Warfarin Therapy in AF Patients: Females Are Still at Risk

Abstract number: P1624

Poli D, Cecchi E, Antonucci E, Mannini L, D'Agnano G, Sabatini F, Martini A, Gensini GF, Abbate R, Prisco D

Over the last years, oral anticoagulant treatment (OAT), has become the cornerstone for stroke prevention in patients with atrial fibrillation (AF). This study was aimed at evaluating the efficacy and safety of OAT managing in a real-practice situation. We studied 1596 consecutive unselected patients (follow-up 3364 patient-years), referred for the control of OAT to our Anticoagulation Clinic. Among these patients, AF was the indication for OAT in 558 (35%) (follow-up 958 patient-years). Looking at the quality of OAT, time spent within, above and below the intended therapeutic range was 66%, 16% and 18% respectively in the whole population and 71%, 13% and 16% in AF patients. 12/558 AF patients had major bleeding events (1.2/100 patient-years), 2 were fatal. In all the other patients, we recorded 26/1038 major bleeding events with a similar rate of incidence (1.1/100 patient-years), one was fatal. In both groups females showed a trend to higher risk of bleeding (P= 0.4). 26/558 AF patients had thrombotic events, 17 of which were major (2.7 and 1.7/100 patient-years, respectively), one was fatal. The other patients had 78/1038 thrombotic events, 46 of which were major (3.2 and 2.2/100 patient-years, respectively). In all patients no significant difference was found in the rate of total thrombotic complications in relation to sex. Instead, the rate of stroke in patients with AF was significantly higher in females with respect to males (1.87 and 0.5/100 patient-years respectively; [RR 3.7 (1.0–22.2 95% CI; P= 0.05)]. This difference was not found in patients on OAT for others reasons (RR 1.4 (0.5–3.6 95% CI; P= 0.3). On the whole AF patients on OAT show a low rate of complications however, females show a trend to high risk of bleeding and are at higher risk of stroke in spite of OAT.