Abstract 9199: Racial Differences in Incident Atrial Fibrillation Among Hypertensive Patients During Antihypertensive Therapy: The LIFE Study
Background: Blacks have a higher prevalence of risk factors for atrial fibrillation (AF) than non-blacks, such as hypertension, obesity and heart failure. Although a recent study found a significantly lower AF incidence in blacks during 17 year follow-up of a population cohort, the relationship of new AF to race in hypertensive patients during aggressive blood pressure lowering has not been examined.
Methods: Incident AF was examined in 518 black and 8313 non-black hypertensive patients with no AF by history or on a baseline ECG who were randomly assigned to losartan- or atenolol-based treatment.
Results: Compared with non-blacks, blacks were younger, more obese, more likely to be male, smoke, have diabetes, a history of ischemic heart disease and stroke, had higher baseline serum creatinine and albuminuria, less severe baseline left ventricular hypertrophy (LVH) by Cornell product criteria and more severe LVH by Sokolow-Lyon voltage. During 4.7±1.1 years mean follow-up, new AF occurred in 701 patients (7.9%); 5-year AF incidence was significantly lower in black than non-black patients (6.1 vs 8.3%, p=0.027). In univariate Cox analyses, black race was associated with a 37% lower risk of new AF (HR 0.63, 95% CI 0.45.1.00, p=0.05). In multivariate Cox analyses adjusting for randomized treatment, age, sex, body mass index, diabetes, history of heart failure, MI, ischemic heart disease, stroke, peripheral vascular disease, smoking status, baseline serum total and HDL cholesterol, creatinine, glucose, urine albumin/creatinine ratio and for incident MI, in-treatment heart rate, diastolic and systolic pressure, Cornell product and Sokolow-Lyon voltage criteria for LVH treated as time-varying covariates, black race remained associated with a 45% decreased risk of developing new AF (HR 0.55, 95% CI 0.35–0.87, p=0.011).
Conclusions: Incident AF is substantially less common among black than non-black hypertensive patients. The lower risk of developing AF in black patients persists after adjusting for the higher prevalence of AF risk factors in blacks, treatment effects, in-treatment blood pressure and the known predictive value of in-treatment ECG LVH and heart rate for incident AF in this population.
- © 2010 by American Heart Association, Inc.