Background: Inflammation plays a major role in the development and progression of atherosclerosis and coronary artery disease (CAD). Inflammation markers, including white blood cell (WBC) count, C-reactive protein (CRP) and interleukin-6 (IL-6), are widely used for cardiovascular risk prediction. The aim of the study was to establish factors associated with WBC, CRP and IL-6 in patients with CAD. Two functional polymorphisms in genes encoding enzymes participating in adenosine metabolism were analyzed (C34T AMPD1, G22A ADA).
Methods: Plasma concentrations of IL-6 were measured using high-sensitivity ELISA kits, and the nephelometric method was used for high-sensitivity CRP (hs-CRP) measurement in 167 CAD patients.
Results: Presence of metabolic syndrome (MS) and its components, presence of heart failure, severity of CAD symptoms, severe past ventricular arrhythmia (sustained ventricular tachycardia [sVT] or ventricular fibrillation [VF]), lower left ventricle ejection fraction, higher left ventricle mass index, higher end-diastolic volume and higher number of smoking pack-years were significantly associated with higher WBC, CRP and IL-6. Strong associations with arrhythmia were observed for IL-6 (median 3.90 vs 1.89 pg/mL, p<0.00001) and CRP concentration (6.32 vs 1.47 mg/L, p=0.00009), while MS was associated most strongly with IL-6. CRP and IL-6 were independent markers discriminating patients with sVT or VF. There were no associations between AMPD1 or ADA genotypes and inflammation markers.
Conclusions: WBC, CRP and IL-6 are strongly associated with components of the metabolic syndrome. Their strong association with life-threatening ventricular arrhythmia emphasizes the proarrhythmic role of inflammation in the increased cardiovascular risk of CAD patients.