Baseline left ventricular function and surgical annular stiffening to predict outcome and reverse left ventricular remodeling after undersized annuloplasty for intermediate-degree ischemic mitral regurgitation

Objective

We sought to identify determinants of clinical and functional outcome after myocardial revascularization and associated undersized annuloplasty in patients with intermediate-degree ischemic mitral regurgitation.

Methods

Fifty-seven patients with 2+ or 3+ ischemic mitral regurgitation underwent coronary bypass surgery and implantation of undersized semirigid or flexible complete ring or autologous pericardial band and were followed up to 8.6 years.

Results

Operative mortality was 5%. Baseline left ventricular end-systolic volume index, the strongest multivariable predictor of early postoperative outcome, was correlated with end-systolic volume index (P < .001, R² = 0.67) and ejection fraction (P < .001, R² = 0.40) after repair. More compromised ejection fraction and end-systolic volume index predicted comparatively greater early functional improvement but higher residual postoperative end-systolic volume index (P < .01). Cox multivariable analysis identified wall motion as the best baseline predictor of late death and heart failure and regional inferoposterior wall motion as the strongest predictor of recurrent mitral regurgitation (P ≤ .01). More rigid annuloplasty carried a higher probability of functional recovery in terms of ejection fraction, wall motion, and the occurrence and earlier timing of left ventricular reverse remodeling, expressed by different degrees of end-systolic volume index reduction (P < .001, hazard ratio >6).

Conclusions

Combination of undersized mitral annuloplasty and coronary revascularization presents low operative mortality and determines left ventricular unloading in patients with intermediate-degree ischemic mitral regurgitation. Global and regional wall motion are powerful predictors of late outcome. Stiffer mitral annular repair promotes functional recovery and predicts higher probability and earlier timing of reverse remodeling.

CTSNet classification: 22, 23, 30, 35

Abbreviations and Acronyms: CABG, coronary artery bypass grafting, ICU, intensive care unit, LV, left ventricular, LVEF, left ventricular ejection fraction, LVESVI, left ventricular end-systolic volume index, MR, mitral regurgitation, WMSI, wall motion score index, WMSInf, regional inferior wall motion score index