The role of beta-adrenergic blocking drugs in the initial management of hypertensive patients has been recently challenged after the publication of the results of two large drug trials (LIFE and ASCOT) and meta-analysis (Lindholm et al.) to the extent that the recent British Hypertension Society Guidelines and the NICE Hypertension Recommendations (2006) stated that "beta-blockers (BB) are no longer preferred as routine initial therapy". This was followed by a number of editorials and comments which stressed the same opinion, that BB should not be among several choices for initial therapy of hypertension. In patients with uncomplicated hypertension, there is paucity of data or absence of evidence to support use of BB as monotherapy or as first-line agents.
However, this policy
is not uniformally accepted and
a different point of view is taken by other investigators and international
organizations. In 2003 WHO/ISH statement on management of hypertension, "the
meta-analysis shows no significant differences between drug classes or between
groups of old and new drugs." The recent ESH/ESC guidelines for the
management of hypertension (2007) stated that "all 5 major
antihypertensive agents (including BB) are suitable for the initiation of
therapy" and that "comparative randomized trials show that for
similar blood pressure (BP) reductions, differences in the incidence of
cardiovascular morbidity and mortality between different drug classes are
small." The 2009 Canadian Hypertension
Education Program
Recommendations stated that "initial therapy for adults without compelling
indications for specific agents should be monotherapy with a thiazide diuretic;
a beta-blocker (in patients younger than 60 years of age, long acting CCB,
………". In 2009 reappraisal of European Guidelines, the document stated that
"diuretics, ACE inhibitors, calcium antagonists, angiotensin receptor
antagonists, and BB do not differ significantly for their ability to reduce BP
in hypertension and that all the agents can be considered suitable for initiation
of antihypertensive treatment, as well as for its maintenance".
In an attempt to resolve controversies
regarding cardiovascular protection,
a number of meta-analyses have been performed (table 1). The meta-analysis of
Law and others (2009) is the largest ever reported including 464000
participants in 147 randomized trials concluded that with the exception of the
extra protective effect of BB given shortly after MI and the minor additional
effect of CCB in preventing stroke, all the classes of BP lowering drugs have a
similar effect in reducing coronary heart disease events and stroke for a given
reduction in BP.
Table (1): Meta-Analysis
Authors/Study |
Year |
Comparison |
No of Trials |
No of Pts |
Results |
BPLTTC |
2003 |
Pl, D |
29 |
162000 |
With |
Carlberg |
2004 |
Pl, D |
9 |
24496 |
Against |
Lindholm |
2005 |
Pl, D |
18 |
127879 |
Against |
Khan |
2006 |
Pl,D, Y,O |
21 |
145811 |
With |
BPLTTC |
2008 |
Pl, D, Y, O |
31 |
190606 |
With |
Law |
2009 |
Pl, D |
147 |
464000 |
With |
Pl: Placebo, D: drug, Y: young, O: old.
With: results of BB better than placebo, same
or better than other drug.
Against: results of BB worse than other drug.
Conclusions: BB are effective
antihypertensive drugs, they improve CV morbidity and mortality and they are
more beneficial in selected patients. They are the drugs of first choice in
hypertensive patients with coronary heart disease, heart failure, tachyarrhythmias
and glaucoma. However, not all BB are the same, the presence of cardioselectivity
is advantageous.
Suggested
Readings
Mancia G, Laurent
S, Agabiti-Rosei
E, Ambrosioni
E, et al. Reappraisal of European Guidelines on Hypertension Management:
a European Society of Hypertension Task Force document. J Hyperten 2009;
27(11): 2121-2158
Cruickshank J M. Are
we misunderstanding beta-blockers. Intern J Cardiol 2007 ;120: 10-27.
Mancia G. Prevention
of risk factors: beta-blockade and hypertension. Eur Heart J Suppl (2009)
11 (suppl A): A3-A8.
Bangalore S, Messerli
F H, Kostis J B and Pepine C J. Cardiovascular Protection Using
Beta-Blockers A Critical Review of
the Evidence. J Am Coll Cardiol 2007; 50;563-572.
Fowler M B.
Hypertension, Heart Failure, and Beta-Adrenergic Blocking Drugs. J Am Coll Cardiol, 2008; 52:1073-1075.
Holman R R, Bethel M
A, Neil H A W, Matthews D R. Long-Term Follow-up after Tight Control of
Blood Pressure in Type 2 Diabetes. N Engl J Med 2008; 359: 1565-76.
Effects of different
regimens to lower blood pressure on major cardiovascular events in older
and younger adults: meta-analysis of randomised trials Blood Pressure
Lowering Treatment Trialists’ Collaboration. BMJ 2008;336:1121-1123
Khan N, McAlister F A.
Re-examining the efficacy of b-blockers for the treatment of hypertension:
a meta-analysis. CMAJ 2006; 174(12): 1737
Law M R, Morris J K,
Wald N J. Use of blood pressure lowering drugs in the prevention of
cardiovascular disease: meta-analysis of 147 randomised trials in the
context of expectations from prospective epidemiological studies. BMJ
2009; 338: b1665
