Blood pressure control by drug group in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Abstract

Blood pressure (BP) control rates and number of antihypertensive medications were compared (average follow-up, 4.9 years) by randomized groups: chlorthalidone, 12.5-25 mg/d (n=15,255), amlodipine 2.5-10 mg/d (n=9048), or lisinopril 10-40 mg/d (n=9054) in a randomized double-blind hypertension trial. Participants were hypertensives aged 55 or older with additional cardiovascular risk factor(s), recruited from 623 centers. Additional agents from other classes were added as needed to achieve BP control. BP was reduced from 145/83 mm Hg (27% control) to 134/76 mm Hg (chlorthalidone, 68% control), 135/75 mm Hg (amlodipine, 66% control), and 136/76 mm Hg (lisinopril, 61% control) by 5 years; the mean number of drugs prescribed was 1.9, 2.0, and 2.1, respectively. Only 28% (chlorthalidone), 24% (amlodipine), and 24% (lisinopril) were controlled on monotherapy. BP control was achieved in the majority of each randomized group-a greater proportion with chlorthalidone. Over time, providers and patients should expect multidrug therapy to achieve BP <140/90 mm Hg in a majority of patients.

Figure

Characteristics that predicted better or worse blood pressure (BP) control (BP <140/90 mm Hg) within each drug group. Depicted are odds ratios (ORs) and their 95% confidence intervals (CIs) from 3 multiple logistic regression analyses of BP control at year 3; separate analyses were done for each randomized treatment group. An OR >1.0 indicates that the corresponding characteristic is associated with better BP control than its complementary subgroup (eg, the OR of 1.2 for men receiving lisinopril indicates 20% better BP control than among women receiving lisinopril); an OR <1.0 indicates worse BP control for the corresponding subgroup relative to its complement. The sample sizes for the respective logistic models were 11,262 (chlorthalidone), 6697 (amlodipine), and 6423 (lisinopril). †In a model combining all 3 treatment groups and including drug main effects and interaction terms (amlodipine/chlorthalidone and lisinopril/chlorthalidone ), the relative odds of BP control differed significantly by treatment group only for race (amlodipine/chlorthalidone interaction: OR, 0.911, P<.01, and lisinopril/chlorthalidone interaction: OR, 0.895, P<.001). SBP indicates systolic blood pressure; ASCVD, atherosclerotic cardiovascular disease; BMI, body mass index; eGFR, estimated glomerular filtration rate; ECG LVH, left ventricular hypertrophy on electrocardiography.