Are thiazide diuretics preferred as first‐line therapy for hypertension? An appraisal of The Antihypertensive and Lipid‐lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

The Antihypertensive and Lipid-lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study1 was a double-blind, concealed, randomized controlled trial, with allocation provided by telephone to external agency. Participants were randomly assigned to diuretic, CCB or ACE-I with intent-to-treat analysis. Participants were recruited from 623 medical centres in USA, Canada, Puerto Rico and US Virgin Islands. Patients The study included men and women aged ≥55 years with mild to moderate hypertension and at least one other coronary risk factor, defined as: (i) previous (>6 months) myocardial infarction (MI) or stroke, (ii) left ventricular hypertrophy (LVH) demonstrated by electrocardiogram or echocardiography, (iii) history of type 2 diabetes, (iv) current smoker, (v) high-density lipoprotein(HDL-) cholesterol <0.91 mmol/L or (vi) documentation of other atherosclerotic cardiovascular disease (CVD). Patients were excluded if they had a history of hospitalized or treated symptomatic heart failure (HF) and/or known left ventricular ejection fraction <35%. Patient characteristics were: (i) mean age 67 years, (ii) 47% women, (iii) 35% black, (iv) 19% Hispanic, (v) 36% diabetic, (vi) 22% smokers, (vii) 51% prior atherosclerotic CVD, (viii) 25% prior coronary heart disease (CHD), (ix) mean body mass index 30, (x) 12% HDL-cholesterol <0.91 mmol/L, (xi) 21% LVH, (xii) 90% receiving antihypertensive treatment at baseline with average pre-randomization blood pressure (BP) of 145/83 mmHg and (xiii) 36% use of aspirin.