Stress test evaluation of patients with poor left ventricular function before and after coronary artery bypass surgery.

Between May 1976 and December 1982 (104 months), 152 patients from a total of 3592 patients who had coronary angiography at the Buffalo Veterans Administration Medical Center had coronary artery disease with left ventricular ejection fractions of 40% or below. Sixty-three patients in this group had coronary bypass surgery. Thirty patients who had graded exercise tests done before and after surgery improved in their peak exercise double product and systolic blood pressure (p value <.05) accompanied by increased work capacity (p value < 0.02). Nineteen patients who had identical exercise protocols also showed increases in exercise time (p value <.05). We believe that coronary artery bypass surgery improves exercise capacity in selected patients with compromised left ventricular function.