Predictive value of interleukin-6 in post-cardiac arrest patients treated with targeted temperature management at 33 °C or 36 °C.

Abstract

AIM:

Post-cardiac arrest syndrome (PCAS) is characterized by systemic inflammation, however data on the prognostic value of inflammatory markers is sparse. We sought to investigate the importance of systemic inflammation, assessed by interleukin-6 (IL-6) in comatose survivors of out-of-hospital cardiac arrest.

METHODS:

A total of 682 patients enrolled in the Target Temperature Management (TTM) trial, surviving >24h with available IL-6 data were included. IL-6 was measured on days 1, 2 and 3 after return of spontaneous circulation. Severity of PCAS was assessed daily by the Sequential Organ Failure Assessment score. Survival status was recorded at 30 days.

RESULTS:

High levels of IL-6 at day 1-3 (all p<0.0001) were independently associated with severity of PCAS with no interaction of target temperature (all p=NS). IL-6 levels did not differ between temperature groups (p(interaction)=0.99). IL-6 levels at day 2 (p<0.0001) and day 3 (p<0.0001) were associated with crude mortality. Adjusted Cox proportional-hazards analysis showed that a two-fold increase of IL-6 levels at day 2 (HR=1.15 (95% CI: 1.07-1.23), p=0.0002) and day 3 (HR=1.18 (95% CI: 1.09-1.27), p<0.0001) were associated with mortality. IL-6 levels at day 3 had the highest discriminative value in predicting mortality (AUC=0.66). IL-6 did not significantly improve 30-day mortality prediction compared to traditional prognostic factors (p=0.08).

CONCLUSIONS:

In patients surviving >24h following cardiac arrest, IL-6 levels were significantly elevated and associated with severity of PCAS with no significant influence of target temperature. High IL-6 levels were associated with increased mortality. Measuring levels of IL-6 did not provide incremental prognostic value.

• Authors: John Bro-Jeppesen, Jesper Kjaergaard, Pascal Stammet, Matthew P Wise, Jan Hovdenes, Anders Åneman, Janneke Horn, Yvan Devaux, David Erlinge, Yvan Gasche, Michael Wanscher, Tobias Cronberg, Hans Friberg, Jørn Wetterslev, Tommaso Pellis, Michael Kuiper, Niklas Nielsen, Christian Hassager, TTM-Trial Investigators
• Journal: Resuscitation (Resuscitation) Vol. 98 Pg. 1-8 (Jan 2016) ISSN: 1873-1570 [Electronic] Ireland
• PMID: 26525271 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Biomarkers
• Interleukin-6

Topics

• Aged
• Biomarkers (blood)
• Coma
• Comorbidity
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Hypothermia, Induced (methods)
• Interleukin-6 (blood)
• Male
• Middle Aged
• Organ Dysfunction Scores
• Out-of-Hospital Cardiac Arrest (blood, mortality, therapy)
• Predictive Value of Tests
• Prognosis
• Survival Rate