RT Journal Article SR Electronic T1 Comparative thromboembolic risk in atrial fibrillation with and without a secondary precipitant—Danish nationwide cohort study JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e028468 DO 10.1136/bmjopen-2018-028468 VO 9 IS 9 A1 Gundlund, A A1 Kümler, Thomas A1 Bonde, Anders Nissen A1 Butt, Jawad Haider A1 Gislason, Gunnar Hilmar A1 Torp-Pedersen, Christian A1 Køber, Lars A1 Olesen, Jonas Bjerring A1 Fosbøl, Emil Loldrup YR 2019 UL http://bmjopen.bmj.com/content/9/9/e028468.abstract AB Objectives We compared long-term outcomes in patients with atrial fibrillation (AF) with and without a secondary precipitant.Design and setting Retrospective cohort study based on Danish nationwide registries.Participants Patients with AF with and without secondary precipitants (1996–2015) were matched 1:1 according to age, sex, calendar year, CHA2DS2-VASc score and oral anticoagulation therapy (OAC), resulting in a cohort of 39 723 patients with AF with a secondary precipitant and the same number of patients with AF without a secondary precipitant. Secondary precipitants included alcohol intoxication, thyrotoxicosis, myocardial infarction, surgery and infection in conjunction with AF.Primary and secondary outcomes The primary outcome in this study was thromboembolic events. Secondary outcomes included AF rehospitalisation and death. Long-term risks of outcomes were examined by multivariable Cox regression analysis.Results The most common precipitants were infection (55.0%), surgery (13.2%) and myocardial infarction (12.0%). The 5-year absolute risk of thromboembolic events (taking death into account as a competing risk) in patients with AF grouped according to secondary precipitants were 8.3% (alcohol intoxication), 8.5% (thyrotoxicosis), 12.1% (myocardial infarction), 11.6% (surgery), 12.2% (infection), 10.1% (>1 precipitant) and 12.3% (no secondary precipitant). In the multivariable analyses, AF with a secondary precipitant was associated with the same or an even higher thromboembolic risk than AF without a secondary precipitant. One exception was patients with AF and thyrotoxicosis: those not initiated on OAC therapy carried a lower thromboembolic risk the first year of follow-up than matched patients with AF without a secondary precipitant and no OAC therapy.Conclusions In general, AF with a secondary precipitant was associated with the same thromboembolic risk as AF without a secondary precipitant. Consequently, this study highlights the need for more research regarding the long-term management of patients with AF associated with a secondary precipitant.