Atrial fibrillation at baseline and during follow-up in ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial).
OBJECTIVE
The ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) determined that treatment with amlodipine, lisinopril, or doxazosin was not superior to thiazide-like diuretic (chlorthalidone) in preventing coronary heart disease (CHD) or other cardiovascular events. This subanalysis examines baseline prevalence and in-trial incidence of new-onset atrial fibrillation (AF) or atrial flutter (AFL) and their influence on clinical outcomes.


BACKGROUND
Limited information is available on whether atrial fibrillation incidence is affected differentially by different classes of antihypertensive medications or treatment with statins.


METHODS
AF/AFL was identified from baseline and follow-up electrocardiograms performed biannually. Analyses were performed to identify characteristics associated with baseline AF/AFL and its subsequent incidence.


RESULTS
AF/AFL was present at baseline in 423 participants (1.1%), more frequent in men (odds ratio: 1.72; 95% confidence interval [CI]: 1.37 to 2.17) and nonblacks (odds ratio: 2.09; 95% CI: 1.58 to 2.75). Its prevalence increased with age (p < 0.001) and was associated with CHD, cardiovascular disease, obesity, and high-density lipoprotein cholesterol <35 mg/dl. New-onset AF/AFL was associated with the same baseline risk factors plus electrocardiogram left ventricular hypertrophy. It occurred in 641 participants (2.0%) and, excluding doxazosin, did not differ by antihypertensive treatment group or, in a subset of participants, by pravastatin versus usual care. Baseline AF/AFL was associated with increased mortality (hazard ratio [HR]: 2.82; 95% CI: 2.36 to 3.37; p < 0.001), stroke (HR: 3.63; 95% CI: 2.72 to 4.86; p < 0.001), heart failure (HR: 3.17; 95% CI: 2.38 to 4.25; p < 0.001), and fatal CHD or nonfatal myocardial infarction (HR: 1.64; 95% CI: 1.22 to 2.21; p < 0.01). There was a nearly 2.5-fold increase in mortality risk when AF/AFL was present at baseline or developed during the trial (HR: 2.42; 95% CI: 2.11 to 2.77; p < 0.001).


CONCLUSIONS
In this high-risk hypertensive population, pre-existing and new-onset AF/AFL were associated with increased mortality. Excluding doxazosin, treatment assignment to either antihypertensive drugs or pravastatin versus usual care did not affect AF/AFL incidence. (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial [ALLHAT]; NCT00000542).
Haywood
L Julian
LJ
Los Angeles County/University of Southern California Medical Center, Los Angeles, California, USA.
Ford
Charles E
CE
Crow
Richard S
RS
Davis
Barry R
BR
Massie
Barry M
BM
Einhorn
Paula T
PT
Williard
Angela
A
D000959:Antihypertensive Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000453:epidemiology*; D001282:Atrial Flutter / Q000453:epidemiology*; D015897:Comorbidity; D017292:Doxazosin / Q000627:therapeutic use; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D006973:Hypertension / Q000453:epidemiology*; D015994:Incidence; D053208:Kaplan-Meier Estimate; D009203:Myocardial Infarction / Q000453:epidemiology / Q000517:prevention & control*; D017035:Pravastatin / Q000627:therapeutic use; D011379:Prognosis; D012907:Smoking / Q000453:epidemiology
D000959:Antihypertensive Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D017035:Pravastatin; D017292:Doxazosin