Inter-arm blood pressure difference ‘reduces 10-year CVD survival’

By Lilian Anekwe

GPs should make sure they check for differences in the systolic blood pressure recorded in each arm of hypertensive patients, after a primary care study found patients with differences of more than 10mmHg are at greater risk of CVD events and mortality.

In an analysis of 246 patients at a practice in Devon, researchers measured patients' blood pressure at three successive appointments, and then prospectively recorded new cardiovascular events and deaths.

After 10 years of follow-up researchers found that patients who had a systolic inter-arm difference of more than 10mmHg had their survival of cardiovascular events reduced on average by 5.5 years compared with patients whose inter-arm difference was less than 10mmHg.

The analysis also showed that patients with a systolic inter-arm difference of more than 10mmHg were 2.8 times more likely to have either a cardiovascular event, or to die from heart disease.

There were similar significant differences in cardiovascular events and death in patients who had a systolic inter-arm difference of 12, 15 and 17mmHg. The mean length of cardiovascular event free survival was also significantly reduced in the patients who had a systolic inter-arm difference of 10, 12 and 15mmHg.

Dr Christopher Clark, a GP in Witheridge, Devon and senior clinical fellow at the Peninsula medical school in Exeter, concluded: ‘A systolic inter-arm difference blood pressure difference of more than 10mmHg remains associated with reduced cardiovascular event-free survival over ten years.'

‘This further supports its potential value as a simple clinical indicator of increased cardiovascular risk. Assessment of blood pressure in both arms should become a core component of blood pressure measurement in primary care.'

The research will be presented at the South West Society for Academic Primary Care annual research conference in Oxford next month.