Correlation of postpercutaneous coronary intervention creatine kinase-MB and troponin 1 elevation in predicting mid-term mortality

Creatine kinase-MB (CK-MB) and troponin I elevations after successful percutaneous coronary intervention (PCI) are common, and different gradations have been correlated with mortality. To establish which of these 2 markers of myonecrosis, CK-MB and troponin 1, accurately predicts mortality after successful PCI, we analyzed 2,873 patients without acute myocardial inforction who underwent PCI for in-hospital events and mid-term mortality. Patients were stratified into 4 groups based on, peak post-PCI cardiac markers values: group 1: normal CK-MB (< 16 U/L) or troponin I (< 2 ng/ml); group III: CK-MB or troponin I levels I to 3 times normal; group III: >3 to 5 times normal; and group IV: >5 times normal. CK-MB elevation occurred in 16.1% of patients, with 12.2%, 2.3%, and 1.6% in groups II to IV, respectively. Troponin, I elevation was detected in 38.9% of patients, with 16.4%, 8.4%, and 14.1 % in groups II to IV, respectively. There was poor correlation between postprocedural CK-MB and troponin I values (r = 0.10) and in their individual subgroups. Kaplan-Meier estimates of death for postprocedure CK-MB were 2.1%,2.7%,1.7%, and 10.3% (p = 0.002) for groups I to IV, respectively; for troponin 1, these estimates were 2.2%, 2.3%, 2.9%, and 2.1 % for groups I to IV, respectively (p = 0.58). A Cox proportional hazards model showed that CK-MB > 5 times normal was the strongest predictor of mortality (hazard ratio 6.7, 95% confidence interval 1.9 to 22.9; p = 0.002), although heart failure, peripheral vascular disease, pre-PCI digoxin therapy, and post-PCl renal failure also predicted mortality. However, neither troponin I peak elevation nor any subgroup predicted mortality. Troponin I is frequently elevated after PCl, but does not predict mortality. Periprocedural CK-MB elevation > 5 times normal remains an independent predictor of mid-term mortality and a valuable marker for PCl prognosis in low-to-medium risk patients. (C) 2003 by Excerpto Medica, Inc.