Young patients in the cardiac intensive care unit: insights from the critical care cardiology trials network registry

Abstract Background Elderly patients treated in the cardiac intensive care unit (CICU) have engendered much warranted investigation. However, little is known about young patients as another distinct population. Purpose: To describe the demographics, clinical profiles, and outcomes of young CICU patients in order to understand any distinct needs and challenges of this population. Methods: We analyzed consecutive admissions to adult CICUs from 2018 to 2023 in the Critical Care Cardiology Trials Network (CCCTN), a multicenter prospective registry of advanced CICUs in North America coordinated by the TIMI Study Group. Patients aged <40 years were classified as "young patients" and compared to patients ≥ 40 years of age. Results: Among 29,035 CICU admissions during the study period, the median age was 67 years (25th, 75th %iles: 56, 70). Admissions 18 to 40 years of age comprised 6.7% (n=1959) of total admissions. The young cohort was more likely to be female (40.0% vs 36.4%, p=0.0015) and non-Caucasian (55.3% vs. 43.0%, p<0.0001). Traditional cardiovascular risk factors were less common among the young, as were prior cardiovascular diagnoses other than congenital heart disease and pulmonary hypertension. Initial SOFA scores and serum lactate levels were similar in the 2 groups (Table). The most common CICU admission diagnoses in the young were heart failure (HF), arrhythmia, and acute coronary syndrome (ACS) (Panel A). Of these, HF was more common in the young (26.4% vs 19.5%, p<0.0001), while arrhythmia (16.8% vs 18.9%, p=0.03) and ACS (10.9% vs 29.4%, p<0.0001) were less common compared to the older group (Panel B). Tamponade, hypertensive emergency, and congenital disease were more common in the young (Panel B). Respiratory insufficiency was the most common indication for admission to CICU in the young (24.6%) followed by cardiogenic shock (22.4%), unstable arrythmia (15.7%), and cardiac arrest (12.7%, Panel C). Critical care resources, other than coronary angiography/PCI, were utilized significantly more often in the young group (Panel D). Overall utilization of mechanical circulatory support (MCS) was modestly higher among the young cohort (13.1% vs. 11.4%, p=0.03, Panel D); however, among those managed with MCS, the % of MCS that was ECMO was higher among the young (29.3% vs 9.9%, p<0.0001). Young admissions had longer CICU stays (2.7 [1.2-5.9] vs 2.3 [1.2-4.9], p<0.0001). CICU mortality (6.5% vs 10.5%, p<0.0001) and hospital mortality (9.5% vs 14.4%, p<0.0001) were significantly lower in the young. Conclusion: Patients under the age of 40 admitted to CICUs presented with similar disease severity to older patients but more often had shock or cardiac arrest, had longer ICU stays, and more use of advanced ICU therapies but with lower in-hospital mortality. This important patient cohort merits continued clinical and research focus.