Minor myocardial injury after elective uncomplicated successful PTCA with or without stenting: Detection by cardiac troponins

Cardiac troponins are sensitive and specific markers for the detection of m inor myocardial injury. However, they have been rarely used to monitor myoc ardial injury after coronary stenting. The purpose of the study was to meas ure cardiac troponin I (cTnI) and cardiac troponin T (cTnT levels after ele ctive uncomplicated successful percutaneous transluminal coronary angioplas ty (PTCA) with or without coronary stenting and to compare their results wi th serum creatinine kinase MB isoenzyme (CKMB). CTnI and cTnT levels were c ompared with those of CK or CKMB in 98 consecutive patients with stable ang ina undergoing elective uncomplicated successful PTCA with stenting (n = 71 ) or without stenting (n = 27). Markers were measured before and 6, 12, 24, and 48 hr after the procedure. Peak postprocedural levels for each marker were compared and related to angiographic and procedural characteristics as well as to the occurrence of sidebranch occlusion. None of the patients ha d abnormal markers before the procedure. Abnormal postprocedural values of one or more markers were observed in 28 patients (29%), 23 after stenting a nd 5 after PTCA alone. The frequencies of abnormal cTnI and cTnT levels wer e significantly higher than that of CKMB after coronary intervention (26% a nd 18% vs. 7%; P = 0.00016 and 0.015, respectively), with cTnI being the mo st significant. When compared with troponin-negative patients, abnormal car diac troponin values were significantly related to total time of inflation (223 +/- 128 vs. 170 +/- 105 sec; P = 0.008) and inflation maximal pressure (12.9 +/- 2.3 vs. 12.0 +/- 2.7 atm; P = 0.04). Small side-branch occlusion was noticed in 36% of the troponin-positive patients and in 6% of the trop onin-negative group (P = 0.00047). In conclusion, minor myocardial injury i s not uncommon after elective uncomplicated successful PTCA with or without stenting. Cardiac troponins, especially cTnI, are more sensitive than CKMB for the detection of this minor myocardial injury. Total time of inflation and inflation maximal pressure are predictors of postprocedural elevation of cardiac troponins. Side-branch occlusion may account for some, but not a ll, periprocedural minor myocardial injury. (C) 2001 Wiley-Liss, Inc.