Racial Differences in Device-Detected Incident Atrial Fibrillation

Background: Prior research suggests Black individuals have a lower risk of atrial fibrillation (AF) than White individuals, but this may be related to the underdetection of AF. Whether this trend persists using highly sensitive methods of AF diagnosis has not been well-studied.

Objectives: The objective of this study was to use cardiac implantable electronic devices (CIEDs) capable of AF diagnosis to compare AF incidence between Black and White individuals.

Methods: This was a retrospective observational study involving Black and White patients who had a CIED implanted between January 1, 2007, and June 1, 2019. Patients with insertable cardiac monitors, insufficient monitoring, or prior AF were excluded. The primary endpoint was the overall adjusted incidence of device-detected AF between Black and White individuals.

Results: Of 441,047 patients with a CIED implanted during the study period, 88,427 patients (mean age, 69 ± 13 years; 80,382 White [91%]; 55,840 male [63%]) were included in analysis. The mean follow-up duration was 2.2 ± 1.7 years, and 35,143 patients (40%) had device-detected AF. The crude incidence of AF was greater among White, compared with Black, individuals (27.95 vs 24.86 cases per 100 person-years, P < 0.001). After adjusting for age, sex, and medical comorbidities, the hazard of AF was similar between Black and White individuals (HR, 1.02; 95% CI: 0.98-1.06). In subgroup analysis by type of CIED, White individuals had a greater hazard of AF in the pacemaker cohort, whereas Black individuals had a greater hazard of AF in the implantable cardioverter defibrillator cohort.

Conclusions: The adjusted hazard of AF was similar between Black and White individuals with CIEDs.