Variability in Coronary Artery Disease Testing for Patients With New-Onset Heart Failure

Background: Coronary artery disease (CAD) is the most common cause of new-onset heart failure (HF). Although guidelines recommend ischemic evaluation in this population, testing has historically been underutilized. Objectives: This study aimed to identify contemporary trends in CAD testing for patients with new-onset HF, particularly after publication of the STICHES (Surgical Treatment for Ischemic Heart Failure Extension Study), and to characterize geographic and clinician-level variability in testing patterns. Methods: We determined the proportion of patients with incident HF who received CAD testing from 2004 to 2019 using an administrative claims database covering commercial insurance and Medicare. We identified demographic and clinical predictors of CAD testing during the 90 days before and after initial diagnosis. Patients were grouped by their county of residence to assess national variation. Patients were then linked to their primary care physician and/or cardiologist to evaluate variation across clinicians. Results: Among 558,322 patients with new-onset HF, 34.8% underwent CAD testing and 9.3% underwent revascularization. After multivariable adjustment, patients who underwent CAD testing were more likely to be younger, male, diagnosed in an acute care setting, and have systolic dysfunction or recent cardiogenic shock. Incidence of CAD testing remained flat without significant change post-STICHES. Covariate-adjusted testing rates varied from 20% to 45% across counties. The likelihood of testing was higher among patients co-managed by a cardiologist (adjusted OR: 5.12; 95% CI: 4.98-5.27) but varied substantially across cardiologists (IQR: 50.9%-62.4%). Conclusions: Most patients with new-onset HF across inpatient and outpatient settings did not receive timely testing for CAD. Substantial variability in testing persists across regions and clinicians.