Abstract 16563: Importance of Exercise Capacity in Predicting Impact of Delaying Surgical Correction in Significant Degenerative Mitral Regurgitation
Background: In degenerative mitral regurgitation (DMR), exercise echocardiography (ExEc) aids in symptom evaluation & timing of mitral valve (MV) surgery. In patients with ≥3+ DMR undergoing MV surgery, we sought to assess a) predictors of outcomes & b) whether delaying MV surgery adversely impacts long-term outcomes in those with good exercise capacity.
Methods: We studied 576 such consecutive patients (57±13 years, 70% men, excluding prior valve surgery, functional & other causes) who underwent ExEc, followed by MV surgery (90% repair). Clinical data was recorded. Echocardiographic [degree of MR, left ventricular (LV) ejection fraction (EF), indexed LV dimensions, right ventricular systolic pressure (RVSP)] & exercise variables [metabolic equivalents (METS)] were recorded. Composite events of death, myocardial infarction, stroke & congestive heart failure (stage C/D) were recorded.
Results: Mean LV ejection fraction, indexed LV end-systolic dimension, rest RVSP, peak-stress RVSP, METs achieved & % age/gender-predicted METs were 58±5%, 1.7±0.5 mm/m2, 32±13 mm Hg, 47±17 mm Hg, 9.8±3 & 113±27, respectively. Mean time between ExEc & MV surgery was 12±21 months (28% delayed ≥1 year). During 6.6±4 years of follow-up, there were 53 events. On stepwise Cox survival analysis, increasing age (Hazard ratio (HR) 1.07 [1.03-1.12], p-value<0.01), lower % age-gender predicted METs achieved (HR 0.82 [0.71-0.94, p<0.007] & lower LV EF (HR 0.94 [0.89-0.99], p=0.04) independently predicted outcomes. Patients achieving > 100 % of predicted METs had better survival (Figure 1a) vs. those who did not. In patients achieving > 100 % predicted METs (n=399), delaying surgery by ≥1 year (n=126, 32%) did not adversely affect outcomes (Figure 1b).
Conclusion: In patients with DMR undergoing ExEc followed by MV surgery, higher age, lower achieved METS & LVEF were associated with worse outcomes. In those with good exercise capacity, delaying MV surgery did not adversely impact outcomes.
- © 2013 by American Heart Association, Inc.