Researchers in Germany have reported that depressed mood tends to be more severe in patients with persistent atrial fibrillation than in patients with paroxysmal atrial fibrillation. The study comparing populations from two large, recent, controlled clinical trials in atrial fibrillation was published ahead-of-print in Europace.
“Evidence suggests that depression is a relevant factor in atrial fibrillation research both as a risk factor for negative health outcomes in atrial fibrillation patients and as a mediator of health related quality of life, which has become an important factor when considering treatment options,” write study authors Alexander F von Eisenhart Rothe (German Research Centre for Environmental Health, Neuherberg, Germany) and others.
The researchers argue that despite the clinical relevance of depression in atrial fibrillation, few studies have investigated its implications, therefore they set out to assess whether depression was more common in persistent or paroxysmal atrial fibrillation patients. They also aimed to identify cases of major depressive disorder in the atrial fibrillation population and to compare these to frequencies shown in population-based studies.
Rothe et al compared data of 310 paroxysmal atrial fibrillation patients taken from the ANTIPAF (Angiotensin II-antagonist in paroxysmal atrial fibrillation) trial with data of 392 persistent atrial fibrillation patients taken from the Flec SL (Targeted pharmacological reversal of electrical remodelling after cardioversion) trial. Both studies were conducted by AFNET (German competence network on atrial fibrillation) and included atrial fibrillation patients in Germany.
Depression was measured by the World Health Organization’s major depression inventory (MDI) scale consisting on 10 items rated on a six-point Likert scale, which classifies patients with mild, moderate or severe depressed mood. The MDI scale was also applied to diagnose major depressive disorder.
The researchers report that in the whole sample 38.8% of patients experienced mild, 19% moderate, and 14.8% severe depressed mood. With regards to diagnosis of frequency of major depressive disorder, 8.4% (n=59) patients were classified with the disorder. Of those, 10.5% were persistent atrial fibrillation patients and 5.8% paroxysmal atrial fibrillation patients. This result was “at first glance slightly counterintuitive, as paroxysmal atrial fibrillation patients tend to be more symptomatic. Hence, atrial fibrillation-related symptoms cannot fully explain depression in persistent atrial fibrillation patients,” write Rothe et al.
“The frequencies of major depressive disorder were alarmingly elevated in comparison with population-based estimates,” highlight the authors. A study by Olsen et al (Acta Psychiatr Scand 2004;109:96–103) estimated a prevalence of 3.3 for major depressive disorder in Denmark. Glaesmer et al (Int Psychogeriatr 2011;23:1–7) calculated a prevalence of 6.6% in Germany. “This study adds to evidence that atrial fibrillation patients have significantly higher rates of depression than expected in general populations,” Rothe et al note.
“Here we report for the first time that depressed mood tends to be more severe in patients with persistent atrial fibrillation than in patients with paroxysmal atrial fibrillation,” write the authors. They comment that so far there is only one study by Dabrowski et al (Kardiol Pol 2010;68:1133–9), which compares depression between paroxysmal, persistent and permanent atrial fibrillation, showing no differences.
“The observed association of persistent atrial fibrillation with depression appears suggestive that the increased duration and regularity of being in arrhythmia is responsible for the association,” Rothe et al note. “In future studies, we aim to analyse the causation of the observed differences in depression risk.”
Andreas Goette, co-author of the study (director of Cardiology and Intensive Care Medicine, St Vincenz Hospital, Paderborn, Germany) told Cardiac Rhythm News: “Duration in atrial fibrillation might be responsible for the observation in the study. We know that atrial fibrillation causes decline of cognitive function, the question is if the irregular rhythm triggers depression in the long-term. This needs to be investigated further.”