How a simple blood test could decrease risk of stroke and heart attack – Australia’s largest study of a common yet underdiagnosed cause of high blood pressure is now underway at Hudson Institute to help prevent heart attack and stroke.
Almost six million Australian adults have high blood pressure, or hypertension, which remains the leading risk factor for heart disease and can lead to a heart attack, stroke or kidney disease.
For between 5 and 15 per cent of patients, the underlying cause is primary aldosteronism (PA) – a potentially curable form of high blood pressure resulting from overproduction of the hormone aldosterone from the adrenal glands. Crucially, many patients aren’t even aware they have this little known condition.
“Primary aldosteronism often doesn’t have specific symptoms other than high blood pressure, so it’s easy to miss,” Dr Jun Yang, an endocrinology clinician-researcher and lead investigator says.
“An estimated 1 in 10 people with high blood pressure have PA, but only 1 in 200 are diagnosed because many doctors do not screen for it. As a result, many patients with undiagnosed PA are taking blood pressure medications that won’t help.”
The lack of awareness around PA can be life-threatening. Hudson Institute group head, Dr Morag Young showed that aldosterone is more harmful to the heart and blood vessels than just high blood pressure alone. If left undiagnosed, the condition can get worse over time, leaving sufferers more prone to stroke and heart attack at a younger age.
GP referral clinic
In 2016, Dr Yang and Professor Peter Fuller, Hudson Institute Centre Head, established the Endocrine Hypertension Service at Monash Health, where GPs and specialists can refer patients with suspected PA for early diagnosis and targeted treatment to prevent permanent damage.
The clinic was established after Dr Yang streamlined the complex diagnostic tests for PA, leading to a dramatic rise in detection at Monash Health, from three patients per year in 2011 to more than 60 in 2017.
The next phase is a research study asking GPs to screen hypertensive patients using a simple blood test to find out exactly how common PA is in the community.
“If this simple screening process is found to be cost-effective, it will inform new management guidelines so that more patients with hypertension can benefit from the early detection, treatment and cure of PA,” Dr Yang says.
For nearly eight years, David Dent experienced routine dizzy spells, but he dismissed them as being nothing out of the ordinary.
A friend suggested that David get his blood pressure checked. The advice was timely and ultimately life-saving because David’s blood pressure was dangerously high.
Referred to Dr Yang and the Monash Health service by his GP, David underwent adrenal vein sampling, showing he had PA caused by a tumour in his left adrenal gland. The tumour produced high levels of aldosterone, leading to very high blood pressure.
Within four weeks of diagnosis, David underwent surgery to have the benign tumour removed. Now, eight months on, his life – and his blood pressure – are returning to normal. He now takes just one instead of eight blood pressure tablets per day.
“I don’t take nearly as much medication as I used to. I’ll be glad to be off it.”
“Dr Yang has just been amazing. I’m coming good and my blood pressure’s coming back down to normal,” David says.
Dr Maree Bilandzic