Detection of minor myocardial injury after successful percutaneous transluminal coronary angioplasty with or without stenting.

Cardiac troponins are sensitive and specific markers for the detection of minor myocardial injury. However, they have been rarely used to monitor myocardial injury after coronary stenting. The purpose of the study was to measure cardiac troponin I (cTnI) and cardiac troponin T (cTnT) levels after apparently successful percutaneous transluminal coronary angioplasty (PTCA) with or without coronary stenting and to compare their results with serum creatine kinase (CK) and its isoform, creatine kinase-MB (CKMB). CTnI and cTnT levels were compared with those of CK or CKMB in 50 consecutive patients with stable angina undergoing visually successful PTCA with stenting (n = 35) or without stenting (n = 15). Cardiac TnI, cTnT, CK and CKMB levels were measured before and 6, 24, and 48 hours after the procedures was performed. None of the patients had abnormal cTnI or cTnT levels, CK activity, or CKMB levels before the procedures. Moreover, no patient showed electrocardiographic evidence of myocardial infarction. 13 patients (26%) had abnormal peak values of one or more markers at 24 hours after coronary intervention. Troponin I was elevated in 10/35 patients after coronary stenting (29%) and in 2/15 patients after PTCA (13%) (P = 0.327). Troponin T was elevated in 6 patients (17%) and CKMB activity was elevated in 3 patients (9%) of the coronary stenting group. CTnI was more significant than CKMB (P = 0.023) in detecting minor myocardial injury. When compared with cTnI and CKMB, cTnT did not reach significance (P = 0.129 and 0.489, respectively). 5 out of the 13 patients with abnormal markers (38%) developed side branch occlusion after stenting. In conclusion, cTnI was a very sensitive marker in detecting minor myocardial injury after coronary angioplasty with or without stenting. The frequency of increased serum levels of cardiac troponins was higher in patients undergoing stent implantation than in those treated with angioplasty alone but did not reach significance. Side branch occlusion may have accounted for some, but not all, periprocedural minor myocardial injury in the stent group.