Gender differences in stroke risk of atrial fibrillation patients on oral anticoagulant treatment

Daniela Poli; Emilia Antonucci; Elisa Grifoni; Rosanna Abbate; Gian Franco Gensini; Domenico Prisco

doi:10.1160/TH08-10-0635

Thrombosis and Haemostasis, Table of Contents

Thromb Haemost 2009; 101(05): 938-942
DOI: 10.1160/TH08-10-0635

Cardiovascular Biology and Cell Signalling

Schattauer GmbH

Gender differences in stroke risk of atrial fibrillation patients on oral anticoagulant treatment

Authors

Daniela Poli

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
Emilia Antonucci

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
Elisa Grifoni

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
Rosanna Abbate

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
Gian Franco Gensini

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy

²Centro S. Maria agli Ulivi, Fondazione Don Carlo Gnocchi Onlus IRCCS, Impruneta, Florence, Italy
Domenico Prisco

¹Department of Medical and Surgical Critical Care, University of Florence and Department of Heart and Vessels, Thrombosis Centre, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy

Abstract

Summary

The efficacy of adjusted-dose oral anticoagulant treatment (OAT) in the prevention of stroke in atrial fibrillation (AF) is well documented. Available data show that AF patients are widely heterogeneous in terms of ischaemic stroke risk. The role of female gender as a predictor of stroke risk is inconsistent, in particular it is unclear if warfarin treatment is able to prevent stroke equally in both sexes. We performed a prospective study on 780 AF patients on OAT, followed by an Anticoagulation Clinic, to evaluate if female gender is a risk factor for stroke among patients on OAT and if the quality of anticoagulation is different between genders. No difference was found in relation to the quality of anticoagulation between genders (p=0.5). During follow-up 33 patients had major bleedings (rate 1.37x100 pt/yrs) but no difference was found between genders in bleeding risk. Forty patients had ischaemic events [rate 1.66x100 pt/yrs; males rate 1.2 x100 pt/yrs; females rate 2.43x100 pt/yrs; p=0.042; relative risk (RR) of females vs. males 2.0 (95% confidence interval [CI] 1.3–3.1); p= 0.004]. The higher rate of ischaemic events in females with respect to males was confirmed at Cox regression analysis after correction for age (p=0.009). In addition, strokes occurring in females were more disabling, and RR for severe and fatal stroke, defined according to Modified Rankin scale, of females vs. males was 3.1 (95% CI 1.3–6.5; p=0.001). In conclusion, our data show a higher risk of stroke in anticoagulated AF females with respect to males, despite a similar quality of anticoagulation.

Keywords

Atrial fibrillation - stroke - warfarin - female gender - quality of anticoagulation

Full Text

References

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