Impact of the discrepancy between predicted and actual ring size on the outcomes of mitral valve repair using the loop technique

Objective To investigate the impact of the discrepancy between the predicted annuloplasty ring size determined by preoperative transesophageal echocardiography and the actual ring size on the outcomes of mitral valve repair (MVr) using primarily the loop technique. Methods Among 370 patients who underwent MVr between January 2008 and December 2024, 154 who underwent MVr with the semirigid ring for degenerative disease were involved in this study. Ring size was estimated according to the lengths of A2 and P2 by transesophageal echocardiography. Patients were classified into 3 groups—small, match, and large—based on the discrepancy between the predicted and actual ring sizes. Results Compared with the other small and match groups, patients in the large group had shorter anterior leaflet length (P = .03), smaller posterior leaflet angle (P = .01) and smaller coaptation depth (P = .03) in the coaptation triangle. There was no significant difference in coaptation length among the 3 groups. The cumulative incidence of mitral regurgitation (MR) grade ≥2 was 0.6% at 1 year, 5% at 5 years, and 24% at 10 years, whereas that of a mean transmitral pressure gradient ≥5 mm Hg were 5%, 13%, and 16%, respectively. Fine-Grey multivariable analysis identified larger posterior leaflet angle after repair as a risk factor for recurrence of MR grade ≥2 and larger body surface area, smaller prosthesis size, and shorter coaptation length as risk factors for functional mitral stenosis. Conclusions Size mismatch of the prosthesis ring did not change the coaptation length, late MR recurrence, or functional mitral stenosis after MVr.