Safety multifly set

Venous blood was obtained in the morning (between 9 and 11 a.m.) from healthy and fasting volunteers who gave their informed consent and had not taken any drugs affecting platelet function in the previous 2 weeks. A clean puncture of an antecubital vein was performed with a 20-gauge needle (Safety^®-Multifly-Set, Sarstedt, Nümbrecht, Germany) following the application of a light tourniquet, while blood collection was performed without applying venostasis. After discarding of the first 2–3 ml of blood, S-Monovette^® tubes (Sarstedt) containing 100 μmol/L PPACK (Enzo Life Sciences Inc., Farmingdale, NY, USA) were used as collection tubes and anticoagulant was immediately mixed with blood by gentle inversion. PPACK was used as anticoagulant in order to maintain physiological calcium concentration in plasma. Transportation of blood tubes to the laboratory was careful to avoid unnecessary agitation; for this purpose, a box maintaining the tubes in a steady vertical position was used. Samples were kept at room temperature (20–24°C) and the delay before the first centrifugation was less than 1 h.

Venous blood was collected using a 21 G butterfly needle (Safety-Multifly®-Set, Sarstedt, Nümbrecht, Germany) and anticoagulated to a final concentration of  > 15 μg/ml r-hirudin (SARSTEDT Monovetten, Nümbrecht, Germany) on day 1–3 after PCI. Clopidogrel was administered orally and blood was drawn approximately 1 h later. Multiple electrode aggregometry (MEA, Roche Diagnostics, Rotkreuz, Switzerland) was performed within three hours after blood draw.
To assess the overall capacity of platelet aggregation, blood samples were stimulated with thrombin receptor activating peptide-6, TRAP-6 (final concentration 32 μM). Whole blood was stimulated with adenosine diphosphate, ADP (final concentration 6.4 μM) to monitor platelet reactivity. Aggregation was quantified as area under the curve (AUC) of aggregation units up to six minutes after addition of the stimulant. High on-clopidogrel platelet reactivity (HPR) was defined as ADP AUC ≥ 46 U (Units) and low platelet reactivity (LPR) as ADP AUC ≤ 18 U [14 (link)–16 (link)]. Reference values for normal TRAP-6-induced aggregation were defined as AUC 94–156 U as suggested by the manufacturer.

Venous blood samples were taken using 21 G butterfly needle (Safety-Multifly^®-Set, Sarstedt, Nümbrecht, Germany) to a final concentration of >15 μg/mL r-hirudin (SARSTEDT Monovetten, Nümbrecht, Germany) for MEA and 17 IU/mL Li-heparin (Becton, Dickinson and Company, Heidelberg, Germany) for TEG. Blood samples were stored at room temperature, and platelet function was analyzed according to the manufacturer’s instructions.