All adults would benefit from taking a daily blood pressure pill to reduce their risk of heart attack and stroke, a study has found.
The major review by Oxford University concluded that reducing blood pressure was protective even when it is within what is considered to be the healthy range.
In what is being described as a “paradigm shift”, the review found that one daily dose reduced the risk of serious cardiovascular disease by around 10 per cent. The results were the same regardless of an individual’s blood pressure to start with.
The findings, published in The Lancet, indicate that potentially millions who are not currently eligible could benefit from antihypertensive medications including commonly-prescribed drugs such as Ramipril – sold under the brand name Altace – Amlodipine and various beta blockers.
Around 14 million people in the UK are thought to have high blood pressure, with five million living with the condition undiagnosed, according to the British Heart Foundation. Medical guidelines say only individuals with high blood pressure – above 140/90mmHg – should normally be considered for antihypertensives.
However, the new study of 340,000 people across 48 randomised clinical trials found that the size of an individual’s relative increase or decrease in blood pressure determined their risk of heart attack or stroke rather than the level itself.
The authors have called for the guidelines to be changed so people are not blocked from receiving antihypertensives simply because their blood pressure is not high enough or because they have not previously suffered a cardiovascular event.
Prof Kazem Rahimi, who led the research, told The Telegraph: “Antihypertensive medication is a preventative measure regardless of what your blood pressure is. It is likely that many people are not getting it who need it.”
The authors stopped short of calling for all adults to start taking the pills, saying there would be significant cost implications for the NHS, and the inconvenience may outweigh the benefit for people with a very low risk of cardiovascular disease .
But Prof Rahimi added: “At the population level, if you were to treat everyone you would have an average 10 per cent relative risk reduction. That’s great – but it’s before factoring in other things.”
He said many patients currently prescribed antihypertensives take a combination, often up to three medications a day, meaning the protective effect is significantly greater.
And he added that doctors should disregard an apparently healthy blood pressure when deciding whether to prescribe the drugs and instead assess a patient’s risk of heart attack and stroke using factors such as cholesterol levels, age and evidence of diabetes.
Heart disease and stroke are the leading causes of death in much of the Western world, and it is widely accepted that blood pressure medication protects people who have had a prior event from having a second. However, the use of the drugs in people with normal or only mildly elevated blood pressure has been hotly debated, with studies producing conflicting conclusions.
For the new analysis, the experts pooled data from 157,728 participants with a prior diagnosis of cardiovascular disease, and 186,988 with no such diagnosis. Each group was then divided into seven subgroups based on levels of systolic blood pressure.
After four years’ follow-up, 42,324 participants had at least one major cardiovascular event. But for every 5mmHg reduction in systolic blood pressure, the risk of stroke or heart failure fell 13 per cent, ischaemic heart disease by eight per cent and death from cardiovascular disease by five per cent.
The beneficial effects of the treatment did not differ based on whether the person had previously had cardiovascular disease.
Zeinab Bidel, a co-author and also at Oxford, said: “It is important that people are considered for blood pressure-lowering treatment based on their cardiovascular risk, rather than focusing on blood pressure itself as a qualifying factor for or target of treatment.
Prof Sir Nilesh Samani, the medical director of the British Heart Foundation, who was not involved in the study, said: “The benefits of lowering blood pressure are there whether you have pre-existing heart disease or not, and this study shows that lowering blood pressure – even if it is in the normal range – is associated with fewer heart attacks and strokes.”