Two-Year Outcomes of Surgical Treatment of Severe Ischemic Mitral Regurgitation

Abstract

Background: In a randomized trial comparing mitral-valve repair with mitral-valve replacement in patients with severe ischemic mitral regurgitation, we found no significant difference in the left ventricular end-systolic volume index (LVESVI), survival, or adverse events at 1 year after surgery. However, patients in the repair group had significantly more recurrences of moderate or severe mitral regurgitation. We now report the 2-year outcomes of this trial.

Methods: We randomly assigned 251 patients to mitral-valve repair or replacement. Patients were followed for 2 years, and clinical and echocardiographic outcomes were assessed.

Results: Among surviving patients, the mean (±SD) 2-year LVESVI was 52.6±27.7 ml per square meter of body-surface area with mitral-valve repair and 60.6±39.0 ml per square meter with mitral-valve replacement (mean changes from baseline, -9.0 ml per square meter and -6.5 ml per square meter, respectively). Two-year mortality was 19.0% in the repair group and 23.2% in the replacement group (hazard ratio in the repair group, 0.79; 95% confidence interval, 0.46 to 1.35; P=0.39). The rank-based assessment of LVESVI at 2 years (incorporating deaths) showed no significant between-group difference (z score=-1.32, P=0.19). The rate of recurrence of moderate or severe mitral regurgitation over 2 years was higher in the repair group than in the replacement group (58.8% vs. 3.8%, P<0.001). There were no significant between-group differences in rates of serious adverse events and overall readmissions, but patients in the repair group had more serious adverse events related to heart failure (P=0.05) and cardiovascular readmissions (P=0.01). On the Minnesota Living with Heart Failure questionnaire, there was a trend toward greater improvement in the replacement group (P=0.07).

Conclusions: In patients undergoing mitral-valve repair or replacement for severe ischemic mitral regurgitation, we observed no significant between-group difference in left ventricular reverse remodeling or survival at 2 years. Mitral regurgitation recurred more frequently in the repair group, resulting in more heart-failure-related adverse events and cardiovascular admissions. (Funded by the National Institutes of Health and Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00807040.).

Figure 1. Time-to-Event Curves for Death

Shown are the proportions of patients who died in the mitral-valve (MV) repair group and the mitral-valve replacement group at 2 years. The most frequent underlying causes of death were multisystem organ failure (in 20.8% of patients), heart failure (in 17.0%), and sepsis (in 13.2%). The tick marks indicate censored data.

Figure 2. Cumulative Failure of Mitral-Valve Repair or Replacement

Failure of the intervention was defined as death, moderate or severe mitral regurgitation (MR) as seen on transthoracic echocardiography, or mitral-valve reintervention.

Figure 3. Time-to-Event Curves for Major Adverse Cardiac or Cerebrovascular Events (MACCE)

MACCE was defined as death, stroke, hospitalization for heart failure, worsening heart failure, or mitral-valve reintervention. The tick marks indicate censored data.

Figure 4. Quality-of-Life Scores

Shown are the mean scores on the Medical Outcomes Study 12-Item Short-Form General Health Survey (SF-12) for physical health (Panel A) and mental health (Panel B). The SF-12 scale ranges from 0 to 100, with higher scores indicating better health. Panel C shows mean scores on the Minnesota Living with Heart Failure questionnaire, which ranges from 0 to 105, with higher scores indicating a lower quality of life. Panel D shows mean scores on the European Quality of Life–5 Dimensions (EQ-5D) survey, with scores ranging from 0 to 100, with higher scores indicating a better quality of life.