Context Few cardiovascular outcome data are available for blacks with hypertension
treated with angiotensin-converting enzyme (ACE) inhibitors or calcium channel
blockers (CCBs).
Objective To determine whether an ACE inhibitor or CCB is superior to a thiazide-type
diuretic in reducing cardiovascular disease (CVD) incidence in racial subgroups.
Design, Setting, and Participants Prespecified subgroup analysis of ALLHAT, a randomized, double-blind,
active-controlled, clinical outcome trial conducted between February 1994
and March 2002 in 33 357 hypertensive US and Canadian patients aged 55
years or older (35% black) with at least 1 other cardiovascular risk factor.
Interventions Antihypertensive regimens initiated with a CCB (amlodipine) or an ACE
inhibitor (lisinopril) vs a thiazide-type diuretic (chlorthalidone). Other
medications were added to achieve goal blood pressures (BPs) less than 140/90
mm Hg.
Main Outcome Measures The primary outcome was combined fatal coronary heart disease (CHD)
or nonfatal myocardial infarction (MI), analyzed by intention-to-treat. Secondary
outcomes included all-cause mortality, stroke, combined CVD (CHD death, nonfatal
MI, stroke, angina, coronary revascularization, heart failure [HF], or peripheral
vascular disease), and end-stage renal disease.
Results No significant difference was found between treatment groups for the
primary CHD outcome in either racial subgroup. For amlodipine vs chlorthalidone
only, HF was the only prespecified clinical outcome that differed significantly
(overall: relative risk [RR], 1.37; 95% confidence interval [CI], 1.24-1.51;
blacks: RR, 1.46; 95% CI, 1.24-1.73; nonblacks: RR, 1.32; 95% CI, 1.17-1.49; P<.001 for each comparison) with no difference in treatment
effects by race (P = .38 for interaction).
For lisinopril vs chlorthalidone, results differed by race for systolic BP
(greater decrease in blacks with chlorthalidone), stroke, and combined CVD
outcomes (P<.001, P = .01,
and P = .04, respectively, for interactions).
In blacks and nonblacks, respectively, the RRs for stroke were 1.40 (95% CI,
1.17-1.68) and 1.00 (95% CI, 0.85-1.17) and for combined CVD were 1.19 (95%
CI, 1.09-1.30) and 1.06 (95% CI, 1.00-1.13). For HF, the RRs were 1.30 (95%
CI, 1.10-1.54) and 1.13 (95% CI, 1.00-1.28), with no significant interaction
by race. Time-dependent BP adjustment did not significantly alter differences
in outcome for lisinopril vs chlorthalidone in blacks.
Conclusions In blacks and nonblack subgroups, rates were not lower in the amlodipine
or lisinopril groups than in the chlorthalidone group for either the primary
CHD or any other prespecified clinical outcome, and diuretic-based treatment
resulted in the lowest risk of heart failure. While the improved outcomes
with chlorthalidone were more pronounced for some outcomes in blacks than
in nonblacks, thiazide-type diuretics remain the drugs of choice for initial
therapy of hypertension in both black and nonblack hypertensive patients.