Prognostic Impact of Right Ventricular to Pulmonary Arterial Coupling for Patients Undergoing Surgery for Severe Mitral Regurgitation

Abstract Background Cardiac surgery may induce abrupt changes in preload, afterload, and right ventricular contractility. The ability of the right ventricle to maintain systolic performance in the presence of increased afterload is referred to as right ventricular–pulmonary artery (RV–PA) coupling. Objectives To assess RV–PA coupling in patients undergoing surgery for severe mitral regurgitation, to identify a TAPSE/PASP threshold for RV–PA uncoupling, and to evaluate its prognostic value for early mortality, right heart failure (RHF), postoperative course, and late mortality. Methods This retrospective single-centre observational study included 277 patients who underwent surgery for severe mitral regurgitation between January 2018 and March 2023. RV–PA coupling was assessed using the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) derived from preoperative transthoracic echocardiography. The primary endpoint was early all-cause mortality within 30 days. Secondary endpoints included mortality from RHF, length of intensive care unit (ICU) stay, length of hospital stay, and late all-cause mortality. Results ROC analysis identified an optimal TAPSE/PASP cut-off of 0.30 mm/mmHg to define RV–PA uncoupling. Patients with TAPSE/PASP ≤0.30 mm/mmHg had significantly higher early mortality and worse postoperative outcomes. In multivariable logistic regression, TAPSE/PASP remained an independent predictor of early mortality together with EuroSCORE II, cardiopulmonary bypass time, and weaning from bypass requiring ECMO or inotropic support. In a sensitivity analysis restricted to isolated mitral valve surgery, TAPSE/PASP remained the only independent predictor of early mortality. RV–PA uncoupling was also associated with excess early mortality from RHF and longer ICU and hospital stay, but not with late mortality. Conclusions Preoperative RV–PA uncoupling assessed by TAPSE/PASP is strongly associated with early mortality and postoperative RHF after mitral valve surgery for severe mitral regurgitation and may help refine perioperative risk stratification.