Predictors of Long-Term Outcomes in Patients with Significant Myxomatous Mitral Regurgitation Undergoing Exercise Echocardiography
Background—Significant myxomatous mitral regurgitation (MR) leads to progressive left ventricular (LV) decline, resulting in congestive heart failure (CHF) and death. Such patients benefit from mitral valve (MV) surgery. Exercise echocardiography (ExEc) aids in risk stratification and helps decide surgical timing. We sought to assess predictors of outcomes in such patients undergoing ExEc.
Methods and Results—This is an observational study of 884 consecutive patients (58±14 years, 67% men) with ≥III+ myxomatous MR who underwent ExEc between 1/2000 and 12/2011 (excluding functional MR, prior valvular surgery, hypertrophic cardiomyopathy, rheumatic valvular disease or >mild mitral stenosis). Clinical and echocardiographic data [MR, LV ejection fraction, LV dimensions, right ventricular systolic pressure (RVSP)] & exercise variables [metabolic equivalents (METS), heart rate recovery (HRR) at 1st minute post-exercise] were recorded. Composite events of death, myocardial infarction, stroke and progression to CHF were recorded. Mean LV ejection fraction, indexed LV end-systolic dimension, rest RVSP, peak-stress RVSP, METs achieved and HRR were 58±5%, 1.6±0.4 mm/m2, 31±12 mm Hg, 46±17 mm Hg, 9.6±3 and 33±14 beats, respectively. During 6.4±4 years of follow-up, there were 87 events. On stepwise multivariable Cox analysis, %age-gender predicted METs (Hazard ratio or HR 0.99 [0.98-0.99], p=0.005), HRR (HR 0.29 [0.17-0.50], p<0.001), resting RVSP (HR 1.03 [1.004-1.05], p=0.02), atrial fibrillation (HR 1.91 [1.07-3.41], p=0.03) and LV ejection fraction (HR 0.96 [0.92-0.99], p=0.04) predicted outcomes.
Conclusions—In patients with ≥III+ myxomatous MR undergoing ExEc, lower %age-gender predicted METS, lower HRR, atrial fibrillation, lower LV ejection fraction and high resting RVSP predicted worse outcomes.
- Received July 25, 2013.
- Revision received December 12, 2013.
- Accepted December 20, 2013.