Epidemiology and Outcomes of Patients with Adult Congenital Heart Disease in Queensland Intensive Care Units: A Multicentre Retrospective Observational Study

Abstract

To describe the epidemiology, clinical characteristics, and outcomes of adult congenital heart disease (ACHD) patients admitted to intensive care units (ICUs) across Queensland, Australia. A multicenter, retrospective cohort study. Twelve adult ICUs across Queensland, including tertiary referral and regional centers, from January 1, 2015, to December 31, 2021. Adults (≥18 years) with ACHD. No interventions. ACHD cases were stratified by lesion complexity and admission type (medical vs surgical). Outcomes included ICU and hospital length of stay and 30-day and 1-year mortality. Of 89,184 ICU admissions, 1,870 (2.1%) involved ACHD. The most common diagnoses were valvular (57.9%) and septal (31.0%) malformations. Lesion complexity was classified as simple (1,543/1,870; 82.5%), moderate (220/1,870; 11.8%), and complex (60/1,870; 3.2%). Medical patients (253/1,870; 13.5%) had greater illness severity, more frequent use of renal replacement therapy and ECMO, and longer ICU (3 [2-6] v 2 [2-6] days; p < 0.001) and hospital length of stay: 18 [10-33] v 8 [6-13] days; p < 0.001) when compared to surgical patients. Mortality was significantly higher in medical admissions (30 day: 34/253: 13.4%; 1 year: 50/253: 19.8%) than in surgical (30 day: 20/1,617: 1.2%; 1 year: 42/1617: 2.6%; p < 0.001). One-year mortality was also higher in patients with complex lesions (11/60; 18.3%) versus simple (67/1,543; 4.3%). ACHD patients are an uncommon but important ICU population. Outcomes vary significantly by admission type and lesion complexity. Emergency and medical admissions are associated with disproportionately high mortality compared to elective surgical admissions and should prompt early escalation of care.