Abstract 14174: Abnormal Exercise Electrocardiography With Normal Stress Echocardiography is Associated With Increased Subclinical Coronary Atherosclerosis: Insights From the Project Baseline Health Study

Abstract

Introduction Patients with an abnormal (positive) exercise electrocardiography (ECG), but normal stress echocardiography (+ECG/-Echo) have more adverse cardiac events than patients with a negative ECG and normal stress Echo (-ECG/-Echo). However, it is unclear if ECG/Echo discordance is associated with a greater burden of concurrent subclinical coronary atherosclerosis. Methods In the Project Baseline Health Study (PBHS), participants underwent stress Echo and a coronary artery calcium (CAC) scan. For this PBHS substudy, participants with no known coronary artery disease (CAD) were analyzed by stress result: -ECG/-Echo, +ECG/-Echo, or +Echo (with or without +ECG). Patients with a submaximal stress test, uninterpretable ECG, resting wall motion abnormality, and/or baseline ejection fraction <50% were excluded. Clinical characteristics, exercise performance, and CAC results were compared between the -ECG/-Echo and +ECG/-Echo groups using the chi-squared test and Student’s t-test for categorical and continuous variables, respectively. ANOVA or Kruskal-Wallis test was used, as appropriate, to compare all 3 groups. Results Among 1466 participants, 1357 (92.6%) had a -ECG/-Echo; 85 (5.8%) had a +ECG/-Echo; and 24 (1.6%) had a +Echo. Compared to the -ECG/-Echo group, participants in the +ECG/-Echo group were older with shorter exercise duration, but younger with fewer risk factors than participants with a +Echo. The median 10-year ASCVD risk score was 2% for -ECG/-Echo, 3% for +ECG/-Echo, and 10% for +Echo (p<0.001). Greater abnormalities by exercise stress Echo were associated with an increased burden of concurrent coronary atherosclerosis as assessed by CAC score and CAC volume (Table). Conclusions Individuals with positive exercise ECG, even with normal stress Echo, have a higher burden of subclinical coronary atherosclerosis than those with -ECG/-Echo, which may explain the increased risk for adverse cardiac events in the +ECG/-Echo population.