Effects of β-Blockers With and Without Vasodilating Properties on Central Blood Pressure: Systematic Review and Meta-Analysis of Randomized Trials in Hypertension

Abstract

β-Blockers are less effective than other antihypertensive drug classes in reducing central systolic blood pressure (cSBP) as compared with peripheral SBP (pSBP). Whether this effect is less pronounced with vasodilating β-blockers (VBB) when compared with nonvasodilating β-blockers (NVBB) remains unsettled. We conducted a systematic review and meta-analysis of randomized trials exploring the effects of β-blockers on both pSBP and cSBP in hypertension. We selected 20 studies, for a total of 32 treatment arms (n=21 for NVBB, n=11 for VBB) and 1263 participants (n=962 for NVBB, n=301 for VBB). pSBP decreased from 150 to 133 mm Hg for NVBB and from 145 to 134 mm Hg for VBB. cSBP decreased from 137 to 126 mm Hg for NVBB and from 132 to 123 mm Hg for VBB. SBP amplification (pSBP-cSBP) decreased significantly under VBB (-5.6 mm Hg; 95% confidence interval, -7.8, -3.4 mm Hg), but not under NVBB (-1.1 mm Hg; 95% confidence interval, -3.4, +1.2 mm Hg; P<0.01 versus NVBB). There was high heterogeneity both within and between β-blockers subclasses. In a meta-regression model, the weighted difference in treatment-induced changes in SBP amplification between NVBB and VBB lost its significance after adjustment for mean age and baseline pSBP and heart rate (-2.9±2.3 mm Hg; P=0.22) and was almost abolished after adjustment for treatment-induced heart rate changes (-0.1±0.5 mm Hg; P=0.78). In conclusion, NVBBs, but not VBBs, determine a lower reduction in cSBP than in pSBP. However, the difference in treatment-induced SBP amplification changes between NVBB and VBB is nearly abolished after accounting for differences in heart rate changes.

Keywords: antihypertensive agents; aortic blood pressure; beta-adrenergic blockers; blood pressure; confidence intervals; heart rate; hypertension.