New Heart Failure After AF Diagnosis Merits More Attention

After an atrial fibrillation (AF) diagnosis, roughly two out of every five patients will develop heart failure, making it a much more frequent complication than stroke, according to a nationwide study from Denmark.

Moreover, the burden of heart failure in the AF population has remained constant over the past two decades while lifetime risks of stroke have slightly declined during the direct oral anticoagulant (DOAC) era, Nicklas Vinter, MD, PhD (Aalborg University, Denmark), and colleagues report in a study published online in the BMJ this week.

Patients with AF “are often told that the main risk is stroke after the diagnosis, but A-fib is also associated with other complications—for instance, heart failure or myocardial infarction,” Vinter told TCTMD, noting that his team conducted the study to better understand the long-term risks of those complications and how they might have changed over time.

He said the study could not capture the severity of heart failure, stroke, or other complications, so future research would be required to delve into the clinical impacts, but added that it’s known that patients who have a double diagnosis of heart failure and AF have a very high risk of mortality. “So I think this study underlines . . . that we need to focus even more on the prevention of heart failure, but still we need to improve prevention of stroke as well,” Vinter said, pointing out that the lifetime risk of stroke is still around 20%.

I hope the future guidelines will focus more on heart failure. Nicklas Vinter

Commenting for TCTMD, Renate Schnabel, MD (Universitätsklinikum Hamburg-Eppendorf, Germany), said a novel aspect of the study is that lifetime risks of AF and its complications can be compared between two time periods. The slight decline in stroke may be related to the introduction of DOACs, which have made protection against thromboembolism easier and safer compared with use of vitamin K antagonists, or to greater awareness of the need to treat AF to prevent stroke, she proposed.

The fact that the lifetime risk of heart failure was around 40% and didn’t change over the two time periods is important to know, Schnabel added. That “really tells us something about the disease burden in the population,” she said. “It’s important for health economics and that’s important for the healthcare system. And we now, with this study, have really very current data that can inform [not only] the healthcare system but also better communication among healthcare professionals and individuals at risk of atrial fibrillation.”

Lifetime Risk of AF Rises

For the study, the investigators examined data from Danish national registries spanning 2000 to 2022. The first part of the analysis included more than 3.5 million individuals ages 45 to 95 (median age 48 years; 51.7% women) who did not have AF at baseline. During the entire study period, the lifetime risk of AF was 27.7% overall, with greater risks observed in men and those with higher educational attainment, higher family income, hypertension, heart failure, MI, cardiomyopathy, dyslipidemia, and valvular heart disease.

Splitting the study period into two parts, Vinter et al found that the lifetime risk of AF increased from 24.2% in 2000-2010 to 30.9% in 2011-2022, consistent with prior research. Possible contributors to the rise are improved detection of AF, increased life expectancy, better survival after MI and heart failure, and growing prevalence of key risk factors like hypertension, dyslipidemia, and diabetes, according to the authors.

The second part of the analysis focused on the 362,721 patients (median age 76 years; 46.4% women) who developed AF during the study period and did not have complications at the time of diagnosis; they were followed for incident heart failure, stroke, or MI.

The most frequent complication was heart failure, with a lifetime risk of 41.2%; there was no significant change from the first to the second half of the study period. That lifetime risk was greater than what was observed for any stroke (21%), ischemic stroke (13%), and MI (12%).

In contrast to what was seen with heart failure, however, lifetime risks declined for the other complications between the first and second halves of the study period—by 5.2% for ischemic stroke, 3.9% for MI, and 2.5% for any stroke. These changes were similar in men and women.

Contributing to the slight decline in stroke risk, Vinter et al say, could be the incorporation of evidence regarding better treatments into AF guidelines over the past few decades or the influence of having more lower-risk patients with AF due to enhanced awareness and earlier detection of the arrhythmia.

Important to consider when interpreting the findings, according to senior author Ludovic Trinquart, PhD (Tufts Medical Center, Boston, MA), is that Denmark, in contrast to some other parts of the world, including the United States, has very high rates of both anticoagulation initiation and adherence among patients newly diagnosed with AF. The lifetime risk of stroke “decreased, but only by less than 3 percentage points,” he stressed. “So I think it highlights that there are still opportunities to improve stroke prevention.”

Expanding the Focus Beyond Stroke

Trinquart said these findings could be used to inform future changes to AF guidelines, which currently focus on stroke prevention and management. “There is an opportunity to improve recommendations for management focusing beyond stroke risk management, and there is also probably a need to evaluate interventions and therapies focusing on heart failure prevention,” he told TCTMD.

Vinter agreed, saying, “I hope the future guidelines will focus more on heart failure.”

Asked whether heart failure risk after an AF diagnosis is getting the appropriate attention, Schnabel said, “probably not yet,” adding that the high risk of stroke is easier for patients to understand and that “everybody fears debilitating stroke.” Moreover, she said, DOACs provide a good treatment option for reducing that risk.

On the other hand, “it’s more difficult, I think, in communication and understanding for heart failure, although we certainly know that heart failure is the most common cause of death in atrial fibrillation patients,” Schnabel said. “This is known also to healthcare professionals, but it’s probably the emotionality that is behind stroke that really puts it into the foreground.”

It’s probably the emotionality that is behind stroke that really puts it into the foreground. Renate Schnabel

Schnabel noted that rhythm-control therapies, like catheter ablation, have been shown to improve outcomes for patients AF and heart failure, including those with advanced disease, and that novel heart failure therapies like sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to be beneficial as well. “But this is rather new and has come to the patient over the last 5 to 10 years, and maybe it will take some more time for the effects to develop, so that maybe in the future we see a lower risk of incident heart failure,” she said. “But still, with the high comorbidity burden, I think heart failure will be a major outcome that we need to prevent in atrial fibrillation patients.”

More broadly, however, this study “is also a call to action to address known risk factors, identify new risk factors for atrial fibrillation, and detect the disease earlier,” Schnabel said. “And this means that we should take atrial fibrillation prevention, detection, and treatment very seriously because it poses a significant burden” around the world.

In an accompanying editorial, Jianhua Wu, PhD (Wolfson Institute of Population Health, Queen Mary University of London, England), and Ramesh Nadarajah, MB BChir, PhD (University of Leeds, England), also argue for expanding the scope of AF management.

“Interventions to prevent stroke have dominated atrial fibrillation research and guidelines during the study period in Vinter and colleagues’ analysis, but no evidence suggests that these interventions can prevent incident heart failure,” they write. “Alignment of both randomized clinical trials and guidelines to better reflect the needs of the real-world population with atrial fibrillation is necessary because further improvements to patient prognosis are likely to require a broader perspective on atrial fibrillation management beyond prevention of stroke.”