CLINICAL IMPACT OF HORMONE REPLACEMENT THERAPY ON LONE ATRIAL FIBRILLATION IN POSTMENOPAUSAL WOMEN: A NATIONWIDE COHORT STUDY

Abstract

Individuals with atrial fibrillation (AF), especially women, have an increased risk of stroke and death. Hormone replacement therapy (HRT) is widely used to control symptoms of menopause and treat osteoporosis in postmenopausal women. However, the association between HRT use and AF risk has been scarcely explored. Thus, we aimed to investigate the association between various types of HRT and lone AF in a national cohort of Korean menopausal women. In total, 21,023 women enrolled in the Korean National Health Insurance Service-National Sample Cohort database were included. Participants were aged 45–60 years and were free from cardiovascular disease and AF at baseline. For analysis, participants were classified into groups of HRT never users, past users, and current users, and subgroup analysis was performed according to the specific type of HRT. In the overall population, 13,458 (64.02%) women never received HRT, 5,685 (27.04%) had received HRT previously, and 1,880 (8.94%) were currently receiving HRT. In multivariable analysis, the relative hazards for AF were higher among HRT current users (hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.26-2.75; p=0.002) and significantly lower among HRT past users (HR: 0.73; 95% CI: 0.56-0.95; p=0.021). For current users, an increased AF risk was observed for all HRT users except for estradiol-only HRT users (HR: 1.25, 95% CI: 0.40-3.90, p=0.703). For past users, reduced AF risk was observed in estradiol plus progestin HRT (comparison: HRT never users) after adjusting for covariates (HR: 0.62; 95% CI: 0.39-0.97; p=0.038). We observed that ongoing HRT posed an increased risk of AF. The degree of AF risk varied based on the specific type of estrogen and whether progestins were co-administered. These data support the assertion that HRT containing estradiol is more beneficial than other types of HRT in terms of AF risk.