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SECOND AUSTRALIAN NATIONAL BLOOD PRESSURE STUDY (ANBP-2)

• Enalapril/ACEI vs. HCTZ, n = 6,083

• Randomized, open-label (blinded endpoint review)

• All CV events or death from any cause

– HR = 0.89 (0.79-1.00), p=0.05

• First events

– CVD: HR = 0.88 (0.77-1.01), p = 0.07

– CHD: HR = 0.86 (0.70-1.06), p = 0.16

– Stroke: HR = 1.02 (0.78-1.33), p = 0.91

– HF: HR = 0.85 (0.62-1.18), p = 0.33NEJM 2003;348:583-92

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SECOND AUSTRALIAN NATIONAL BLOOD PRESSURE STUDY (ANBP-2)

Results by Gender

NEJM 2003;348:583-92

HR (95% CI) p

p for interaction

All CVD / Total Mortality

Men 0.83 (0.71-0.97) 0.02

0.15Women 1.00 (0.83-1.21) 0.98

1st CVD / Total Mortality

Men 0.83 (0.71-0.97) 0.02

0.14Women 1.00 (0.83-1.20) 0.98

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ALLHAT vs. ANBP2Baseline Characteristics

ALLHAT ANBP2

N 24,309 6,083

Women, % 47 51

Black, % 35 --

Mean age, years 66.9 71.9

Baseline BP, mm Hg* 146 / 84 168 / 91

Previous treatment, % 90 62

BMI, kg/m2 30 27

Current smoking, % 22 7

Diabetes, % 36 7* ALLHAT: no washout, ANBP2: after washout

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ALLHAT vs. ANBP2Blood Pressure & Endpoints

ALLHAT Total

ANBP2

N (ACE / diuretic) 9,054 / 15,255 3,044 / 3,039

1-year BP delta

(ACE - diuretic)

3 / 1 2 / 0

1st CVD / Total Mortality

1.07 (1.03-1.12)

p=.002

0.89 (0.79-1.01)

p=.06

1st CHD 1.05 (0.98-1.11)

p=.18

0.86 (0.70-1.06)

p=.16

Heart Failure 1.19 (1.07-1.31)

p<.001

0.85 (0.62-1.18)

p=.85

Stroke 1.15 (1.02-1.30)

p=.02

1.02 (0.78-1.33)

p=.91

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ALLHAT vs. ANBP-2

• Randomized double-blind vs. PROBE design

• ACEI vs. thiazide-type diuretic, n = 24,309 vs. 6,083

• Number of patients with events

– CVD: n = 6,455 vs. 823

– CHD: n = 3,956 vs. 368

– Stroke: n = 1,132 vs. 219

– Heart failure: n = 1,482 vs. 147

• Treatment differences consistent across gender

subgroup vs. differences noted only in men

• SBP slightly lower with diuretic in both trials

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CONCLUSIONS – ALLHAT vs. ANBP2

• ALLHAT had 4 times the number of participants, 5-10 times more endpoints, and a double-blinded design

• Even so, the upper 95% CI of ANPB2 compatible with ALLHAT point estimates of relative risk:

– Coronary events

– Stroke

– Heart failure

• ALLHAT - no ACE advantage for any outcomes in either men or women, and heart failure outcomes were worse compared to the diuretic.

• While the aggregate analyses will have to await those planned by the Blood Pressure Lowering Treatment Trialists’ Collaboration, the totality of trial evidence from ALLHAT and other individual trials favors the diuretic.