Left ventricle-mitral valve ring size mismatch following ring annuloplasty for nonischemic dilated cardiomyopathy

Background: In patients with ischemic mitral regurgitation (MR) undergoing restrictive mitral annuloplasty (RMA), the ratio of left ventricular (LV) end-systolic dimension (LVESD) to mitral valve (MV) ring size (ie, LV-MV ring mismatch) is associated with postoperative recurrent MR. However, the impact of LV-MV ring mismatch on postoperative recurrent MR, LV function recovery, and long-term survival in patients with nonischemic dilated cardiomyopathy (DCM) remains unknown.

Methods: Sixty-six patients with nonischemic DCM (mean LVESD, 62 mm) underwent RMA (mean ring size, 26 mm) between 2003 and 2014. Recurrent MR was defined as MR grade ≥2+ at a 6-month echocardiographic evaluation.

Results: At the 6-month follow-up, 23 patients (35%) had developed recurrent MR. In univariable logistic regression analysis, larger LVESD (P = .012) and LVESD/ring size ratio (P = .008) were associated with recurrent MR. In multivariable models adjusted for age, sex, baseline LV ejection fraction, and severe MR, only LVESD/ring size ratio (odds ratio, 4.65; 95% confidence interval, 1.04-25.0; P = .048) remained significantly associated with MR recurrence. Receiver operating characteristic curve analysis demonstrated an optimal cutoff value for the LVESD/ring size ratio of 2.42. Patients with an LVESD/ring size ratio >2.42 (n = 30; mismatch) had a lower 5-year cumulative survival rate compared with those with an LVESD/ring size ratio ≤2.42 (n = 36; nonmismatch) (52% vs 71%; P = .045). Postoperatively, LV dimensions were significantly reduced in both groups; however, improvements in LVEF were only modest in the mismatched group (P = .091).

Conclusions: LV-MV ring size mismatch was associated with an increased risk of recurrent MR in our series. This finding may aid the formulation of surgical strategies for patients with nonischemic DCM.