Background: Compared with medical therapy alone, coronary artery bypass surgery improves survival in patients with coronary disease and left ventricular dysfunction. Many of these patients have a hibernating myocardium secondary to chronic ischemia with the potential for improvement in left ventricular function and heart failure symptoms following revascularization therapy. Cardiac transplantation remains the treatment of choice for patients with severe congestive heart failure.
Methods: From January 1992 to June 2000, 351 consecutive patients (318 men, 33 women, mean age 62.8 +/- 8.9 years) with a left ventricular ejection fraction (EF) < or = 35% and with multivessel coronary artery disease underwent isolated coronary artery bypass grafting. Preoperatively 226 patients were in CCS class III-IV and 113 in NYHA class III-IV. The mean number of grafts was 3.4 +/- 0.8/patient and complete revascularization was achieved in 98.6% of cases. The internal mammary artery was used in 341 patients (97.2%) and in 328 (96%) as a graft for the left anterior descending artery. Follow-up was obtained in 97% of the patients and on average lasted 42 +/- 28 months.
Results: The hospital mortality was 5.9%. At multivariate analysis urgent operation (p < 0.01) and a lower EF (25.9% in deaths vs 29.1%, p < 0.05) were predictors of an increased operative mortality. EF (assessed postoperatively at transthoracic echocardiography in survivors) improved from 28.9 +/- 5.7 to 34.4 +/- 7.7% (p < 0.0001). At 1, 3, 5, 7, and 9 years respectively, the all-cause survival was 93 +/- 1.5, 85 +/- 2.2, 77 +/- 3.1, 69 +/- 4.9, and 60 +/- 7.3% and the freedom from cardiac death was 94 +/- 1.4, 89 +/- 1.9, 88 +/- 2, 80 +/- 4.7, and 76 +/- 5.7% with an improvement in the anginal and congestive heart failure status (p < 0.0001).
Conclusions: In patients with coronary artery disease and severe left ventricular dysfunction, after evaluation of the clinical presentation, of the usefulness of vessels as grafts and of the presence of myocardial viability, 1) coronary artery bypass grafting can be performed with a low mortality and a good mid-term survival, 2) improvement in left ventricular function can be documented after coronary bypass surgery, 3) the internal mammary artery can be safely used as a graft, 4) the quality of life is improved as demonstrated by the improvement in the anginal and congestive heart failure status.