Sex-Based Utilization of Guideline Recommended Statin Therapy and Cardiovascular Disease Outcomes: A Primary Prevention Healthcare Network Registry.

BACKGROUND: In the US, women have similar cardiovascular death rates than men. Less is known about sex differences in statin use for primary prevention and associated atherosclerotic cardiovascular disease (ASCVD) outcomes.

METHODS: Statin prescriptions using electronic health records were examined in patients without ASCVD (myocardial infarction (MI), revascularization or ischemic stroke) between 2013-2019. Guideline-directed statin intensity (GDSI) at index and follow-up visits were compared among sexes across ASCVD risk groups, defined by pooled-cohort equation. Cox regression hazard ratios (HR) [95% CI] were calculated for statin use and outcomes (myocardial infarction, stroke/transient ischemic attack (TIA), and all-cause mortality) stratified by sex. Interaction terms (statin and sex) were applied.

RESULTS: Among 282,298 patients, (mean age ∼ 50 years) 17.1% women and 19.5% men were prescribed any statin at index visit. Time to GDSI was similar between sexes, but the proportion of high-risk women on GDSI at follow-ups was lower compared to high-risk men (2-years: 27.7 vs 32.0%, and 5-years: 47.2 vs 55.2%, p<0.05). When compared to GDSI, no statin use was associated with higher risk of MI and ischemic stroke/TIA amongst both sexes. High-risk women on GDSI had a lower risk of mortality (HR=1.39 [1.22-1.59]) versus men (HR=1.67 [1.50-1.86]) of similar risk (p value interaction=0.004).

CONCLUSION: In a large contemporary healthcare system, there was underutilization of statins across both sexes in primary prevention. High-risk women were less likely to be initiated on GDSI compared with high-risk men. GDSI significantly improved the survival in both sexes regardless of ASCVD risk group. Future strategies to ensure continued use of GDSI, specifically among women, should be explored.