An exploration of sex differences in pharmacotherapy following invasive angiography for coronary artery disease

Abstract Introduction Coronary artery disease (CAD) remains the number one cause of death in women worldwide despite advances in treatment (1). Women who experience myocardial infarction (MI) and undergo invasive angiography, experience higher morbidity and mortality compared to age-matched male counterparts. Data suggests that this mortality difference may be predominantly in women 55 years (2). The prognostic benefit of optimal medical therapy (OMT) following MI is well established, however literature suggests treatment biases exist in delivery of pharmacotherapy between the sexes (3, 4). Purpose We aimed to explore sex differences in prescribing trends of OMT following invasive angiography for obstructive CAD at a high throughput regional cardiac centre serving a multi-ethnic population. Methods In this single centre retrospective study, we determined medication received by females and males undergoing invasive angiography in 2017, 2019 and 2022 with proven obstructive CAD (angiographic lesion ≥50% luminal diameter). Discharge medications were extracted from electronic patient records and entered into a bespoke database. Pooled analysis of sex differences and sub-group analysis by diagnosis (STEMI, NSTEMI, stable angina) and age ( 55 or ≥55 years) was performed. This age cut-off was taken to represent accepted cut-off for pre and post-menopause. Multivariate binomial logistic regression was used to adjust for key potential confounders including age, BMI, hypertension, hypercholesterolaemia, previous MI and previous percutaneous coronary intervention. Results 6,278 patients (23.0 % female) were included. Pooled analysis revealed females received fewer β-blockers (OR=0.79, p=0.003) and ACE-I/ARBs (OR=0.81, p=0.003) compared to males. In the acute coronary syndrome (ACS) group, females were less likely to receive β-blockers (OR=0.72, p=0.002), and there was a trend to fewer P2Y12 inhibitor (OR=0.81, p=0.079), aspirin (OR=0.80, p=0.092) and ACE-I/ARB (OR=0.85, p=0.092) medications. Further sub-group analysis showed differences were primarily driven by the NSTEMI group. Analysis by age group reflected patterns in the overall cohort. Compared to males in the same age group, stronger differences were observed in women 55 with fewer β-blockers (OR=0.51, p0.001) and ACE/ARBs (OR=0.60, p=0.001), compared to women ≥55 (OR=0.86, p=0.079, OR 0.86, p=0.048). Females 55 were also less likely to receive aspirin (OR=0.48, p=0.003). We noted fewer differences in 2022 compared to previous years and there was a trend towards increased prescribing of β-blockers in females versus males over time (p=0.069). Conclusion Women undergoing invasive angiography for obstructive CAD, including ACS populations, were less likely to receive several OMT drugs compared to males, findings occurred across age groups. Future work will be directed at understanding why differences occurred and mechanistic consequences of differences in OMT pharmacology between females and males.