Impact of gender on event rates at 1 year in patients with newly diagnosed non-valvular atrial fibrillation: contemporary perspective from the GARFIELD-AF registry

Abstract

Objectives: Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) explored the impact of gender, risk factors and anticoagulant (AC) treatment on 1-year outcomes in patients with non-valvular atrial fibrillation (NVAF). Design: GARFIELD-AF is a prospective non-interventional registry. Setting: Investigator sites (n=1048) are representative of the care settings/locations in each of the 35 countries. Participants: Patients ≥18yrs with newly diagnosed (≤6 weeks' duration) NVAF and ≥1 investigator-determined stroke risk factors. Main outcome measures Event rates per 100 person-years were estimated from the Poisson model and HRs and 95% CIs calculated. Results: Of 28 624 patients (women 44.4%; men 55.6%) enrolled, there were more elderly (≥75 years) women (46.9%) than men (30.4%). All-cause mortality rates per 100 person-years (95% CI) for women and men were 4.48 (4.12 to 4.87) and 4.04 (3.74 to 4.38), respectively, stroke/systemic embolism (SE) (1.62 (1.41 to 1.87) and 1.17 (1.01 to 1.36)) and major bleeding (0.93 (0.78 to 1.13) and 0.79 (0.66 to 0.95)). After adjustment for baseline risk factors in treated and untreated patients, HRs (95% CI) for women (relative to men) for stroke/SE rates were 1.3-fold higher in women (HR 1.30 (1.04 to 1.63)), and similar for major bleeding (1.13 (0.85 to 1.50)) and all-cause mortality (1.05 (0.92 to 1.19)). Antithrombotic treatment patterns in men and women were almost identical. 63.8% women and 62.9% men received AC± antiplatelets. Relative to no AC treatment, the reduction in stroke/SE rates with AC treatment was greater (p=0.01) in men (HR 0.45 (0.33 to 0.61)) than women 0.77 (0.57 to 1.03). All-cause mortality reduction with AC treatment was similar (women: 0.65 (0.54 to 0.77); men: 0.57 (0.48 to 0.68)). The risk of major bleeding when treated with AC versus no AC was 2.33 (1.41 to 3.84) in men and 1.86 (1.16 to 2.99) in women (p value=0.53). Conclusions: Women have a higher risk of stroke/SE and the reduction in stroke/SE events rates with AC treatment is less in women than in men. Trial registration number NCT01090362.