EXERCISE STRESS-TESTING - CORRELATIONS AMONG HISTORY OF ANGINA, ST-SEGMENT RESPONSE AND PREVALENCE OF CORONARY-ARTERY DISEASE IN THE CORONARY-ARTERY SURGERY STUDY (CASS)

To determine to what extent the diagnostic accuracy of stress testing is influenced by the prevalence of coronary-artery disease, we correlated the description of chest pain, the result of stress testing and the results of coronary arteriography in 1465 men and 580 women from a multicentered clinical trial. The pre-test risk (prevalence of coronary-artery disease) varied from 7 to 87 per cent, depending on sex and classification of chest pain. A positive stress test increased the pre-test risk by only 6 to 20 per cent, whereas a negative test decreased the risk by only 2 to 28 per cent. Although the percentage of false-positive results differed between men and women (12±1 per cent versus 53±3 per cent P < 0.001), this difference was not seen in a subgroup matched for prevalence of coronary-artery disease. We conclude that the ability of stress testing to predict coronary-artery disease is limited in a heterogeneous population in which the prevalence of disease can be estimated through classification of chest pain and the sex of the patient. (N Engl J Med 301:230–235, 1979) THE exercise test has been used to help detect ischemic heart disease. Correlations between results on the exercise test and coronary arteriography have demonstrated that, in symptomatic men, the presence of an abnormal ST-segment response to stress almost always correctly predicts the presence of clinically important coronary-artery disease.1 2 3 Similar studies in women, however, suggest that no such correlation exists, although most reported series deal with small numbers of patients.4,5 The three principal aims of this study were: to determine whether readily available base-line information, such as a detailed description of chest pain and electrocardiographic results at rest, could predict the. © 1979, Massachusetts Medical Society. All rights reserved.