Young adults in the cardiac intensive care unit: insights from the Critical Care Cardiology Trials Network registry

AIMS: While the aging cardiac intensive care unit (CICU) population has been well studied, young adults represent a distinct and under-explored subgroup. We aimed to characterize the demographics, clinical presentations, resource utilization, and outcomes of young adults admitted to contemporary CICUs. METHODS AND RESULTS: We analyzed consecutive adult CICU admissions from 2018 to 2023 within the Critical Care Cardiology Trials Network (CCCTN), a multicenter registry of advanced CICUs in North America. Patients aged 18 to 39 years were classified as "young adults" and compared with those aged ≥40 years. Among 29,035 CICU admissions, 6.7% (n=1,959) were aged 18-39 years. Young adults were more likely to be female (40.0% vs. 36.4%, p=0.001) and non-white (55.3% vs. 43.0%, p<0.001), with fewer traditional cardiovascular risk factors. Heart failure was the leading admission diagnosis among young adults (26.4% vs. 19.5%, p<0.001). Compared to older adults, young patients were more likely to present with cardiogenic shock (22.4% vs. 18.7%, p<0.001) and cardiac arrest (12.7% vs. 10.6%, p=0.003). Utilization of critical care therapies was higher, including mechanical circulatory support (13.1% vs. 11.4%, p=0.02), with ECMO comprising a greater share (29.3% vs. 9.9%, p<0.001). Young admissions had longer CICU stays (2.7 [1.2-5.8] vs. 2.2 [1.1-4.6] days, p<0.001). CICU mortality (6.5% vs 10.5%, p<0.001) and hospital mortality (9.5% vs 14.4%, p<0.001) were significantly lower in the young. CONCLUSION: Young adults admitted to the CICU represent a clinically distinct population, with higher rates of high acuity presentations and intensive resource use, yet lower short-term mortality.