Prevalence of Non-Cardiac Multimorbidity in Patients Admitted to Two Cardiac Intensive Care Units and Their Association with Mortality.

BACKGROUND Current cardiac intensive care unit (CICU) practice has seen a rise in patient complexity, including an increase in non-cardiac organ failure, critical care therapies, and comorbidities. We sought to describe the changing epidemiology of non-cardiac multimorbidity in the CICU population. METHODS We analyzed consecutive unique patient admissions to two geographically distant tertiary care CICU's (n=16,390). We assessed for the prevalence of 0, 1, 2, and ≥3 non-cardiac comorbidities (diabetes, chronic lung, liver, and kidney disease, cancer, and stroke/transient ischemic attack) and their associations with hospital and post-discharge one-year mortality using multivariable logistic regression. RESULTS The prevalence of 0, 1, 2, and ≥3 non-cardiac comorbidities was 37.7%, 31.4%, 19.9%, and 11.0%, respectively. Increasing non-cardiac comorbidities were associated with a stepwise increase in mortality, length of stay, non-cardiac indications for ICU admission, and increased utilization of critical care therapies. After multivariable adjustment, compared to those without non-cardiac comorbidities, there was an increased hospital mortality for patients with 1 (odds ratio [OR] 1.30; 95% confidence interval [CI]: 1.10-1.54, p=0.002), 2 (OR 1.47; 95% CI: 1.22-1.77, p<0.001), and ≥3 (OR 1.79; 95% CI: 1.44-2.22, p<0.001) non-cardiac comorbidities. Similar trends for each additional non-cardiac comorbidity were seen for post-discharge one-year mortality (p<0.001, all). CONCLUSIONS In two large contemporary CICU populations, we found that non-cardiac multimorbidity was highly prevalent and a strong predictor of short and long-term adverse clinical outcomes. Further study is needed to define the best care pathways for CICU patients with acute cardiac illness complicated by non-cardiac multimorbidity.