Effect of long-term aspirin use on embolic events in infective endocarditis

Background. In a recent clinical trial, aspirin therapy was initiated similar to 34 days after the onset of symptoms but did not reduce the risk of embolism in patients with endocarditis. However, it is possible that aspirin used early in the course of the disease may be beneficial. The purpose of the study is to assess the effect of long-term daily aspirin use on the risk of embolic events in patients with infective endocarditis. Methods. The clinical characteristics and outcomes of patients excluded from the Multi-Centre Aspirin Trial in Infective Endocarditis because of long-term aspirin use (n = 84) were compared with the data for patients randomized to the placebo arm (n = 55). The former patients took aspirin before and during the early stages of infective endocarditis, whereas the latter patients were not exposed to aspirin before and during the entire hospitalization. Logistic modeling was used to assess the effect of long-term aspirin use on embolism and bleeding. Results. There was a trend toward excess bleeding in long-term aspirin recipients, compared with placebo recipients (P = .065). Logistic modeling revealed that long-term aspirin use may be associated with excess bleeding (unadjusted odds ratio, 2.35 [P = .059]; adjusted odds ratio, 2.08 [P = .1181), but it had no impact on the risk of embolic events in either model. Conclusions. In patients with endocarditis, long-term daily use of aspirin does not reduce the risk of embolic events but may be associated with a higher risk of bleeding. In the acute phase of endocarditis, aspirin should be used with caution.