Abstract 16415: Racial Differences in Incidence of Atrial Fibrillation After Cryptogenic Stroke

Abstract

Introduction: The incidence of atrial fibrillation (AF) is lower among non-whites compared to whites, despite a higher burden of AF risk factors. Current knowledge of first detection of AF after cryptogenic stroke (CS) by an implantable cardiac monitor (ICM) is based on a predominantly white cohort. The incidence of new AF after CS among minorities is unknown. We hypothesized that the incidence of AF after CS would be lower in non-whites. Methods: We reviewed charts of all patients without a history of AF undergoing implantation of an ICM after CS at our hospital from July 2014 to December 2019. Incidence of AF was identified through review of ICM monitoring for each patient, including adjudication of AF episodes for accuracy. Kaplan Meier survival analysis was performed, and cumulative incidence of AF using adjusted Cox proportional hazards regression was compared by race. Results: We identified 417 patients who underwent ICM implant after CS during the study period, with a mean follow-up time of 1.5 ± 1.1 years. Mean age was 62 ± 12 years, and 46% (n=190) were male. The majority of patients were non-white (white, 15%, n=63; black, 59%, n=244; Hispanic, 26%, n=110). At baseline, blacks, Hispanics, and whites were of similar age (mean 62.2, 62.1, and 61.5 years, respectively), and blacks and Hispanics had more AF risk factors, including heart failure, hypertension, diabetes, chronic kidney disease, and higher BMI, than whites. Hispanics had more coronary artery disease than whites and blacks (25.5%, 17.5%, 9.1% respectively, p < 0.001). Among blacks, the cumulative incidence of newly detected AF at one, two, and three years was 13.0%, 18.9%, and 23%, which was similar to Hispanics (12.9%, 18.2%, and 20.9%). By comparison, the incidence in whites was significantly higher (20.8%, 34.3%, 40.3%; blacks p=0.02; Hispanics p=0.01) Conclusion: In patients undergoing ICM after CS, the incidence of newly detected AF is approximately double in whites compared to both blacks and Hispanics.