Sex Differences in Cardiac Medication Use Post-Catheterization in Patients Undergoing Coronary Angiography for Stable Angina with Nonobstructive Coronary Artery Disease.

BACKGROUND

Treatment of patients with stable angina and nonobstructive coronary artery disease (CAD) has not been well characterized. We comparatively evaluated medication use in males and females with stable angina with no CAD, nonobstructive CAD, and obstructive CAD.

METHODS

We studied all patients ≥20 years old with stable angina undergoing coronary angiography in British Columbia (BC), Canada, from January 2008 to March 2010 (n = 7,535). No CAD, nonobstructive CAD, and obstructive CAD were defined as 0%, 1%-49%, and ≥50% luminal narrowing in any epicardial coronary artery, respectively. Medication use, 3 months before and 3 months following angiography, was obtained through BC PharmaNet for angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), beta-blockers, statins, antiplatelet agents, and prescriptions for all three ACE-I/ARBs, beta-blockers, and statins (combination therapy).

RESULTS

Following angiography, patients with no and nonobstructive CAD had significantly lower rates of prescription use of all medications, including combination therapy, than patients with obstructive CAD (p < 0.001). Use of ACE-I/ARBs, beta-blockers, statins, and combination therapy did not differ by sex, but females had higher use of CCB in all CAD groups, and clopidogrel in nonobstructive and obstructive CAD groups, compared to males.

CONCLUSIONS

In patients with stable angina, medication use following angiography is low in nonobstructive CAD with only 58.9% prescribed a statin and 19.4% on combination therapy at 3 months. There are no important sex differences in medication use in any CAD category post-angiography. Future studies should explore methods of improving quality of care in patients with nonobstructive CAD.