Conflict of interest: A.B. reports grant support paid to the department from Atrial Fibrillation NETwork (AFNET), German Centre for Cardiovascular Research (DZHK), German Research Foundation (DFG), EU Horizon 2020, Innovationsfond Neue Versorgungsformen, Biotronik, Daiichi Sankyo, Preventicus, Corsano/MMT and Getemed, outside the submitted work. K.W. reports personal fees from Biotronik, Boston Scientific and Novartis, and grant support from German Federal Ministry for Education and Research (BMBF), Atrial Fibrillation NETwork (AFNET), German Centre for Cardiovascular Researcher, EU Horizon 2020, Adrenomed AG and Biotronik, outside the submitted work. K.G.H. reports a study grant by Bayer, lecture fees/advisory board fees from Abbott, Alexion, AMARIN, AstraZeneca, Bayer, Biotronik, Boehringer Ingelheim, Bristol-Myers-Squibb, Daiichi Sankyo, Edwards Lifesciences, Medtronic, Pfizer, Premier Research, SUN Pharma and W. L. Gore & Associates. U.R. receives research support for a basic science project from AMGEN (USA). P.K. receives research support for basic, translational, and clinical research projects from European Union, British Heart Foundation, Leducq Foundation, Medical Research Council (UK), and German Centre for Cardiovascular Research, from several drug and device companies active in atrial fibrillation, and has received honoraria from several such companies in the past but not in the last three years. P.K. is listed as inventor on two patents held by University of Birmingham (Atrial Fibrillation Therapy WO 2015140571, Markers for Atrial Fibrillation WO 2016012783). All other authors have nothing to declare.