Usefulness of Early Exercise Testing and Clinical Risk Score for Prognostic Evaluation in Chest Pain Units Without Preexisting Evidence of Myocardial Ischemia

We investigated whether the result of early exercise testing yields prognostic information in addition to that afforded by a clinical risk score in patients who present with chest pain in the emergency department. The study group consisted of 340 patients without preexisting evidence of myocardial ischemia. A clinical risk score was calculated. Primary (mortality or myocardial infarction) and secondary (mortality, myocardial infarction, or rehospitalization due to unstable angina) end points at 1 year were defined. Patients with a positive exercise test result underwent invasive management. Frequencies of primary (7.4% vs 2.1%, p = 0.06) and secondary (9.3% vs 2.8%, p = 0.04) end points and risk score (1.6 ± 1.0 vs 1.0 ± 0.9 points, p = 0.0001) were higher in patients with a positive exercise test result. However, in multivariate analysis, clinical risk score was the only independent predictor for the primary (hazard ratio 2.0, 95% confidence interval 1.2 to 3.2, p = 0.004) and secondary (hazard ratio 1.9, 95% confidence interval 1.2 to 2.9, p = 0.003) end points. In conclusion, if a policy of invasive management is implemented for patients with positive exercise test results, the clinical risk score constitutes the main prognostic predictor of 1-year outcome.