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

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.

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.

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).

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.