse prevalence of pulmonary hypertension (33.3% vs. 35% vs. 90% vs. 97.6%, P<0.001). By multivariate analysis, Ees/Ea ratio (hazard ratio [HR] 0.225, P=0.004) and Ea (HR 2.194, P=0.003) were independently associated with event-free survival. Patients with Ees/Ea ratio >0.80 and Ea <0.59mmHg/mL had better outcomes (P<0.05). In patients with Ees/Ea ratio >0.80, those with Ea ≥0.59mmHg/mL had a higher adverse outcome risk (P<0.05). Ees/Ea ratio ≤0.80 was associated with adverse outcomes, even when Ea was <0.59mmHg/mL (P<0.05). Approximately 86% of patients with ESP-BSP >5mmHg had an Ees/Ea ratio ≤0.80 and/or an Ea ≥0.59mmHg/mL (V=0.336, P=0.001). Combined use of Ees/Ea ratio and Ea could be a comprehensive approach to assessing RV function and predicting outcomes. An exploratory analysis demonstrated that Ees/Ea ratio and Ea might be roughly estimated based on RV systolic pressure differential.