Age-race subgroup compared with renin profile as predictors of blood pressure response to antihypertensive therapy. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

CONTEXT: Renin profiling and age-race subgroup may help select single-drug therapy for stage 1 and stage 2 hypertension. OBJECTIVE: To compare the plasma renin profiling and age-race subgroup methods as predictors of response to single-drug therapy in men with stage 1 and 2 hypertension as defined by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. DESIGN: The Veterans Affairs Cooperative Study on Single-Drug Therapy of Hypertension, a randomized controlled trial. SETTING: Fifteen Veterans Affairs hypertension centers. PATIENTS: A total of 1105 ambulatory men with entry diastolic blood pressure (DBP) of 95 to 109 mm Hg, of whom 1031 had valid plasma and urine samples for renin profiling. INTERVENTIONS: Randomization to 1 of 6 antihypertensive drugs: hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem (sustained release), or prazosin. MAIN OUTCOME MEASURE: Treatment response as assessed by percentage achieving goal DBP (<90 mm Hg) in response to a single drug that corresponded to patients' renin profile vs a single drug that corresponded to patients' age-race subgroup. RESULTS: Clonidine and diltiazem had consistent response rates regardless of renin profile (76%, 67%, and 80% for low, medium, and high renin, respectively, for clonidine and 83%, 82%, and 83%, respectively, for diltiazem for patients with baseline DBP of 95-99 mm Hg). Hydrochlorothiazide and prazosin were best in low- and medium-renin profiles; captopril was best in medium- and high-renin profiles (low-, medium-, and high-renin response rates were 82%, 78%, and 14%, respectively, for hydrochlorothiazide; 88%, 67%, and 40%, respectively, for prazosin; and 51%, 83%, and 100%, respectively, for captopril for patients with baseline DBP of 95-99 mm Hg). Response rates for patients with baseline DBP of 95 to 99 mm Hg by age-race subgroup ranged from 70% for clonidine to 90% for prazosin for younger black men, from 50% for captopril to 97% for diltiazem for older black men, from 70% for hydrochlorothiazide to 92% for atenolol for younger white men, and from 84% for hydrochlorothiazide to 95% for diltiazem for older white men. Patients with a correct treatment for their renin profile but incorrect for age-race subgroup had a response rate of 58.7%; patients with an incorrect treatment for their renin profile but correct for age-race subgroup had a response rate of 63.1% (P = .30). After controlling for DBP and interactions with treatment group, age-race subgroup (P<.001) significantly predicted response to single-drug therapy, whereas renin profile was of borderline significance (P= .05). CONCLUSIONS: In these men with stage 1 and stage 2 hypertension, therapeutic responses were consistent with baseline renin profile, but age-race subgroup was a better predictor of response.