Sex Differences in the Use of Oral Anticoagulants for Atrial Fibrillation: A Report From the National Cardiovascular Data Registry (NCDR ^® ) PINNACLE Registry

Abstract

BackgroundDespite higher thromboembolism risk, women with atrial fibrillation have lower oral anticoagulation (OAC) use compared to men. The influence of the CHA 2 DS 2‐VASc score or the introduction of non–vitamin K OACs on this relationship is not known.Methods and ResultsUsing the PINNACLE National Cardiovascular Data Registry from 2008 to 2014, we compared the association of sex with OAC use (warfarin or non–vitamin K OACs) overall and by CHA 2 DS 2‐VASc score and examined temporal trends in OAC use by sex. Multivariable regression models assessed the association between sex and OAC use in those with CHA 2 DS 2‐VASc scores ≥2. Temporal analyses assessed changes in OAC use by sex over time. Of the 691 906 atrial fibrillation patients, 48.5% were women. Women were significantly less likely than men to use any OAC overall (56.7% versus 61.3%; P<0.001) and at all levels of CHA 2 DS 2‐VASc score (adjusted risk ratio 9% to 33% lower, all P<0.001). Compared to other thromboembolic risk factors, female sex was associated with lower use of OAC (risk ratio 0.90, 95%CI 0.90‐0.91). Over time, non–vitamin K OAC use increased at a slightly higher rate in women (56.2% increase per year, 95%CI 54.6% to 57.9%) compared to men (53.6% increase per year, 95%CI 52.0% to 55.2%), yet women remained less likely to receive any OAC at all time points (P<0.001).ConclusionsAmong patients with atrial fibrillation, women were significantly less likely to receive OAC at all levels of the CHA 2 DS 2‐VASc score. Despite increasing non–vitamin K OAC use, women had persistently lower rates of OAC use compared to men over time.

Trends and Variation in Oral Anticoagulant Choice in Patients with Atrial Fibrillation, 2010–2017

“…This may be related to a slightly higher rate of increasing prescription of apixaban over time among women than men. A prior U.S. study using registry data in 2010–2014 also found that NOAC use increased at a slightly higher rate in women relative to men . According to a meta‐analysis, compared with men, women treated with a NOAC had a lower risk of major bleeding while those treated with warfarin had a higher risk of stroke and systemic embolism, suggesting an increased net clinical benefit of NOACs compared with warfarin in preventing stroke among women with AF …”

Risk factors for severe bleeding events during warfarin treatment: the influence of sex, age, comorbidity and co-medication

“…Our findings of a lower risk of severe bleeding in women compared to men should be viewed in the light of the risk benefit balance for stroke prevention in women with AF on warfarin, where the differences in the epidemiology of stroke among women and men must be acknowledged. In Sweden, men are more frequently prescribed antithrombotic treatment compared to women [44], and the national US registry data show that women were significantly less likely to use any oral anticoagulant for AF overall and at all levels of CHA 2 DS 2 -VASc score compared to men [45]. Data from a global register study on patients with newly diagnosed NVAF show that the use of anticoagulant therapy for stroke prevention is similar for women and men (approximately 60%), with underuse of anticoagulation therapy in high-risk patients reported for both sexes.…”

Gender Differences in Atrial Fibrillation: A Review of Epidemiology, Management, and Outcomes

“…The South Korean CODE-AF registry showed no significant difference in the prescription of anticoagulation between women and men, though women prescribed DOACs were more likely to be insufficiently dosed [ 29 ]. The PINNACLE National Cardiovascular Data Registry from 2008-2014 showed women were less likely to receive oral anticoagulation at all CHA 2 DS 2 -VASc scores, by a factor of up to 33% [ 65 ].…”