INFLUENCE OF PATIENT SEX AND CLINICAL HISTORY ON WORKING CAPACITY ANDMYOCARDIAL-ISCHEMIA AFTER CORONARY-ARTERY BYPASS-SURGERY

Background: Coronary artery bypass grafting (CABG) is generally accept ed as effective in relieving patients from angina pectoris, and in imp roving survival in subgroups. However, subset evaluations of myocardia l ischemia and exercise capacity after CABG are scarce. The aim of thi s study was to determine the outcome of CABG in terms of exercise capa city and stress ECG findings in subgroups of patients. Methods: A step wise bicycle exercise ECG (in most cases computerized) was performed o n 362 patients within 1 year before and 2 years after CABG. Results: E xercise capacity increased from a median value of 90 to 130 W (P < 0.0 001), more marked (P < 0.0001) in men (100-140 W) than in women (75-90 W). Improvement was not significantly related to age. Occurrence of S T-segment depression at exercise decreased, 76% showing ST-segment dep ression of at least 1 mm before the operation and 35% (P < 0.0001) 2 y ears after. Exercise-induced signs of ischemia on ECG did not differ b etween men and women. Maximum heart rate increased from a median value of 109 to one of 133 beats/min (P < 0.0001), and maximum systolic blo od pressure from 170 to 210 mmHg (P < 0.0001). Termination of exercise because of chest pain decreased from 48 to 6% (P < 0.0001). Most subs ets of patients improved exercise capacity with a reduction of ST-segm ent depression irrespective of their previous history and manifestatio ns of cardiovascular disease. Conclusions: CABG caused a marked increa se in exercise capacity and reduced signs of myocardial ischemia. Alth ough men increased their working capacity by a greater extent than wom en, reduction in signs of myocardial ischemia was similar in both sexe s.