Predictors of Major Vascular Events in Patients With a Transient Ischemic Attack or Minor Ischemic Stroke and With Nonrheumatic Atrial Fibrillation

Abstract

The risk of major vascular events after an initial episode of cerebral ischemia in patients with nonrheumatic atrial fibrillation (NRAF) varies from 2% to 15% in the first year and is approximately 5% yearly thereafter. Few studies have reported on risk factors that can be used to identify high-risk subgroups within this patient population. We studied the predictive value of several easily obtainable clinical characteristics in a group of 375 placebo-treated patients with NRAF and a recent episode of transient or nondisabling cerebral ischemia who were entered in a multicenter clinical trial. The mean follow-up was 1.6 years. By means of multivariate modeling, six independent variables were identified: history of previous thromboembolism, ischemic heart disease, enlarged cardiothoracic ratio on chest roentgenogram, systolic blood pressure greater than 160 mm Hg at study entry, NRAF for more than 1 year, and presence of an ischemic lesion on CT scan. These variables could also be used to stratify patients in low-, medium-, and high-risk subgroups for the other two arms of the trial, those treated with anticoagulation and aspirin. Patients older than 75 years with three or more risk factors seemingly benefited less from both aspirin and anticoagulant treatment. Easily obtainable patient characteristics are helpful in estimating the potential effect of adequate secondary prevention in patients with NRAF who recently suffered a transient ischemic attack or minor ischemic stroke.