GPs treating patients with high blood pressure should not delay intensifying therapy, new research has suggested.
The study published in the BMJ, scrutinised 10 years’ worth of primary care records for almost 150,000 patients in the UK, concluding that waiting until systolic pressure reached above 150 mmHg led to a progressively worse prognosis, with cardiovascular GP specialists saying the study provided ‘corroborative evidence’ for GPs to follow current guidance.
For example, the risk of a cardiovascular event or death rose by 20% if blood pressure reached 160mmHg before treatment was intensified, compared with upping treatment at 140-150mmHg. Above 170mmHg, the risk was 40% higher and above 180mmHg it reached 70%.
The study also looked at time elapsed before patients had their treatment upped, finding that patients who waited more than around a month and a half after a high reading had progressively worse outcomes than those treated more promptly.
However a majority of the study population (60%) had intensification of their treatment delayed by almost five months or longer, leading to a 20% increased risk of cardiovascular events or deaths. The researchers also found prompt follow-up to intensified treatment was important, with patients waiting more than around three months for a follow up, again, having a progressively worse prognosis.
The report said: ‘Systolic intensification thresholds higher than 150mmHg, delays of greater than 1.4 months before medication intensification after systolic blood pressure elevation, and delays of greater than 2.7 months before blood pressure follow-up after antihypertensive medication intensification were associated with increased risk of an acute cardiovascular event or death.
‘These findings support the importance of timely medical management and follow-up in the treatment of patients with hypertension.’
Writing in a related editorial, professor Jonathan Mant, professor of primary care research at the University of Cambridge, and Professor Richard McManus, professor of primary care at the University of Oxford, said the study highlighted the importance to GPs to follow existing guidance.
They said: ‘For general practitioners, this study provides some corroborative evidence for the treatment thresholds advocated by current guidelines and reinforces the importance of timeliness in establishing a diagnosis of hypertension, intensifying treatment when blood pressure remains above target, and scheduling follow-up after treatment intensification.’
Currently, NICE recommends that GPs confirm a hypertension diagnosis via ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) if a reading is above 140/90mmHg in the clinic, however the guidance adds that if ‘the person has severe hypertension, consider starting antihypertensive drug treatment immediately, without waiting for the results of ABPM or HBPM’.
GPs should aim for a target clinic blood pressure below 140/90mmHg in patients under 80 with treated hypertension and below 150/90 in those aged 80 and over – or below an average ABPM/HBPM reading of 145/85mmHg or 135/85mmHg, respectively.