Incidence and clinical significance of transient creatine kinase elevations and the diagnosis of non-Q wave myocardial infarction associated with coronary angioplasty

To assess the incidence and clinical significance of elevated total plasma creatine kinase (CK) and MB isoenzyme fraction after apparently successful coronary angioplasty, a prospective study of 272 consecutive elective procedures was undertaken. Total CK (normal <200 IU/liter) and CK MB isoenyzme (normal ≤4%) were measured immediately after successful completion of the procedure and every 6 h for 24 h. All nonelective procedures and results not fulfilling all American Heart Association/American College of Cardiology Task Force guideline criteria for a successful result were excluded from analysis.Of the 272 elective procedures, 249 (92%) were successful; abnormally elevated CK or CK MB serum levels, or both, were found in 38 (15%) of the successful outcomes. Three patterns of abnormal enzymes were identified: 15 patients with CK ≥200 IU/liter and CK MB ≥5% (group 1), 4 patients with CK ≥200 IU/liter and CK MB ≤4% (group 2) and 19 patients with CK <200 IU/liter and CK MB ≥5% (group 3). The three groups were distinguishable by the nature of the complications causing the enzyme release (in particular, the etiology and clinical manifestations). There were significantly more clinically apparent events in group 1 than in the other groups (13 of 15 versus 11 of 23, p < 0.01) and more events associated with persistent electrocardiographic changes (p = 0.05) and chest pain (p < 0.05). However, no clinically important sequelae were recognizable in any group at hospital discharge.Thus, abnormal cardiac serum enzyme release after apparently successful coronary angioplasty is 1) relatively common; 2) has many possible causes, including both minor complications and early reversibility of impending major complications; and 3) results in no permanent clinical sequelae