Impact of the elevation of biochemical markers of myocardial damage on long-term mortality after percutaneous coronary intervention: results of the CK-MB and PCI study.

Abstract

Retrospective studies and post hoc analyses have suggested that mild elevations in the creatine kinase-MB (CK-MB) isoenzyme following percutaneous coronary intervention (PCI) may be associated with an increased risk of death in the long term. However, this finding is still controversial, and the prognostic significance of elevations of more sensitive markers of myocardial damage, such as the cardiac troponins, has not been established. In this multicentre prospective cohort study, we evaluated the influence of post-procedural elevations of CK-MB and troponin I (cTnI) on long-term mortality. The CK-MB and PCI study included 3494 consecutive patients undergoing PCI from February 2000 to October 2000 in 16 Italian tertiary centres. Blood samples were collected at baseline, and at 8-12 and 18-24 h after the procedure, and were analysed in a core biochemistry laboratory. CK-MB elevation was detected in 16% of the patients, and was associated with increased 2-year mortality [7.2 vs. 3.8%; odds ratio (OR): 1.9; 95% confidence interval (CI): 1.3-2.8; P<0.001). The degree of CK-MB elevation (peak CK-MB ratio) independently predicted the risk of death (adjusted OR per unit: 1.04; 95% CI: 1.01-1.07; P=0.009). A cTnI elevation was detected in 44.2% of the cases and was not associated with a significant increase in mortality (4.9 vs. 4.0%; OR: 1.2; 95% CI: 0.9-1.7; P=0.2). Post-procedural elevations of CK-MB, but not cTnI, influence 2-year mortality.