How Does Mitral Valve Repair Fail in Patients With Prolapse?-Insights From Longitudinal Echocardiographic Follow-Up.

BACKGROUND: Repair of mitral regurgitation (MR) caused by prolapse has been well validated. Although favorable early and late results after repair have been reported, few data are available that mechanistically describe how a mitral repair fails beyond the mere need for mitral valve reoperation. We therefore sought to determine the modes of valve repair failure in patients who underwent surgical correction of MR caused by prolapse.

METHODS: Between 2001 and 2015, 855 patients underwent repair of MR caused by prolapse. Patients were a mean age of 63.7 ± 12.7 years, and 380 (44%) had bileaflet prolapse. The overall repair rate was 97.2%. These patients were monitored as part of a cohort initiative and underwent serial clinical and echocardiographic assessments at 1, 3 to 6, and 12 months after the operation. Beyond the first year of the MR repair, patients were assessed by echocardiography every 1 to 2 years or when clinically indicated. Clinical and echocardiographic follow-up averaged 4.3 ± 3.5 years.

RESULTS: Freedom from recurrent MR of 2+ or higher was 92.4% ± 1.3% at 5 years and 86.6% ± 2.4% at 10 years. Overall, recurrent MR of 2+ or higher developed in 49 patients (5.7%) at a mean of 3.1 ± 2.5 years after the repair, of whom 14 (1.6%) had recurrent MR of 3+ or 4+. Among patients with bileaflet prolapse, recurrent MR of 2+ or higher was observed in 24, of whom 9 had 3+ or 4+ MR., The development of recurrent MR of 2+ or higher was categorized as prolapse in 6 and nonprolapse in 43. Severe mitral stenosis occurred in 3 patients at 8.2 years after the MR repair. Mitral reoperation was ultimately performed in 21 patients. Patients who had recurrent MR 2+ or higher within the first year after the operation were more likely to undergo a subsequent mitral valve reoperation (incident rate ratio, 5.2 ± 2.9; p = 0.003), although no association between recurrent MR and reoperation was observed after the first year.

CONCLUSIONS: Severe MR after repair is rare, although some may have recurrent moderate MR. Patients who required a subsequent mitral valve reoperation were most likely to have recurrent MR of 2+ or higher within the first year after the operation.