Visualisation and quantification of peri-operative myocardial infarction after coronary artery bypass surgery with contrast-enhanced magnetic resonance imaging.

Abstract

To evaluate if elevated biochemical marker levels after coronary artery bypass grafting (CABG) correspond to the amount of peri-operatively infarcted myocardium, quantified by magnetic resonance imaging (MRI) post-operatively. A total of 23 patients without evidence of previous myocardial infarction or myocarditis and with normal pre-operative ECG and left ventricular function and who underwent elective, primary CABG, without any other concomitant cardiac surgery, were included. Plasma creatinine kinase MB (CK-MB) and troponin I and T were measured on the first, second and fourth post-operative days. Between the fourth and ninth post-operative days, cardiac MRI was carried out. Infarctions were found in 18 patients. The infarction mass at MRI was numerically largest in patients with transmural infarctions, all of whom had a CK-MB more than five times the upper normal limit. All three cardiac markers correlated to the mass of infarction. Elevated biochemical markers after CABG correspond to the amount of peri-operatively infarcted myocardium.