Clinical management

Night-time blood pressure assessment

• Home blood-pressure monitoring (HBPM) is often preferred to Ambulatory blood-pressure monitoring (ABPM) but misses night-time blood pressure (BP). Patients whose night-time BP does not dip or rises have poorer cardiovascular outcomes.

• A retrospective cohort study aimed to investigate the importance of measuring night-time BP when assessing for hypertension.  The two study populations were:

  • A 'hospital cohort' - patients admitted to 4 Oxfordshire hospitals

  • The 'BP-Eth cohort' - participants in the 'Blood Pressure in different Ethnic groups' study

• Systolic BP was higher at night compared to the daytime in 48.9% in the hospital cohort and 10.8% of the BP-Eth cohort, leaving them at risk of undiagnosed hypertension.

• GPs should consider offering ABPM to all patients aged ≥60 years as a minimum when assessing for hypertension.

WiseGP Actions:

• If your practice doesn’t offer ABPM, explore opportunities to acquire an appropriate monitor, possibly across your PCN. Discuss with your practice-based pharmacist if they could lead a quality improvement project, to introduce and review the impact of ABPM rather than HBPM for patients aged ≥60 years to assess for hypertension.

Read more about the research informing this GEM here:

bjgp.org

Background Ambulatory blood-pressure monitoring (ABPM) has become less frequent in primary care since the COVID-19 pandemic, with home blood-pressure monitoring (HBPM) often the preferred alternative; however, HBPM cannot measure night-time blood pressure (BP), and patients whose night-time BP does not dip, or rises (reverse dipping), have poorer cardiovascular outcomes. Aim To investigate the importance of measuring night-time BP when assessing individuals for hypertension. Design and setting Retrospective cohort study of two patient populations — namely, hospital patients admitted to four UK acute hospitals located in Oxfordshire, and participants of the BP in different ethnic groups (BP-Eth) study, who were recruited from 28 UK general practices in the West Midlands. Method Using BP data collected for the two cohorts, three systolic BP phenotypes (dipper, non-dipper, and reverse dipper) were studied. Results Among the hospital cohort, 48.9% ( n = 10 610/21 716) patients were ‘reverse dippers’, with an average day–night systolic BP difference of +8.0 mmHg. Among the community (BP-Eth) cohort, 10.8% ( n = 63/585) of patients were reverse dippers, with an average day–night systolic BP difference of +8.5 mmHg. Non-dipper and reverse-dipper phenotypes both had lower daytime systolic BP and higher night-time systolic BP than the dipper phenotype. Average daytime systolic BP was lowest in the reverse-dipping phenotype (this was 6.5 mmHg and 6.8 mmHg lower than for the dipper phenotype in the hospital and community cohorts, respectively), thereby placing them at risk of undiagnosed, or masked, hypertension. Conclusion Not measuring night-time BP puts all groups, other than dippers, at risk of failure to identify hypertension. As a result of this study, it is recommended that GPs should offer ABPM to all patients aged ≥60 years as a minimum when assessing for hypertension.

Measure BP in both arms and use the higher arm reading for diagnosis and management

• Guidelines recommend measuring blood pressure (BP) in both arms, adopting the higher arm readings for diagnosis and management, but data to support this recommendation has been lacking.

• Data was analysed from over 53,000 people who participated in the Inter-arm Blood Pressure Difference-Individual Participant Data Collaboration.

• When BP readings were used from the arm with a higher reading, instead of the lower reading, 12% of participants who had previously been classed as normotensive, moved over the threshold for diagnosis of hypertension. Prediction models for cardiovascular disease performed better when using the arm with a higher BP reading.

• BP in both arms should be measured for accurate diagnosis and management of hypertension.

WiseGP Actions:

• Prior to ambulatory BP monitoring do patients at your practice have their BP measured in both arms, with the higher arm chosen for monitoring?

• If your practice relies on HBPM, do your instructions to patients include to measure their BP using the higher BP arm measurement?

Read more here:

https://pubmed.ncbi.nlm.nih.gov/35916147/