Risk factors for atrial fibrillation and their population burden in postmenopausal women: the Women's Health Initiative Observational Study

Abstract

Objective Atrial fibrillation (AF) is the most common arrhythmia in women. Large studies evaluating key AF risk factors in older women are lacking. We aimed to identify risk factors for AF in postmenopausal women and measure population burden of modifiable risk factors. Design Prospective observational study. Setting The Women's Health Initiative (WHI) Observational Study. Patients 93 676 postmenopausal women were followed for an average of 9.8 years for cardiovascular outcomes. After exclusion of women with prevalent AF or incomplete data, 8252 of the remaining 81 892 women developed incident AF. Main outcome measures Incident AF was identified by WHI-ascertained hospitalisation records and diagnosis codes from Medicare claims. Multivariate Cox hazard regression analysis identified independent risk factors for incident AF. Results Age, hypertension, obesity, diabetes, myocardial infarction and heart failure were independently associated with incident AF. Hypertension and overweight status accounted for 28.3% and 12.1%, respectively, of the population attributable risk. Hispanic and African-American participants had lower rates of incident AF (HR 0.58, 95% CI 0.47 to 0.70 and HR 0.59, 95% CI 0.53 to 0.65, respectively) than Caucasians. Conclusions Caucasian ethnicity, traditional cardiovascular risk factors and peripheral arterial disease were independently associated with higher rates of incident AF in postmenopausal women. Hypertension and overweight status accounted for a large proportion of population attributable risk. Measuring burden of modifiable AF risk factors in older women may help target interventions.

Associations of Abdominal Obesity and New‐Onset Atrial Fibrillation in the General Population

“…Similarly, each 1‐kg/m 2 increase in BMI adjusted for age and sex was associated with a 5% increased risk of AF in the present study. Overweight status was identified as a risk factor for AF, contributing a 10‐year population‐attributable risk of 12% in the Women's Health Initiative study (mean age: 63±7 years) 28. Black participants had a lower AF incidence rate by 41% compared with white participants in the Women's Health Initiative study.…”

“…The population‐attributable risks of overweight status or obesity and abdominal obesity were calculated by subtracting the rate of AF in the entire cohort from the rate of AF in those who carried the risk factor and dividing it by the rate of AF in the entire cohort 28, 29…”

Associations of Lipoprotein(a) Levels With Incident Atrial Fibrillation and Ischemic Stroke: The ARIC (Atherosclerosis Risk in Communities) Study

“…Despite higher Lp(a) levels, blacks18, 19 and women20 have a lower incidence of AF, and little is known on whether race or sex could exhibit effect modification on Lp(a)‐related risk. Furthermore, there are limited data on the associations of Lp(a) and the risk of AF‐related stroke.…”

Association of Peripheral Artery Disease With Incident Atrial Fibrillation: The ARIC (Atherosclerosis Risk in Communities) Study

“…The WHI analysis10 showed an HR (95% CI) 1.53 (1.37–1.72). Of 81 892 women, 8252 developed AF over a mean follow up of 9.8 years.…”

“…In the REACH registry, there was an 11.5% prevalence of AF among patients with PAD compared with an estimated prevalence of 2.3% and 5.9% in the general population aged ≥40 and ≥65 years, respectively 8, 9. PAD is associated with incident clinical AF regardless of age, sex, race, and cardiovascular risk factors among postmenopausal women10 and the general population 11, 12…”