Influence of patient sex and clinical history on working capacity and myocardial ischemia after coronary artery bypass surgery.
BACKGROUND
Coronary artery bypass grafting (CABG) is generally accepted as effective in relieving patients from angina pectoris, and in improving survival in subgroups. However, subset evaluations of myocardial ischemia and exercise capacity after CABG are scarce. The aim of this study was to determine the outcome of CABG in terms of exercise capacity and stress ECG findings in subgroups of patients.


METHODS
A stepwise bicycle exercise ECG (in most cases computerized) was performed on 362 patients within 1 year before and 2 years after CABG.


RESULTS
Exercise capacity increased from a median value of 90 to 130 W (P < 0.0001), 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 ST-segment depression at exercise decreased, 76% showing ST-segment depression of at least 1 mm before the operation and 35% (P < 0.0001) 2 years after. Exercise-induced signs of ischemia on ECG did not differ between 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 blood 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 subsets of patients improved exercise capacity with a reduction of ST-segment depression irrespective of their previous history and manifestations of cardiovascular disease.


CONCLUSIONS
CABG caused a marked increase in exercise capacity and reduced signs of myocardial ischemia. Although men increased their working capacity by a greater extent than women, reduction in signs of myocardial ischemia was similar in both sexes.
Sjöland
H
H
Division of Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden.
Herlitz
J
J
Karlson
B W
BW
Karlsson
T
T
Caidahl
K
K
D000368:Aged; D001026:Coronary Artery Bypass; D004562:Electrocardiography / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology*; D012727:Sex Characteristics; D018709:Statistics, Nonparametric; D013997:Time Factors