Individuals with clinical depression could face a more than seven-fold increased risk of atrial fibrillation (AF), especially in the earliest stages of their diagnosis, a population study out of Denmark suggests.
The work, led by Morten Fenger-Grøn, a senior statistician at Aarhus University, and colleagues, assessed the risk of AF in connection with depression in all Danish residents who initiated antidepressant treatment between 2000 and 2013. The researchers said prior studies have highlighted a link between depression, increased symptom burden and increased mortality in AF patients, as well as a link between depressive symptoms and increased risk of AF recurrence after cardioversion.
“Yet studying the relationship between depression and atrial fibrillation is methodologically challenging,” Fenger-Grøn and co-authors wrote in the European Journal of Preventive Cardiology, where they published their findings Nov. 20. “Difficulties in assessing the onset of both conditions could lead to detection bias and reverse causation.
“Additionally, antidepressant medication treatment may constitute an independent risk factor for developing atrial fibrillation since some antidepressants may hold risk of other arrhythmias.”
Fenger-Grøn’s team matched 785,254 Danes diagnosed with depression 1:5 with a control sample from the general Danish population. Patients were considered depressed if they filled their first prescription for antidepressants during the study period.
Considering the risk of AF both before and after initiating treatment—Fenger-Grøn and colleagues evaluated data from a month before treatment since patients were likely depressed, just untreated, at that point—the researchers found patients taking antidepressants had a 3.18-fold higher risk of atrial fibrillation compared to the general population. That risk gradually declined over time, from a 1.37-fold increased risk at two to six months to a 1.11-fold increased risk at six to 12 months.
Patients’ risk of AF was even higher before beginning treatment on antidepressants, the authors found. It was 7.65-fold higher in the month before starting antidepressants and 4.29-fold higher in the 15 days before initiating treatment.
“The present study identifies an association between depression and/or antidepressant treatment and increased risk of AF, but the underlying mechanisms remain unclear,” Fenger-Grøn et al. wrote. “The simplest explanation, that antidepressant medications increase the risk for incident AF, is inconsistent with our finding that the associated risk peaks before antidepressant initiation. Furthermore, this explanation goes against other studies, which conclude that antidepressant use per se is not associated with AF risk.”
They said a plausible explanation for their results, which is supported by an “extensive” body of research suggesting depression is associated with dysregulation in the autonomic nervous system, is that depression simply increases the risk of incident AF. They said other work has established a connection between acute emotional distress or anxiety disorders and an increased risk of arrhythmia, and at least one study has independently linked panic disorder to an elevated risk for atrial fibrillation.
In a release, Fenger-Grøn also said the findings might be attributable to cultural differences, since in Denmark “it is not typical for doctors to prescribe antidepressants at the first appointment.” Either way, he said the takeaway for patients and their providers is that while depression might have something to do with AF, antidepressants themselves don’t.
“The message for patients who already have atrial fibrillation is that you do not need to be concerned about taking antidepressant medication if you need it,” he said. “Look after your mental health, because our study supports existing evidence that problems with the mind can be detrimental for the heart.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.