Preventive Management of Nonobstructive CAD After Coronary CT Angiography in the Emergency Department

Objectives: This study sought to assess medical management of patients found to have nonobstructive coronary artery disease (CAD) on coronary computed tomography angiography (CCTA) performed in the emergency department (ED).

Background: Contemporary recognition and management of nonobstructive CAD discovered on CCTA performed in the ED is unknown.

Methods: Patients undergoing CCTA in the authors' hospital's ED between November 2013 and March 2018 who also received primary care within the authors' health system were studied. All patients with nonobstructive CAD, defined as 1% to 49% maximum luminal stenosis on CCTA, were included, along with a control group without CAD in a 1 case:1 control fashion. Ten-year atherosclerotic cardiovascular disease (ASCVD) risk prior to CCTA was estimated using the Pooled Cohort Equations. Management changes were recorded until 6 months after CCTA. Multivariate logistic regression tested the association between CCTA result and follow-up statin prescription, adjusting for cardiovascular risk factors and baseline statin use.

Results: The cohort included 510 patients with nonobstructive CAD and 510 controls. Prevalence of statin prescription increased from 38.8% to 56.1% among patients with nonobstructive CAD (p < 0.001) and 18.0% to 20.4% among controls (p = 0.01), representing a 7.1-fold relative difference (95% confidence interval [CI]: 4.4 to 23.0; p < 0.001) in multivariate analysis. However, 30.0% of patients with nonobstructive CAD and ≥20% 10-year ASCVD risk were not prescribed a statin at the end of follow-up. Cardiologist evaluation was independently associated with statin prescription after adjustment for ASCVD risk factors (odds ratio [OR] 4.4; 95% CI: 2.4 to 8.5; p < 0.001). A Coronary Artery Disease Reporting and Data System class 1 to 2 result was associated with lower low-density lipoprotein cholesterol by 12.1 mg/dl at mean 1.9-year follow-up (p < 0.001).

Conclusions: Incidental subclinical atherosclerosis on CCTA performed in the ED increases the likelihood of statin prescription, but opportunities to improve allocation of indicated preventive therapies remain.