Significance of mildly elevated creatine kinase (myocardial band) activity after elective abdominal aortic aneurysmectomy

The clinical significance of mildly elevated creatine kinase (CK) myocardial band (MB) enzyme levels in patients undergoing elective repair of an abdominal aortic aneurysm was evaluated retrospectively in 348 patients. For each patient, preoperative and postoperative electrocardiograms (ECGs) were interpreted blindly for left ventricular hypertrophy, ST segment abnormality, left bundle branch block, right bundle branch block, left axis deviation, atrial fibrillation, T wave abnormality, and Q waves. A total of 107 patients (31 %) had postoperative CK-MB elevations of trace or greater; 37 had trace, 35 had 1 % to 4%, and 35 had ≥ 5% elevation. There was no difference in survival between those with trace and no CK-MB elevation. Patients with increased CK-MB (≥ 1 %) values were more likely to have ECG abnormalities. The following ECG (either preoperative or postoperative) abnormalities were univariately related to decreased postoperative survival: left ventricular hypertrophy (P < 0.001), ST segment abnormalities (P < 0.001), left bundle branch block (P < 0.001), the combination of right bundle branch block and left axis deviation (P = 0.006), O wave infarction (P < 0.001), and atrial fibrillation (P < 0.001). There were 15 in-hospital deaths, and 333 patients were discharged and followed-up for a median of 4.6 years. There were 97 posthospitalization deaths, 61 % of which were due to cardiac causes. Overall survival was associated with the degree of CK-MB elevation; the higher the CK-MB, the worse the survival. In patients undergoing elective repair of an abdominal aortic aneurysm, even a minor elevation in postoperative CK-MB is associated with ECG abnormalities and reduced postoperative survival. After convalescence, closer cardiac follow-up and more aggressive postoperative cardiac assessment seem warranted in patients with CK-MB elevations ≥ 1 %.