Influence of beta-blockers on endothelial function: A meta-analysis of randomized controlled trials.

BACKGROUND Endothelial dysfunction (ED) frequently precedes cardiovascular diseases (CVD) and is a well-established risk factor of major adverse cardiac events. Beta-blockers are the fundamental drugs used in CVD treatment. METHODS A systematic literature search for randomized controlled trials investigating influence of beta-blockers on endothelial function assessed by flow-mediated dilation (FMD) was performed in the PubMed and Cochrane Databases. RESULTS Sixteen full-text studies involving a total of 1,273 patients were included in the final analysis. The mean age of participating patients ranged from 44.9 to 63.2 years, the follow-up duration from 1 to 12 months. The comparison of FMD change between the beta-blockers and placebo groups showed a statistically significant effect of beta-blockers on endothelial function (mean difference [MD] 0.83; 95% confidence interval [CI] 0.11-1.55; p = 0.02). Third generation beta-blockers improved FMD in a statistically significant manner compared with second generation beta-blockers (MD 1.65; 95% CI 0.17-3.11; p = 0.03). Beta-blockers gave an FMD change similar to that obtained with angiotensin receptor blockers (ARB), calcium channel blockers (CCB) or hydrochlorothiazide. The FMD value in the beta-blocker group was significantly lower compared with the group treated with angiotensin converting enzyme inhibitors (ACEI) (MD -0.79; 95% CI -1.37-(-0.21); p = 0.008) and higher than in the ivabradine group (1.6 ± 3.61 vs -0.3 ± 1.66; p = 0.02). CONCLUSIONS Beta-blockers improve the endothelial function compared with placebo. More-over, third generation beta-blockers improve FMD values significantly better than the second generation ones. Beta-blockers had similar effect on endothelial function as did ARB, CCB or diuretics. However, the beneficial effect of beta-blockers was lower when confronted with ACEI.