Effects of antihypertensive treatment in Asian populations: a meta-analysis of prospective randomized controlled studies (CARdiovascular protectioN group in Asia: CARNA)

Abstract

To examine the effects of antihypertensive treatment on cardiovascular disease (CVD) in Asian populations, we systematically evaluated prospective randomized studies carried out in Asia (1991-2013). We identified 18 trials with 23,215 and 21,986 hypertensive patients in the intervention (ie, strict blood pressure [BP] lowering or add-on treatment) and reference groups, respectively (mean age, 65 years; follow-up duration, 3.2 years). Analysis was performed through 1) first subgroup: eight trials that compared active antihypertensive treatment with placebo or intensive with less intensive BP control and 2) second subgroup: 10 trials that compared different antihypertensive treatments. In the first subgroup analysis, BP was reduced from 160.3/87.3 mm Hg to 140.2/78.4 mm Hg in the intervention group with a -6.7/-2.2 mm Hg (P < .001) greater BP reduction than the reference group. Compared with the reference group, the intervention group had a lower risk of composite CVD events (odd ratio [OR], 0.73; 95% confidence interval [CI], 0.66-0.81), myocardial infarction (OR, 0.79; 95% CI, 0.63-1.0), stroke (OR, 0.71; 95% CI, 0.63-0.80), and CVD mortality (OR, 0.81; 95% CI, 0.68-0.97; all P ≤ .05). In the second subgroup analysis, no difference was found for any outcome between renin-angiotensin blockers and calcium-channel blockers or diuretics. The meta-regression line among the 18 trials indicated that a 10 mm Hg reduction in systolic BP was associated with a reduced risk for composite CVD events (-39.5%) and stroke (-30.0%). Our meta-analysis shows a benefit when a BP target of less than 140/80 mm Hg is achieved in Asian hypertensives. BP reduction itself, regardless of BP lowering agents, is important for achieving CVD risk reduction.

Keywords: Asia; Hypertension; cardiovascular disease; randomized control trial.