Correlations between cardiac troponin I, cardiac troponin T, and creatine phosphokinase MB elevation following successful percutaneous coronary intervention and prognostic value of each marker

Abstract

Aims: The aim of this prospective cohort study was to examine correlation between the postprocedural absolute rise of cardiac troponin (cTn-I), cardiac troponin T (cTn-T), and creatine phosphokinase MB (CK-MB), and predictive value of each marker for the long-term cardiac events following successful percutaneous coronary interventions.

Methods: The study consisted of 111 consecutive patients who had angiographically successful coronary balloon angioplasty with or without stent implantation. cTn-I, cTn-T, and CK-MB were measured before, immediately after the procedure, and every 6 hours for the first 24 hours. Patients were followed-up for major adverse cardiac events including acute myocardial infarction, death, recurrent angina, and revascularization for a period of 21+/-8.2 months.

Results: Total 45 patients (40%) had postprocedural cTn-I elevation, 27 patients (24%) cTn-T elevation, and 17 patients (15%) CK-MB elevation. There were strong correlations between the absolute values of the postprocedural maximal cTn-I and cTn-T, cTn-I and CK-MB, cTn-T and CK-MB (r: 0.64, r: 0.64, and r: 0.70 respectively, p<0.0001 for all correlations). There was also a significant concordance between the post-procedural positivity (higher than upper limit of normal) of cTn-I and cTn-T (kappa: 0.59), but CK-MB did not show significant concordances with c-Tn-T (kappa: 0.42), and cTn-I (kappa: 0.38). Long-term major cardiac events were observed in 29 patients (27%). Higher than 4-fold increase in cTn-I (log rank: 5.0, p: 0.02), and cTn-T (log rank: 10.7, p<0.001), and 2- to 4-fold in CK-MB (log rank: 17.9, p<0.0001) showed marked decremental effects on the event free survival.

Conclusion: Although the cTn-I is found to be relatively more sensitive cardiac marker, cTn-T can be used as an alternative assay with significant correlation, concordance, and prospective value. Both troponins have predictive value for long-term event free survival; particularly 4-fold increase is associated with worse event free survival.