Association Between Early Surgical Intervention vs Watchful Waiting and Outcomes for Mitral Regurgitation Due to Flail Mitral Valve Leaflets

Study Questions:

Is there a difference in clinical outcomes (survival, heart failure, new-onset atrial fibrillation) based on initial surgical versus nonsurgical management of patients with mitral regurgitation (MR) due to flail leaflet?

Methods:

The Mitral Regurgitation International Database (MIDA) registry was used to examine outcomes of 2,097 consecutive patients with MR and leaflet flail, enrolled between 1980 and 2004, at one of six tertiary medical centers in Europe (France, Italy, Belgium) or the United States (Rochester, MN). Mean follow-up was 10.3 years, and was 98% complete. Of 1,021 patients with MR without American College of Cardiology (ACC) /American Heart Association (AHA) guideline Class I indication for surgery, 575 patients initially were managed conservatively and 446 underwent mitral valve surgery within 3 months following detection of MR. Clinical outcomes were measured for survival, heart failure, and new-onset atrial fibrillation.

Results:

There was no significant difference in early (3-month) rates of mortality (1.1% for early surgery vs. 0.5% for medical management, p = 0.28) or new-onset heart failure (0.9% for early surgery vs. 0.9% for medical management, p = 0.96). In contrast, long-term survival rates were higher for patients who underwent early surgery (86% vs. 69% at 10 years, p < 0.001), which was confirmed in adjusted models (hazard ratio [HR], 0.55; 95% CI, 0.41-0.72; p < 0.001), a propensity-matched cohort (32 variables; HR, 0.52; 95% CI, 0.35-0.79; p = 0.002), and an inverse probability-weighted analysis (HR, 0.66; 95% CI, 0.52-0.83; p < 0.001), and associated with a 52.6% (p < 0.001) relative risk reduction in 5-year mortality. Similar results were found with a 59.3% (p = 0.002) relative reduction in 5-year mortality following surgery among patients with an ACC/AHA Class II indication for intervention. Long-term heart failure risk also was lower after early surgery (7% vs. 23% at 10 years, p < 0.001), which was confirmed in a propensity-matched cohort (HR, 0.44; 95% CI, 0.26-0.76; p = 0.003), and in the inverse probability-weighted analysis (HR, 0.51; 95% CI, 0.36-0.72; p < 0.001). Reduction in late-onset atrial fibrillation was not observed (HR, 0.85; 95% CI, 0.64-1.13; p = 0.26).

Conclusions:

Among registry patients with MR due to flail mitral leaflet, performance of early surgery compared to initial conservative management was associated with greater long-term survival and lower risk of heart failure, with no difference in new-onset atrial fibrillation.

Perspective:

This is an important report from this large multicenter registry, with lower observed rates of long-term mortality and heart failure (but not of new-onset atrial fibrillation) among patients with MR and flail leaflet who underwent surgical intervention within the first 3 months of detection of MR. As an observational study, the possibility of imperfect control for confounding clinical variables remains possible despite statistical propensity matching—the measured clinical outcome was all-cause mortality, not cardiac mortality, raising concern that patients with other comorbid diseases were less likely to undergo surgery and more likely to die of noncardiac causes. A major challenge of managing asymptomatic patients with mitral valve prolapse and MR (with or without leaflet flail) should include absolute certainty that MR is severe before referring for surgical intervention; experience dictates that patients with non-holosystolic and/or clearly not severe MR are referred to surgeons for intervention, despite no data suggesting that surgery is beneficial in the absence of severe MR.

Clinical Topics: Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Follow-Up Studies, Risk Reduction Behavior, Mitral Valve Insufficiency, Belgium, Europe, Heart Valve Prosthesis Implantation, Italy, Heart Diseases, Incidence, France, Mitral Valve Prolapse, Survival Rate, Cardiology, Heart Failure, Watchful Waiting, United States


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