Surgical Revascularization Is Associated With Maximal Survival in Patients With Ischemic Mitral Regurgitation: A 20-Year Experience

Study Questions:

What treatment strategy for ischemic mitral regurgitation (IMR) is associated with the best survival?

Methods:

Data from patients diagnosed with significant coronary artery disease and moderate or severe IMR from 1990–2009 at a single large tertiary-care medical center were retrospectively reviewed. Treatment was categorized as medical treatment alone (MED), percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), or CABG + mitral valve repair or replacement (MVRR); based on initial therapy within 30 days of heart catheterization. Kaplan-Meier methods and multivariable Cox proportional hazard analyses were performed to assess the relationship between treatment strategy and survival, using propensity scores to account for nonrandom treatment assignment.

Results:

A total of 4,989 patients were included: MED = 36%, PCI = 26%, CABG = 33%, and CABG + MVRR = 5%. Median follow-up was 5.37 years. Compared to MED, significantly lower mortality was observed in patients treated with PCI (adjusted hazard ratio [AHR], 0.83; 95% confidence interval [CI], 0.76-0.92; p = 0.0002), CABG (AHR, 0.56; 95% CI, 0.51-0.62; p < 0.0001), and CABG + MVRR (AHR, 0.69; 95% CI, 0.57-0.82; p < 0.0001); the lowest mortality was associated with CABG. There was no significant difference in these results based on MR severity.

Conclusions:

Patients with significant coronary artery disease and moderate or severe IMR undergoing CABG alone demonstrated the lowest risk of death. CABG with or without mitral valve surgery was associated with lower mortality than either PCI or MED.

Perspective:

This is another large retrospective single-center study that offers data regarding the optimal treatment of IMR. This study, with data from the Duke Databank of Cardiovascular Disease, suggests that CABG alone is associated with the best survival, superior to (in rank order) CABG + MVRR, PCI, and MED. Limitations include its retrospective, nonrandomized nature; and, perhaps of equal importance, analysis based on treatment assignment within 30 days of heart catheterization, even if patients subsequently underwent different intervention. (Presumably, a ‘hybrid’ approach in a high-risk patient of PCI followed by mitral valve surgery with or without CABG would be considered PCI alone, and medical therapy for 2 months followed by CABG + MVRR would be considered as MED.) The authors point out the multiple calls for and potential benefit of a prospective randomized trial to address this topic. I agree.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Cardiac Surgery and VHD, Interventions and Coronary Artery Disease, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Coronary Artery Disease, Propensity Score, Mitral Valve Insufficiency, Cardiac Catheterization, Coronary Artery Bypass, Mitral Valve, Percutaneous Coronary Intervention


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