Beta-Blockers for Hypertension
Abstract & Commentary
By Michael H. Crawford, MD, Professor of Medicine, Chief of Clinical Cardiology, University of California, San Francisco. Dr. Crawford is on the speaker's bureau for Pfizer.
Source: Lindholm LH, Carlberg B, Samuelsson O. Should Beta Blockers Remain First Choice in the Treatment of Primary Hypertension? A Meta-Analysis. Lancet. 2005;366:1545-1553.
For the past 3 decades, beta-blockers have been first-line therapy for hypertension. However, recently the efficacy of beta-blockers for treating primary hypertension has been challenged. Thus, Lindholm and colleagues from Sweden conducted a meta-analysis of 13 randomized, controlled trials for the treatment of primary hypertension where a beta-blocker was used in at least 50% of the patients. Both placebo-controlled and drug comparison studies were considered. End points were stroke, death, and myocardial infarction (MI). In comparison to other drugs, the risk of stroke was 16% higher with beta-blockers (P < .01). All-cause mortality and MI were not different. The main difference in stroke rates was observed in the trials involving atenolol. In the non-atenolol trials there were too few strokes to analyze. Compared to placebo, beta-blockers reduced the risk of stroke by 19%, which is half the magnitude of reduction seen in other studies. Lindholm et al concluded that in comparison to other therapy in patients with hypertension, beta-blockers are less efficacious and increase the risk of stroke.
Commentary
Propelled by its benefits in post MI patients and low costs, beta-blockers have become first-line therapy for hypertension. Proponents have impugned the motives of anyone who thought that newer and more expensive drugs were better (eg, calcium blockers, ACE inhibitors, ARBs). Since beta-blockers lowered blood pressure as much as newer agents, they must be as effective. Large trials published since 2002 have shown otherwise, and these trials dominate this meta-analysis. Also, many older studies combined diuretics with beta-blockers, which obscure the effect of beta-blockers alone. In this meta-analysis beta-blockers had no affect on MI or death, and lowered stroke 19%. A similar meta-analysis of newer antihypertensives showed stroke reduced by 38%. Lindholm et al estimated based on this difference that if newer drugs were used instead of beta-blockers in the European Union, 125,000 stokes would be prevented in 5 years.
Given identical lowered blood pressure reduction, why would beta-blockers be less effective? Some have suggested the deleterious metabolic effects on lipids and glucose, which would be exacerbated by thiazides, is the reason. Others believe beta-blockers lower peripheral blood pressure more than central, hence they observed lesser effects on left ventricular hypertrophy regression. Whatever the reason, the proponents of using newer drugs rather than beta-blockers seem vindicated, rather than being pharmaceutical company shills.
For the past 3 decades, beta-blockers have been first-line therapy for hypertension. However, recently the efficacy of beta-blockers for treating primary hypertension has been challenged. Thus, Lindholm and colleagues from Sweden conducted a meta-analysis of 13 randomized, controlled trials for the treatment of primary hypertension where a beta-blocker was used in at least 50% of the patients.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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