Many over-40s living with undiagnosed AF time bomb
28th Nov 2011
Catherine Hanrahan all articles by this author
AT LEAST 50,000 Australians aged 40 years or more may have atrial fibrillation without knowing it
AT LEAST 50,000 Australians aged 40 years or more may have atrial fibrillation (AF) without knowing it, new data suggest.
The incidence of undiagnosed AF in the community could be as high as one in 200 in this age group, the annual scientific meeting of the Australasian College for Emergency Medicine was told in Sydney last week.
With Australian Bureau of Statistics data showing more than 10 million Australians are aged 40 or older, around 50,000 may have AF based on this estimate.
Professor Ben Freedman, professor of cardiology at Concord Hospital and deputy dean of the Sydney Medical School, told the meeting his study of more than 1000 pre-admission ECGs in over-40s patients showed 3.1% were in AF.
Of those, 0.5% were cases of incidental, unrecognised AF not associated with symptoms or elevated resting heart rate.
“This means there’s a lot of people out there who have AF who don’t know about it,” Professor Freedman told MO.
Asymptomatic AF episodes were more common than symptomatic episodes, and silent AF led to stroke.
“The first time many stroke patients knew they had AF was when they presented with stroke, and stroke is a very poor warning symptom of AF,” he said.
The study showed only half of the patients with known AF and a CHADS2 score of two or more were taking warfarin.
The CHADS2 score is calculated using history of congestive heart failure, hypertension, diabetes, stroke symptoms and age.
Professor Freedman said doctors were not anticoagulating on the basis of stroke risk, and an appreciable asymptomatic group may benefit from recognition and thromboprophylaxis to reduce future stroke.
“I think there’s been an increase in the last 2–3 years in the use of risk calculators, and it’s partly because of the realisation that there are other drugs now that could be used for anticoagulation,” Professor Freedman said.
“But there still is an evidence practice gap, and I think we still need to close it if we are serious about preventing stroke.”
The new anticoagulants may assist in closing this gap, he said.
Tags: atrial fibrillation, stroke, undiagnosed, asymptomatic, CHADS2
