In the present study 99 patients undergoing CABG because of stable angina pectoris due to significant coronary artery disease were prospectively included. Coronary angiography was repeated 3 months after CABG in 81 patients in order to evaluate early graft occlusion. Blood samples were collected before CABG in all patients. Patients were followed up for a median of 5 (3–7) years after CABG.
Twenty-five patients (31 % ) had one or more occluded grafts at the 3-month control coronary angiography. The patients with occluded grafts had higher preoperative CRP and IL-6 levels in plasma [CRP 2.22 (1.11–4.47) mg/L vs. 1.23 (0.71–2.27) mg/L P = 0.03] and [IL-6 2.88 (1.91–5.94) pg/mL vs. 2.15 (1.54–3.14) pg/mL P = 0.006]. There were 23 late cardiovascular events among the 99 patients during the follow-up. Patients experiencing late cardiovascular events had higher preoperative IL-6 levels than those without late cardiovascular events [4.13 (1.83–5.87) pg/mL vs. 2.08 (1.53–2.29) pg/mL, P = 0.002] whereas CRP levels did not differ significantly between the two groups [1.5 (0.79–4.41) mg/L vs. 1.33 (0.74–2.48) mg/L, P = 0.41]. Looking at IL-6, a cut off value more than 3.8 pg/ml was associated with a significant higher risk for an early graft occlusion (P = 0.04) and late cardiovascular events (P = 0.00003). Preoperative endothelin-1 did not predict early graft occlusions or late cardiovascular events.
Raised preoperative IL-6 levels are predictors of both early graft occlusion and late cardiovascular events after CABG. Elevated preoperative CRP levels can predict early graft occlusion after CABG. Endothelin did not differ between the two groups.