Aims: To determine the value of fibrinogen-positive platelet-analysis in predicting restenosis after stent implantation in acute myocardial infarction patients.
Methods and results: Our patient population comprised 50 patients who underwent intravascular ultrasound (IVUS) guided stent implantation for acute myocardial infarction. In all cases, IVUS confirmed a deep vessel wall injury due to a ruptured plaque within the culprit lesion. Flow cytometry quantified the amount of platelets with surface-bound fibrinogen and thrombospondin before and immediately after the intervention. After 5 months, IVUS was repeated to assess the long-term results. In-stent restenosis - defined as a percent diameter stenosis of >50% - was detected in 11 of 45 patients who attended follow-up angiography. The amount of fibrinogen-positive platelets was significantly higher among patients who subsequently developed in-stent restenosis (50.5+/-6.8% fibrinogen-positive platelets immediately after intervention) than among those who did not (39.7+/-12.3% fibrinogen-positive platelets, p<0.005). Receiver operating characteristic curve revealed a 40% cut-off for fibrinogen-positive platelets immediately after the intervention to predict restenosis (p<0.05, sensitivity: 90.9%, specificity: 47.1%).
Conclusion: The amount of fibrinogen-positive platelets immediately after stent implantation predicts the occurrence of in-stent restenosis, as confirmed by IVUS in acute myocardial infarction patients.