In-Hospital Mortality in Children Undergoing Congenital Heart Surgery in North Brazil: A 9-Year Analysis From a Regional Referrel Center

<b>Objective:</b> To analyze in-hospital mortality in children undergoing congenital heart interventions in the only public referral center in Amazonas, North Brazil, between 2014 and 2022. <b>Methods:</b> This retrospective cohort study included 1041 patients undergoing cardiac interventions for congenital heart disease, of whom 135 died during hospitalization. Records were reviewed to obtain demographic, clinical, and surgical data. Descriptive statistics were applied for categorical and continuous variables. <b>Results:</b> In-hospital mortality was 12.96% (135/1041). Most deaths occurred in infants (97/135, 71.8%), and the median survival postsurgery was 1 day. The majority of patients were male (70/135, 51.8%), mixed-race (119/135, 88.2%), and born in Manaus (88/135, 65%). Only 5/135 (3.7%) underwent fetal echocardiography. Extracardiac malformations were present in 76/135 (56.3%), and 123/135 (91%) required mechanical ventilation postoperatively. Blalock-Taussig-Thomas shunt was the most frequent surgery among those who died. The RACHS-1 Category 3 concentrated 51.8% (70/135) of deaths. Temporal trends showed increased mortality after 2016, coinciding with the rise in neonatal and infant surgeries. Surgical complications (81/135, 60%) and hospital-acquired infections (34/135, 25%) were the leading causes of death. Cardiopulmonary bypass was used in 92/135 (68%) of cases, with a mean duration of 84 min. <b>Conclusion:</b> In-hospital mortality following congenital heart surgery in the Brazilian Amazon remains elevated, particularly among infants and in intermediate-risk RACHS-1 categories. These findings suggest that factors beyond surgical complexity-such as late diagnosis, referral delays, and resource limitations-contribute to adverse outcomes. Strengthening early diagnosis, improving perioperative care, and expanding regional surgical capacity are essential to reducing disparities in pediatric cardiac care.