Redefining Right Ventricular Function: Incremental Prognostic Utility of Effective RVEF on CMR in Functional Tricuspid Regurgitation—A Multicenter Validation Study

BACKGROUND: Right ventricular ejection fraction (RVEF) is a known predictor of adverse outcomes; however, its prognostic value diminishes in tricuspid regurgitation (TR).

OBJECTIVES: This study aims to assess whether effective right ventricular ejection fraction (eRVEF) offers a more physiologic assessment of RV function and improves risk stratification in patients with TR.

METHODS: The derivation cohort comprised 453 consecutive patients with at least moderate functional TR (regurgitant fraction ≥30% or volume ≥30 mL) on cardiac magnetic resonance (CMR). eRVEF was calculated as the ratio of forward volume to RV end-diastolic volume. The eRVEF threshold (≤25%) was derived based on all-cause mortality data. Clinical data were collected from standardized questionnaires at the time of CMR and supplemented with electronic health records; the primary outcome was all-cause mortality. External validation was performed in 2 independent cohorts, totaling 316 patients using identical inclusion criteria.

RESULTS: In the derivation cohort, impaired eRVEF was associated with more advanced biventricular remodeling, worse biventricular function, and greater burden of late gadolinium enhancement (P < 0.05 for all), which was paralleled by higher TR volume and fraction (both P < 0.05). Over a median follow-up period of 2.7 years (Q1-Q3: 0.6-6.6 years), 20% of the patients died; mortality was higher in patients with impaired versus preserved eRVEF (28% vs 12%; HR: 1.72 [95% CI: 1.16-2.54]; P = 0.007). After adjusting for known TR risk markers including age, RV size, TR severity, conventional RVEF, and clinical markers of right-sided congestion, eRVEF remained independently predictive of mortality (HR: 0.49 [95% CI: 0.24-0.97]; P = 0.042). Adding eRVEF to a model inclusive of RVEF improved mortality prediction (chi-square from 30.6 to 37.0; P = 0.011) whereas adding RVEF to eRVEF did not (chi-square from 35.4 to 37.0; P = 0.199). External validation confirmed the prognostic significance of eRVEF ≤25% in both cohorts (HR: 2.66-2.86; both P < 0.05).

CONCLUSIONS: eRVEF independently predicts mortality in TR and provides incremental prognostic value over conventional prognostic markers.