Wide Variation in Mitral Valve Repair Rates Among U.S. Surgeons: Analysis of Medicare Claims Data.

Objective: Mitral valve repair is the preferred treatment for primary mitral regurgitation, offering significant short- and long-term advantages over valve replacement. This study was designed to evaluate the contemporary national mitral valve surgery practice patterns, focusing on the impact of surgeon-specific factors, such as operative volume and years of practice, on repair rates.

Methods: A retrospective analysis was conducted using 100% Medicare fee-for-service claims data over a 3-year period (January 2020 to December 2022). Mitral valve procedures were identified using specific CPT codes. We excluded patients with active infective endocarditis, mitral stenosis, or a history of prior mitral valve repair or replacement. Multivariable binomial regression was used to assess the impact of surgeon-specific factors on repair rates.

Results: We identified 2,072 surgeons in 770 hospitals who performed 12,339 mitral valve operations, with an overall repair rate of 68.8%. The median number of mitral valve operations performed per surgeon during the three-year study period was 3 (IQR 2 - 7), and the median number of mitral valve repairs was 2 (IQR 1 - 5). A subset of 312 surgeons (15%) performed more than 10 mitral valve procedures each and over half (57%) of all repairs nationally. This subgroup's median repair rate was 77%, with significant variability within the group: 17% of surgeons had a repair rate below 50%, 59% had a repair rate between 50 - 90%, and 24% had a repair rate above 90%. Multivariable regression analysis indicated significant associations between repair rates and surgeon-specific factors, including surgical volume, years of practice, and region of practice. Each additional procedure was associated with a 1.5% average increase in repair rate likelihood (95% CI 1.2 - 1.8%, p < 0.001), and each additional year of practice was associated with a 1.4% average increase (95% CI 0.8 - 2%, p < 0.001). Regional differences were notable: surgeons in the South demonstrating lower repair rates (median 71%, IQR 55% - 85%) compared to those in the Northeast (median 78%, IQR 68% - 91%, p = 0.02) and Midwest (median 86%, IQR 63% - 92%, p = 0.04).

Conclusions: This study has identified significant variability in mitral valve repair rates among surgeons treating Medicare beneficiaries. Notably, even among the surgeons responsible for most of these procedures, the variability in repair rates is pronounced. These findings suggest substantial opportunities to improve outcomes for patients undergoing mitral valve operations in North America.