Longitudinal outcome of isolated mitral repair in older patients: results from 14,604 procedures performed from 1991 to 2007

Background: Mitral valve (MV) repair is performed with less frequency than MV replacement in older persons, with referral often delayed until symptoms are severe. Surgical practice in this population remains inconsistent in the absence of national MV repair outcomes. The goal of this study was to assess durability and longitudinal outcomes after isolated primary MV repair in patients aged 65 years or more.

Methods: We linked clinical data from The Society of Thoracic Surgeons adult cardiac surgery database (STS) to longitudinal claims data from the Centers for Medicare and Medicaid Services (CMS). Between January 1991 and December 2007, we identified 14,604 isolated nonemergent primary MV repair operations in STS-CMS data. These were longitudinally examined for mortality, mitral reoperation, and readmissions for heart failure, bleeding, and stroke. Predictors of 5-year death after MV repair were identified using Cox proportional hazard modeling.

Results: The study cohort had a mean age of 73.3±5.5 years, ejection fraction 54.0%±12.9%; 55.8% (8,148 of 14,604) were female; and 8.4% (1,233 of 14,604) were non-Caucasian. Operative mortality was 2.59% (378 of 14,604). Mean follow-up was 5.9±3.9 years (range, 1.0 to 18.0). Survival during follow-up was 74.9% (10,934 of 14,604). The number of observed events for mitral reoperation, heart failure, bleeding, and stroke were 552 of 14,604 (3.7%), 2,681 of 14,604 (18.4%), 1,051 of 14,604 (7.2%), and 1,131 of 14,604 (7.7%), respectively. The 10-year Kaplan-Meier event rates for mitral reoperation, heart failure, bleeding, and stroke were 6.2%, 30.1%, 15.3%, and 16.4%, respectively. The 10-year actuarial survival of 57.4% was equivalent to the matched US population.

Conclusions: Utilizing linked STS and CMS databases, we demonstrate that MV repair is a safe and durable long-term option for older patients. Survival restored to the normal population suggests repair may suppress the longitudinal impact of mitral regurgitation in the elderly and that the practice of delayed referral should be reevaluated. These data provide a contemporary longitudinal benchmark of MV repair outcomes.