Abstract 242: Assessment of Biomarkers After Standard Cardiopulmonary Resuscitation versus Extracorporeal Cardiopulmonary Resuscitation

Background: Multiple biomarkers have been used in prognostication of outcome after out-of-hospital cardiac arrest (OHCA) and standard cardiopulmonary resuscitation (CPR). Limited evidence exists for patients resuscitated with extracorporeal CPR (ECPR). We hypothesized that (1) the time course and (2) prognostic performance of biomarkers will differ between CPR and ECPR. Methods: This is a pre-planned sub-analysis of Prague-OHCA study. Patients were randomized to either CPR or ECPR. The primary outcome was poor neurologic outcome at 180 days, defined as a cerebral performance category (CPC) of 3-5. Secondary outcomes included assessment of biomarkers of neurologic injury (NSE), inflammation (procalcitonin - PCT, C-reactive protein - CRP, neutrophil-lymphocyte ratio - NLR) and hematology (platelets - Plt, D-dimers - D-dim, and fibrinogen - Fg) using Mann-Whitney test with Bonferroni correction, and ROC analysis of data at 24-72 h. Results: In as-treated analysis, ECPR was used in 92 patients. The primary outcome was not different between groups: CPR, CPC 1-2 48 (29.3%) vs CPC 3-5 116 (70.7%); ECPR, CPC 1-2 20 (21.7%) vs CPC 3-5 72 (78.3%); p= 0.191. In general, individual biomarkers exhibited similar trajectories over 72 h, with worse values in patients with CPC 3-5 in both CPR and ECPR groups. PCT was higher in ECPR group at 24-72 h (all p<0.01). NSE, CRP and NLR did not differ between groups. Plt, D-dim and Fg were lower in ECPR vs CPR groups at 24-72 h (all p<0.001). ROC analysis showed the best performance of NSE in both CPR and ECPR groups (AUC 24 h: 0.89 vs 0.78; 48 h: 0.9 vs 0.9; 72 h: 0.91 vs 0.9). PCT showed good performance specifically in ECPR (AUC 24 h: 0.72 vs 0.84; 48 h 0.73 vs 0.87; 72 h: 0.73 vs 0.86). Optimal cutoff points were higher in ECPR vs CPR in NSE (24 h: 60 vs 84; 48 h: 65 vs 61; 72 h: 39 vs 57) and PCT (24 h: 1.8 vs 11, 48 h: 1.0 vs 5.3, 72 h: 0.9 vs 5.6). Conclusions: Biomarkers have similar trajectories after OHCA rescued with either CPR or ECPR although absolute values were higher in ECPR. NSE had superior prognostic value in both groups while PCT showed a good prognostic performance specifically in the ECPR group. Additional studied biomarkers may have modest incremental value. Prognostication algorithms using biomarkers should reflect a mode of resuscitation.