Association Between Albumin Level and Mortality Among Cardiac Intensive Care Unit Patients

Abstract

Purpose: To study the effect of hypoalbuminemia on short- and long-term mortality in Cardiac Intensive Care Unit (CICU) patients. Methods: We reviewed 12,418 unique CICU patients from 2007 to 2018. Hypoalbuminemia was defined as an admission albumin level <3.5 g/dL. Predictors of hospital mortality were identified using multivariable logistic regression. Results: We included 2,680 patients (22%) with a measured admission albumin level. The median age was 68 (39% females). Admission diagnoses included acute coronary syndrome, heart failure, cardiac arrest, and cardiogenic shock. The median albumin level was 3.4 g/dL and 55% of patients had hypoalbuminemia. Hospital mortality occurred in 16%, and patients with hypoalbuminemia had higher hospital mortality (21% vs. 9%, adjusted OR 2.64, 95% CI 2.09-3.34, p < 0.001). Albumin level was inversely associated with hospital mortality (adjusted OR 0.60 per 1 g/dL higher albumin level, 95% CI 0.47-0.75, p <0.001), with a stepwise increase in the hospital mortality at lower albumin levels. Post-discharge mortality was higher in hospital survivors with hypoalbuminemia, and increased as a function of lower albumin levels. Conclusion: Hypoalbuminemia is common in CICU patients and associated with higher short- and long-term mortality. Progressively lower serum albumin was incrementally associated with higher hospital and post-discharge mortality.