Prognostic value of serum levels of interleukin-6 in patients with ST-segment elevation acute myocardial infarction.

Background: Interleukin-6 (IL6) plays a role in atherogenesis as well as in most atherothrombotic phenomenon such as ST-segment elevation acute myocardial infarction (STEAMI). Our objective was to evaluate serum levels of IL6 as prognostic value for major clinical in-hospital events in patients with STEAMI.

Methods: We studied consecutive patients with diagnosis of STEAMI according to ACC/AHA/ESC criteria. Twenty four hours after the acute event, IL6 was determined by chemiluminescence method. The major cardiovascular end points were arrhythmias, angina, heart failure, reinfarction and death.

Results: Included were 97 patients. The level of IL6 to identify high-risk patients was 20 pg/ml. Forty six patients had <20 pg/ml (group I), and 51 patients had >20 pg/ml (group II). Mean value of IL6 was 11.52 +/- 4.83 pg/ml vs. 63.19 +/- 44.4 pg/ml (p <0.0001). Death was more frequent (2.2 vs. 15.7%, p = 0.023, RR 1.16 95% CI 1.02-1.31) and the end point combined during hospitalization in group II was 21.7 vs. 51% (p = 0.003 RR 1.59 95% CI 1.16-2.19). Multivariate logistic regression analysis identified Killip class > or = 2 and IL6 levels > or = 20 pg/ml as predictors for in-hospital end point.

Conclusions: Serum levels of IL6 >20 pg/ml in the first 24 h after STEAMI were significantly associated with higher frequency of in-hospital outcomes such as arrhythmias and death.