Subjective multivariable analysis bu computer for evaluation of coronary artery bypass

J. S. Carey and R. A. Cukingnan

Subjective multivariable analysis by computer was utilized to evaluate the results in a series of 659 patients undergoing coronary artery saphenous vein bypass surgery. A video terminal gave access to a remote computer. The postoperative subjective response was evaluated by questionnaires sent to patients at 6- to 12-month intervals, and was augmented by treadmill testing and postoperative coronary arteriography. Operative risk and subjective response are related only to the degree of ventricular function lost prior to surgery. Long-term results were best in patients in whom complete revascularization was possible. Current operative risk is less than 1%; a five-year survival rate of 90% to 95% is predicted. More than 90% of patients were asymptomatic or "greatly improved." Postoperative treadmill tests were negative in 88% of patients in these groups. In patients who were only "slightly improved" or "not improved," repeat catherization showed a graft patency rate of 84%, suggesting that recurrent symptoms were related to the extent of preoperative disease or to the progression of disease in nongrafted vessels, rather than to graft occlusion.