title: Immediate response to prasugrel loading in patients with ST-elevation myocardial infarction: Predictors and outcome.
abstract: BACKGROUND
  Information regarding immediate response to novel P2Y12 inhibitors in ST-elevation myocardial infarction (STEMI) is scarce and has been associated with adequate reperfusion. Recent studies have shown that the onset of anti-platelet effects of novel P2Y12 inhibitors in patients with STEMI might be slower and more variable than in stable coronary syndrome. We aimed to assess the predictors and significance of immediate platelet response to prasugrel loading in STEMI.
  
  
  METHODS
  Platelet aggregation (PA) was prospectively evaluated in STEMI patients upon prasugrel loading and at primary percutaneous coronary intervention (PPCI). Early platelet responsiveness was defined as percent reduction of PA from baseline to PPCI, divided by the time lapse from loading to PPCI. High- and low-platelet responsiveness was defined as above and below the median value respectively.
  
  
  RESULTS
  Fifty consecutive STEMI patients (age 58±8, 90% male) underwent PPCI with a mean door-to-balloon time of 42±15min. Mean PA upon prasugrel loading and at PPCI was 76±9% and 63±19%, respectively. Older age and prior aspirin use were predictors of low platelet responsiveness to prasugrel [β=(-0.33), p=0.02 and β=(-0.28), p=0.04, respectively]. Fast compared with slow responders demonstrated more frequent early ST resolution (93% vs. 72%, p=0.02) and lower peak troponin levels (76±62μg/L vs. 48±28μg/L, p=0.05).
  
  
  CONCLUSIONS
  Immediate platelet responsiveness to prasugrel among STEMI patients is highly variable and inversely associated with older age and prior aspirin use. Fast compared with slow responders have improved reperfusion and infarct size markers.
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Edward
authors.initials: E
authors.lastname: Koifman
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Roy
authors.initials: R
authors.lastname: Beigel
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Romana
authors.initials: R
authors.lastname: Herscovici
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Paul
authors.initials: P
authors.lastname: Fefer
authors.affiliation: Coagulation Unit, Sheba Medical Center, Tel Hashomer, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Rozenberg
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Avi
authors.initials: A
authors.lastname: Sabbag
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yitschak
authors.initials: Y
authors.lastname: Biton
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Segev
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Shechter
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Asher
authors.affiliation: Leviev Heart Center, Tel Aviv University, Tel Aviv, Israel. Electronic address: Shlomi.Matetzky@sheba.health.gov.il.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Matetzky
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy*; D062645:Percutaneous Coronary Intervention; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D000068799:Prasugrel Hydrochloride / Q000627:therapeutic use*; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000627:therapeutic use; D000072657:ST Elevation Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000068799:Prasugrel Hydrochloride
keywords: Acute platelet aggregation; Myocardial infarction; Prasugrel