Acute Noncardiovascular Illness in the Cardiac Intensive Care Unit

Background: Fifty years after the inception of the cardiac intensive care unit (CICU), noncardiovascular illnesses have become more prevalent and may contribute to morbidity and mortality.

Objectives: The authors performed multivariate statistical analyses to determine the association of acute noncardiovascular illnesses with outcomes, including length of stay (LOS), mortality, and hospital readmission.

Methods: We studied 1,042 admissions between October 12, 2013 and November 28, 2014 to the CICU at the University of Virginia Health System, a tertiary-care academic medical center. Through systematic inspection of individual charts, we identified primary and secondary diagnoses, vital sign measurements, length of stay (LOS), hospital readmissions, and mortality.

Results: The most common primary diagnosis was acute coronary syndrome (25%), which consisted of both non-ST-segment elevation acute coronary syndrome (14%) and ST-segment elevation myocardial infarction (11%). Sepsis was the most frequent noncardiovascular primary diagnosis (5%), but it only occurred in 16% of all admissions. Acute kidney injury and acute respiratory failure each occurred in 30% of admissions. One-half of all admissions (n = 524; 50%) were marked by acute respiratory failure, acute kidney injury, or sepsis. Median LOS in the CICU and the hospital were 2 days (interquartile range [IQR]: 1 to 5 days) and 6 days (IQR: 3 to 11 days). Mortality was 7% in the CICU and 12% in the hospital. Of the 920 patients who survived to hospital discharge, 171 (19%) were readmitted within 30 days. Sepsis, acute kidney injury, and acute respiratory failure were associated with mortality. Acute kidney injury, acute respiratory failure, and new-onset subclinical atrial fibrillation, which occurred in 8% of admissions, were all associated with CICU LOS.

Conclusions: Many patients in the modern CICU have acute noncardiovascular illnesses that are associated with mortality and increased LOS.