Australia will not rush to emulate the US example of moving the goalposts to widen the definition of hypertension, according to Professor Garry Jennings, Chief Medical Advisor of the National Heart Foundation.
While US guidelines have re-defined a BP of 130-139/80-89 mmHg as Stage 1 hypertension, the recently revised NHF guidelines can continue to define this level as ‘high normal’ for the time being, Professor Jennings writes in a commentary published in Heart Lung and Circulation.
In his review of the controversial update to US guidelines based on the SPRINT trial findings, Professor Jennings says a key challenge is how developers of guidelines keep pace with the constant changes in evidence, some of which may be contentious.
Noting that National Heart Foundation guidelines take about three years and enormous resources to develop, he says the findings of the SPRINT trials were made public just after the most recent update.
“The Heart Foundation has not revised its 2016 blood pressure guideline and is sensibly watching the impact of the new ACC/AHA recommendations. When the time comes to review them, the evidence will be different,” he writes.
He acknowledges the SPRINT trial as providing good evidence of the benefits of treating BP to a lower target of 120/80mmHg in selected patient groups, but observes that many clinicians have questioned whether the findings can be generalised to the broad population.
If adopted in Australia, the definitions recommended by the American College of Cardiology would result in half the adult population being defined as having hypertension, and entering the “scary realm of chronic disease”, including impacts on insurance and increased healthcare utilisation
And if 50% of adults are to be defined as having hypertension, this raises the question of whether individual or population approaches are needed to such a widespread chronic disease, he adds.
Many of the people redefined as hypertensive would be younger than seen under current criteria, and this would require new ways of assessing absolute risk. Nevertheless, there may be benefits in intervening to control BP more aggressively at a young age before irreversible vascular damage occurs.
However, Professor Jennings also notes that many subgroups of patients are already recommended for more aggressive control of BP – as recommended in the latest US advice – under current Australian guidelines.