title: Effect of low-dose aspirin on the international normalized ratio variability in patients with mechanical heart valve prostheses.
abstract: An increased risk of bleeding is associated with a more intense oral anticoagulation, a greater international normalized ratio (INR) variability and the use of aspirin. We studied the INR variability of patients (n = 121) with modern heart valves who had been prospectively randomized to receive acenocoumarol at a targeted INR of 2.4-3.6 plus aspirin 100 mg/day or acenocoumarol alone at the same dosage, to evaluate whether aspirin influences variability and thus the risk of bleeding. Variability was similar in patients with no events regardless of the use of aspirin. A statistically significantly higher variability was observed in patients with bleeding events independently of the use of aspirin. Nevertheless, the concomitant use of aspirin in patients with a high variability should be monitored closely and thoroughly.
authors.affiliation: Hemostasis and Thrombosis Department, Institute of Hematological Research, National Academy of Medicine, Buenos Aires, Argentina. casais@hematologia.anm.edu.ar
authors.forename: Patricia
authors.initials: P
authors.lastname: Casais
authors.forename: Susana S
authors.initials: SS
authors.lastname: Meschengieser
authors.forename: Analia G
authors.initials: AG
authors.lastname: Sanchez Luceros
authors.forename: Emilse I
authors.initials: EI
authors.lastname: Bermejo
authors.forename: Maria A
authors.initials: MA
authors.lastname: Lazzari
mesh_terms: D000074:Acenocoumarol / Q000008:administration & dosage / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D019934:International Normalized Ratio / Q000592:standards*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012306:Risk; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D000074:Acenocoumarol; D001241:Aspirin