[Inflammatory cytokines and long-term prognosis after cardiac arrest]

The long-term survival rate after sudden cardiac arrest remains low despite progress in resuscitation, possibly due to acute ischemia of vital organs and subsequent general inflammatory reaction. We investigated a possible relationship between inflammatory cytokine concentrations and cardiac arrest (CA) survival.

Fifty one adult acute coronary syndrome patients, 35 males and 16 females, aged 62 +/- 12 years, who survived out-of-hospital CA (45%) and in-hospital CA (55%) were enrolled in the study. Twenty four of the patients died (D-CA); the other 27 survived and were discharged from the hospital (S-CA). Clinical conditions were rated by the Simplified Acute Physiology Score II (SAPS II) and Multiple Organ Dysfunction Score (MODS). Blood samples were obtained immediately after cardiac arrest. Serum concentrations of IL-6, IL-10 and TNF-alpha were analysed and rated against survival rates.

Higher mean concentrations of all cytokines were found in the D-CA group, when compared to the S-CA group. The mean concentration of IL-6 was 225 +/- 178 IU mL(-1) in the D-CA patients and 88 +/- 120 IU mL(-1) in the S-CA group (p = 0.006), and correlated inversely with survival (p = 0.018). The higher concentrations of IL-10 and TNF-alpha in non-survivors were not significant and bore no relation to survival rates. We also found significantly higher SAPS II and MODS scores, which correlated with both IL-6 levels and survival rates.

The relationship between the concentration of inflammatory cytokines and survival has been reported by others and should be regarded as a marker of generalized inflammatory response. A concentration of IL-6 is of high prognostic value.