Effects of β-blocker selectivity on blood pressure variability and stroke A systematic review

Objectives: beta-Blockers increase variability in systolic blood pressure (SBP), which probably explains their lesser effectiveness in preventing stroke vs myocardial infarction compared with other agents. This increase in variability in blood pressure (BP) may be particularly marked on non-cardioselective agents, potentially calling into question the widespread first-line use of propranolol in migraine with aura, elderly patients with essential tremor or anxiety, and other groups at risk of stroke. Methods: We determined beta-blocker subclass effects on variability in BP and stroke risk in a systematic review of randomized controlled trials (RCTs) comparing different types of beta-blocker with placebo or other agents. We determined pooled estimates of the effect of treatment on group variability in BP (ratio of the variances [VR]) and on the risk of stroke vs myocardial infarction during follow-up. Results: Compared with other antihypertensives, variability in SBP was increased more by nonselective beta-blockers (VR = 1.34, 1.13-1.59, p = 0.002, 25 comparisons, 9,992 patients) than by beta 1-selective agents (VR = 1.09, 95% confidence interval 1.00-1.19, p = 0.053, 68 comparisons, 40,746 patients; difference-p = 0.038). In direct comparisons, variability in SBP was also significantly lower with beta 1-selective vs nonselective beta-blockers (VR = 0.81, 0.68-0.97, p = 0.03, 18 comparisons, 954 patients). In comparisons with other antihypertensives, the increase in stroke risk with nonselective beta-blockers ([OR] = 2.29, 1.32-3.96, p = 0.002) was more marked than with beta 1-selective agents (OR = 1.24, 1.08-1.42, p = 0.003, difference-p = 0.03), as was the risk of stroke relative to the risk of myocardial infarction: OR = 1.50 (0.93-2.42) vs 0.99 (0.82-1.19). Conclusion: Use of beta 1-selective rather than nonselective agents may be advisable when beta-blockers are indicated for patients at risk of stroke. Neurology (R) 2011;77:731-737