Atrial fibrillation (AF), a growing epidemic worldwide, has been associated with increased risk for many adverse cardiovascular events. In recent years, an expanding body of literature has emerged suggesting that there may be gender differences in cardiovascular outcomes for men compared with women, given the same set of risk factors. Yet, the risk of AF based on gender and resultant outcomes has not been well studied and remained an outstanding question until now.
A meta-analysis of 30 studies with >4 million participants over nearly 50 years (1966-2015) sheds some light on this issue. Only studies that had at least 50 participants in each arm and reported on sex-specific associations and cardiovascular events were included. Recently published in the British Medical Journal, this study demonstrates that AF is a stronger risk factor for cardiovascular events and for death in women compared with men. In particular, this included a 1.12X higher risk for all-cause mortality, 1.99X higher risk for stroke, 1.93X higher risk of cardiovascular mortality, 1.55X more cardiac events, and 1.16X higher risk of heart failure.
The authors offered several hypotheses for these observed differences, including possible undertreatment of women and physiologic or psychosocial differences between women and men. However, the true mechanism of these findings remains uncertain and warrants additional research and it is not clear whether this relationship is associative or causative.
Because this meta-analysis is comprised of observational studies, its conclusions cannot be considered definitive. However, as a hypothesis-generating study, these findings are relevant to the clinician insofar as women with newly diagnosed AF may represent a particularly high-risk population in need of more aggressive care of comorbidities.
Emdin CA, Wong CX, Hsiao AJ et al. Atrial fibrillation as risk factor for cardiovascular disease and death in women compared with men: systematic review and meta-analysis of cohort studies. BMJ 2016; 352 doi: http://dx.doi.org/10.1136/bmj.h7013 (Published 19 January 2016).