Right ventricular function and pulmonary pressure interaction as a predictor of mortality in tricuspid regurgitation

Abstract Background Right ventricular–pulmonary arterial (RV–PA) coupling reflects the ability of the right ventricle to adapt contractility to afterload. Reduced coupling, measured by the TAPSE/PASP ratio, indicates RV–PA uncoupling and impaired reserve. Although linked to poor outcomes in multiple cardiac diseases, its prognostic role in tricuspid regurgitation remains uncertain. Objectives To determine whether RV–PA coupling (TAPSE/PASP) predicts mortality in tricuspid regurgitation (TR) and to assess a new composite index, (TAPSE×FAC)/PASP, combining RV function and afterload for enhanced prognostic precision. Methods We retrospectively included all patients in the all-cause TR database who had tricuspid annular planar systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) measurements available. RV-PA coupling was assessed by dividing TAPSE by PASP, and patients were divided into two groups based on the median value. Additionally, an alternative parameter was created by multiplying TAPSE by the RV fractional area change (FAC) and dividing by SPAP. The primary endpoint was all-cause mortality. The mentioned parameters and other covariates were examined for their predictive value regarding all-cause mortality using both univariable and multivariable Cox regression analyses. In addition, the area under the receiver operating characteristic curve (AUC) was analyzed to compare the different predictors in predicting 1-year mortality and to define cut-off values. Results Among 247 patients (median age 80 years; 61% female), median TAPSE/PASP was 0.404 (IQR 0.273–0.583). Patients with TAPSE/PASP ≤0.404 had higher pulmonary pressures, right atrial pressures, and serum creatinine levels. One-year mortality was 41.9% versus 16.3% in those with preserved coupling (P0.001), with significantly lower 3-year survival (log-rank P0.001). The optimal cutoff for 1-year mortality was 0.4046 (AUC 0.666), exceeding FAC/PASP and TR EROA. In multivariable analysis adjusted for clinical covariates, lower TAPSE/PASP independently predicted all-cause mortality (HR 0.22 95% CI, 0.06–0.79; P = 0.021). In a subgroup of patients with severe TR (EROA ≥0.30 cm²; n=88), one-year mortality was 38% with low TAPSE/PASP versus 14% with preserved coupling (P0.001). TAPSE/PASP remained an independent predictor of mortality (HR 2.74 95% CI 1.42–5.28; P=0.003), and the composite index (TAPSE×FAC)/PASP provided the highest prognostic discrimination (AUC 0.691). Conclusions Reduced TAPSE/PASP, indicating RV–PA uncoupling, independently predicts mortality in tricuspid regurgitation. Incorporating both TAPSE and RV FAC into a composite coupling index may enhance prognostic assessment, though further validation in larger cohorts is warranted.KM - Tricuspid regrgitationFor image description, please refer to the figure legend and surrounding text. ROC CurveFor image description, please refer to the figure legend and surrounding text.