Serum creatine kinase kinetics after endomyocardial biopsy in cardiac transplant patients.
The objective of this study was to define the changes in serum creatine kinase (CK) and creatine kinase-MB isoenzyme (CK-MB) activities following endomyocardial biopsy. Ten cardiac transplant recipients underwent routine surveillance endomyocardial biopsy via the right internal jugular vein with single-use disposable bioptomes. Serum CK and CK-MB levels were measured at baseline and post-biopsy at 15, 30, and 45 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, 20, and 24 hours. There was no significant increase in serum total CK after biopsy. No measurable change in CK-MB was observed in 40% of patients. CK-MB increased significantly in the remaining patients (N = 6) at 30 minutes (p < 0.05), and continued to rise to a peak at 4 hours post-biopsy, after which CK-MB gradually decreased to baseline. However, the increase in CK-MB did not meet criteria for the diagnosis of myocardial necrosis, hence should not be confused with the change in CK-MB occurring with myocardial infarction. These findings suggest that serum CK-MB activity is useful in the differential diagnosis of chest pain in cardiac transplant patients in the setting of recent biopsy.