Do all antihypertensive drugs improve carotid intima-media thickness? A network meta-analysis of randomized controlled trials.

The many clinical trials investigating the effect of various antihypertensive drugs on carotid intima-media thickness (CIMT) produced conflicting results. We used meta-analysis to evaluate CIMT changes and network meta-analysis to rank drugs according to the magnitude of these changes. We identified 31 randomized controlled trials listed in three databases as of January 2008. Using a random-effects model, we found a significant CIMT decrease with antihypertensive drugs compared to placebo (-0.10 [-0.16; -0.04]). Overall effect sizes vs. placebo were significant for angiotensin-converting enzyme (ACE) inhibitors (-0.08 [-0.14; -0.02]), and a trend was found for beta-blockers (-0.09 [-0.19; 0.01]). The data did not allow other direct comparisons vs. placebo. Significant benefits were found for calcium-channel blockers (CCBs) compared to both ACE inhibitors (0.37 [0.20; 0.54]), as well as for angiotensin II receptor blockers (ARBs) compared to beta-blockers (0.42 [0.29; 0.55]). Diuretics were less efficient than CCBs (-0.09 [-0.16; -0.02]). Indirect comparisons with network meta-analysis showed significant effects of CCBs and ARBs vs. placebo (both P < 0.05) and vs. diuretics (both P < 0.001). The CIMT decrease with ACE inhibitors and beta-blockers was greater than with diuretics (both P < 0.05) but was not different from the placebo effect. In subgroup analyses, significant benefits occurred with lower baseline CIMT values and shorter treatment durations but were unrelated to the size of the blood pressure decrease. In conclusion, among antihypertensive drugs, CCBs and ARBs have the greatest effect on CIMT.