2.4. Light transmission Aggregometry

The APACT 4S Plus aggregometer (LABiTec, Ahrensburg, Germany) was used for LTA as previously published [17]. Platelet rich plasma (PRP) was obtained by centrifugation of citrate-anticoagulated whole blood at 150× g for 10 min at room temperature. Subsequently, platelet poor plasma (PPP) was generated by re-centrifugation of the remaining specimen at 2000× g for 10 min. The light transmittance of PPP was considered as 100% aggregation. Thrombin receptor-activating peptide (TRAP; 25 µM; Rolf Greiner BioChemica, Flacht, Germany) was used as agonist to initiate platelet aggregation. Maximal aggregation % was calculated by comparing the increase in light transmittance through PRP after addition of TRAP to the optical density of PPP.