EMB COMMENTARY
SHOULD BETA BLOCKERS STILL BE RECOMMENDED AS FIRST-LINE THERAPY FOR ESSENTIAL HYPERTENSION IN YOUNGER PATIENTS?
LW Ng, CL Teng MMed (FamMed), FRACGP, AM
Ling-Wei Ng is a medical student, and Cheong-Lieng Teng is an Associate Professor in the Department of Family Medicine, International Medical University, Seremban, Negeri Sembilan, Malaysia.
Address for correspondence: Dr CL Teng, Associate Professor, International Medical University, Jalan Rasah, 70300 Seremban, Malaysia. Tel: 06-76777798, Fax: 06-7677709, E-mail: tengcl@gmail.com
Conflict of interest: None
Ng LW, Teng CL.Should beta-blockers still be recommended as first-line therapy for essential hypertension in younger patients? Malaysian Family Physician. 2008;1(1):32-33.
CASE SCENARIO
Mr. M is a 48 year-old male teacher who has had essential hypertension for the past 2 years. He is a non-smoker and is not diabetic. There is no family history of heart disease. His blood pressure is well-controlled at 129/78 mmHg (pulse rate 60/min) with atenolol at 100mg daily. Clinically, there is no target organ damage. He has heard that the use of beta-blockers in hypertension is now controversial and has asked if he should continue taking atenolol.
Question: In a hypertensive patient of less than 60 years in age without co-morbidity, should beta-blockers be the first-line therapy?
COMMENTARY
Hypertension is a major risk factor of stroke and other cardiovascular events. It is important to maintain good control of blood pressure to prevent end-organ damage. Beta-blockers have been widely used for the last four decades as the first-line treatment for hypertension but their efficacy was recently questioned. Messerli et al,1 in a meta-analysis of ten randomised controlled trials (RCTs) of hypertension treatment in the elderly (aged ³60 years), found that beta-blockers were inferior to diuretics for blood pressure control and long-term outcome measures1 (e.g. fatal stroke, coronary artery disease, cardiovascular mortality, all-cause mortality).
A widely publicised meta-analysis (based on 18 RCTs) by Lindholm et al2 found that beta-blockers were more effective than placebos for blood pressure control and produced a 19% reduction in the risk of stroke. However, when compared with other anti-hypertensive drugs, there was a 16% increase in the risk of stroke, although the incidences of myocardial infarction (MI) and all-cause mortality were not statistically significant.2 A meta-analysis published earlier by the same group of investigators even found that atenolol, when compared to other anti-hypertensives, was associated with higher Chances of total mortality, cardiovascular mortality and stroke, despite equivalent reduction in blood pressure3 (where the mean ages of patients in the atenolol arm were between 52 and 70 years)
Khan et al,4 extended Lindholm’s meta-analysis by including 21 RCTs published between 1982 and 2005. This meta-analysis compared the outcome of beta-blockers in younger (<60 years) and older (³60 years) patients. They found that in placebo-controlled trials, beta-blockers reduced major events (death, MI, stroke) in younger patients by 14% (RR=0.86, 95%CI 0.74 to 0.99) but not in older patients (RR=0.89, 95%CI 0.75 to 1.05). When compared to other classes of anti-hypertensives, there was no difference in the event rates in younger patients (RR=0.97, 95% CI 0.88 to 1.07) but an excess risk of 18% in older patients was observed (RR 1.18, 95%CI 1.07 to 1.30).4
In summary, Lindholm et al2 showed that beta-blockers are effective for blood pressure reduction and prevention of stroke when compared to placebos (or no treatment) but they are inferior to other anti-hypertensives (e.g. diuretics, angiotensin-converting enzymes inhibitors and angiotensin receptor blockers). Beta-blockers, especially atenolol, are clearly less effective in elderly hypertensive patients2,3 but may be as good as other anti-hypertensives in younger hypertensive patients for the prevention of long-term outcomes.3 In a review of 13 hypertension drug trials published in the last 10 years, Ong5 concluded that prevention of cardiovascular events is attributed more to the achievement of targeted blood pressure treatment rather than anti-hypertensive drug choice. In younger patients with isolated hypertension and no other morbidity, as in our patient Mr. M, it is acceptable to continue using beta-blockers as the first-line anti-hypertensive agent.
References
- Messerli FH, Grossman E, Goldbourt U. Are ß-blockers efficacious as first-line therapy for hypertension in the elderly? A systemic review. JAMA. 1998;279(23):1903-7. [Pubmed] [Full text]
- Lindholm LH, Carlberg B, Samuelsson O. Should ß blockers remain first choice in the treatment of primary hypertension? A meta-analysis. Lancet. 2005;366(9496):1545-53. [Pubmed]
- Carlberg B, Samuelsson O, Lindholm LH. Atenolol in hypertension: is it a wise choice? Lancet 2004;364(9446):1684-9. [Pubmed]
- Khan N, McAlister FA. Re-examining the efficacy of ß-blockers for the treatment of hypertension: a meta-analysis. CMAJ. 2006;174(12):1737-42. [Pubmed] [Full text]
- Ong HT. What we really need to do to reduce cardiovascular events in hypertensive patients. J Fam Pract. 2007;56(9):727-34. [Pubmed] [Full text]