Background: In this prospective study, we compared the degree of myocardial injury in patients undergoing elective coronary interventions (CI) for revascularization or off-pump coronary artery bypass surgery (OPCAB).

Methods: The study included 100 consecutive patients (83 males, 17 females; mean age 53 years; range 34 to 78 years) who underwent intracoronary stent implantation (n=50) or OPCAB (n=50) for coronary artery disease. To evaluate the degree of myocardial injury, blood samples were taken preoperatively and at postoperative 12 hours to measure cardiac troponin (cTn), creatine kinase MB (CKMB), high sensitive CRP (hsCRP), and lactate levels. A 12-lead electrocardiogram was obtained before and following the procedure.

Results: There were significant differences between the two groups with regard to smoking, acetyl salicylic acid use, previous history of myocardial infarction, and left ventricular ejection fraction, whereas the mean number of affected vessels was similar. Compared to the basal values, cTn levels increased by 7.1% and 2.0%, CK-MB activity increased by 2.0% and 1.2% following OPCAB and CI, respectively (p<0.001). The increases were two-fold or more for cTn in 46% and 14% (p=0.001), CK-MB in 38% and 4% (p=0.001), hsCRP in 94% and 0% (p<0.001), and lactate in 38% and 0% (p=0.001) of OPCAB and CI patients respectively.

Conclusion: The extent of myocardial injury is significantly greater in the off-pump surgery group, as reflected by higher releases of biochemical cardiac markers.

Keywords : Cardiac surgical procedures; cardiopulmonary bypass; creatine kinase isoenzymes/blood; coronary artery bypass; troponin/analysis; myocardial ischemia