Predicting long-term outcomes after cardiac arrest by using serum neutrophil gelatinase-associated lipocalin

Abstract Objectives Neutrophil gelatinase-associated lipocalin (NGAL) is secreted by various tissues in pathologic states. Previous studies reported that post-cardiac arrest serum NGAL levels correlate with short-term neurologic outcomes and survival. The aim of this study was to examine the associations between NGAL levels post-cardiac arrest and long-term outcomes and survival. Methods This prospective observational study and retrospective review included adult out-of-hospital cardiac arrest survivors who were treated by hypothermia-targeted temperature management. Serum NGAL was assessed at 0, 24, 48, and 72 h after return of spontaneous circulation. The primary outcome was poor outcome at six months after cardiac arrest, defined as cerebral performance category score of 3–5. The secondary outcome was six-month mortality. Results In total, 76 patients were analyzed. The patients with poor outcomes showed significantly higher NGAL levels at 24, 48 and 72 h after cardiac arrest than the patients with good outcomes. Long-term survival rates were significantly lower in the high-NGAL group than in the low-NGAL group at each time point. Subgroup analysis of patients who survived 72 h showed that only serum NGAL 72 h after cardiac arrest had prognostic value for long-term outcomes (area under the receiver operating characteristic curve = 0.72; p  = 0.02). Conclusions Post-cardiac arrest serum NGAL is associated with long-term outcomes and survival; particularly, three days post-cardiac arrest is the optimal time point for predicting long-term outcomes. However, the predictive power of NGAL is unsatisfactory, and it should be regarded as an additional prognostic modality.