Give Blood Pressure Drugs to All
News Author: Fran Lowry
CME Author: Désirée Lie, MD, MSEd
May 28, 2009 — Blood-pressure-lowering drugs should be offered to everyone, regardless of their blood pressure level, as a safeguard against coronary heart disease and stroke, researchers who conducted a meta-analysis of 147 randomized trials (comprising 958,000 people) conclude in the May 19 issue of BMJ .
"Guidelines on the use of blood-pressure-lowering drugs can be simplified so that drugs are offered to people with all levels of blood pressure," write Drs Malcolm R Law and Nicholas Wald (Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, UK). "Our results indicate the importance of lowering blood pressure in everyone over a certain age, rather than measuring it in everyone and treating it in some."
"Whatever your blood pressure, you benefit from lowering it further," Law told heartwire . "Everyone benefits from taking blood-pressure-lowering drugs. There is no one who does not benefit because their blood pressure is so-called normal."
Six years ago, Law and Wald advocated the use of a polypill--containing a statin, three blood-pressure-lowering drugs (each at half the standard dose), folic acid, and aspirin--which they maintained could prevent heart attacks and stroke if taken by everyone 55 years and older and by everyone with existing cardiovascular disease .
In the current meta-analysis, which included people aged 60 to 69, they singled out blood-pressure-lowering drugs to determine the quantitative efficacy of different classes of antihypertensive agents in preventing coronary heart disease (CHD) and stroke. They also sought to determine who should receive treatment.
All Antihypertensives Prevent CHD and Stroke
Overall, the results of the meta-analysis showed that in people aged 60 to 69 with a diastolic blood pressure before treatment of 90 mm Hg or a systolic blood pressure of 150 mm Hg, three drugs at half standard dose in combination (as in the polypill) reduced the risk of CHD by approximately 46% and of stroke by 62%. However, when used individually, a single antihypertensive agent at standard dose had about half this effect.
The five main classes of blood-pressure-lowering drugs--thiazides, beta blockers, angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, and calcium-channel blockers--were similarly effective in preventing CHD events and strokes, with the exception of calcium-channel blockers, which had a greater preventive effect on stroke than the other four agents (relative risk, 0.92; 95% confidence interval, 0.85 to 0.98).
People with and without cardiovascular disease derived equal benefit, with similar percentage reductions in CHD events and stroke, and regardless of what their blood pressure was before treatment. Even patients with blood pressures considered to be low--110 mm Hg systolic and 70 mm Hg diastolic--showed fewer CHD events and a reduced incidence of stroke when taking an antihypertensive.
Law and Wald also report that calcium-channel blockers reduced the incidence of heart failure by 19%, and that the other antihypertensive agents reduced heart failure by 24%.
In an accompanying editorial , Dr Richard McManus (University of Birmingham, UK) and Dr Jonathan Mant (University of Cambridge, UK) write that the findings of Law and Wald will contribute to debate on the management of hypertension in several areas. "Taken at face value, these findings provide tacit support for the use of a 'polypill' to lower the risk of cardiovascular disease in people likely to be at high risk (such as all people over the age of 55) without first checking their blood pressure."
In a comment to heartwire , McManus added that he believes that the findings reinforce the view that treatment to lower blood pressure should be offered on the basis of risk, regardless of blood pressure.