Side-branch occlusion during percutaneous transluminal coronary angioplasty.

Concentrations of creatine kinase (CK) MB mass and cardiac troponin T were measured in serial peripheral venous blood samples from 21 patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Angiography showed side-branch occlusion during PTCA without clinical signs of myocardial injury in 5 patients. After PTCA, CKMB mass concentrations were substantially higher than normal in all 5 patients with side-branch occlusion, and troponin T concentrations were high in 3. By contrast, only 2 patients and 1 patient, respectively, without side-branch occlusion had slight rises in CKMB and troponin T. Release of the contractile protein troponin T reflects more severe damage to myocytes than simple leakage of CKMB. Therefore, myocardial damage induced by side-branch occlusion can be graded by measurement of troponin T in plasma.