Abstract 4138517: Role of Coronary Computed Tomographic Angiography in Patients with Discordant Findings on Exercise Stress Echocardiography

Background: Exercise stress echocardiography is routinely used for risk stratification and diagnosis of myocardial ischemia in low-to-intermediate risk patients with suspected coronary artery disease (CAD). Discrepancies between exercise electrocardiography (EKG) and echocardiography (ECHO) are common in clinical practice. Prior literature suggests that patients with discordant stress test results generally have worse outcomes, though the extent of epicardial atherosclerotic disease remains unclear. Coronary computed tomographic angiography (CTA) has gained a class I recommendation for the assessment of atherosclerotic burden per ACC/AHA chest pain guidelines. Using non-invasive fractional flow reserve (CT-FFR), the functional significance of lesions can also be assessed. This study investigates the incidence and burden of CAD in patients with discordant exercise echocardiography findings. Methods: Patients aged 18 or older who had exercise echocardiography followed by CTA from January 1, 2013, to January 31, 2023, were retrospectively enrolled in this study and categorized into two discordant result groups: EKG+/ECHO- or EKG-/ECHO+. Those who failed to achieve the target heart rate or had a paced rhythm/left bundle branch block on baseline EKG were excluded. CTA findings were classified as no CAD, non-obstructive CAD (<50% stenosis), obstructive CAD (≥50% stenosis), and obstructive CAD with FFR+ (<0.75). Results: The study included 198 patients, the majority female (56.0%), with a mean age of 61 ±10 years. Among them, 159 (80.3%) were EKG+/ECHO- and 39 (19.7%) were EKG-/ECHO+ (Table 1). In the EKG+/ECHO- group, 55 (34.6%) had no CAD, 48 (30.2%) had non-obstructive CAD, and 56 (35.2%) had obstructive CAD, out of which 19 (33.9%) were FFR+. In the EKG-/ECHO+ group, 13 (33.3%) had no CAD, 17 (43.6%) had non-obstructive CAD, and 9 (23.2%) had obstructive CAD of which 3 (33.3%) was FFR+. There was no statistically significant difference in the degree of CAD between the two cohorts. Conclusions: The majority of patients with discordant results on exercise echocardiography were found to have CAD. There was no significant difference in the degree of disease between the EKG+/ECHO- or EKG-/ECHO+ groups. Overall, discordant results on exercise echocardiography should not be discounted and warrant further evaluation. CTA provides important information that can impact the diagnosis and further medical management of patients with chest pain and suspected CAD.