title: Platelet function recovery after ticagrelor withdrawal in patients awaiting urgent coronary surgery.
abstract: Dual antiplatelet therapy with ticagrelor and aspirin is associated with an increased risk of perioperative bleeding complications. Current guidelines recommend therefore discontinuation of ticagrelor 5 days before surgery to allow sufficient recovery of platelet function. It is not known how the time to recovery varies between individual patients after discontinuation of ticagrelor.
  
  
  
  Twenty-five patients accepted for urgent coronary artery bypass surgery and treated with ticagrelor and aspirin were included in a prospective observational study. Platelet aggregation was evaluated with impedance aggregometry at five timepoints 12-96 h after discontinuation of ticagrelor. In a subset of patients ( n  = 15), we also tested the ex vivo efficacy of platelet concentrate supplementation on platelet aggregation.
  
  
  
  There was a gradual increase in mean adenosine diphosphate-induced platelet aggregation after discontinuation of ticagrelor. After 72 h, mean aggregation was 38 ±23 aggregation units (U), which is above a previously suggested cut-off of 22 U, when patients can be operated without increased bleeding risk. However, there was a large interindividual variability (range 4‒88 U at 72 h) and 6/24 patients (25%) had <22 U after 72 h. Ex vivo administration of platelet concentrate did not improve adenosine diphosphate-induced aggregation at any timepoint after ticagrelor discontinuation.
  
  
  
  Adenosine diphosphate-induced aggregation was acceptable after 72 h in the majority of patients but with a large interindividual variability. Due to the large variability, platelet function testing may prove to be a valuable tool in timing of surgery in patients with ongoing or recently stopped ticagrelor treatment. Adenosine diphosphate-induced aggregation was not improved by addition of platelet concentrate.
authors.affiliation: Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.|Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Emma C
authors.initials: EC
authors.lastname: Hansson
authors.affiliation: Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.|Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Malm
authors.affiliation: Department of Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Camilla
authors.initials: C
authors.lastname: Hesse
authors.affiliation: Department of Medicine, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Hornestam
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.|Department of Medicine, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Dellborg
authors.affiliation: Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Rexius
authors.affiliation: Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.|Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Jeppsson
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D000368:Aged; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D010979:Platelet Function Tests; D017713:Platelet Transfusion; D011300:Preoperative Care / Q000379:methods; D057234:Preoperative Period; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D000077486:Ticagrelor; D028761:Withholding Treatment
chemical_list: D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000077486:Ticagrelor; D000241:Adenosine
keywords: Acute coronary syndrome; Cardiac surgery; Platelet aggregation inhibitors; Platelet function test; Platelet transfusion