More than a quarter of the world's adult population, totalling nearly one billion people, have high blood pressure. For three decades, beta blockers have been widely used in the treatment of high blood pressure and are recommended as first-line drugs in several current treatment guidelines. In the UK, more than 2 million people are treated with beta-blockers. However, the effectiveness of beta blockers has recently been challenged. A preliminary study published last year in The Lancet (Lancet 2004; 364: 1648-89) concluded that one beta blocker, called atenolol, is less effective than other drugs at reducing the cardiovascular risks in patients with high blood pressure.
Lars Hjalmar Lindholm (Umea University Hospital, Sweden) and colleagues investigated the effectiveness of atenolol and other beta blockers on stroke, myocardial infarction, and all-cause mortality. The researchers combined data from 13 randomised trials, involving over 105,000 people, that compared beta blockers with other antihypertensive drugs. They found that the risk of stroke was 16% higher with beta blockers than with other drugs, while all-cause mortality was 3% higher. However, there was no difference between the drugs in relation to heart problems. When the team looked at atenolol separately, the risk of stroke was 26% higher than for other drugs. In seven other studies involving 27, 500 people, they also found that when the effect of beta blockers was compared with that of no treatment, the risk of stroke was reduced by 19%, which is about half that expected from previous trials.
Professor Lindholm concludes: "Switching hypertension treatment from beta blockers to other low-cost antihypertensive drugs in patients without heart disease should have a major health effect without increasing the cost. Such a change, however, should be carried out slowly and under a doctor's supervision…In comparison with other antihypertensive drugs, the effect of beta blockers is clearly suboptimum with a higher risk of stroke. We therefore believe that beta blockers should not remain as first choice in the treatment of primary hypertension."
See also accompanying comment.
Contact: Professor Lars Hjalmar Lindholm, Department of Public Health and Clinical Medicine, Umea University Hospital, SE 901 85 Umea, Sweden T) +46 90 785 35 26 /mobile +46 70 585 35 26 LarsH.Lindholm@fammed.umu.se
Journal
The Lancet