Characteristics and clinical impact of coronary computed tomography angiography following exercise stress testing for evaluating coronary artery disease

Exercise stress testing (EST) remains effective in assessing coronary artery disease (CAD), especially in developing countries, while coronary computed tomography angiography (CCTA) is being increasingly utilized. However, limited data exist on whether CCTA following EST can affect diagnosis or treatment. This study aimed to characterize patients who underwent CCTA following EST and evaluate its clinical impact. Consecutive patients who underwent CCTA after EST for CAD assessment between 2014 and 2021 were included in the study. CCTA results were categorized as obstructive CAD, nonobstructive CAD, and normal. Clinical and EST characteristics were compared among groups. Multivariable logistic regression analysis was used to identify independent predictors of obstructive CAD. The diagnostic impact and therapeutic consequences of CCTA were assessed at the subsequent clinic visits. A total of 209 patients (64% male, age 60 ± 10 years) with 26% known CAD were included. The most common indication for CCTA was an inconclusive EST (31%). CCTA revealed obstructive CAD in 53 patients, nonobstructive CAD in 111 patients, and normal results in 45 patients. Multivariable analysis identified hyperlipidemia (odds ratio 3.60, 95% confidence interval 1.27-10.22, P = .01) and the Duke Treadmill Score (odds ratio 0.86, 95% confidence interval 0.80-0.92, P < .001) as independent predictors of obstructive CAD. CCTA had a diagnostic impact on 69% of all patients (76% for patients with no known CAD and 50% for patients with known CAD), including the exclusion of obstructive CAD in patients with a positive EST; the diagnosis of obstructive CAD, nonobstructive CAD, or normal CCTA in patients with an inconclusive EST; and the diagnosis of both obstructive and nonobstructive CAD in patients with a negative EST. Therapeutically, CCTA led to medication changes in 38% of patients, while 24% underwent invasive procedures. In conclusion, among patients undergoing CCTA following EST for CAD assessment, hyperlipidemia and the Duke Treadmill Score were identified as independent predictors of obstructive CAD. CCTA also had significant diagnostic and therapeutic impacts in this population.