Abstract 21495: The Utility of Exercise Stress Test in Predicting Coronary Plaque and Stenosis as detected by Coronary Computed Tomography Angiography: The ROMICAT Study
Background: Despite the recent adoption of advanced imaging techniques such as Coronary CT angiography (CTA) and myocardial perfusion imaging, exercise treadmill testing (ETT), remains an inexpensive, safe, and efficient initial test for the evaluation of low to intermediate risk patients who have a normal baseline ECG and can exercise. The aim of our study was to examine how data from ETT can identify patients who have coronary plaque or stenosis, using CTA as the reference standard.
Methods:. The rule out myocardial infarction using computer assisted tomography trial (ROMICAT) was an observational cohort study of acute chest pain patients presenting to the emergency department (ED) with normal initial troponin and nonischemic electrocardiogram. 224 out of 368 patients had an ETT as part of their standard clinical care and are included in the present study. Positive ETT was defined as >1.5 mm upsloping ST depression or >1 mm horizontal or downsloping ST depression. Univariate and multivariate analysis were performed to assess the relationship of baseline clinical data and ETT parameters with coronary plaque and stenosis >50% on CTA.
Results: Out of the 224 patients who had ETT (mean age 51, 63% male.), 23 (10%) had positive results. On CTA, 35% of patients with abnormal ETT had stenosis compared to 7% of those with normal ETT (P<0.001); sensitivity= 75%, specificity= 96%. Patients with a positive ETT had a significantly higher number of segments with plaque than those with a normal ETT (4.3 vs. 1.7; P<0.001). On univariate analysis exercise time, number of METS and Duke treadmill score were all predictive of plaque. However in a multivariate model including baseline clinical characteristics, none of the ETT parameters remained significant. The predictors of stenosis on multivariate analysis included age (OR=3), male gender (OR=4.2), diabetes (OR=3.2) and a positive ETT (OR=16).
Conclusions: Among low to intermediate risk patients presenting to the ED, positive ETT is associated with a significantly higher plaque burden and exhibits high specificity for the detection of coronary stenosis. However, after accounting for baseline clinical data, ETT does not improve the identification of patients with non-obstructive plaque.
- © 2010 by American Heart Association, Inc.