The amount of fibrinogen-positive platelets predicts the occurrence of in-stent restenosis

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.