Reversal of the platelet inhibitory effect of the P2Y12 inhibitors clopidogrel, prasugrel, and ticagrelor in vitro: a new approach to an old issue.

AIM: Platelet transfusion is an effective option to reverse platelet inhibition in thienopyridine-treated patients suffering from bleedings or requiring urgent surgery. However, in ticagrelor-treated patients, the previous studies revealed significant clinical effects to platelet rich plasma (PRP) but poor response to pooled platelets (PP) as used in clinical routine. The aim of this study was to elucidate a potential pathomechanism to explain the poor response of ticagrelor to PP. METHODS AND RESULTS: From 79 whole blood samples of patients treated with ticagrelor, prasugrel, or clopidogrel, the PRI-VASP was determined before and after in vitro platelet supplementation of PP or PRP at increasing concentrations. Compared to prasugrel- and clopidogrel-treated patients, the PRI-VASP of ticagrelor-treated patients showed no significant increase after in vitro administration of PP. PRI-VASP was performed in ticagrelor-treated samples after in vitro addition of 1: centrifuged PRP platelets resuspended in PP buffer, 2: PP with human serum, 3: human serum alone. Surprisingly, PP with human serum or human serum alone were able to significantly increase PRI-VASP in samples of ticagrelor-treated patients (11.7 ± 10.9 â†’ 61.3 ± 10.9%, p = 0.006; 11.7 ± 10.9 â†’ 54.1 ± 2.7%, p < 0.001). This effect could also be shown using human albumin (18.9 ± 5.1% â†’ 80 g/l human albumin: 48.1 ± 8.3%, p < 0.001). CONCLUSION: The present study demonstrates that addition of human serum and human albumin alone is able to reverse the ticagrelor effects in vitro and supports our novel hypothesis of the importance of proteins in reversing the effects of ticagrelor by binding active ticagrelor.

A novel interventional method for treating femoral pseudoaneurysms: results from a monocentric experience.

AIMS: Iatrogenic pseudoaneurysms of the femoral artery lead to increased morbidity and mortality, especially when surgical treatment is necessary. Manual compression and thrombin injection are commonly used to occlude the pseudoaneurysms. However, in some cases these treatment options are inapplicable or unsuccessful. The aim of the present study was to examine the feasibility, effectiveness and safety of a novel approach with the use of suture-based closure devices to treat pseudoaneurysms. METHODS AND RESULTS: Between January 2014 and May 2016, a total of eight iatrogenic pseudoaneurysms of the femoral artery were treated by the interventional closure technique after at least one ineffective attempt at manual compression. After puncture of the cavity, a PTCA guidewire was used to pass the neck of the pseudoaneurysm and a sheath was inserted in the femoral artery. Afterwards, a suture-based closure system (ProGlide) was used to occlude the neck. All eight pseudoaneurysms were successfully obliterated. No complications occurred during the procedure. CONCLUSIONS: The new interventional technique presented in this study fills the gap in successfully treating pseudoaneurysms that cannot be obturated with conventional techniques. By implementing this new technique in clinical practice, a significant number of open surgical repairs could be prevented.