Acetylsalicylic acid reduces vegetation bacterial density, hematogenous bacterial dissemination, and frequency of embolic events in experimental Staphylococcus aureus endocarditis through antiplatelet and antibacterial effects

• Published in: Circulation (New York, N.Y.) N.Y.), 1999-06, Vol.99 (21), p.2791-2797
• Main Authors: Kupferwasser, L I, Yeaman, M R, Shapiro, S M, Nast, C C, Sullam, P M, Filler, S G, Bayer, A S
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - therapeutic use; Aspirin - therapeutic use; Colony Count, Microbial; Embolism - microbiology; Endocarditis, Bacterial - drug therapy; Endocarditis, Bacterial - microbiology; Microbial Sensitivity Tests; Platelet Aggregation Inhibitors - therapeutic use; Rabbits; Staphylococcal Infections - drug therapy; Staphylococcus aureus
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/01.CIR.99.21.2791

Platelets are integral to cardiac vegetations that evolve in infectious endocarditis. It has been postulated that the antiplatelet aggregation effect of aspirin (ASA) might diminish vegetation evolution and embolic rates. Rabbits with Staphylococcus aureus endocarditis were given either no ASA (controls) or ASA at 4, 8, or 12 mg. kg-1. d-1 IV for 3 days beginning 1 day after infection. Vegetation weights and serial echocardiographic vegetation size, vegetation and kidney bacterial densities, and extent of renal embolization were evaluated. In addition, the effect of ASA on early S aureus adherence to sterile vegetations was assessed. In vitro, bacterial adherence to platelets, fibrin matrices, or fibrin-platelet matrices was quantified with either platelets exposed to ASA or S aureus preexposed to salicylic acid (SAL). ASA at 8 mg. kg-1. d-1 (but not at 4 or 12 mg. kg-1. d-1) was associated with substantial decreases in vegetation weight (P