Right ventricular-pulmonary arterial uncoupling and ventricular-secondary mitral regurgitation: relationship with outcomes in advanced heart failure

Background Secondary mitral regurgitation (MR) is common in heart failure with reduced ejection fraction (HFrEF) and associated with poor outcomes. However, there is little evidence regarding secondary MR in advanced HFrEF. Poor outcomes for MR intervention suggest a need for further risk stratification. Objectives We hypothesized adverse prognosis in right ventricles (RV) less able to compensate for increased pulmonary pressures of post-capillary cause in the context of secondary MR. Methods Patients were assessed with echocardiography, right heart catheterisation (RHC) and cardiopulmonary exercise testing. Ventricular-secondary MR was identified by echocardiography and categorised mild, moderate, or severe according to guidelines. RV ability to compensate for pulmonary pressure rise was assessed by RV-pulmonary artery (PA) coupling, calculated as ratio of tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (SPAP) (echocardiography for TAPSE and RHC for SPAP). Primary endpoint was a composite of all-cause mortality, urgent heart transplantation or mechanical circulatory support. Results 456 patients with ventricular-secondary MR were followed up for a median of 2.39 years, with 237 reaching a primary endpoint. Severe MR conferred a worse prognosis than mild or moderate (HR 2.6, p<0.001). Right atrial pressure was predictive of survival. RV-PA uncoupling, defined as TAPSE/SPAP below median value of 0.37, was associated with reduced survival across all severities of mitral regurgitation (p<0.001). Conclusions Ventricular-secondary MR is common and severity correlates with adverse prognosis in advanced heart failure. RV-PA uncoupling can improve risk stratification in all grades of MR severity, particularly with PA pressure determined invasively.