RESUMO
INTRODUCTION: Studies of sex-based differences in atrial fibrillation (AF) suggest an influence of sex on cardiovascular death and stroke, however, results are conflicting.1,2 Discrepant findings could reflect sex-based differences in access to care, but no studies have explored sex-based differences in treatment and outcomes among countries with differing income levels and gender parity. Such data are needed to understand if sex-based care gaps exist and are associated with differences in outcomes. This knowledge could lead to country and sex-specific treatment recommendations. This study explores how sex differences in AF treatment and outcomes vary between countries based on their economic status and degree of gender parity in the Global RE-LY AF Registry. METHODS Study population and data collection From the prospective RE-LY registry [n = 15 400 patients presenting to an emergency department (ED) with AF in 47 countries between 2007 and 2011],3,4 we excluded patients without AF as primary listed reason for ED presentation (n = 8561), or missing outcomes or CHADS2 score (n = 213), resulting in a sample of 6626 patients. We defined rhythm control as treatment with cardioversion, AF ablation, or the use of any anti-arrhythmic drug. Outcomes were obtained at one-year follow-up and included repeated hospitalization for AF, heart failure (HF) hospitalization, stroke or transient ischaemic attack (TIA), and death.3 Statistical analysis Selected baseline variables are presented as means ± standard deviation, median [interquartile range (IQR)] or proportion. Sex-based differences in treatments and outcomes are presented as crude proportions, with odds ratios (OR) for female sex compared to male sex and P-values derived from multi-level logistic regression with a random effect on country, adjusted for CHADS2 score, which was the recommended risk stratification tool at the time of study initiation.4 To explore the influence on outcome risks by gender-based disparities or economic factors, we stratified on the World Economic Forum (WEF) Global Gender Gap score for 2011, which estimates country-level overall gender parity with a 0100 score annually. We used World Bank classifications of income for 2011 to group countries as 'low and lower-middle', 'upper-middle', and 'high' income countries. Interaction parameters were assessed in CHADS2-adjusted logistic regression models. All statistical analyses were performed using Stata v 17.0 for Mac (StataCorp, College Station, TX, USA). The study conforms to the Declaration of Helsinki and received ethical approval at all sites. All subjects gave written informed consent. RESULTS: Overall, females were older (65.5 ± 14.4 vs. 61.5 ± 14.2 years, P < .0001), had a higher median CHADS2 score [1 (IQR 1) vs. 1 (IQR 2), P < .0001], and more permanent AF (21.5% vs. 18.9%, P = .008). The ED visit resulted in hospitalization in 56.1% of females and 53.6% of males (P = .09).