Frequency of cardiac troponin-t elevation after successful direct stenting

Direct stenting (stenting without balloon predilation) is a novel approach in percutaneous treatment of coronary artery lesions. This approach may also significantly lower the rate of procedural ischaemic complications by reducing aggression to the vessel wall and immediately sealing the dissections created due to balloon inflation by the endoprosthesis. However, the incidence of minor myocardial infarction after direct stenting is unknown. The purpose of this study was to measure cTnT, creatine kinase and its isoform, CK-MB after apparently successful elective stent implantation without balloon predilation. Enzyme levels were measured just before and 16 hours after the procedures. A second-generation commercial ELISA cTnT assay (Boehringer Mannheim Corporation) was used to measure cTnT with a cutoff of 0.1 ng/dl. There was no abnormality in all three enzymes before the procedure. CTnT was elevated in 6 patients (13.6%), CK and CK-MB were elevated in 1 (2.3%) patient at 16 hours after the procedure. Both CK and CK-MB elevation were observed in the patient with side branch occlusion. In all others cTnT measurements in addition to CK-MB measurements are needed to detect this minor myocardial damage. To the best of our knowledge this is the first report evaluating the incidence of myocardial injury after direct stenting. Direct stenting by avoiding balloon-induced complications may decrease procedural myocardial necrosis. Randomized studies with larger patient populations should be conducted to compare this approach with conventional stenting. CTnT measurements in addition to CKMB measurements are essential in detecting this minor myocardial damage.