Microembolization and myonecrosis during elective percutaneous coronary interventions in diabetic patients: an intracoronary Doppler ultrasound study with 2-year clinical follow-up.

Elevation of cardiac troponin I (cTnI) is a well-known complication after percutaneous coronary interventions (PCI). The aims of this study were to quantify the extent of coronary microembolization during elective PCI, to identify predisposing anatomical and procedural factors, and to evaluate its impact on long-term outcome in diabetic patients with a high cardiovascular risk. 48 patients (pts, median 66.7 years) with type 2 diabetes and coronary artery disease underwent elective PCI with stenting to treat single-vessel lesions. Real-time microembolization during PCI ("HITS") was detected by an intracoronary Doppler guide wire. Peak levels of cTnI were measured within 24 h after PCI. Pts were followed for 2 years to record major cardiac events (MACE: death, myocardial infarction, revascularization of target and non-target vessels). In 47 patients microemboli were detected during PCI. Nineteen patients showed pathologic cTnI elevation (0.13-28.9, median 0.39 μg/l). The amount of HITS correlated with cTnI levels (r = 0.43, p = 0.003), but not with other clinical or angiographic data. Within 2 years MACE were detected in 9 patients, who had significantly more microemboli (15.4 ± 11.8 vs. 28.2 ± 16.0 HITS; p = 0.009, OR 1.07; 95 % CI 1.011-1.13) during PCI. HITS >23, but not cTnI elevation, predicted later MACE (ROC analysis, p = 0.025). A high amount of microembolization during elective PCI in diabetic patients appears to be an indicator of greater atherosclerotic burden and accelerated coronary artery disease progression, associated with acute biomarker elevation and adverse long-term outcomes.