Background:As a result of medical advances, the adult congenital heart disease population is rapidly expanding. Nonetheless, most patients remain prone to increased morbidity and mortality. Therefore, long-term medical resource use is required. This systematic review aims to present the trends over the past decades of medical resource utilization in adult congenital heart disease as well as its current status, with a focus on hospitalizations, emergency department visits, outpatient cardiology visits, and visits to other healthcare professionals.Methods:MEDLINE (Pubmed), Embase, and Web of Science were searched for retrospective database research publications. The ISPOR checklist for retrospective database research was used for quality appraisal. Trends over time are explored.Results:Twenty-one articles met the inclusion criteria. All but one of the studies was conducted in Western Europe and North America. The absolute number of hospitalizations has been increasing over the last several decades. This increase is highest in patients with mild lesions, although these numbers are largely driven by hospitalizations of patients with an atrial septal defect or a patent foramen ovale. Meanwhile, outpatient cardiology visits are increasing at an even higher pace, and occur most often in geriatric patients and patients with severe lesions. Conversely, the number of hospitalizations per 100 patients is decreasing over time. Literature is scarce on other types of healthcare use.Conclusion:A strong rise in healthcare utilization is noticed, despite the mitigating effect of improved efficiency levels. As the population continues to grow, innovative medical management strategies will be required to accommodate its increasing healthcare utilization.