Background and objectives: Some patients with suspected unstable angina show ischemia at the exercise treadmill test despite having been medically stabilized. The objective of this study was to determine clinical characteristics predicting a positive exercise treadmill test in patients with suspected unstable angina after medical stabilization.
Methods: In 885 hospitalized patients with medically stabilized unstable angina, the relationship between the result of the pre-discharge exercise treadmill test and clinical characteristics was studied.
Results: Mean age was 62+/-9 years and 668 (75%) were male. Exercise test was positive (chest pain and/or ST depression > or =1 mm) in 288 patients (33%). Univariate analysis showed the following associated with ischemia at the exercise test: male gender (56% vs. 20%, P<0.001 ), diabetes mellitus (41% vs. 31%, P=0.009), previous unstable angina (41% vs. 24%, P=0.001), previous stable angina (44% vs. 30%, P<0.001), previous coronary artery bypass grafting (43% vs. 31%, P=0.043), peripheral artery disease (45% vs. 31%) and progressive angina (55% vs. 31%, P<0.001). Multivariate analysis showed the following as independent predictors of ischemia: male gender (OR=2.25), diabetes (OR=4.12), previous unstable angina (OR=3.89), previous stable angina (OR=3.74) and progressive angina (OR=4.05).
Conclusions: In patients with suspected unstable angina, after medical stabilization: (1) the exercise treadmill test is positive in one-third of cases; (2) male gender, diabetes, previous angina (unstable and stable) and progressive angina are independent predictors of ischemia.