Abstract 10279: Black Race is Associated With an Increased Risk of Sudden Cardiac Death in Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study
Background: We have recently reported that incident atrial fibrillation (AF) is associated with an increased risk of sudden cardiac death (SCD) in the general population. We now aim to identify predictors of SCD in subjects with incident AF in the ARIC study.
METHODS: We included 892 subjects (aged 45-64 years at baseline, 58% male, 18% black) with incident AF, enrolled in 1987 and followed through 2001. AF cases were identified from study ECGs and hospitalization discharge codes. SCD was physician-adjudicated, defined as a sudden pulseless event from a cardiac cause in a previously stable person. We used a multivariable Cox proportional hazards model to assess association between baseline risk factors and SCD and a stepwise selection method to fit the most parsimonious model for predicting SCD. For comparison, we fitted the same model for predicting SCD in subjects without AF.
RESULTS: During follow-up (median 13.1 years), there were 40 SCD cases among subjects with incident AF. Table 1 shows the full multivariable model in relation to SCD. The most parsimonious model for SCD in subjects with incident AF comprised higher age (hazard ratio [HR] per year, 1.08; 95% CI, 1.01-1.15, P=0.03), black race (HR, 4.26; 95% CI, 2.16-8.41, P<0.0001), and coronary heart disease (CHD) (HR, 5.56; 95% CI, 2.90-10.64, P<0.0001). In 15,500 subjects without AF (263 SCD cases), the model comprised higher age (HR per year, 1.07; 95% CI, 1.04-1.09, P<0.0001), black race (HR, 2.52; 95% CI, 1.97-3.21, P<0.0001), and CHD (HR, 8.23; 95% CI, 6.24-10.85, P<0.0001). Black race was a stronger predictor of SCD in AF vs. non AF, and the test for interaction with incident AF was almost statistically significant (P=0.06).
Conclusions: The predictors of SCD in persons with AF include higher age, black race, and CHD. These are also predictors of SCD in persons without AF; however, the association of black race with SCD is greater in persons with AF. Further research to identify risk factors for SCD in persons with AF is warranted.
- © 2013 by American Heart Association, Inc.