Outcome prediction and temperature dependency of MR-proANP and Copeptin in comatose resuscitated patients

OBJECTIVE: To evaluate the prognostic potential of serum C-terminal provasopressin (CT-proAVP or Copeptin) and midregional pro-A-type natriuretic peptide (MR-proANP) to predict neurological outcome following resuscitation from cardiac arrest.

METHODS: In this prospective observational study, we employed novel ultra sensitive immunoassay technology to examine serial serum samples from 134 cardiac arrest patients. Patients were either allocated to mild therapeutic hypothermia using an endovascular device or normothermia. Serial blood samples were obtained from resuscitated cardiac arrest survivors during their first 7 days in an intensive care unit, and serum Copeptin and MR-proANP were measured. Cerebral function assessments were made using cerebral performance categorization (CPC) at discharge from hospital. Copeptin and MR-proANP data were analyzed using dichotomized CPC scores (1-2 versus 3-5).

RESULTS: Sixty-nine patients (51%) had a poor outcome (CPC 3-5) at hospital discharge. MR-proANP and Copeptin peaked on day 1 (i.e. 0-24h) with the medians being 249.3pmol/L and 77.2pmol/L, respectively. In the first 48h maximum levels of MR-proANP and Copeptin showed an AUC in the ROC of 0.743 (95% CI: 0.658-0.828) and 0.677 (95% CI: 0.583-0.771). Binary logistic regression revealed MR-proANP and Copeptin within 48h after ROSC being significantly associated with functional outcome (p<0.05). Copeptin within 48h was also associated with outcome in the hypothermia group (p<0.05).

CONCLUSION: Systemic levels of MR-proANP and Copeptin peak early in cardiac arrest patients in the 48h post-resuscitation period. MR-proANP and Copeptin were highly predictive for poor outcome in comatose resuscitated patients.