Prognostic impact of right ventricular dysfunction in rheumatic mitral stenosis

Background Right ventricular dysfunction (RVD) is a common complication in patients with rheumatic mitral stenosis (MS) but its prognostic value has not been explored. Purpose The aim of this study was to determine the association of RVD with clinical outcomes in patients with rheumatic MS in a multi-center setting. Methods Patients presenting with isolated rheumatic MS at four tertiary cardiac centers were included. Patients with concomitant other severe valve disease, or a valve prosthesis at baseline, were excluded. RVD was defined as a tricuspid annular plane systolic excursion <17 mm and/or RV fractional area change <35%. The primary outcome was a composite of all-cause death, heart failure hospitalization (HFH), or cerebrovascular stroke (CVA). The secondary outcome was all-cause death. Results A total of 571 patients were included, of which 206 (36%) presented with RVD at inclusion. Patients with RVD were significantly younger, more symptomatic, and had higher rates of atrial fibrillation (Fig 1). Moreover, they had significantly smaller mitral valve areas, with more frequently very severe MS, larger left atrial volumes and higher systolic pulmonary pressures (SPAP). During a median follow-up of 3.8 [1.6 – 8.5] years, 303 (53%) patients received valve intervention, and 203 (36%) patients reached the primary composite endpoint of death, HFH, or CVA, while 145 (25%) patients reached the secondary endpoint of all-cause death. Kaplan Meier analysis showed a significantly higher cumulative incidence of events in the RVD group, for both the primary and secondary endpoints (P < 0.001 for both) (Fig 2A). At multivariable analysis, after sequential adjustment for relevant clinical and echocardiographic covariates including severity of MS and valve intervention (as a time dependent covariate), RVD maintained an independent association with both endpoints (Fig 2B). When stratified according to intervention during follow-up, RVD retained its independent association with the primary endpoint both in patients under medical management (HR 1.54, P = 0.032) as well as post-intervention (HR 2.18, P = 0.008). Moreover, RVD was also associated with the outcomes in different patient subgroups at univariable analysis (Fig 2C). In particular, in patients with SPAP <50 mmHg, RVD was independently associated with the primary outcome (HR 2.0, P = 0.006) as well as the secondary outcome (HR 1.9, P = 0.016) after adjustment for relevant covariates. Conclusions In patients with rheumatic MS, the presence of RVD was independently associated with a two-fold increase in the risk of death, HFH, or CVA. This association was significant across all patient subgroups, and under both medical management as well as after valve intervention.Figure 1Figure 2