Abstract 417: The Prognostic Value of Lactate in Cardiac Intensive Care Unit Patients With and Without Cardiac Arrest

Abstract

Introduction: Lactate is a known prognostic marker in critically ill patients, including patients with shock and cardiac arrest (CA). We sought to describe the association between admission lactate and hospital mortality in cardiac intensive care unit (CICU) patients, particularly those with CA. Methods: We retrospectively evaluated adult patients admitted to a tertiary care CICU from January 1, 2007, to April 30, 2018, with measured lactate on admission. We examined hospital mortality as a function of admission lactate level in patients with and without CA. Multivariable logistic regression was used to determine predictors of hospital mortality in the overall cohort, after adjustment for clinical characteristics, therapies, and illness severity. Results: We included 3,042 patients with a median age of 70 years (IQR 60-80), including 40.5% (n=1,233) females. There were 789 patients (26.1%) with a diagnosis of CA. The median APACHE-4 predicted mortality was 24.2% (IQR 10.9-50.7), and 50.8% (n=1546) were treated with vasoactive infusions. The median lactate on admission was 1.8 mmol/L (IQR 1.1-3.0). CICU mortality occurred in 478 (15.7%) patients) and hospital mortality occurred in 706 (23.2%) patients. Hospital mortality rose progressively as a function of admission lactate ( Figure ). On univariable analysis, lactate was associated with increased hospital mortality among the overall cohort (OR 1.36, CI 1.31-1.42, P < .001; AUROC 0.71), patients with CA (OR 1.33 (95% CI 1.25-1.41, P < .01; AUROC 0.73), and patients without CA (OR 1.27, CI 1.21-1.34, P < .01; AUROC 0.64). On multivariable analysis, lactate was one of the most significant predictors of hospital mortality (adjusted OR 1.13 per mmol/L, 95% CI 1.08-1.18, P < .001). Conclusions: Admission lactate levels are strongly associated with increased hospital mortality among CICU patients, especially those with CA. The prognostic value of lactate levels may help inform clinicians caring for CICU patients.