Indications for angiography subsequent to coronary artery bypass grafting

Common signs of myocardial ischemia usually allow to diagnose unstable angina or myocardial infarction under native conditions. In contrast, these criteria frequently fail after CABG. Combined diagnostic criteria of elevated leukocytes (>14 000 G/L, at hour 0) and either ST elevation or CK-MB concentrations >35 U/L (at hour 6) at least seem to be very useful in detecting myocardial infarction after bypass grafting. In parallel, CK-MB elevation (>70 U/L, at hour 6) alone seems to predict ischemia. Both criteria should indicate angiography and potential revascularization. If these conditions were not fulfilled, the risk of perioperative myocardial infarction appears to be moderate.