Objectives: To investigate the prognostic factors in patients who come to the emergency room with chest pain but without ST segment elevation.
Patients and method: 743 consecutive patients were evaluated by recording clinical history, electrocardiogram and troponin I determination, and early (<24 h) exercise testing was done for the low-risk subgroup of patients (n=203). All patients were followed during 3 months for major events (acute myocardial infarction or death).
Results: Major events occurred in 71 patients (9.6%). Multivariate analysis (C statistic=0.79; 95% CI 0.73-0.84; p=0.0001) identified the following predictors: age > or =72 years (OR=1.7; 95% CI, 1.0-2.9; p=0.05), insulin-dependent diabetes mellitus (OR=2.9; 95% CI, 1.5-5.4; p=0.001), previous ischemic heart disease (OR=1.9; 95% CI, 1.1-3.2; p=0.02), ST depression (OR=2.1; 95% CI, 1.2-3.8; p=0.01) and troponin I elevation (OR=2.9; 95% CI, 1.5-5.3; p=0.001). These five predictors were used to construct a risk score based on their odds ratios, which allowed event rate stratification by quartiles of the score: 0-2 points (1.6% events), 3-4 points (8.1% events), 5-7 points (11.9% events) and > or =8 points (26.2% events); p=0.0001. No patient with negative findings in the early exercise testing had major events.
Conclusions: In patients with chest pain, the combination of clinical, electrocardiographic and biochemical data available on admission to the emergency service allows rapid prognostic stratification. Early exercise testing is advisable for the final stratification of low risk patients.