Effects of β-blocker selectivity on blood pressure variability and stroke- A systematic review
Evidence Based Medicine
Webb AJS et al. – Use of β1–selective rather than nonselective agents may be advisable when β–blockers are indicated for patients at risk of stroke.Methods
- β –blocker subclass effects on variability in BP and stroke risk in a systematic review of randomized controlled trials (RCTs) comparing different types of β–blocker with placebo or other agents were determined in this study.
- 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 was determined.
- Compared with other antihypertensives, variability in SBP was increased more by nonselective β–blockers (VR=1.34, 1.13–1.59, p=0.002, 25 comparisons, 9,992 patients) than by β1–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 β1–selective vs nonselective β–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 β–blockers ([OR]=2.29, 1.32–3.96, p =0.002) was more marked than with β1–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).