Predicting long-term functional results after myocardial revascularization in ischemic cardiomyopathy

Objective: The goal of the present study was to define the early and late functional results after revascularization in ischemic cardiomyopathy and to identify variables predictive of a favorable outcome. Methods: A retrospective review of all consecutive patients with ischemic cardiomyopathy undergoing myocardial revascularization between January 1991 and June 1998 was undertaken. One hundred sixty-seven patients (140 men) aged 60 +/- 8 years (range, 39-77 years) with angina (n = 107), congestive heart failure (n = 54), or silent ischemia (n = 6) were identified. One hundred six (63%) patients with angina were in Canadian Cardiovascular Society class III or IV, and 40 (24%) patients with congestive failure were in New York Heart Association class III or IV. The preoperative left ventricular ejection fraction averaged 0.28 +/- 0.05 (range, 0.16-0.30). Thirteen (8%) patients required preoperative mechanical life support. A mean of 2.9 +/- 0.9 grafts per patient were performed, with an average myocardial ischemia time of 53 +/- 23 minutes and bypass time of 104 +/- 31 minutes. Results: There were 3 (1.7%) early deaths and 21 (13%) deaths during follow-up (2.7 +/- 2.1 years; range, 0.3-7.8 years), producing a survival of 94% +/- 2% and 75% +/- 10% at 1 and 5 years, respectively. Despite a significant increase in left ventricular ejection fraction (0.28 +/- 0.05 vs 0.38 +/- 0.09, P = .0001), only 89 (54%) patients were symptom-free at follow-up. Freedom from recurrent angina was 98% +/- 1% and 81% +/- 8%, whereas freedom from congestive failure was 78% +/- 11% and 37% +/- 20% at 1 and 5 years, respectively. Follow-up New York Heart Association class in patients with congestive failure was improved (40/54 class III-IV vs 11/54 class III-IV, P = .0001). Multivariate analysis showed a lower ejection fraction (P = .01), preoperative congestive failure (P = .03), and a need for preoperative intra-aortic balloon pumping (P = .03) to be associated with a greater prevalence of recurrent congestive failure, whereas male sex (P = .01), preoperative angina (P = .04), use of the internal thoracic artery (P = .03), and higher number of grafts (P = .01) were associated with lower prevalence. Male sex (P = .06), higher number of grafts (P = .04), and shorter duration of myocardial ischemia (P = .04) were also predictive of improvement in New York Heart Association class at follow-up. Conclusions: Despite satisfactory early and late survival, late functional outcome after myocardial revascularization in ischemic cardiomyopathy remains suboptimal because of recurrence or persistence of congestive failure. Selection of appropriate surgical candidates and extensive use of complete revascularization with the internal thoracic artery may substantially improve functional results.