Early Surgery versus Watchful Waiting for Mitral Valve Regurgitation

The vast majority of patients with degenerative mitral regurgitation have symptoms improved and normal life expectancy restored with surgical intervention. In patients without American College of Cardiology (ACC)/American Heart Association (AHA) guideline class I triggers (no or minimal symptoms and absence of left ventricular dysfunction), there is ongoing debate regarding the need for early surgical intervention.

Researchers recently conducted an analysis of a large multicenter registry of patients diagnosed with flail mitral valve regurgitation to determine the comparative effectiveness of initial medical management (nonsurgical observation) versus early mitral valve surgery. They reported results of the analysis in JAMA [2013;310(6):6090616].

The analysis utilized the Mitral Regurgitation International Database (MIDA), a registry that includes 2097 consecutive patients with flail mitral valve regurgitation (1980-2004) receiving routine cardiac care from 6 tertiary centers in France, Italy, Belgium, and the United States. Mean follow-up was 10.3 years. Of 1021 patients without ACC/AHA guideline class I triggers, 575 were initially medically managed and 446 underwent mitral valve surgery within 3 months of diagnosis.

At 3 months, there were no statistically significant differences for early surgery versus medical management in early mortality (1.1% vs 0.5%, respectively; P=.28) and new-onset heart failure rates (0.9% vs 0.9%, respectively; P=.96).

However, long-term (10 years) survival rates were higher for patients with early surgery (86% vs 69%; P<.001). This finding was confirmed in adjusted models (hazard ratio [HR], 0.55 [95% confidence interval (CI) 0.41-0.72]; P<.001), a propensity-matched cohort (32 variables; HR, 0.52 [95% CI, 0.35-0.79]; P=.002), and in the inverse probability-weighted analysis (HR, 0.66 [95% CI, 0.52-0.83]; P<.001), associated with a 5-year reduction in mortality of 52.6% (P<.001). There were similar results in relative reduction in morality following early surgery in the subset with class II triggers (59.3 after 5 years; P=.002).

Early surgery also reduced the long-term risk of heart failure (7% vs 23% at 10 years; P<.001). This finding was confirmed in risk-adjusted models (HR, 0.29 [95% CI, 0.19-0.43]; P<.001), a propensity-matched cohort (HR, 0.44 [95% CI, 0.26-0.76]; P=.003), and in the inverse probability-weighted analysis (HR, 0.51 [95% CI, 0.36-0.72]; P<.001).

The analyses did not reveal statistically significant reduction in late-onset atrial fibrillation (HR, 0.85 [95% CI, 0.64-1.13]; P=.26).

The authors said, “Although propensity score matching and inverse probability weighting adjusts for known interactions, while unlikely, residual confounding cannot be ruled out. Although these results were derived from a population of patients with flail mitral valve leaflets, they may not apply to those with other etiologies of mitral valve disease.”

The authors stated, “The advantages associated with early surgical correction of mitral valve regurgitation were confirmed in both unmatched and matched populations, using multiple statistical methods. Among patients with mitral valve regurgitation due to flail mitral leaflets, prompt surgical intervention within 3 months following detection was associated with greater long-term survival and lower heart failure risk, even in the absence of traditional class I triggers for surgery.”