Comprehensive Long-Term Follow up of Adults with Arterial Switch Operation- European Collaboration for Prospective Outcome Research in Congenital Heart Disease (EPOCH-ASO)-Study Design and Protocols

Background: Long-term outcomes in adults with prior arterial switch operation (ASO) have not yet been well defined. The aim of this study is to elucidate incidence and predictors of adverse cardiac outcomes in a prospectively followed cohort of adults after their ASO. Methods: The comprehensive longterm follow up of adults with ASO is a project within the European collaboration for prospective outcome research in congenital heart disease (EPOCH). It is designed as a prospective, international multicenter cohort study. Consecutive patients (age ≥ 16 years) with prior ASO will be included at 11 European tertiary care centers. Participants will be followed according to a standardized protocol following international recommendations, including standardized protocols for imaging and for exercise testing. Results: Main outcome measures are all-cause and cardiac-related mortality, rate of cardiac re-intervention, neo-aortic dissection, myocardial infarction, stroke, infective endocarditis, sustained atrial and ventricular arrhythmias, new-onset or worsening pulmonary hypertension or heart failure. Secondary endpoints are frequency and progression of right ventricular outflow stenosis, neo-aortic root dilatation, neo-aortic valve regurgitation and ventricular dysfunction. The impact of demographic, anatomic (e.g., coronary artery anatomy) and functional variables on the above-mentioned outcomes, as well as quality of life and incidence of pregnancy related complications will also be assessed. Conclusion: The prospective, international, multicenter EPOCH-ASO study will provide a better understanding of adverse outcomes and their predictors in adults after ASO. The results of the EPOCH-ASO study may help to optimize future care of this novel patient cohort in adult cardiology.