Background and aim of the study: Combined coronary artery bypass grafting (CABG) and mitral annuloplasty for ischemic mitral regurgitation (MR) is historically associated with high operative mortality, and remains controversial in the setting of moderate ischemic MR. Herein, operative mortality rates in patients undergoing combined CABG and mitral annuloplasty for moderate ischemic MR were examined.
Methods: Between January 1992 and August 1999, 108 patients with moderate (grade 3+) ischemic MR and coronary artery disease underwent combined CABG and mitral annuloplasty. Univariable analysis was used to identify perioperative risk factors associated with operative mortality in patients undergoing surgery during two different time periods (1992-95 versus 1996-99). Bivariable logistic regression was used to evaluate the possible effect of era on operative mortality, while controlling for potential confounders.
Results: The overall operative mortality was 6.4%. During 1992-95 the operative mortality was 14% (4/28), but fell to 3.7% (3/80) during 1996-99 (p = 0.07). Patients from the earlier period were more likely to have unstable angina, worse NYHA functional class, and preoperative atrial fibrillation. Patients from the latter period were more likely to have peripheral vascular disease and chronic obstructive pulmonary disease. The unadjusted odds ratio (OR) for operative mortality associated with the earlier era was 4.3 (95% CI 9-20.8; p = 0.07). In the bivariable logistic regression models, where patient characteristics that potentially were responsible for the difference in mortality were added, the OR for operative mortality associated with the 1992-95 era ranged from 3.4 to 6.7. None of the patient characteristics appreciably reduced this risk.
Conclusion: Recent decreased operative mortality in combined CABG and mitral annuloplasty for moderate ischemic MR suggests that a more liberal application of this approach may be warranted.