Study: Patients Admitted to a CICU Have Diverse Range of Illnesses, Varied Outcomes

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A new study examining the characteristics of patients seen in a cardiac intensive care unit found that the range of acute conditions is diverse, including acute coronary syndrome, heart failure, respiratory insufficiency, and shock, suggesting that optimizing staffing for increased efficiency might be useful.

Cardiac intensive care units (CICU) have to adapt to a changing cardiac care landscape, according to a new study published in Jama Cardiology.

Investigators found that there is a shifting CICU patient demographic. CICUs are seeing a more varied array of cardiovascular conditions. Not only are the cardiovascular conditions becoming more varied, there is also a significant overlap with noncardiac conditions like diabetes. Additionally, investigators found that many of the people admitted to the CICU had a low mortality risk, suggesting that they could be cared for in a lower intensity setting. However, the study notes that the positive outcomes for that group may be because of the expertise provided in the CICU.

The study, which was composed of data collected between September 2017 and September 2018, included an analysis of 3049 patients. Of those patients, 46.9% were directly admitted to an CICU and 36.5% were directly transferred to an CICU from another hospital. Woman made up 37.1% of the sample. People of color made up 31.4% of the sample. The median age was 65 years.


Investigators found that the most common reasons for CICU admission was acute coronary syndrome (31.8%) and heart failure (18.6%). Investigators found that the prevalence of acute coronary syndrome was highly varied. The most common chronic cardiac were ischemic heart disease (41.6%) and heart failure (36.2%). Heart failure was most commonly due to reduced ejection fraction. The most common noncardiac comorbidity was diabetes at 34.8%. A close second was found to be chronic kidney disease at 24.1%.

The primary indications for CICU care included respiratory insufficiency (26.7%), shock (21.1%), unstable arrhythmia (17.1%), and cardiac arrest (8.7%).

Advanced CICU therapies or monitoring were required for a little more than 58% of the patients; the overall CICU mortality rate was 8.3% but varied by site, primary indication, and CICU indication. Stratified by primary admission diagnosis, the highest mortality rate was in patients with cardiac arrest at 45.3%. In addition to cardiac arrest, the indications for CICU-level care that carried the highest mortality rates were shock (cardiogenic, 30.6%; other, 23.8%), the need for renal replacement therapy (34.5%), neurologic emergencies (30.6%), respiratory failure (24.1%), or use of mechanical circulatory support (26.6%; Figure 3B). Patients triaged to be admitted to the CICU solely for postprocedural observation or frequent laboratory testing or monitoring (more than one-third of patients) had very low rates of CICU mortality at 0.2% to 0.4%.

“In a network of academic, tertiary CICUs, respiratory failure and shock are currently the predominate indications for CICU admission,” researchers wrote. “With patient heart failure with an increased need for resources in the CICU. Patterns of practice varied substantially across centers and revealed potential areas for quality improvement.”

Investigators stated that their data is underscores the need for advanced training for those working in CICUs. Investigators found that areas where advanced training were needed coincided with higher mortality rates. For example, for patients with cardiac arrest, the mortality rate was 38%. Mortality rates were also high for patients with cardiogenic shock and respiratory failure, with mortality rates of 31% and 24% respectively.

“While leadership of the CICU was guided historically by research interests and expertise in acute reperfusion therapy, based on observations from the CCCTN registry, the current training of practitioners with a career focus on cardiac critical care should include expertise in acute heart failure management, management of mechanical support, post-cardiac arrest care, electrical storm, and the ability to integrate significant noninvasive cardiovascular imaging data into acute clinical decision making,” investigators wrote.


Bohula E, Katz JN, van Diepen S, et al. Demographics, care patterns, and outcomes of patients admitted to cardiac intensive care units: The Critical Care Cardiology Trials Network prospective North American multicenter registry of cardiac critical illness [published online July 24, 2019]. JAMA Cardiol. doi:10.1001/jamacardio.2019.2467.