Higher mortality among off-hours versus regular-hours admissions to the cardiac intensive care unit (CICU): insights from the critical care cardiology trials network registry (CCCTN)

Abstract

Abstract Funding Acknowledgements None. Background The outcomes of patients admitted to general intensive care units vary significantly according to the time of admission. Whether this applies to the CICU setting is unknown. Purpose We sought to determine if patient characteristics, admission source, critical care therapy utilization, and clinical outcomes differ according to whether CICU admission occurred during regular-hours or off-hours. Methods CCCTN is a multicenter prospective registry of consecutive admissions to CICUs in North America coordinated by the TIMI Study Group. For this analysis of admissions during calendar year 2022, "regular-hours" was defined as 7 a.m.- 7 p.m. Monday-Friday, and "off-hours" was defined as 7 p.m.- 7 a.m. on weekdays or at any time on Saturday or Sunday. Logistic regression analysis was used to adjust in-hospital mortality rates for admission time (on-hours vs. off-hours), age, sex, SOFA score, and cardiac arrest. Results Among 5238 CICU admissions, 2956 (56.4%) occurred during off-hours. Patient demographics (mean age: 67.0 years, 35.7% female, 51.1% white) and comorbidities were generally similar among off-hours and regular-hours admissions. The median SOFA score was 3.0 in both groups. Compared to regular-hours admissions, off-hours admissions were more likely to originate from the ED (39.9% vs. 29.4%, p<0.0001) and less likely to originate from a procedural area (24.5% vs. 41.8%, p<0.0001). ST-elevation MI was a more common admission diagnosis among off-hours vs. regular-hours admissions (19.2% vs. 16.4%, p=0.009). Primary CICU indications of respiratory insufficiency, unstable arrhythmia, cardiac arrest, and distributive/mixed shock were more common among off-hours admissions (Table). Mechanical ventilation, IV vasoactive therapy, and targeted temperature management (TTM) were utilized more frequently among patients admitted during off-hours. Median ICU (2.5 vs. 2.0d) and hospital length of stay (6.2 vs. 5.8d) were longer for off-hours admissions (both p<0.0001). Crude CICU mortality (11.4% vs. 8.5%, p=0.0005) and in-hospital mortality (15.6% vs. 11.7%, p<0.0001) were significantly higher among off-hours admissions (Figure). After adjustment, off-hours admission remained significantly associated with higher in-hospital mortality (OR 1.2, 95% CI 1.02 – 1.49, p=0.03). Conclusions Off-hours and regular-hours admissions to the CICU had similar baseline characteristics but differed significantly regarding source of admission, indication for admission, and utilization of critical care therapies. These differences were associated with worse clinical outcomes among off-hours admissions, which may suggest the need for more intensive staffing in CICUs during these times.FigureTable