Writing in The Lancet journal a group of researchers have published their work looking into the effects of lowering blood pressure, in which they report positive effects in terms of prevention of cardiovascular disease across groups of patients with various levels of disease risk.
Prof. Anna Dominiczak, Regius Professor of Medicine, University of Glasgow, said:
“The paper by Rahimi et al, together with the recently published SPRINT trial (New England J Med 2015; 373:2103-16) both provide a call for action for all clinicians who treat patients with hypertension. There is now evidence that the systolic blood pressure could be safely lowered below 130mmHg with no J-shaped relationship and independent of other co-morbidities. There is also very highly significant reduction of mortality and morbidity for cardiovascular events including coronary heart disease, stroke, heart failure and renal failure.
“In my role of the Editor in Chief of Hypertension, the Journal of American Heart Association, I plan to call for a discussion and debate of the current hypertension guidelines world-wide. The paper by Rahimi et al, will strengthen and greatly facilitate this debate.”
Prof. Peter Weissberg, Medical Director at the British Heart Foundation, said:
“Traditionally, blood pressure is categorised as either high or normal, with current medical guidelines proposing that only people with ‘high’ blood pressure should be offered blood pressure lowering drugs, regardless of their overall risk of heart disease.
“However, these important findings show that the lower your blood pressure is – within reason – the lower your chance of suffering from a cardiac event such as a heart attack or stroke.
“This study calls for a reconsideration of how blood pressure lowering drugs should be used to prevent heart attacks and strokes in patients who are already at high risk. It suggests that more lives could be saved and more heart attacks and strokes prevented if doctors considered using blood pressure lowering drugs in patients at high risk of a cardiovascular event, particularly those with a history of cardiovascular disease, even if their blood pressure is not considered ‘high’.”
Prof. Liam Smeeth, Head of the Department of Non-Communicable Disease, London School of Hygiene & Tropical Medicine, said:
“This study brings together the research on treating blood pressure from over 100 studies. It reaffirms the benefits of controlling blood pressure as a way of preventing strokes and heart attacks in the future. The study adds to the growing body of evidence that there are no thresholds for high blood pressure above which treatment is needed. Benefits of treatment are seen across the whole blood pressure spectrum. This strongly suggests that rather than basing treatment decisions on blood pressure values alone, we should be considering a patient’s overall future risk of vascular disease.
“Blood pressure needs to be managed as one important part of vascular risk, alongside other factors such as age, smoking, weight, physical activity levels, cholesterol, and whether people have conditions such as diabetes. What is completely clear is that people at higher risk of future vascular disease have more to gain from blood pressure lowering. One important caveat is that not everyone will be able to tolerate having their blood pressure reduced to low levels, and there is a need to balance possible drug side effects and likely benefits.”
Dr Tim Chico, Reader in Cardiovascular Medicine / consultant cardiologist, University of Sheffield, said:
“This study analysed data from a large number of previously published studies to attempt to define the benefit of lowering blood pressure in people whose readings would not have previously been considered particularly high. Its findings are consistent with other evidence suggesting that there is a linear relationship between blood pressure and risk of future cardiovascular disease, with no ‘safe’ level. Although very low blood pressure in the context of other disease (such as infection or injury) is dangerous, there are not many people who suffer consequences of having a normally low blood pressure, apart from a tendency to occasional dizziness.
“Patients often ask me what their blood pressure should be. The answer is almost always “lower than it is right now”. Whatever your blood pressure is, your risk of cardiovascular disease would be less if you had a lower blood pressure. Although this study suggests reducing blood pressure by 10mmHg leads to a ‘relative reduction’ in cardiovascular risk of around 20% whoever you are, and whatever your blood pressure is, the impact of this reduction varies a lot depending on what your actual (called ‘absolute’) risk is. For example, if you are already at a low risk, reducing this by 20% isn’t all that important, and probably isn’t either cost-effective or desirable. However, if you are at high risk (such as if you already have cardiovascular disease, diabetes, or smoke) then a 20% reduction in risk makes a big difference and saves a lot of lives.
“Although lowering blood pressure with drugs is generally safe, effective, and clearly reduces cardiovascular risk, often a combination of different tablets is needed. Few people like to take these, especially since they never experience a benefit (since they don’t make you feel better and you never know whether the tablets have prevented you having a heart attack or stroke). This leads to a tendency among both patients and doctors not to start or increase blood pressure medications.
“We can all reduce our blood pressure. We can do this safely, cheaply, and as effectively at tablets by eating healthily, taking more physical activity, reducing alcohol intake, and maintaining a healthy weight.”
Prof. David Webb, Professor of Therapeutics & Clinical Pharmacology, University of Edinburgh, and President, British Pharmacological Society, said:
“This large systematic review and meta-analysis, in over half a million patients, provides strong evidence that blood pressure lowering produces a similar proportionate reduction in cardiovascular risk independent of baseline risk, with those at the highest absolute risk (those with diabetes, chronic kidney disease or a previous cardiovascular event) having the most to gain from treatment.
“This study provides support for lowering systolic blood pressure to less than 130 mmHg, confirming the findings of a paper in the New England Journal of Medicine*, which showed that a lower target blood pressure was associated with reduction in both cardiovascular events and overall mortality. Together these studies argue for a change in guidelines to achieve lower on-treatment blood pressure and save lives.
“The PATHWAY-2 trial led by the British Hypertension Society, and funded by the British Heart Foundation, also published recently in The Lancetǂ, suggests that the addition of spironolactone to the combination of ACE inhibitor/angiotensin receptor blocker, calcium antagonist and diuretic will help reach these tougher blood pressure targets in patients with treatment-resistant hypertension.”
* ‘A randomized trial of intensive versus standard blood-pressure control’ by SPRINT Research Group was published in the New England Journal of Medicine in November 2015 (N Engl J Med. 2015;373:2103-16)
ǂ ‘Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial’ by Williams B, MacDonald TM, Morant S, Webb DJ, Sever P, McInnes G, Ford I, Cruickshank JK, Caulfield MJ, Salsbury J, Mackenzie I, Padmanabhan S, Brown MJ; British Hypertension Society’s PATHWAY Studies Group was published in the Lancet in September 2015 (Lancet. 2015;386:2059-68)
‘Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis’ by Dena Ettehad et al. published in the Lancet on Wednesday 23 December 2015.
Prof. Anna Dominiczak: “I am an immediate past-president of the European Society of Hypertension, a Trustee of the British Heart Foundation and Editor in Chief of Hypertension, Journal of the American Heart Association.”
Prof. Liam Smeeth declares than he has no relevant interests to declare.
Dr Tim Chico: “I am a committee member and Treasurer of the British Atherosclerosis Society, a non-profit-making organisation established in 1999 with the aim of promoting UK atherosclerosis research.”
Prof. David Webb: “In addition to work for University of Edinburgh and the British Pharmacological Society, my research is funded by BHF, MRC and Wellcome Trust. I am also a Non-Executive Director of MHRA. The views expressed are my own.”
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