Creatine kinase release after successful percutaneous transluminal coronary angioplasty

After successful percutaneous transluminal coronary angioplasty (PTCA), 25 (20%) of 128 patients had elevation of creatine kinase MB isoenzyme (CK-MB). The increase was mild (mean 9% MB with total creatine kinase of 179 U/L). Three variables were significantly related to the enzyme elevation: chest pain, small branch vessel occlusion, and recent myocardial infarction. Of the patients with CK-MB elevation, 60% experienced chest pain and 32% sustained a small branch vessel occlusion during PTCA, compared with 11% and 8%, respectively, of the 103 patients without enzyme elevation (p < 0.001 and p < 0.01). Of 16 patients with recent myocardial infarction, seven (44%) had release of CK-MB. Although mild enzyme elevation after successful PTCA is likely due to a small amount of myocardial necrosis, this phenomenon was not associated with increased cardiac morbidity or mortality. Therefore, release of CK-MB without other clinical evidence for myocardial infarction after successful PTCA does not in itself warrant longer hospitalization, and routine serial enzyme determinations are probably unnecessary. By reducing the number of laboratory tests and the duration of hospitalization, the cost effectiveness of PTCA may be increased.