Background: Off-pump coronary artery bypass surgery is considered to be less invasive compared with a conventional coronary artery bypass surgery, while objective assessment of its invasiveness has not been well established. The grade of invasiveness of off-pump CABG was evaluated by biochemical markers released from the myocardium.
Methods: Perioperative serial changes of myocardial enzyme leakage (creatine kinase-MB isoenzyme and troponin T) were evaluated in 217 patients who underwent coronary artery bypass surgery (28 off-pump CABG patients and 189 conventional CABG patients). Serial changes of atrial natriuretic peptide and brain natriuretic peptide secretion as markers of heart failure were also evaluated in 12 off-pump CABG patients and 49 conventional CABG patients.
Results: Myocardial enzyme leakage was significantly less in the off-pump CABG group, while increase of brain natriuretic peptides secretion were similar in both groups with its peak at the first postoperative day (246+/-46 pg/ml in the off-pump CABG group and 312+/-57 pg/dl in the conventional CABG group).
Conclusions: Although off-pump CABG seems to be less invasive to the myocardial cells from the aspect of enzyme leakage, ischemic stress to the heart assessed by brain natriuretic peptide secretion was similar to that of conventional CABG. Careful monitoring and management throughout postoperative period is mandatory even in off-pump CABG procedure.