A Risk Score for Predicting Stroke or Death in Individuals With New-Onset Atrial Fibrillation in the Community

To derive risk scores for stroke alone and stroke or death in community-based individuals with new-onset AF. DESIGN, SETTING, AND PARTICIPANTS: Prospective, community-based, observational cohort in Framingham, Mass. We identified 868 participants with new-onset AF, 705 of whom were not treated with warfarin at baseline. Risk scores for stroke (ischemic or hemorrhagic) and stroke or death were developed with censoring when warfarin initiation occurred during follow-up. Event rates were examined in low-risk individuals, as defined by the risk score and 4 previously published risk schemes. MAIN OUTCOME MEASURES: Stroke and the combination of stroke or death.

During a mean follow-up of 4.0 years free of warfarin use, stroke alone occurred in 83 participants and stroke or death occurred in 382 participants. A risk score for stroke was derived that included the following risk predictors: advancing age, female sex, increasing systolic blood pressure, prior stroke or transient ischemic attack, and diabetes. With the risk score, 14.3% of the cohort had a predicted 5-year stroke rate