The impact of baseline right ventricular-pulmonary artery coupling on the short-term outcome after valve replacement surgery for rheumatic mitral stenosis.

Background: Right ventricular dysfunction (RVD) signals poor prognosis in mitral valve replacement (MVR) patients. Right ventricular-pulmonary artery (RV-PA) coupling reflects how efficiently RV stroke work transfers to the pulmonary artery. This study evaluated the effect of RVD (due to impaired RV-PA coupling) on the short-term prognosis of rheumatic mitral stenosis (RMS) patients post-MVR. Methods: RV-PA coupling parameters were calculated by the ratio of tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) from transthoracic echocardiography. The characteristics and outcomes of RMS patients with MVR were compared according to the TAPSE/PASP ratio. The primary outcome was 90-day mortality, and the secondary outcome was perioperative adverse events. Results: A total of 286 RMS patients were finally included, 112 patients had RVD (39.2% TAPSE/PASP ≤0.32 mm/mmHg). RVD patients showed higher 90-day mortality (16.1% vs. 2.9%; P<0.001) and perioperative adverse events (41.1% vs. 17.8%; P<0.001). In multivariate analyses, a decreased TAPSE/PASP ratio was an independent predictor of 90-day mortality in MVR patients [hazard ratio (HR) =4.41; 95% confidence interval (CI): 1.60-12.15; P=0.004]. Kaplan-Meier analysis showed that patients with impaired RV-PA coupling had lower survival rates than those with preserved RV-PA coupling (HR =6.01; 95% CI: 2.59-13.99; P<0.001). This difference remained in the subgroup of RMS patients with mild pulmonary hypertension (PH). Conclusions: Impaired baseline RV-PA coupling predicts poor outcomes in RMS patients undergoing MVR. Echocardiography is valuable for RMS severity assessment, particularly for overlooked severe RMS cases with mild PH.