Outcomes and Predictors of Mortality Among Cardiac Intensive Care Unit Patients With Heart Failure

Background: Little is known regarding the causes of critical illness and determinants of prognosis of patients with heart failure (HF) admitted to the modern cardiac intensive care unit (CICU). We sought to describe the epidemiology and outcomes of patients with HF admitted to the contemporary CICU. Methods and Results: Retrospective cohort analysis of Mayo Clinic CICU patients admitted with HF from 2007 to 2018 who had left ventricular ejection fraction (LVEF) data. HF with reduced LVEF (HFrEF) was defined as a LVEF of less than 50%, and HF with preserved LVEF (HFpEF) as a LVEF of 50% or greater. In-hospital mortality was analyzed using multivariable logistic regression. Survival to 1 year was analyzed using a Kaplan–Meier analysis. We included 4012 patients, including 67.8% with HFrEF and 32.2% with HFpEF. Patients with HFrEF and HFpEF were comparable and had equivalent severity of illness. Critical care therapies were used in 59.4%, with a slight preponderance in patients with HFrEF. In-hospital mortality occurred in 12.5% of patients and was similar in HFrEF vs HFpEF. Shock and cardiac arrest were the strongest predictors of adjusted in-hospital mortality, followed by Braden skin score and serum chloride level; patients with HFrEF and HFpEF had similar adjusted mortality rates. The 1-year survival after hospital discharge was 74.5% and was slightly lower for patients with HFpEF. All-cause rehospitalization occurred in 36.6%, and 52.8% of hospital survivors died or were readmitted within 1 year. Conclusions: CICU patients with HF have a substantial burden of critical illness, high use of critical care therapies, and poor outcomes regardless of LVEF. This finding emphasizes the potential unmet care needs in this cohort. Lay summary: Patients with heart failure who require admission to the cardiac intensive care unit have high severity of illness and are at significant risk of death during and after hospitalization. These patients often require specialized critical care therapies to treat manifestations of critical illness. Patients who are admitted with cardiac arrest or shock, including those who require mechanical ventilation or vasopressors, are at particularly high risk of death. Patients’ left ventricular ejection fraction is not strongly associated with the risk of death when accounting for other major predictors including frailty and laboratory abnormalities.