Abstract 12602: The Combined Use of Clinical Risk Profiling, Exercise-Electrocardiogram and Cardiac Computed Tomography Angiography; Incremental Prognostic Value for Cardiovascular Events
Introduction: Although the standard diagnostic work-up of patients with chest pain has included mainly clinical risk factor profile assessment and exercise-ECG, more recently cardiac computed tomographic angiography (CTA) has been tacitly employed. We prospectively evaluated the contribution of CTA work-up with the expectation that CTA will provide substantial incremental prognostic value over clinical risk profiling and exercise-ECG.
Methods: In 239 patients presenting with chest pain at the outpatient clinic, Framingham risk score and exercise-ECG were routinely obtained. Subsequently, all patients underwent CTA to evaluate coronary artery disease (>50% stenosis). After a mean 20 months follow-up, acute coronary syndrome (ACS) was recorded as primary endpoint, and elective PCI or CABG as secondary endpoints. Odds ratio, Fisher's exact test and receiver operating characteristic (ROC) curves with area under the curve (AUC) were calculated to determine the combined prognostic value of Framingham, exercise-ECG and CTA in predicting ACS, PCI and CABG.
Results: Only positive CTA predicted significantly for ACS (odds ratio 16.5, p=0.002); not exercise-ECG (odds ratio 3.9, p=0.08); nor high Framingham (odds ratio 2.0, p=0.60). ROC-analysis for prediction of ACS, PCI and CABG showed incremental value of CTA over Framingham and exercise-ECG (AUC from 0.64 in Framingham, to 0.75 in Framingham plus exercise-ECG, to 0.92 when CTA is added, figure). In perspective, AUC of CTA alone was 0.87.
Conclusions: In this study, CTA predicted significantly for ACS, while Framingham and exercise-ECG did not. In predicting all events, exercise-ECG provided limited incremental prognostic value over clinical risk profiling. On the other hand, CTA offered a substantial adjunctive value in predicting for all cardiovascular events in chest pain patients [Figure].
- © 2010 by American Heart Association, Inc.