What Is the Optimal Mitral Valve Repair for Isolated Posterior Leaflet Prolapse to Achieve Long‐Term Durability?

BACKGROUND: This study assessed risk factors for mitral regurgitation (MR) recurrence or functional mitral stenosis during long‐term follow‐up in patients undergoing mitral valve repair for isolated posterior mitral leaflet prolapse. METHODS AND RESULTS: We assessed a consecutive series of 511 patients who underwent primary mitral valve repair for isolated posterior leaflet prolapse between 2001 and 2021. Annuloplasty using a partial band was selected in 86.3%. The leaflet resection technique was used in 83.0%, whereas the chordal replacement without resection was used in 14.5%. Risk factors were analyzed for MR recurrence ≥grade 2 or functional mitral stenosis with mean transmitral pressure gradient ≥5 mm Hg using a multivariable Fine–Gray regression model. The 1‐, 5‐, and 10‐year cumulative incidence of MR ≥grade 2 was 7.8%, 22.7%, and 30.1%, respectively, whereas that of mean transmitral pressure gradient ≥5 mm Hg was 8.1%, 20.6%, and 29.3%, respectively. Risk factors for MR ≥grade 2 included chordal replacement without resection (hazard ratio [HR], 2.50, P<0.001) and larger prosthesis size (HR, 1.13, P=0.023), whereas factors for functional mitral stenosis were use of a full ring (partial band versus full ring, HR, 0.53, P=0.013), smaller prosthesis size (HR, 0.74, P<0.001), and larger body surface area (HR, 3.03, P=0.045). Both MR ≥grade 2 and mean transmitral pressure gradient ≥5 mm Hg at 1 year post surgery were significantly associated with the long‐term incidence of reoperation. CONCLUSIONS: Leaflet resection with a large partial band may be an optimal strategy for isolated posterior mitral valve prolapse.