title: Platelet Larger Cell Ratio and High-on Treatment Platelet Reactivity During Dual Antiplatelet Therapy.
abstract: BACKGROUND
  Low response to antiplatelet agents has been associated to an increased risk of thrombotic complications and recurrent ischemic events. Platelet size has been proposed as a potential marker of platelet reactivity. Therefore, the aim of the present study was to evaluate the impact of platelet Larger Cell Ratio (p-LCR) on platelet aggregation and the prevalence of residual high-on treatment platelet reactivity (HRPR) in patients receiving dual antiplatelet therapy (DAPT) after a recent acute coronary syndrome or coronary revascularization.
  
  
  METHODS
  Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. HRPR was considered for ASPI test >862 AU*min (for ASA) or ADP test values ≥417 AU*min (for ADP-antagonists) using impedance aggregometry.
  
  
  RESULTS
  Our population consisted of 530 patients receiving DAPT, who were divided in tertiles according to values of p-LCR (< 27.6; 27.6-34.7; ≥34.7 l). p-LCR was related with use of beta-blockers (p = 0.02) and statins (p = 0.002), and inversely with acute presentation (p = 0.05). Higher platelet count (p < 0.001) and haemoglobin levels (p = 0.001) were observed in higher p-LCR tertiles. The prevalence of HRPR for ASA was low and not significantly different across tertiles of p-LCR (1.1 vs 1.1 vs 1.7%, p = 0.66; adjusted OR[95%CI] = 1.68[0.66-4.29], p = 0.27). Moreover, p-LCR did not influence the occurrence of HRPR for ADP-antagonists (24.4% vs 20.9% vs 25.6 %%, p = 0.80, adjusted OR[95%CI] = 0.88[0.67-1.17], p = 0.38) and similar results were obtained when considering separately patients receiving clopidogrel (adjusted OR[95%CI] = 1.21[0.86-1.69], p = 0.29) or ticagrelor (adjusted OR[95%CI] = 1.17[0.69-2], p = 0.56).
  
  
  CONCLUSIONS
  In patients receiving DAPT for coronary artery disease, p-LCR does not impact platelet reactivity. Larger platelets did not influence the prevalence of high-on treatment platelet reactivity with the antiplatelet agents ASA, clopidogrel or ticagrelor.
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Verdoia
authors.affiliation: Clinical Chemistry, Ospedale "Maggiore della Carità", Eastern Piedmont University, Novara, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pergolini
authors.affiliation: Clinical Chemistry, Ospedale "Maggiore della Carità", Eastern Piedmont University, Novara, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Rolla
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Nardin
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Barbieri
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy.
authors.forename: Alon
authors.initials: A
authors.lastname: Schaffer
authors.affiliation: Clinical Chemistry, Ospedale "Maggiore della Carità", Eastern Piedmont University, Novara, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bellomo
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Marino
authors.affiliation: Cardiology, UMC St Radboud, Nijmegen, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Suryapranata
authors.affiliation: Department of Cardiology, Ospedale "Maggiore della Carità", Eastern Piedmont University, C.so Mazzini, 18, 28100, Novara, Italy. giuseppe.deluca@maggioreosp.novara.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Luca
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000368:Aged; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D000077144:Clopidogrel; D003324:Coronary Artery Disease / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010979:Platelet Function Tests; D000077486:Ticagrelor; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D000077486:Ticagrelor; D000241:Adenosine; D013988:Ticlopidine; D001241:Aspirin
keywords: Clopidogrel; Coronary artery disease; Dual antiplatelet therapy; Platelet aggregation; Platelet larger cell ratio; Ticagrelor