Risk stratification by early exercise testing after an episode of unstable coronary artery disease. The RISC Study Group.
After stabilization of symptoms by medication a predischarge exercise test was performed in 855 men admitted with suspected unstable angina (54%) or non-Q-wave myocardial infarction (46%). Multiple logistic regression analysis demonstrated that the number of leads with ST-depression at exercise, low maximal work load, increasing age and ST-elevation in electrocardiogram at rest had independent prognostic value concerning the risk of myocardial infarction or death during the following year. Therefore a combination of extension of ST-depression and peak work load was used to define 'high and low risk response' at the exercise test. After 1 year the mortality in patients with 'high risk' compared to 'low risk' exercise response was 3.6% and 0% (P < 0.001) and the risk of either myocardial infarction or death was 15.4% and 3.9% (P < 0.0001), respectively. ST-depression, occurrence of angina and low peak load at exercise were independent predictors of future severe angina. After 1 year 29.5% of patients with any of these indicators at exercise had incapacitating symptoms that necessitated referral for coronary angiography compared to 4.8% in the group without these findings (P < 0.0001). The predictive value of the exercise test remained high in subgroups based on inclusion diagnosis, age or findings in electrocardiogram at rest and independently of treatment with beta-blockade, other antianginal medication or aspirin at the time of the exercise test.
Nyman
I
I
Department of Internal Medicine, District Hospital, Eksjö, Sweden.
Wallentin
L
L
Areskog
M
M
Areskog
N H
NH
Swahn
E
E
D000368:Aged; D000789:Angina, Unstable / Q000188:drug therapy* / Q000503:physiopathology; D001241:Aspirin / Q000008:administration & dosage*; D003327:Coronary Disease / Q000188:drug therapy* / Q000503:physiopathology; D004562:Electrocardiography / Q000187:drug effects; D005080:Exercise Test / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors
D006493:Heparin; D001241:Aspirin