Cancer increases the risk of atrial fibrillation during long-term follow-up (OPERA study)

INTRODUCTION: Relation between atrial fibrillation (AF) and cancer is known but not very well understood. The purpose of this prospective study was to find out whether subjects with cancer were at greater risk of AF than subjects without cancer. MATERIALS AND METHODS: The study was based on the OPERA (Oulu Project Elucidating Risk of Atherosclerosis) material and had 1045 subjects and the mean follow-up time of 16.3 years. During the follow-up AF and cancer diagnosis were made (atrial flutter included) if these events were listed in the National Death Registry and/or hospital discharge registry. RESULTS: In this study 130 subjects (12%) had cancer and 19% of these had AF, whereas only 9% of those without cancer experienced AF during the follow-up (p<0.001). Subjects in the cancer group had greater probability of developing atrial fibrillation during the follow-up time in comparison to the subjects without cancer (Hazard ratio (HR) 2.47 (95%CI) 1.57–3.88) in multivariate model including relevant confounding factors. CONCLUSION: The main finding of this OPERA study was that cancer is an independent risk factor of atrial fibrillation. Still it remains unclear whether this association is causative or whether cancer and atrial fibrillation just share the same pathophysiologic mechanisms.