Time course of transcardiac interleukin-6 release after coronary stenting for stable angina

Abstract

C ytokines are known to play a critical role in the atherosclerotic process. 1 The cytokine interleukin-6 (IL-6) is involved in a variety of physiological functions ultimately leading to macrophage activation, platelet aggregation, and stimulation of matrix degrading enzymes. An increase in circulating concentrations of IL-6 and of its hepatic byproduct C reactive protein (CRP) has been reported in unstable angina 2 and after percutaneous coronary intervention (PCI); high concentrations of IL-6 and CRP are considered to be markers of poor prognosis, probably related to the intensity of plaque inflammation. The present study was designed specifically to evaluate whether transmyocardial production of IL-6 could be measured immediately and within two hours of a successful elective PCI and stent implantation in stable patients. METHODSThe study involved 11 patients with stable angina, admitted for an elective PCI of the proximal segment of the left anterior descending coronary artery. All patients received standard medical treatment consisting of intravenous heparin (70 U/kg body weight), acetylsalicylic acid, and nitrates. No glycoprotein IIb/IIIa inhibitors were given. A six French Cournand catheter was introduced through the right femoral vein in the coronary sinus and the left coronary ostium was catheterised through the right femoral artery. Coronary sinus and arterial blood samples were taken simultaneously at baseline, immediately after stent deployment and two hours later to determine IL-6 and lactate concentration. Additional blood samples were obtained from a peripheral vein before the procedure for measurement of CRP and troponin I circulating concentrations and also 12 hours later for measurement of troponin-I concentration. RESULTSAt baseline, mean (SD) IL-6 concentrations were similar in the aorta and in the coronary sinus (3.82 (3.25) v 3.84 (3.09) pg/ml respectively, not significant), the coronary sinus to aorta ratio averaging 1.02 (0.13). A transcardiac extraction of lactate was observed in all cases, with a coronary sinus to aorta ratio averaging 0.77 (0.22) and mean serum concentrations of 0.61 (0.16) mM/l in the aorta and 0.47 (0.21) mM/l in the coronary sinus. The systemic troponin I concentration was within the normal range in all patients (0.03 (0.01) ng/ml) and CRP concentration averaged 0.28 (0.20) mg/dl, confirming the stability of the coronary disease. Immediately after stenting, blood sampled in the coronary sinus during the hyperaemic phase following balloon deflation showed a consistent increase in lactate concentration (1.38 (0.76) mM/l, p = 0.0008 v baseline), the lactate coronary sinus to aorta ratio increasing significantly to 2.42 (1.06) (p = 0.0001). Simultaneously, the IL-6 coronary sinus to aorta ratio (fig 1) increased in all but one patient (mean 1.17 (0.17), not significant v baseline) but these changes remained insignificant. Two hours after the procedure, IL-6 concentrations increased both in the aorta and in the coronary sinus (7.33 (5.20) and 8.67 (4.89) pg/ml, p , 0.01 v...

Off-Pump Coronary Surgery causes Immediate Release of Myocardial Damage Markers

“…13 Transmyocardial release of IL-6 has been described after cardiac surgery with cardiopulmonary bypass and coronary stenting for stable angina. 14,15 OPCAB surgery can now be added, indicating that even minor myocardial injury during the procedure is sufficient to activate the proinflammatory reaction. Increases in arterial IL-6 most probably reflect a nonspecific whole-body inflammatory response to the surgery.…”