Management of high blood pressure is crucial, to forestall end organ damage, disability, and death and to reduce societal costs from cardiovascular disease, including stroke. Good management of high blood pressure is particularly important in general practice, where most patient care occurs. Recent clinical practice guidelines recommend that treatment aims to reduce blood pressure, aiming for specific targets, but the best way to use targets is not at all clear. This study, led by Professor Jonathan Mant at the Primary Care Unit with colleagues from Oxford and Birmingham, set out to determine whether setting targets in primary care would lead to lower blood pressure and compared two targets – one more intensive than the other.
The study, called PAST_BP, compared two groups of patients recruited from the ‘stroke registers’ of 106 general practices, who were randomly allocated to either an intensive blood pressure target or a standard target. Apart from the different blood pressure targets, the management of blood pressure was the same in both groups and was carried out by a practice nurse (to monitor blood pressure) and a general practitioner (responsible for modifying blood pressure treatment). General practitioners were provided with treatment protocols that reflected the national guidelines for blood pressure lowering in operation at the time of the trial.
The researchers found that the treatment for the intensive target group did deliver lower blood pressure in patients, compared with results for the standard group. But the difference was small (about 3 mm Hg) and was associated with increased workload for general practices (one extra consultation a year each for general practitioners and nurses). The intensive target group treatment was not associated with more side effects but more changes to treatment occurred because of side effects during the trial. More people from the intensive target group withdrew consent for the trial, and this might have reflected unwillingness to persevere with the increased treatment regimen. Perhaps the most important finding was the substantial reduction (greater than 10 mm Hg) in blood pressure in both study groups. More than 80% of participants in each group had achieved a blood pressure of below 140 mm Hg by the end of the trial, compared with less than 50% at the start. The study indicates that active management of blood pressure after stroke/transient ischaemic attack is more important than the target that is set.
Read the BMJ paper, ‘Different systolic blood pressure targets for people with history of stroke or transient ischaemic attack: PAST-BP (Prevention After Stroke—Blood Pressure) randomised controlled trial’, 25th Feb 2016
See the BMJ Editorial ‘Blood pressure targets in primary care’, 25th Feb 2016