Sex differences in optimal medical therapy following invasive angiography for coronary artery disease
Authors: Sullivan A , Rawat N , Walker R , Kythreotis A , Shabbir A , Jones D , Mathur A , Rathod K , Ahluwalia A 
Published: May 2024

Abstract

Funding Acknowledgements
Type of funding sources: Other. Main funding source(s): HARP Wellcome Trust PhD Fellowship Grant & NIHR Biomedical Research Centre

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 their male counterparts. Data suggests that this mortality difference may be predominantly in women &gt;55 years (2). Treatment bias may be an important factor. Prognostic benefit of optimal medical therapy (OMT) following MI is well established, however studies and meta-analyses suggest women may be less likely to receive this compared to men e.g (3, 4).

Purpose
We aimed to establish whether there were sex differences in OMT received following invasive angiography for obstructive CAD at a large cardiac centre.

Methods
In this single centre retrospective study, we examined OMT received by females and males undergoing invasive angiography in 2019 with proven obstructive CAD, as defined by an angiographic lesion ≥50% of luminal diameter. Discharge medications were extracted from the electronic patient record and entered into a database. Pooled analysis of sex differences and sub-group analysis according to diagnosis (STEMI, NSTEMI, stable angina) and age (≤ 55 years or &gt;55 years) was performed. Multivariate binomial logistic regression was used to adjust for confounders including BMI, diabetes, hypertension, hypercholesterolaemia, previous MI and previous percutaneous coronary intervention.

Results
4,346 patients underwent invasive angiography during the study period. 2,358 with obstructive CAD and full medication details available at the present time were included (STEMI: 649 [mean age: 59.7, 20.6 % female], NSTEMI: 439 [mean age 63.4, 22.6% female], Stable angina: 1,270 [mean age 63.7, 22.2% female]). Pooled analysis showed females were less likely to receive aspirin and beta-blockers (OR=0.64, p=0.009, OR=0.66, p=0.001). They also received fewer angiotensin-converting enzyme inhibitors (ACE-I) but more angiotensin receptor blockers (ARB) (OR=0.58, p&lt;0.001, OR=1.45, p=0.009). Subgroup analysis revealed females &gt;55 with STEMI were less likely to receive beta-blockers and high potency antiplatelets compared to males (OR=0.49, p=0.009, OR=0.44, p=0.011). In the NSTEMI group females ≤55 received fewer beta-blockers and statins (OR=0.16, p=0.020, OR=0.004, p=0.045). In the stable angina group females ≤55 were less likely to receive aspirin (OR=0.07, p&lt;0.001). Fewer ACE-I and more ARB in females was predominantly in the stable angina group (OR=0.56, p&lt;0.001, OR= 1.50, p=0.021).

Conclusion
Women undergoing invasive angiography for obstructive CAD appeared to receive less OMT compared to men across several drug categories, diagnoses and age groups. Future work will be directed at understanding why these differences occurred and the mechanistic consequences of these differences in OMT pharmacology between females and males.