One in three patients who experience their first bout of atrial fibrillation (AFib) during hospitalization can expect to experience a recurrence of the arrhythmia within the year, new research shows.
The findings, reported in 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, Hamilton, Ont., who led the study. These new insights into AFib management suggest there is a need for primary care physicians to be on the lookout for potential recurrence.
AFib 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, Dr. 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,” Dr. McIntyre said.
Dr. McIntyre and colleagues followed 139 patients (mean age, 71 years) at three medical centers in Ontario who experienced new-onset AFib during their hospital stay, along with an equal number of patients who had no history of AFib and who served as controls. The research team used a Holter monitor to record study participants’ heart rhythm for 14 days to detect incident AFib 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 AFib were excluded from the analysis.
The primary outcome of the study was an episode of AFib that lasted at least 30 seconds on the monitor or one detected during routine care at the 12-month mark.
Patients who experienced AFib 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%; confidence interval, 0%-6.4%).
“This study has important implications for management of patients who have a first presentation of AFib that is concurrent with a reversible physiologic stressor,” the authors wrote. “An AFib recurrence risk of 33.1% at 1 year is neither low enough to conclude that transient new-onset AFib in the setting of another illness is benign nor high enough that all such transient new-onset AFib can be assumed to be paroxysmal AFib. Instead, these results call for risk stratification and follow-up in these patients.”
The researchers reported that among people with recurrent AFib 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 AFib screening in patients with implanted continuous monitors,” they wrote. “These results suggest that the patients in our study who had AFib detected in follow-up are similar to contemporary patients with AFib for whom evidence-based therapies, including oral anticoagulation, are warranted.”
Dr. McIntyre and colleagues were able to track outcomes and treatments for the patients in the study. In the group with recurrent AFib, 1 had a stroke, 2 experienced systemic embolism, 3 had a heart failure event, 6 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 AFib 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 AFib detected during follow-up and 39% who did not have AFib detected during follow-up,” they wrote.
The uncertain nature of AFib recurrence complicates predictions about patients’ posthospitalization experiences within the following year. “We cannot just say: ‘Hey, this is just a reversible illness, and now we can forget about it,’ ” Dr. 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.”