Operational Aspects of Terminating the Doxazosin Arm of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

ABSTRACT: The Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized, practice-based trial sponsored by the National Heart, Lung, and Blood Institute (NHLBI). The double-blind, active-controlled component of ALLHAT was designed to determine whether the rate of the primary outcome—a composite of fatal coronary heart disease and nonfatal myocardial infarction—differs between diuretic (chlorthalidone) treatment and each of three other classes of antihyper-tensive drugs: a calcium antagonist (amlodipine), an angiotensin-converting enzyme inhibitor (lisinopril), and an alpha-adrenergic blocker (doxazosin) in high-risk hyperten-sive persons ages 55 years and older (n 5 42,448). In addition, 10,377 ALLHAT partici