Moreover, there was a trend toward more bleeding episodes in the aspirin-treated patients. Aspirin levels, a critical correlate of antimicrobial efficacy in an animal model, were not monitored in this study.289 Retrospective, observational studies290 296 have examined the impact, if any, of long-term antiplatelet therapy before the onset of IE on infection-related outcomes. Findings from these investigations have been mixed in terms of IE-related outcomes. Until definitive data are available, the initiation of aspirin or other antiplatelet agents as adjunctive therapy in IE is not recommended. In contrast, the continuation of long- term antiplatelet therapy at the time of development of IE with no bleeding complications may be considered. Recommendations 1. Discontinuation of all forms of anticoagulation in patients with mechanical valve IE who have expe- rienced a CNS embolic event for at least 2 weeks is reasonable (Class IIa; Level of Evidence C). 2. Initiation of aspirin or other antiplatelet agents as adjunctive therapy in IE is not recommended (Class III; Level of Evidence B). 3. The continuation of long-term antiplatelet therapy at the time of development of IE with no bleeding complications may be considered (Class IIb; Level of Evidence B). Periannular Extension of Infection Extension of IE beyond the valve annulus predicts a higher mortality rate, more frequent development of heart fail- ure, and more frequent need for cardiac surgery.284,297,298 Perivalvular cavities form when annular infections break through and spread into contiguous tissue. 