Exercise Echocardiography Predicts Major Clinical Events in Patients With Significant Asymptomatic Mitral Regurgitation

Introduction: Significant mitral regurgitation (MR) often results in progressive cardiac dysfunction that frequently requires surgical intervention. This study aims to assess the prognostic value of exercise stress echocardiography (ESE) in the evaluation of asymptomatic patients with significant MR. Methods: 295 patients with predominantly organic, moderate-to-severe and severe MR underwent ESE. Baseline characteristics at the time of the stress test, exercise variables and echocardiographic parameters are shown in Table 1. We have evaluated the incidence of and identified risk factors for death and the following major clinical events (MCEs): atrial fibrillation (afib), pulmonary hypertension (pHTN), heart failure (HF), and stroke/TIA. Multivariable Cox regression models were used to identify demographic, echocardiographic and exercise parameters associated with MCEs. Results: Patients were followed for a median of 4.2 years (IQR 5.5) and 50% of them experienced at least one MCE. In this cohort, 23% of the patients underwent mitral valve surgery during the follow-up period. Longer exercise time was associated with a lower risk of HF/death (hazard ratio 0.88, 95% CI [0.81, 0.96]), as well as stroke/death (0.77 [0.71, 0.85]). A higher biplane ejection fraction (EF) also was associated with a lower risk of HF/death (0.95 [0.93, 0.98]). A higher baseline right ventricular systolic pressure (RVSP) was associated with a higher risk of pHTN/death (1.1 [1.0, 1.1]), while left atrial volume index (LAVI) greater than or equal to 48 mL/m 2 was associated with a higher risk of afib/death (2.4, [1.4, 4.1]). Conclusions: In asymptomatic patients with significant organic MR, there is a high incidence of heart valve disease-related MCEs. Higher LAVI, higher RVSP, and lower EF were associated with worse outcomes and could inform the process of earlier surgical referral.