title: Effect of pre-infarction angina on platelet reactivity in acute myocardial infarction.
abstract: BACKGROUND
  Previous studies demonstrated that patients with PIA have a smaller infarct and better in-hospital outcome after acute myocardial infarction, than those without angina. This protective effects has been attributed to ischemic preconditioning (PC), to earlier reperfusion after fibrinolysis or its better collateral circulation development. In this study we aimed at assessing platelet reactivity in patients with history of pre-infarction angina (PIA) in the acute phase of ST segment elevation myocardial infarction (STEMI) and 1 month later.
  
  
  METHODS
  85 consecutive patients (63 ± 10.5 years, 60 male) with a first STEMI treated by primary percutaneous coronary intervention (PCI) were studied at admission and 1 month later. Platelet reactivity was evaluated by flow cytometry with and without adenosine diphosphate (ADP) stimulation, by measuring monocyte-platelet aggregates (MPAs) and glycoprotein IIb/IIIa (CD41) expression in the MPA gate, and CD41 and fibrinogen receptor (PAC-1) expression in the platelet gate.
  
  
  RESULTS
  MPAs and expression of platelet receptors CD41 and PAC-1 were significantly lower in patients with than patients without PIA, both with and without ADP stimulation. After 1 month, all cytometry variables both with and without ADP stimulation were similar in the two groups.
  
  
  CONCLUSIONS
  This study shows, for the first time, that patients with a first STEMI who experience PIA show a lower platelet reactivity as compared with those without history of PIA.
authors.affiliation: Catholic University of Sacred Heart, Rome, Italy.
authors.forename: Giancarla
authors.initials: G
authors.lastname: Scalone
authors.forename: Cristina
authors.initials: C
authors.lastname: Aurigemma
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Tomai
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Corvo
authors.forename: Irma
authors.initials: I
authors.lastname: Battipaglia
authors.forename: Gaetano A
authors.initials: GA
authors.lastname: Lanza
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000453:epidemiology / Q000628:therapy*; D001792:Blood Platelets / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000453:epidemiology / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000379:methods; D010974:Platelet Aggregation / Q000502:physiology*; D016896:Treatment Outcome