Background Spontaneous coronary artery dissection (SCAD) is an under-recognized cause of acute coronary syndrome. Data regarding contemporary treatment outcomes remain limited, providing the rationale for the establishment of the SwissSCAD registry. Objectives The primary objective of the SwissSCAD registry, described in this manuscript, is to address contemporary characteristics, management and in-hospital major adverse cardiac events (MACE; defined as a composite of stroke/transient ischemic attack, reinfarction, repeat revascularization and in-hospital death) of patients presenting with SCAD in Switzerland. Methods We performed an investigator initiated, multicentre, retrospective and prospective observational study including patients with non-atherosclerotic SCAD in 8 centres in Switzerland. Institutional ethics approval and patient consents were obtained. We recorded baseline demographics, precipitating/predisposing conditions, angiographic features, as well as in-hospital treatment and MACE. Results From August 2020 to March 2024, 264 patients were enrolled. Mean age was 53.4±10.7 years, 85% were women. Cardiovascular risk factors included hypertension (31%), familial history of myocardial ischaemic disease (31%), hypercholesterolemia (25%), active smoking (23%), and diabetes mellitus (3%). Patients presented with STEMI in 35% and with NST-ACS in 59% of cases. Treatment was conservative in 96% of patients. Percutaneous coronary intervention was performed in 4% of patients, coronary artery bypass grafting was limited to 1 patient. In-hospital MACE occurred in 11% of patients with following distribution: stroke/transient ischemic attack (4%), re-infarction (3%), repeat revascularization (2%), in-hospital death (2%). Dual anti-platelet therapy was prescribed in 55% of patients at discharge. Conclusions Contemporary SCAD patients are treated almost exclusively conservatively. In-hospital MACE rates are sizable, though in-hospital mortality is low.

Sophie Degrauwe reports grants to the institution from Abbott and Biotronik. Marco Roffi reports research grants to the institution from Biotronik, Medtronic, Terumo, Cordis and Boston Scientific. Matthias Bossard reports speaker and consultant fees from Abbott Vascular, Abiomed, Amarin, Amgen, Astra Zeneca, Bayer, Biosensors S.A., Boehringer Ingelheim, Daichii, MedAlliance S.A., Mundipharma, Novartis, NovoNordisk, OM Pharma S.A., Sanofi S.A., SIS Medical and Vifor. Dik Heg is employed by the Department of Clinical Research (DCR), University of Bern, which has a staff policy of not accepting honoraria or consultancy fees. However, DCR is involved in design, conduct, or analysis of clinical studies funded by not-for-profit and for-profit organizations. In particular, pharmaceutical and medical device companies provide direct funding to some of these studies. For an up-to-date list of our conflicts of interest see https://www.ctu.unibe.ch/research_projects/declaration_of_interest/index_eng.html Hans Rickli reports institutional research grants from Biotronik, Medtronic, Cordis and Boston Scientific. Gregor Fahrni, Marion Dupré, Stéphane Cook, Thomas Gillhofer, Christoph Kaiser, Franz Eberli and Daniel Weilenmann report no conflict of interest in connection with the submitted article.

The study was registered at ClinicalTrials.gov (NCT 04457544)

Sophie Degrauwe reports grants to the institution from Abbott and Biotronik. Marco Roffi reports research grants to the institution from Biotronik, Medtronic, Terumo, Cordis and Boston Scientific. Matthias Bossard reports speaker and consultant fees from Abbott Vascular, Abiomed, Amarin, Amgen, Astra Zeneca, Bayer, Biosensors S.A., Boehringer Ingelheim, Daichii, MedAlliance S.A., Mundipharma, Novartis, NovoNordisk, OM Pharma S.A., Sanofi S.A., SIS Medical and Vifor. Dik Heg is employed by the Department of Clinical Research (DCR), University of Bern, which has a staff policy of not accepting honoraria or consultancy fees. However, DCR is involved in design, conduct, or analysis of clinical studies funded by not-for-profit and for-profit organizations. In particular, pharmaceutical and medical device companies provide direct funding to some of these studies. For an up-to-date list of our conflicts of interest see https://www.ctu.unibe.ch/research_projects/declaration_of_interest/index_eng.html Hans Rickli reports institutional research grants from Biotronik, Medtronic, Cordis and Boston Scientific. Gregor Fahrni, Marion Dupré, Stéphane Cook, Thomas Gillhofer, Christoph Kaiser, Franz Eberli and Daniel Weilenmann report no conflict of interest in connection with the submitted article.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The central ethic committee was the Geneva Cantonal Commission on Research Ethics (CCER). The study was approved by the local research ethic committee in each participating centre.

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