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

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.