Significance of Mild Transient Release of Creatine Kinase–MB Fraction After Percutaneous Coronary Interventions

BACKGROUND: The clinical significance of minor elevations in creatine kinase-myocardial band isoenzyme (CK-MB) after coronary interventions has not been systematically evaluated. METHODS AND RESULTS: We examined 4484 patients who underwent successful percutaneous transluminal coronary angioplasty or directional coronary atherectomy and whose peak CK levels did not exceed twice the upper limit of laboratory normal. Group 1 (3776 patients) had no CK or MB elevation after the procedure (ie, CK 4%, and group 3 (258 patients) had a peak CK level between 181 and 360 IU/L, with MB fraction > 4%. The strongest correlate of postprocedure CK-MB elevation was the performance of directional coronary atherectomy (odds ratio, 4.1; P or = 1 in-1ab minor procedural complication (odds ratio, 2.6; P < .0001). Clinical follow-up was available in 4461 patients (99.5%), with a mean duration of 36 +/- 22 months. Survival analysis, adjusted with Cox proportional hazards regression model, showed that the groups with elevated CK-MB had a significantly higher incidence of cardiac death (risk ratio, 1.3; P = .04) and myocardial infarction (risk ratio, 1.3; P = .03). Major ischemic complications (death, myocardial infarction, and coronary revascularization) occurred more frequently in the groups with increased CK-MB (groups 1 versus 2 versus 3, 37.3% versus 43.3% versus 48.9%; P = .01). CONCLUSIONS: This study shows that minor elevations of CK-MB after successful coronary interventions identify a population with a worse long-term prognosis compared with patients with no enzyme elevations and appear to have an adverse effect on long-term prognosis. Future studies of percutaneous coronary revascularization should include routine measurements of biochemical cardiac markers as important predictors of long-term prognosis.