Atenolol vs Nonatenolol β-Blockers for the Treatment of Hypertension: A Meta-analysis

BACKGROUND: Previous reviews have shown that β-blocker use for the treatment of hypertension without compelling indications was associated with increased risk of stroke in the elderly. It remains unclear whether this increased risk was driven by the type of β-blocker. We sought to compare the efficacy of atenolol vs nonatenolol β-blockers in clinical trials enrolling young (< 60 years) and older patients with hypertension. METHODS: The Cochrane and MEDLINE databases were searched (January 2006-May 2013) for randomized trials evaluating stroke, myocardial infarction, death, or composite cardiovascular end points. Twenty-one hypertension trials with data on 145,811 participants were identified: 15 used atenolol, 7 were placebo-controlled trials, and 14 were active comparator trials. There were no trials of newer generation β-blockers identified. RESULTS: Among the elderly, atenolol was associated with an increased risk of stroke (relative risk [RR], 1.17; 95% confidence interval [CI], 1.05-1.30) compared with other antihypertensive agents. The risk of stroke for nonatenolol β-blockers compared with other agents (RR, 1.22; 95% CI, 0.99-1.50) did not reach statistical significance in the elderly. In the young, atenolol was associated with reduced risk of stroke compared with other agents (RR, 0.78; 95% CI, 0.64-0.95), whereas nonatenolol β-blockers were associated with a lower risk of composite cardiac events (RR, 0.86; 95% CI, 0.75-0.996) compared with placebo, with no significant difference in events compared with active controls. CONCLUSIONS: In the young, both atenolol and nonatenolol β-blockers are effective in reducing cardiovascular end points for hypertension without compelling indications. Atenolol is associated with increased stroke in the elderly but whether this extends to nonatenolol β-blockers remains uncertain.