Intensively lowering blood pressure below currently recommended targets significantly cuts rates of major cardiovascular events among a wide range of high-risk patients, according to researchers.
The analysis involved almost 45,000 individuals. It found more intensive management of high blood pressure achieved an average 7.0mmHg lower systolic blood pressure and reduced risk of heart attacks by about 14% and stroke by roughly a quarter, compared to standard treatment.
“Treating blood pressure to a lower level than currently recommended targets results in better health outcomes for patients”
Study co-author Professor Jicheng Lv, from Peking University First Hospital in China, said: “A key finding was the consistency of findings across major patient groups – those with cardiovascular disease, diabetes, renal disease and also those with just hypertension.”
Based on the findings, which are published today in The Lancet, the study authors have called for revision of current clinical guidelines for patients who are already at high risk of having heart attack or stroke, such as those with CVD, kidney disease, or diabetes.
Lead author Professor Anthony Rodgers, from the George Institute of Global Health in Australia, said: “Several major clinical guidelines on managing high blood pressure, including those of NICE and the European Society of Hypertension, have recently raised blood pressure targets from 130/85mmHg to 140/90mmHg for high-risk patients.
“But our robust evidence clearly shows that treating blood pressure to a lower level than currently recommended targets results in better health outcomes for patients,” he said.
“A key finding was the consistency of findings across major patient groups”
The researchers reviewed all randomised trials comparing different blood pressure targets from 1950 up to the end of October 2015. In particular, they examined the potential benefits and safety of additional blood pressure lowering in high-risk individuals whose systolic blood pressure was under the current target of 140mmHg.
Analysis of 19 trials showed that average systolic blood pressure was 6.8mmHg lower and diastolic blood pressure 4.5mmHg lower – on average 133.2/76.4 mmHg versus 140.4/80.9 mmHg – in patients who received more intensive treatment compared to those given a standard regimen.
As well as the reduced risk of myocardial infarction and stroke, progressive retinopathy was also reduced by about a fifth.
The absolute benefits were greatest in trials in which all patients had vascular disease, kidney disease, or diabetes. Reductions in disease were similar regardless of age or blood pressure before treatment.
“These adverse effects are important but do not outweigh the benefits of lowering blood pressure using intensive treatment in high-risk patients”
Although there were encouraging trends, the researchers acknowledged that more intensive treatment had no clear effect on risk of heart failure, cardiovascular death, end stage kidney disease, or life expectancy.
Blood-pressure lowering treatment was well tolerated, with serious adverse events occurring in similar numbers of individuals in both intensive and standard treatment groups, they added.
However, more intensive treatment almost tripled the risk of hypotension, compared with standard regimens.
Professor Rodgers said: “These adverse effects are important but do not outweigh the benefits of lowering blood pressure using intensive treatment in high-risk patients.”
Christopher Allen, senior cardiac nurse at the British Heart Foundation, said: “High blood pressure is known as a ‘silent killer’ and poor management of the condition can lead to serious complications like heart attack and stroke.
“For most people a blood pressure of less than 140/90mmHg is acceptable, but this large trial suggests that some people at higher risk might benefit from more intensive treatment to bring their blood pressure even lower,” he said.
“If we were able to identify these individuals and treat them appropriately we could potentially save more lives however further analysis is needed if current guidelines are to be reviewed,” he added.