Arianna Sarjoo
One in three patients who experience their first bout of atrial fibrillation (AF) during hospitalization can expect to experience a recurrence of the arrhythmia within the year, new research shows.
The findings, reported today in the Annals of Internal Medicine , suggest these patients may be good candidates for oral anticoagulants to reduce their risk for stroke.
“Atrial fibrillation is very common in patients for the very first time in their life when they’re sick and in the hospital,” said William F. McIntyre, MD, PhD, a cardiologist at McMaster University in Hamilton, Ontario, Canada, who led the study. These new insights into AF management suggest there is a need for primary care physicians to be on the lookout for potential recurrence, he said.
AF is strongly linked to stroke, and patients at greater risk for stroke may be prescribed oral anticoagulants. Although the arrhythmia can be reversed before the patient is discharged from the hospital, risk for recurrence was unclear, McIntyre said.
“We wanted to know if the patient was in atrial fibrillation because of the physiologic stress that they were under, or if they just have the disease called atrial fibrillation, which should usually be followed lifelong by a specialist,” McIntyre said.
McIntyre and colleagues followed 139 patients (mean age, 71 years) at three medical centers in Ontario who experienced new-onset AF during their hospital stay, along with an equal number of patients who had no history of AF and who served as controls. The research team used a Holter monitor to record study participants’ heart rhythm for 14 days to detect incident AF at 1 and 6 months after discharge. They also followed up with periodic phone calls for up to 12 months. Among the study participants, half were admitted for noncardiac surgeries, and the other half were admitted for medical illnesses, including infections and pneumonia. Participants with a prior history of AF were excluded from the analysis.
The primary outcome of the study was an episode of AF that lasted at least 30 seconds on the monitor or one detected during routine care at the 12-month mark.
Patients who experienced AF for the first time in the hospital had roughly a 33% risk for recurrence within a year, nearly sevenfold higher than their age- and sex-matched counterparts who had not had an arrhythmia during their hospital stay (3%; CI, 0% to 6.4%).
“This study has important implications for management of patients who have a first presentation of AF that is concurrent with a reversible physiologic stressor,” the authors write. “An AF recurrence risk of 33.1% at 1 year is neither low enough to conclude that transient new-onset AF in the setting of another illness is benign nor high enough that all such transient new-onset AF can be assumed to be paroxysmal AF. Instead, these results call for risk stratification and follow-up in these patients.”
The researchers reported that among people with recurrent AF in the study, the median total time in arrhythmia was 9 hours. “This far exceeds the cutoff of 6 minutes that was established as being associated with stroke using simulated AF screening in patients with implanted continuous monitors,” they write. “These results suggest that the patients in our study who had AF detected in follow-up are similar to contemporary patients with AF for whom evidence-based therapies, including oral anticoagulation, are warranted.”
McIntyre and his colleagues were able to track outcomes and treatments for the patients in the study. In the group with recurrent AF, one had a stroke, two experienced systemic embolism, three had a heart failure event, six experienced bleeding, and 11 died. In the other group, there was one case of stroke, one of heart failure, four cases involving bleeding, and seven deaths. “The proportion of participants with new-onset AF during their initial hospitalization who were taking oral anticoagulants was 47.1% at 6 months and 49.2% at 12 months. This included 73% of participants with AF detected during follow-up and 39% who did not have AF detected during follow-up,” they note.
We cannot just say, ‘Hey, this is just a reversible illness, and now we can forget about it.’
The uncertain nature of AF recurrence complicates predictions about patients’ post-hospitalization experiences within the following year. “We cannot just say, ‘Hey, this is just a reversible illness, and now we can forget about it,'” McIntyre said. “Nor is the risk of recurrence so strong in the other direction that you can give patients a lifelong diagnosis of atrial fibrillation.”
Role for Primary Care
Without that certainty, physicians cannot refer everyone who experiences new-onset AF to a cardiologist for long-term care. The variability in recurrence rates necessitates a more nuanced and personalized approach. Here, primary care physicians step in, offering tailored care based on their established, long-term patient relationships, McIntyre said.
The study participants already have chronic health conditions that bring them into regular contact with their family physician. This gives primary care physicians a golden opportunity to be on lookout and to recommend care from a cardiologist at the appropriate time if it becomes necessary, he said.
“I have certainly seen cases of recurrent atrial fibrillation in patients who had an episode while hospitalized, and consistent with this study, this is a common clinical occurrence,” said Deepak L. Bhatt, MD, MPH, director of Mount Sinai Heart in New York City. Primary care physicians must remain vigilant and avoid the temptation to attribute AF solely to illness or surgery, Bhatt said.
“Ideally, we would have randomized clinical trial data to guide the decision about whether to use prophylactic anticoagulation,” said Bhatt, who added that a cardiology consultation may also be appropriate.
McIntyre reports no relevant financial relationships. Bhatt reports numerous relationships with industry.
Ann Intern Med. Published online October 2, 2023. Abstract
Arianna Sarjoo is a medical writer in New York City.
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