Baseline characteristics of participants in the Antihypertensive and LipidLowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Diuretics and beta -blockers have been shown to reduce the risk of cardiova scular morbidity and mortality in people with hypertension in long-term cli nical trials. No study has compared newer more costly antihypertensive agen ts (calcium antagonists, ACE inhibitors, and a-adrenergic blockers) with di uretics for reducing the incidence of cardiovascular disease in an ethnical ly diverse group of middle-aged and elderly hypertensive patients. The stud y is a randomized, double-blind, active-controlled clinical trial designed to determine whether the incidence of the primary outcome, fatal coronary h eart disease or nonfatal myocardial infarction, differs between treatment i nitiation with a diuretic versus each of 3 other antihypertensive drugs. Me n and women aged greater than or equal to 55 years with at least 1 other ca rdiovascular disease risk factor were randomly assigned to chlorthalidone ( 12.5 to 25 mg/d), amlodipine (2.5 to 10 mg/d), lisinopril (10 to 40 mg/d), or doxazosin (2 to 8 mg/d) for planned follow-up of 4 to 8 years. This repo rt describes the baseline characteristics of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants. A total of 42 448 participants were randomized from 625 sites in the United S tates, Canada, Puerto Rico, and the US Virgin Islands. The mean age was 67 years, with 35% aged greater than or equal to 70 years. Among those randomi zed, 36% were black, 19% were Hispanic, and 47% were women. The sample incl udes a high proportion of people with diabetes (36%), patients with existin g cardiovascular disease (47%), and smokers (22%). There were no important differences between the randomized treatment groups at baseline. ALLHAT wil l add greatly to our understanding of the management of hypertension by pro viding an answer to the following question: are newer antihypertensive agen ts similar, superior, or inferior to traditional treatment with diuretics?