Repair of Ischemic Mitral Regurgitation: Comparison Between Flexible and Rigid Annuloplasty Rings

Background: The surgical treatment of ischemic mitral regurgitation (MR) usually involves implantation of an annuloplasty ring. We compared results of mitral valve repair using a flexible or a rigid annuloplasty ring in patients with ischemic MR undergoing coronary artery bypass graft surgery.

Methods: There were 169 patients. A flexible ring was implanted in 117 and a rigid ring in 52. Age and clinical profile, degree of left ventricular dysfunction, and degree of MR (mean 3.2) were similar between groups.

Results: Operative mortality was 9% in each group. Follow-up (58 +/- 30 months for flexible group and 14 +/- 7 months for rigid group) was available for 91%. For the flexible and rigid ring groups, respectively, mean New York Heart Association functional class was 1.9 and 1.6, with 33% and 14% in classes III to IV (p = 0.03); mean MR grade was 1.25 and 0.7 (p = 0.006). There was no difference in left ventricle function or dimensions. At follow-up, 29 patients (34%) in the flexible group had residual MR of moderate degree or greater compared with 6 (15%) in the rigid group (p = 0.03). Mean tricuspid incompetence gradient was 39 and 34 mm Hg (p = nonsignificant); however, the degree of reduction was greater in the rigid group (p = 0.001). Late mortality was observed in 32 patients, all in the flexible group.

Conclusions: Clinical and hemodynamic results are better with rigid mitral annuloplasty rings compared with flexible rings. That result may be due to ring design, which dictates not only the annular diameter but also annular configuration. Longer follow-up is needed to determine differences in survival.