title: Fast platelet suppression by lysine acetylsalicylate in chronic stable coronary patients. Potential clinical impact over regular aspirin for coronary syndromes.
abstract: BACKGROUND
  The rapid utilization of fibrinolytics following Q-wave myocardial infarction has clearly modified the evolution of this disease. However, it is still not known whether the immediate inhibition of platelet aggregation (PA) during the coronary event improves outcomes.
  
  
  OBJECTIVE
  The present study was designed to test, in patients with known coronary artery disease (chronic stable angina), whether the particular kinetic pattern of lysine acetylsalicylate (LA) compared with aspirin may affect the time to onset of inhibition of platelet aggregation.
  
  
  METHODS
  Ten patients suffering from chronic stable angina participated in this study to compare the efficacy and speed of the inhibition of PA with 320 mg of LA versus 320 mg of aspirin. All patients discontinued the use of aspirin and any other anti-inflammatory agents for 15 days prior to the beginning of the study. They were randomly assigned to LA or aspirin. Blood specimens were obtained to measure the PA at admission, and 5, 10, 20, 30, and 60 min after ingestion. Patients continued to take the assigned drug once a day for the following 4 days. On Day 5, a new blood sample was taken. After this, patients underwent a 15-day wash-out period, and then crossed over to the opposite drug. The samples were analyzed immediately using platelet-rich plasma stimulated with adenosine diphosphate (ADP) 2 mumol/l, collagen 1 microgram/ml, epinephrine 20 mumol/l, and sodium arachidonate acid 0.75 mm/l.
  
  
  RESULTS
  The same level of PA inhibition after 30 and 60 min of aspirin administration can be obtained with LA 5 min following ingestion (sodium arachidonate acid: LA: 16.3 +/- 25.9 vs. aspirin 57.6 +/- 8.2; p = 0.00014; collagen: LA 18.9 +/- 20.1 vs. aspirin 47.2 +/- 10.5; p = 0.00092; ADP: LA 27.3 +/- 18.4 vs. aspirin 39.7 +/- 21.8, p = 0.18; epinephrine: LA 22.0 +/- 9.9 vs. aspirin 55.4 +/- 10.9, p = 0.00002.
  
  
  CONCLUSIONS
  Platelet aggregation inhibition immediately following LA may have significant clinical implications for the treatment of coronary syndromes.
authors.affiliation: Centro de Estudios Medicos y Bioquímicos, Buenos Aires, Argentina.
authors.forename: E P
authors.initials: EP
authors.lastname: Gurfinkel
authors.forename: R
authors.initials: R
authors.lastname: Altman
authors.forename: A
authors.initials: A
authors.lastname: Scazziota
authors.forename: R
authors.initials: R
authors.lastname: Heguilen
authors.forename: B
authors.initials: B
authors.lastname: Mautner
mesh_terms: D000704:Analysis of Variance; D000787:Angina Pectoris / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D001241:Aspirin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics* / Q000494:pharmacology; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008239:Lysine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000493:pharmacokinetics* / Q000494:pharmacology; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D010975:Platelet Aggregation Inhibitors; D008239:Lysine; D001241:Aspirin; C010395:acetylsalicylic acid lysinate