Leaflet Resection vs Preservation for Degenerative Mitral Regurgitation: Functional Outcomes and Mitral Stenosis at 12 Months in a Randomized Trial.

Background: Mitral valve repair is the gold standard treatment for degenerative mitral regurgitation (MR). The Canadian Mitral Research Alliance (CAMRA) CardioLink-2 trial showed no significant association between repair strategy, that is, leaflet resection vs preservation, and risk of functional mitral stenosis. In this subanalysis, we compared outcomes and functional tests at 12 months.

Methods: CAMRA CardioLink-2 was a multicentre randomized controlled trial that allocated patients with degenerative MR and posterior leaflet prolapse to leaflet resection (n = 54) or preservation (n = 50). Stress echocardiography and functional status assessments, including the 6-minute walk test, were compared 12 months after repair.

Results: Baseline demographics, stress echocardiographic findings, and mitral annuloplasty prosthesis size (33.0 ± 3.0 vs 33.6 ± 3.4 mm; P = 0.4) were similar between the two groups. There were no readmissions for heart failure or deaths during the follow-up period. At 12 months, a larger percentage of patients were in NYHA functional class ≥ 2 in the resection group compared with the preservation group (P = 0.01). Exercise capacity, rate-pressure product, 6-minute walk distance, and mean mitral valve gradients were not significantly different between the groups at 12 months. A more prominent increase in mean mitral gradient with smaller annuloplasty sizes was observed in the resection group at both rest (P = 0.03) and peak exercise (P = 0.005) in the linear regression model.

Conclusions: At 12 months, there were no significant differences in mitral valve gradient, exercise capacity, and 6-minute walk test between repair strategies. Leaflet preservation may offer a larger mitral valve orifice with improved gradients in patients requiring smaller annuloplasty sizes.