Extracorporeal Cardiopulmonary Resuscitation: a national study on the association between favourable neurological status and biomarkers of hypoperfusion, inflammation, and organ injury

AIMS: In refractory out-of-hospital cardiac arrest (OHCA) with prolonged whole-body ischaemia, global tissue injury proceeds even after establishment of circulation with extracorporeal cardiopulmonary resuscitation (ECPR). We aimed to investigate the role of biomarkers reflecting hypoperfusion, inflammation, and organ injury in prognostication of patients with refractory OHCA managed with ECPR.

METHODS AND RESULTS: This nationwide retrospective study included 226 adults with refractory OHCA managed with ECPR in Denmark (2011-2020). Biomarkers the first days after ECPR-initiation were assessed. Odds ratio of favourable neurological status (Cerebral Performance Category 1-2) at hospital discharge was estimated by logistic regression analyses. Cut-off values were calculated using the Youden's index. Fifty-six patients (25%) survived to hospital discharge, 51 (91%) with a favourable neurological status. Factors independently associated with favourable neurological status were low flow time <81 min, admission leukocytes ≥12.8 × 109/L, admission lactate <13.2 mmol/L, alkaline phosphatase (ALP) < 56 (day1) or <55 U/L (day2), and day 1 creatine kinase MB (CK-MB) < 500 ng/mL. Selected biomarkers (leukocytes, C-reactive protein, and lactate) were significantly better predictors of favourable neurological status than classic OHCA-variables (sex, age, low-flow time, witnessed arrest, shockable rhythm) alone (P = 0.001) after hospital admission.

CONCLUSION: Biomarkers of hypoperfusion (lactate), inflammation (leucocytes), and organ injury (ALP and CK-MB) were independently associated with neurological status at hospital discharge. Biomarkers of hypoperfusion and inflammation (at hospital admission) and organ injury (days 1 and 2 after ECPR) may aid in the clinical decision of when to prolong or terminate ECPR in cases of refractory OHCA.