Abstract 202: Elevated Plasma Levels of Interleukin 6 Are Associated with Risk of Sudden Death in the Community Even When Measured During the Acute Cardiac Arrest Event
Introduction: Elevated plasma levels of interleukin 6 (IL6) reflect plaque vulnerability and have been associated with sudden death in a cohort study but samples were drawn many years prior to the event. We sought to confirm this relationship by evaluating IL6 at the time of the sudden cardiac arrest (SCA) in a group of men and women in the community.
Hypothesis: Elevated IL6 is a determinant of SCA in the community.
Methods: In an ongoing, prospective, community-based study of SCA in Northwest US, we compared levels of plasma IL6 in 143 adult cases of adjudicated SCA and 149 gender- and age-matched controls with coronary artery disease (73 vs 73% male, age 64.0±11.9 vs. 64.2±11.6 y). Cases with cancer, non-cardiac causes of arrest, or terminal illnesses were excluded. Plasma was obtained from blood drawn at the time of arrest (cases) and at a routine visit (controls), and analyzed using Quantikine Immunoassay (CV <7.8%, normal range 0.4-8.9 pg/ml). IL6 levels were log transformed and compared (T-test and Chi-square test) per quartiles (based on controls). Logistic regression was used to predict the adjusted odds of SCA associated with IL6 levels (per increase in quartile).
Results: IL6 was significantly higher in SCA cases vs controls (median 13.2 [IQR 5.4-25.8] vs 5.3 [1.5-4.6] pg/ml, P<0.0001). Cases and controls did not differ regarding BMI, smoking, diabetes or obesity (all P>0.05). Median CRP levels were below clinical levels of significance and similar between cases and controls (2.5 [1.0-5.4] vs 1.9 [1.0-6.2] ug/ml, P=0.56). In a logistic regression model IL6 was independently associated with increased risk of SCA (OR/increased quartile of IL6: 2.4, 95% CI 1.7 - 3.5, P<0.001) also after adjusting for other risk factors (Table).
Conclusions: Elevated levels of IL6 in plasma are associated with SCA in this community-based study. Further evaluations are needed to elucidate the background of this finding and the potential role of this biomarker in risk stratification of SCA.
- © 2012 by American Heart Association, Inc.