title: Personalized ADP-receptor inhibition strategy and outcomes following primary PCI for STEMI (PASTOR study).
abstract: BACKGROUND
  Adequate antiplatelet therapy in patients with myocardial infarction with ST-elevation (STEMI) is vital in order to avoid ischemic complications. However, especially with the novel potent oral drugs, bleeding is a major concern. We aimed to investigate whether STEMI patients switched to novel ADP receptor inhibitors due to high platelet reactivity (HPR) on clopidogrel have similar outcomes compared to patients with adequate response to clopidogrel.
  
  
  METHODS
  A prospective cohort of 175 STEMI patients (mean age 62.3 years) undergoing primary PCI were included in the PASTOR study. Patients were loaded with 600 mg clopidogrel before the index PCI procedure. Bedside VerifyNow P2Y12 platelet function testing was performed the following morning.
  
  
  RESULTS
  46 patients (26.3%) were found to have HPR on clopidogrel (PRU>235) and were switched to novel ADP receptor antagonists. The remaining 129 patients were treated with clopidogrel. The mean duration of dual antiplatelet therapy (DAPT) was 6.7 months. Duration of entire follow-up of patients was approximately 2 years. Major adverse cardiac events (MACE) while patients were on DAPT occurred in 7.0% in the clopidogrel group compared to 8.7% in the novel ADP receptor antagonist group (p=0.70). No differences were observed between groups off-DAPT either.
  
  
  CONCLUSIONS
  Following primary PCI for STEMI, patients with adequate response to clopidogrel show similar outcomes compared to patients switched to novel ADP receptor antagonists due to HPR on clopidogrel. Platelet reactivity testing can be used to guide the choice of antiplatelet therapy in patients with STEMI treated by primary PCI.
authors.affiliation: Heart Center, Satakunta Central Hospital, Pori, Finland. Electronic address: Jussi.Mikkelsson@satshp.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Mikkelsson
authors.affiliation: Heart Center, Satakunta Central Hospital, Pori, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Paana
authors.affiliation: Department of Hematology, Helsinki University Hospital Comprehensive Cancer Center and University of Helsinki, Finland.
authors.forename: Aino
authors.initials: A
authors.lastname: Lepantalo
authors.affiliation: Heart Center, Satakunta Central Hospital, Pori, Finland.
authors.forename: Pasi P
authors.initials: PP
authors.lastname: Karjalainen
mesh_terms: D000368:Aged; D000991:Antithrombins / Q000008:administration & dosage; D000077144:Clopidogrel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000188:drug therapy / Q000601:surgery / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D057285:Precision Medicine / Q000379:methods*; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D016896:Treatment Outcome
chemical_list: D000991:Antithrombins; D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: Clopidogrel; Myocardial infarction; Platelets; Prasugrel; Ticagrelor