title: Aspirin therapy for inhibition of platelet reactivity in the presence of erythrocytes in patients with vascular disease.
abstract: Inhibition of erythrocyte (RBC) promotion of platelet reactivity could improve the antiplatelet effect of aspirin (ASA). We tested different ASA regimens for optimal inhibition of platelets and the effects of RBC in patients with a history of vascular diseases. Collagen-induced platelet activation (14C-5HT, TXA2 release) and platelet recruitment (proaggregatory activity of cell-free releasates from activated platelets) were measured in PRP, platelet-RBC (Hct 40%), and whole blood (WB) in 206 patients initially on 200-300-mg ASA/day. Their regimen was modified to biweekly 500 mg (loading dose, L) plus daily or twice-daily low-dose ASA (50 or 100 mg). TXA2 was inhibited with all regimens. Percentage of patients with suboptimal inhibition of platelet recruitment in WB was 200-300 ASA/day (41%), L-50/day (87%), L-100/day (58%), L-50/twice-daily (39%), and L-100/twice-daily (20%; P < 0.05 vs other regimens). 14C-5HT release was inhibited to the greatest extent with L-100/twice-daily in PRP + RBC or WB (P < 0.05 vs other regimens) due to greater inhibition of the RBC prothrombotic effect. Compared with other ASA regimens, L-100 twice-daily (equivalent to 221-mg ASA/day in the 14-day cycle), reduced by >50% the proportion of patients with suboptimal inhibition of platelet recruitment in WB and inhibited 14C-5HT release to the greatest extent.
authors.affiliation: Research Center, Hospital Universitario La Fe, Valencia, Spain. santos_ter@gva.es
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Santos
authors.forename: Juana
authors.initials: J
authors.lastname: Vallés
authors.forename: Justo
authors.initials: J
authors.lastname: Aznar
authors.forename: Aida
authors.initials: A
authors.lastname: Lago
authors.forename: Elena
authors.initials: E
authors.lastname: Sanchez
authors.forename: Juan
authors.initials: J
authors.lastname: Cosin
authors.forename: Antonio
authors.initials: A
authors.lastname: Moscardó
authors.forename: Marta
authors.initials: M
authors.lastname: Piñón
authors.forename: M Johan
authors.initials: MJ
authors.lastname: Broekman
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Marcus
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004912:Erythrocytes / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D012701:Serotonin / Q000378:metabolism; D013928:Thromboxane A2 / Q000378:metabolism
chemical_list: D010975:Platelet Aggregation Inhibitors; D012701:Serotonin; D013928:Thromboxane A2; D003094:Collagen; D001241:Aspirin