Exercise tolerance as evidence of quality of life in CAD patients after coronary artery bypass by comparison with medical treatment

The effects of coronary artery bypass (CAB) by comparison with medical treatment were evaluated on exercise tolerance in 68 patients with stable angina on effort, who underwent coronary and left ventricular cineangiography. Stress tests were performed by bicycle ergometer before medical and surgical treatment, and 6 and 12 months thereafter. 35 patients (31 males and 4 females; 7 with one 70% stenosed vessel, 12 with two, 16 with three) underwent CAB; 33 (30 males and 3 females; 9 with one 70% stenosed vessel, 11 with two, 13 with three), having refused CAB, only underwent medical treatment. Both groups were given long-acting oral nitrates, none received digitalis and/or propranolol; antiarrhythmic drugs were only administered in 5% of medical and 4% of surgical patients. Both groups at 6 and 12 months follow-up showed a significant improvement in exercise tolerance. Surgical patients showed a significant increase in exercise tolerance with lower angina incidence (from the preoperative 100% to 26% and 22%, respectively), higher work load (P