Reduced expression of systemic proinflammatory and myocardial biomarkers after off-pump versus on-pump coronary artery bypass surgery: a prospective randomized study

Background: The effects of off-pump (OffPCABG) and on-pump (OnPCABG) coronary artery bypass grafting (CABG) on myocardium and inflammation are unclear.

Objective: Compare the inflammatory response and myocardial injury from patients (pts) submitted to OffPCABG with those that undergo OnPCABG.

Methods: Patients with normal left ventricular function were assigned to OffPCABG (n = 40) and OnPCABG (n = 41). Blood samples were collected before and 24 hours after surgery for determination of creatine kinase (CK)-MB (CK-MB), troponin I (cTnI), interleukin (IL)-6, IL-8, P-selectin, intercellular adhesion molecule (ICAM)-1 and C-reactive protein (CRP). Mortalities were registered at 12 months.

Results: Preoperative CK-MB and cTnI levels were 3.1 +/- 0.6 IU and 1.2 +/- 0.5 ng/mL for OffPCABG and 3.0 +/- 0.5 IU and 1.0 +/- 0.2 ng/mL for OnPCABG pts. Postoperative CK-MB and cTnI levels were 13.9 +/- 6.5 IU and 19.0 +/- 9.0 ng/mL for OffPCABG vs 29.5 +/- 11.0 IU and 31.5 +/- 10.1 ng/mL for OnPCABG (P < .01). OffPCABG and OnPCABG pts had similar preoperative IL-6 (10 +/- 7 and 9 +/- 13 pg/mL), IL-8 (19 +/- 7 and 17 +/- 7 pg/mL), soluble P-selectin (70 +/- 21 and 76 +/- 23 pg/mL), soluble ICAM-1 (117 +/- 50 and 127 +/- 52 ng/mL), and CRP (0.09 +/- 0.05 and 0.11 +/- 0.07 mg/L). At 24 hours, for OffPCABG and OnPCABG: IL-6 was 37 +/- 38 and 42 +/- 41 g/mL; IL-8, 33 +/- 31 and 60 +/- 15 pg/mL; soluble P-selectin, 99 +/- 26 and 172 +/- 30 pg/mL; soluble ICAM-1, 227 +/- 47 and 236 +/- 87 ng/mL; and CRP, 10 +/- 11 and 14 +/- 13 mg/L (P < .01 vs preoperation; P < .01 vs OffPCABG). Increased 24-hour postoperative CRP levels was the only marker to have significant positive correlations with events and occurred just for the OnPCABG pts. In-hospital and 1-year mortalities for the OnPCABG and OffPCABG pts were 2.0% and 2.2% (P = .1) and 2.7% and 4.7% (P = .06), respectively.

Conclusions: Thus, the absence of CPB during CABG preserves better the myocardium and attenuates inflammation-however, without improving survival.