ACE and Hypertension: The randomized, double-blind, active-controlled antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT), conducted from February 1994 through March 2002, evaluated 33,357 participants (age ≥ 55 years) with hypertension and at least one additional CHD risk factor from 623 North American centers to determine if calcium channel blockers or angiotensin-converting enzyme (ACE) inhibitors would lower the incidence of CHD or other CV events vs. treatment with a diuretic.