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

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.