Incidental Coronary Artery Calcification and Stroke Risk in Patients With Atrial Fibrillation.

Abstract

<b>OBJECTIVE.</b> Atrial fibrillation (AF) is a major risk factor for stroke. The CHA₂DS_2-VASc score is used to risk stratify patients, and the score includes known coronary artery disease (CAD) as a variable. The aim of this study was to assess if the presence of incidental coronary artery calcification (CAC), without known CAD, is associated with stroke independent of CHA₂DS₂-VASc variables. <b>MATERIALS AND METHODS.</b> A retrospective review of health records was performed for patients who had AF, a chest CT scan performed within 1 year, and a subsequent visit for stroke. Patients with CAD and other vascular disease, a mechanical valve, or who were older than 74 years old were excluded. Included patients were one-to-one matched by age and CHA₂DS₂-VASc risk factors to patients who had had similar follow-up but who did not have a stroke. Nongated CT images were reviewed for CAC. Univariate and Cox regression analyses were performed. <b>RESULTS.</b> A total of 203 patients met the study criteria, and 203 matched patients without stroke were identified. Median age was 61 years old with stroke and 62 years old without stroke (<i>p</i> = 0.99). In both groups, 82 (39.0%) were women and the median CHA₂DS₂-VASc was 2 (interquartile range, 1-2). Anticoagulation medication was prescribed to 46 (22.7%) patients in the group who had had a stroke and 52 (25.6%) in the group without stroke (<i>p</i> = 0.49). On Cox regression analysis, CAC was associated with stroke (hazard ratio [HR], 1.47; 95% CI, 1.10-1.97; <i>p</i> < 0.01) and mortality (adjusted HR, 1.41; 95% CI, 1.02-1.95; <i>p</i> = 0.04). <b>CONCLUSION.</b> Patients with AF and incidental CAC depicted on chest CT have an increased risk of stroke and mortality beyond established risk factors.