Doctors often put patients with atrial fibrillation on stroke prevention regimens, but the risk of heart failure is actually higher in these patients. — 123rf
The lifetime risk of atrial fibrillation has increased from one in four to one in three over the past two decades, reported a study from Denmark published in The BMJ medical journal on April 17 (2024).
And among those with the condition, two in five are likely to develop heart failure over their remaining lifetime and one in five encounter a stroke.
These risks appeared to remain the same over the 23-year study period.
As such, the researchers say stroke and heart failure prevention strategies are needed for people with atrial fibrillation.
This heart condition causes an irregular and often abnormally fast heart rate.
It is estimated to affect 18 million people in Europe by 2060 and 16 million people in the United States by 2050.
In the English National Health Service (NHS) alone, more new cases of atrial fibrillation are diagnosed each year than the four most common causes of cancer combined, and direct expenditure on the condition has reached GBP2.5 billion (RM14.9 billion).
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Risks for common complications
Once atrial fibrillation develops, patient care primarily focuses on the risk of stroke, but other complications, such as heart failure and heart attack, have yet to be fully explored.
To address this knowledge gap, the researchers analysed national data for 3.5 million Danish adults with no history of atrial fibrillation at age 45 or older, to see whether they developed atrial fibrillation from 2000 to 2022.
All 362,721 individuals with a new diagnosis of atrial fibrillation during this time (46% women and 54% men), but with no complications, were subsequently followed until a diagnosis of heart failure, stroke or heart attack.
Potentially influential factors such as a history of high blood pressure, diabetes, high cholesterol, heart failure, chronic lung and kidney disease, family income, and educational attainment, were taken into account.
The results show that the lifetime risk of atrial fibrillation increased from 24% in 2000-10 to 31% in 2011-22.
The increase was larger among men, and individuals with a history of heart failure, heart attack, stroke, diabetes and chronic kidney disease.
Among those with atrial fibrillation, the most common complication was heart failure (lifetime risk of 41%).
This was twice as large as the lifetime risk of any type of stroke (21%) and four times greater than the lifetime risk of heart attack (12%).
Compared with women, men showed a higher lifetime risk of heart failure (44% vs 33%) and heart attack (12% vs 10%) after being diagnosed with atrial fibrillation.
Meanwhile, the lifetime risk of stroke after atrial fibrillation was slightly lower in men than women (21% vs 23%).
Over the study period, there was virtually no improvement in the lifetime risk of heart failure after atrial fibrillation (43% in 2000-10 vs 42% in 2011-22), and only slight (4-5%) decreases in the lifetime risks of any type of stroke, ischaemic stroke and heart attack.
This lack of risk improvement were similar among men and women.
Aligning research and real life
This is an observational study, so no firm conclusions can be drawn about cause and effect, and the authors acknowledge that they may have missed patients with undiagnosed atrial fibrillation.
Nor did they have information on ethnicity or lifestyle factors, and say results may not apply to other countries or settings.
But despite these caveats, they conclude: “Our novel quantification of the long-term downstream consequences of atrial fibrillation highlights the critical need for treatments to further decrease stroke risk, as well as for heart failure prevention strategies among patients with atrial fibrillation.”
Interventions to prevent stroke have dominated atrial fibrillation research and guidelines during this study period, but no evidence suggests that these interventions can prevent incident heart failure, say UK researchers in a linked editorial.
They call for alignment of both randomised clinical trials and guidelines “to better reflect the needs of the real world population with atrial fibrillation” and say this robust observational research “provides novel information that challenges research priorities and guideline design, and raises critical questions for the research and clinical communities about how the growing burden of atrial fibrillation can be stopped”.
