Abstract 301: Differential Outcomes for Geriatric Patients in Cardiac Intensive Care Unit Compared to Medical Intensive Care Unit

Abstract

Background: The number of older adults admitted to cardiac intensive care units (CICU) have been increasing over the past decade, but it is not known if outcomes vary between CICU and medical intensive care units (MICU). We aimed to describe survival and length of stay (LOS) in older adults admitted to CICU and MICU. Methods: All patients admitted to the CICU or MICU at Beth Israel Deaconess Medical Center from 2001-2012 were identified from MIMIC-III, a large single-center critical care database containing deidentified clinical data for 38,597 patients. Our primary outcomes were ICU mortality and ICU LOS. Regression analyses were performed adjusting for age, gender, ICU setting and Oxford Acute Severity of Illness Score (OASIS), a severity score developed and validated in critically ill patients for ICU mortality. Results: We included 21,088 MICU patients (48.3% female) and 7,726 CICU patients (42% female). Unadjusted mortality was 13.7% in MICU and 12.5% in CICU (p=0.11). When adjusted for age, gender and OASIS, there was no difference in mortality between MICU and CICU (OR 0.62, 95% CI 0.34-1.13, p=0.15). However, we found a significant interaction between older age and type of ICU with mortality (p=0.03) but not with ICU LOS (p=0.15). In patients >75 years (6,837 in MICU and 3,161 in CICU), each 5-year interval of older age was associated with higher mortality when adjusted for gender and OASIS in the CICU (OR 1.05, 95% CI 1.02-1.08 p=0.002), but not in the MICU (OR 1.01, 95% CI 0.99-1.03, p=0.15, Figure). Conclusion: Older adults admitted to the CICU had higher adjusted mortality by age group after age 75, as opposed to older MICU patients in whom mortality was high but remained unchanged after age 75.