On-pump versus off-pump coronary artery bypass grafting: relationship between complications and released cytokines after on-pump surgery

Introduction

Extracorporeal circulation may trigger an extensive inflammatory response and the release of cytokines, which can induce myocardial ischemia.

Objective

The goal of this study was to evaluate the relationship between inflammatory markers and biochemical evidence of myocardial cell injury in patients who underwent coronary bypass grafting (CABG) with (on-pump) or without (off-pump) extracorporeal circulation.

Methods

All patients had myocardial infarction with multivessel coronary artery disease with preserved ventricular function and without renal failure or other cardiac diseases. The mean age was 46.6 ± 12.5 years. Cytokines were measured 6 and 24 hours postoperatively by ELISA and immunoassay, and were correlated to the occurrence of the following clinical complications: fever, atrial fibrillation, significant pericardial effusion, pulmonary complications, and release of CK-MB and troponin I.

Results

Of the 724 CABGs performed in a single-center tertiary hospital, 218 were off-pump and 506 were on-pump. The mean age was 46.6 ± 12.5 years and the mean time of extracorporeal circulation was 72 ± 23 min. Clinical complications were more frequent among on-pump patients (Table 1). This was associated with higher levels of C-reactive protein, CK-MB and troponin I, but not IL-6 (Table 2).

Table 1

Table 2

Conclusions

Postoperative complications and biochemical evidence of myocardial cell damage after CABG were more frequent among on-pump patients, and this was correlated with higher serum levels of C-reactive protein.