New-onset atrial fibrillation - Sex differences in presentation, treatment, and outcome

Background-Although sex differences in coronary artery disease have receive d considerable attention, few studies have dealt with sex differences in th e most common sustained cardiac arrhythmia, atrial fibrillation (AF). Diffe rences in presentation and clinical course may dictate different approaches to detection and management. We sought to examine sex-related differences in presentation, treatment, and outcome in patients presenting with new-ons et AF. Methods and Results-The Canadian Registry of Atrial Fibrillation (CARAF) en rolled subjects at the time of first EGG-confirmed diagnosis of AF. Partici pants were followed at 3 months, at 1 year, and annually thereafter. Treatm ent was at the discretion of the patients' physicians and was not directed by CARAF investigators. Baseline and follow-up data collection included a d etailed medical history, clinical, EGG, and echocardiographic measures, med ication history, and therapeutic interventions. Three hundred thirty-nine w omen and 560 men were followed for 4.14 +/-1.39 years. Compared with men, w omen were older at the time of presentation, more likely to seek medical ad vice because of symptoms, and experienced significantly higher heart rates during AF. Compared with older men, older women were half as likely to rece ive warfarin and twice as likely to receive acetylsalicylic acid. Compared with men on warfarin, women on warfarin were 3.35 times more likely to expe rience a major bleed. Conclusions-Anticoagulants are underused in older women with AF relative to older men with AF, despite comparable risk profiles. Women receiving warfa rin have a significantly higher risk of major bleeding, suggesting the need for careful monitoring of anticoagulant intensity in women.