Abstract 10286: Atrial Fibrillation and Sudden Cardiac Death: The Atherosclerosis Risk in Communities (ARIC) Study
Background Atrial fibrillation (AF) is associated with higher risk of cardiac morbidity and mortality. However, it is unknown whether AF is associated with higher risk of sudden cardiac death (SCD) in the general population. We hypothesized that AF increases the risk of SCD and sought to identify ECG predictors of SCD in subjects with AF in the ARIC cohort.
Methods We included 15,364 subjects (age 45-64 yrs) enrolled 1987-89, and followed through 2001. AF cases were identified from ECGs at 4 exams and hospitalization discharge codes. SCD was physician-adjudicated and was defined as a sudden pulseless event from a cardiac origin in a previously stable person. We used Cox proportional-hazards models to assess association between AF (time-varying exposure) and SCD adjusting for age, sex, race, center, heart rate, smoking, BMI, hypertension, diabetes, coronary heart disease, heart failure, ECG-based LVH, use of β-blockers and antiarrhythmics. We used multivariable proportional-hazards models to determine whether known ECG risk factors for SCD, including 1 mm J-point elevation in 2 contiguous leads, QRS duration, and QTc interval are associated with SCD in persons with AF.
Results During follow-up (median 13.3 yrs), there were 927 AF cases and 313 SCD cases. There were 45 SCD cases among subjects with AF. The incidence rates of SCD in persons with and without AF were 1.4 and 0.6 per 1,000 person-years, respectively. The multivariable HR (95% CI) of SCD associated with AF was 3.1 (2.1-4.5), p<0.0001 (Figure). The multivariable HR after further adjustment for echocardiographic LV fractional shortening in a subgroup with echocardiographic data (n=2,031) was 13.1 (4.7-36.4), p<0.0001. J-point elevation (p=0.79), QRS duration (p=0.08), and QTc interval (p=0.15) were not associated with SCD in persons with AF.
Conclusions AF is associated with higher risk of SCD in the general population. This novel finding warrants further research to identify predictors of SCD in persons with AF. .
- © 2011 by American Heart Association, Inc.