Abstract 235: Therapeutic Levels of Anticoagulation Do Not Increase Embolic Risk Early in the Course of S. Aureus Infective Endocarditis
Therapeutic levels of anticoagulation do not increase embolic risk early in the course of S.aureus infective endocarditis Introduction Current guidelines recommend temporary discontinuation of ongoing anticoagulant therapy early in the course of S. aureus (SA) infective endocarditis (IE). This guideline is based on limited data in patients with SA prosthetic valve IE demonstrating a significant risk of adverse events when anticoagulation is continued. These studies, however, do not stratify the risk of clinical events according to the level of anticoagulation as measured by the INR. We hypothesized that therapeutic levels of anticoagulation do not increase the risk of embolic events in this group of patients.
Methods: This study used the database of the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS) to address the relationship between the level of anticoagulation as measured by the INR and the risk of stroke and other embolic events in anticoagulated patients with SA IE. Of the 5593 patients enrolled in ICE-PCS between January 2000 and December 2006, there were 104 patients with SA IE who were anticoagulated at the time of admission, and had data available on the INR and incidence of stroke and other embolic events at admission.
Results: In patients with SA IE admitted with an INR >3.5, more patients had stroke or other embolic events at admission compared to those admitted with an INR <3.5 [40% (10/25) vs. 21.5% (17/79); OR 2.43, CI 0.93– 6.37, p. 0.07]. More significantly, the rate of stroke or other embolic events was no higher in anticoagulated S. aureus IE patients with INR <3.5 than in patients with S. aureus IE who were not on anticoagulation at all [21.5% (17/79) vs. 21.1% (156/740); OR 1.03, CI 0.58 –1.81, p. 0.93].
Conclusion: An excess risk of stroke and other embolic events in anticoagulated patients early in the course of SA IE appears limited to those patients who are overanticoagulated as measured by the INR. Consideration should be given to the continuation of therapeutic levels of anticoagulation even early in the course of SA IE.