Racial differences in the incidence of atrial fibrillation after cryptogenic stroke

Area of Science:

• Cardiology
• Neurology
• Epidemiology

Background:

• Lower incidence of atrial fibrillation (AF) observed in nonwhite populations compared to white populations.
• Discrepancy exists despite a higher burden of AF risk factors in nonwhite individuals.
• The incidence of new-onset AF following cryptogenic stroke in minority groups remains largely unknown.

Purpose of the Study:

• To investigate and compare the incidence of new-onset atrial fibrillation (AF) after cryptogenic stroke across different racial and ethnic groups.
• To assess racial/ethnic disparities in AF detection post-cryptogenic stroke.

Main Methods:

• Retrospective analysis of 416 patients who received insertable cardiac monitors (ICMs) between 2014 and 2019.
• AF incidence determined via ICM data review and adjudication of episodes.
• Comparison of AF incidence stratified by race/ethnicity.

Main Results:

• The study cohort was predominantly nonwhite (59% Black, 26% Hispanic).
• Black and Hispanic patients exhibited higher rates of hypertension, diabetes, chronic kidney disease, and higher BMI than white patients.
• Cumulative AF incidence at 3 years was 24% for Blacks and 20.9% for Hispanics, versus 40.3% for Whites.
• Adjusted Cox models revealed significantly lower likelihood of incident AF in Blacks (HR 0.49) and Hispanics (HR 0.39) compared to Whites.

Conclusions:

• White patients with cryptogenic stroke had approximately double the incidence of newly detected AF compared to Black and Hispanic patients.
• Findings highlight significant racial/ethnic differences in AF development post-cryptogenic stroke.
• Results have critical implications for the diagnostic workup and therapeutic strategies for cryptogenic stroke patients from diverse backgrounds.