Five-year effect of medical and surgical therapy on resting left ventricular function in stable angina: Veterans Administration Cooperative Study.

The effect of coronary artery bypass grafting (CABG) and medical therapy on 5-year resting left ventricular (LV) function was studied in 194 randomized patients with stable angina in the Veterans Administration Study of Coronary Artery Bypass Surgery. LV ejection fraction (EF) was determined in a central laboratory. The 92 medical and 102 surgical patients were comparable at entry with respect to historic, angiographic and electrocardiographic prognostic indicators. Twenty-eight percent of the medical and 30% of the surgical patients had a baseline EF of less than 50%. There was no significant change in mean EF between baseline and 5-year values in either treatment group. The baseline and 5-year values were 56 and 58% in each treatment group. Intervening myocardial infarction (MI) had an adverse effect in medically treated patients (59 to 46%, p less than 0.01) and in surgically treated patients with late MI (58 to 47%, difference not significant). Perioperative MI was not associated with a decrease in EF (56 to 58%, difference not significant). These findings extend the similar results of previous short-term studies of the effect of coronary bypass surgery on resting LV function to 5 years, and provide data in a comparable medical control group.