Non-cardiac Cause of Death And Organ Dysfunction Common Among Patients Admitted To The Cardiac Intensive Care Unit

Introduction Over the past decade, there has been an increase in the proportion of patients admitted to the cardiac intensive care unit (CICU) with non-cardiac comorbidities and admission diagnoses. However, organ system dysfunction and causes of death in CICU patients remains poorly characterized. Given the increasing proportion of admissions to the CICU for non-cardiac diagnoses, we hypothesized that there would be a substantial proportion of non-cardiac organ dysfunction and death due to non-cardiac causes. Methods We identified adult patients admitted to a CICU at a large tertiary care center (2015-2019) who died during the hospitalization. Principal hospitalization diagnosis, demographics, organ system dysfunctions, cause of death, and withdrawal of life support were abstracted via a standardized tool used in prior studies. The primary cause of death was defined as the organ system that most directly contributed to death or withdrawal of life support. Results We identified 258 decedents admitted to the CICU. Most patients (76%) had cardiac dysfunction, defined as cardiogenic shock or sustained ventricular arrhythmia. However, only 11% of patients had cardiac dysfunction alone, 89% experienced non-cardiac organ dysfunction, and 24% died without cardiac dysfunction. Multi-organ failure and sepsis were present in 70% and 54% of patients, respectively. The most common primary causes of death were cardiac (58%), pulmonary (15%), and neurologic dysfunction (11%). The majority of patients (76%) died after withdrawal of life-sustaining interventions. Conclusions In this contemporary cohort of CICU decedents, 3 of 4 patients had cardiogenic shock or sustained ventricular arrhythmias. However, non-cardiac organ dysfunction occurred in the vast majority, and nearly half had a non-cardiac primary cause of death. The high frequency of multi-organ failure and non-cardiac causes of death underscores the importance of broad cardiac and non-cardiac critical care training among physicians practicing in the CICU.