Adoption of the Coronary Artery Disease-reporting and Data System: Reduced Downstream Testing and Cardiology Referral Rates in Patients with Non-obstructive Coronary Artery Disease

Introduction The coronary artery disease-reporting and data system (CAD-RADS) was developed to standardize communication of per-patient maximal stenosis and provide treatment recommendations that may affect downstream testing. Methods Downstream testing, cardiology referral, and cost were abstracted for 1,796 consecutive patients undergoing coronary CT angiography (CCTA) before and after the adoption of the CAD-RADS reporting template at a single-center closed referral hospital system. Cost analysis was based on direct invasive and non-invasive testing utilizing the Center for Medicare & Medicaid Services (CMS) outpatient prospective payment system (OPPS) final rule for 2018. Results Baseline cardiovascular risk factors were balanced between the groups. Overall, referrals for downstream testing were similar between cohorts (10.7% vs 10.8%; p = 0.939). Referral for downstream testing was reduced in the CAD-RADS 1 & 2 cohort compared to non-obstructive coronary artery disease (CAD) by non-standardized reporting (NSR; 5.1% vs 14.4%, p < 0.001). This was offset by more non-diagnostic scans in the CAD-RADS cohort (9.7% vs 4.2%, p < 0.001), resulting in increased downstream testing (28.8% vs 11.4%, p = 0.038). Overall, cardiology referral rates by primary care providers (PCPs) were similar between the groups (12.2% vs 15.8%, p = 0.197). Cardiology referral rates were increased among patients with non-obstructive CAD in the NSR cohort compared with CAD-RADS 1 & 2 patients (20.5% vs 8.6%, p = 0.021). Referrals for invasive coronary angiography were low in both groups overall (3.5% vs 3.2%, p = 0.726). Median downstream testing costs were similar between the groups (p = 0.554). Conclusions Adoption of the CAD-RADS reporting template was associated with a reduction in downstream testing and cardiology referral rates among non-obstructive CAD (CAD-RADS 1 & 2) patients. Thus, CAD-RADS may impact downstream testing in patients in whom further testing can typically be deferred.