Predicting Operative Mortality After Surgery for Ischemic Cardiomyopathy

Abstract

Ischemic cardiomyopathy accounts for as many as 70% of cases of heart failure with no clear algorithm for the treatment. We assessed the operative risks and mortality of various surgical options: coronary artery bypass grafting (CABG), CABG and mitral valve repair (CABG/MVR), and left ventricular remodeling (LVR) with or without CABG. We hypothesized that additional procedures increased the operative risk. We determined whether preoperative variables (eg, urgency of operation) impacted the surgical outcome. A retrospective analysis of University of Virginia patients from January 2000 until September 2006 was undertaken. Patients with CABG and an ejection fraction less than 35%, ischemic mitral regurgitation by operative characterization, and patients with LVR were identified. The Society of Thoracic Surgeons database risks, complications, and outcomes as well as degree of revascularization, quality of targets, and type of additional procedures were analyzed. Incomplete revascularization was defined as a planned bypass not performed. Poor targets were defined as per the operative note. In all, 382 patients were identified (220 CABG, 97 CABG/MVR, and 65 LVR). The overall operative mortality was 7.9%. Mortality was 9.1% for CABG, 8.2% for CABG/MVR, and 3.1% for LVR. Preoperative risk factors for mortality included diabetes mellitus (p = 0.05), previous cerebrovascular disease (p = 0.05), and chronic renal dysfunction (p = 0.03). Patients with emergency operations had a significantly increased mortality (p < 0.001) as did patients with intra-aortic balloon pumps (p = 0.015). Additional procedures such as MVR or LVR did not add to the operative risk of CABG for ischemic cardiomyopathy. Only preoperative comorbidities and emergency operations increased operative mortality.