Predicting 1-Year Mortality on Admission Using the Mayo Cardiac Intensive Care Unit Admission Risk Score

Abstract

Objective

To determine whether the Mayo Cardiac Intensive Care Unit (CICU) Admission Risk Score (M-CARS) accurately predicts 1-year mortality.

Methods

We retrospectively reviewed adult CICU patients admitted from January 1, 2007, through April 30, 2018, and calculated M-CARS using admission data. We examined the association between admission M-CARS, as continuous and categorical variables, and 1-year mortality.

Results

This study included 12,428 unique patients with a mean age of 67.6±15.2 years (4686 [37.7%] female). A total of 2839 patients (22.8%) died within 1 year of admission, including 1149 (9.2%) hospital deaths and 1690 (15.0%) of the 11,279 hospital survivors. The 1-year survival decreased incrementally as a function of increasing M-CARS (P<.001), and all components of M-CARS were significant predictors of 1-year mortality (P<.001). The 1-year survival among hospital survivors decreased incrementally as a function of increasing M-CARS for scores below 3 (all P<.001); however, there was no further decrease in 1-year survival for hospital survivors with M-CARS of 3 or more (P=.99). The M-CARS components associated with 1-year mortality among hospital survivors included blood urea nitrogen, red blood cell distribution width, Braden skin score, and respiratory failure (all P<.001).

Conclusion

M-CARS predicted 1-year mortality among CICU admissions, with a plateau effect at high M-CARS of 3 or more for hospital survivors. Significant added predictors of 1-year mortality among hospital survivors included markers of frailty and chronic illness.