For a study, researchers determined that the best time to treat mitral regurgitation surgically was still up for debate. The potential short- and long-term postoperative outcome penalty associated with the type of guideline-based indication for surgery is a major topic of disagreement. Between 1990 and 2000, 1,512 patients (aged 64 ± 14 years, mitral prolapse in 89%, valve replacement in 88%) had pure organic mitral regurgitation surgically corrected. Class I triggers (ClassI-T: heart failure symptoms, ejection fraction less than 0%, end-systolic diameter 40 mm, n = 794), class II triggers based on clinical complications (ClassII-CompT: atrial fibrillation or pulmonary hypertension, n=195), and early class II triggers based on a combination of severe mitral regurgitation and a high probability of valve repair (ClassII-Early, n=253)

ClassI-T had the highest operative mortality (1.1% vs 0% and 0%, respectively, P=.016). ClassI-T (15-year 42% ± 2%; adjusted hazard ratio [HR], 1.89; 95% CI, 1.53-2.34; P=.0001) and ClassII-CompT (15-year 53% ± 4%, adjusted HR, 1.39; 95% CI, 1.04-1.84; P=.027) had lower long-term survival than ClassII-EarlyT (15-year 70% ± 3%, P =.0001). Age stratification, inverse probability weighting, and anticipated survival correction indicated postoperative mortality increased with ClassI-T and ClassII-CompT. ClassI-T had the highest rates of postoperative heart failure (adjusted HR, 1.98; 95% CI, 1.30-3.00; P=.002). Despite the low operating risk and high repair rates, the guideline-based rationale for surgical correction of organic mitral regurgitation was linked to significant long-term postoperative mortality and heart failure. Surgical correction of severe mitral regurgitation with a high likelihood of repair was associated with improved survival and a lower risk of heart failure. It should be the preferred treatment in valve centers with low operating risk and high repair rates.