Abstract
BACKGROUND: Patients often have chest pain during exercise treadmill testing (ETT). However, the evidence supporting chest pain as an independent adverse prognostic factor during ETT has been inconsistent. The objective of this study was to determine the importance of chest pain during ETT in predicting future nonfatal cardiac hospitalizations. METHODS: This was a prospective cohort study of all patients undergoing ETT between July 2001 and June 2004 in a large managed care organization. The primary outcome of interest was nonfatal cardiac hospitalizations including myocardial infarction and unstable angina. Multivariable Cox proportional hazards regression assessed the independent association between chest pain during ETT and subsequent nonfatal cardiac hospitalizations, adjusting patient, clinical and other treadmill variables. RESULTS: Of the 8,459 patients undergoing ETT, 697 (8.2%) patients had chest pain during the test. Patients with chest pain during ETT had more nonfatal cardiac hospitalizations compared to patients without chest pain (11.9% vs. 2.6%; p < 0.0001). In multivariable Cox regression analysis, patients with chest pain during ETT remained at significantly increased risk of nonfatal cardiac hospitalizations (HR 3.44; 95% CI 2.60-4.56). The association between chest pain and adverse outcomes was consistent among prespecified subgroups including patients without ST-segment changes and with good functional capacity on ETT. CONCLUSIONS: Chest pain during ETT, even without ECG changes, predicts subsequent cardiac hospitalizations. Future studies should evaluate whether aggressive management of such patients can prevent subsequent hospitalizations.