Utilization of secondary prevention therapies in patients with nonobstructive coronary artery disease identified during cardiac catheterization: Insights from the national cardiovascular data registry cath-PCI registry

Background: Secondary prevention therapies are indicated for patients with coronary artery disease (CAD). However, patients with nonobstructive CAD may be less likely to receive these therapies compared with patients with obstructive CAD. Therefore, we compared rates of secondary prevention medication prescription between patients with nonobstructive and obstructive CAD. Methods and Results: We conducted a retrospective cohort study of 1 489 745 CAD patients undergoing cardiac catheterization in 786 US centers between 2004 and 2007. We measured rates of aspirin, statin, β-blocker, and angiotensin-converting enzyme inhibitor (ACEI)/angiotensin II receptor blocker (ARB) prescription at hospital discharge among eligible patients; 237 167 (15.9%) patients had nonobstructive CAD and 1 252 578 (84.1%) had obstructive CAD. Compared with obstructive CAD patients, nonobstructive CAD patients had significantly lower rates of rates of aspirin (72.7% versus 90.9%), statin (60.0% versus 80.3%), β-blocker (57.9% versus 79.4%), and ACEI/ARB (45.9% versus 58.6%; all probability values <0.0001) prescription at hospital discharge. After multivariable adjustment, nonobstructive CAD patients remained significantly less likely to receive prescriptions for aspirin (odds ratio, 0.37; 95% confidence interval, 0.35 to 0.39), statins (odds ratio, 0.45; 95% confidence interval, 0.43 to 0.48),/3-blockers (odds ratio, 0.46; 95% CI, 0.44 to 0.47), or ACEI/ARBs (odds ratio, 0.83; 95% confidence interval, 0.8 to 0.86) compared with obstructive CAD patients. Secondary analyses of selected subgroups supported the primary findings. Conclusions: Patients with nonobstructive CAD were significantly less likely to receive secondary prevention medication prescription at hospital discharge, as compared with patients with obstructive CAD. These findings highlight an opportunity to improve the quality of care for CAD patients with nonobstructive disease.