Global variations in AF complications substantial
medwireNews: Rates of stroke, heart failure and death vary significantly by global region in patients presenting to emergency departments with atrial fibrillation (AF), study findings indicate.
A considerable proportion of this variation was “unexplained”, suggesting “that factors other than clinical variables might be important”, Jeff Healey (McMaster University, Hamilton, Ontario, Canada) and fellow researchers remark.
Healey and team prospectively enrolled and followed-up 15,361 patients in 47 countries who presented to a hospital emergency department with AF or atrial flutter as a primary or secondary diagnosis.
One year after their initial presentation, 1758 (11%) patients had died. There were significantly more deaths among patients presenting with a secondary diagnosis of AF, at 16%, than among those with a primary AF diagnosis, at 6%.
And there was large variation across the regions, with 20% of patients from Africa dying within 1 year, compared with 17% in South America, 14% in China and 10% in the reference region that comprised North America, western Europe and Australia.
Heart failure was the leading cause of death, accounting for nearly a third of all deaths, and was the leading cause of death in every region except South America and southeast Asia, where infectious causes were slightly more common.
Furthermore, 13% of patients worldwide were admitted to hospital for heart failure within 1 year of their initial visit, with rates ranging from 4% in India to 34% in Africa, and 11% in the reference population.
These findings highlight “the importance of heart-failure prevention and treatment for patients with atrial fibrillation”, say Healey et al.
For stroke, the overall rate was 4% at 1 year, with significantly more cases occurring in patients with a secondary diagnosis of AF compared with those with a primary diagnosis, at 5% versus 3%.
The highest number of strokes occurred in patients in Africa, at 8%, followed by China and southeast Asia, at 7% each. The lowest rate occurred in India (0.8%), while the rate in the reference population was 3%.
The researchers note that patient characteristics, treatments and socioeconomic factors varied between the regions. Adjustment for these factors significantly reduced the magnitude of the variations in mortality and stroke among the regions, but most regional differences persisted, even after adjustment.
“There are opportunities to improve outcomes in most countries by fuller use of proven therapies, such as oral anticoagulation, and pharmacotherapies for hypertension and heart failure”, Healey and co-authors write in The Lancet.
“Prevention of heart failure death should be a major priority in the treatment of patients with atrial fibrillation”, they conclude.
By Laura Cowen
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