In a study from 1991, the embolic rate dropped from 13 to <1.2 embolic events per 1000 patient-days during that time.58 Vilacosta et al278 confirmed the reduced frequency of embolization after 2 weeks of therapy. Moreover, the latter study reemphasized the increased risk of embolization with increasing vegetation size during therapy, mitral valve involvement, and staphylococcal pathogenesis. In a survey that included the International Collaboration on Endocarditis cohort, Dickerman and colleagues280 focused on the incidence of stroke in a multicenter IE population and demonstrated that acute stroke rates fell significantly after initiation of antibiotic therapy regardless of valve involved or pathogen identified. Moreover, only 3.1% of the cohort suf- fered stroke after the first week of antimicrobial therapy; this finding has led to the opinion that stroke prevention as a sole indication for valve surgery after 1 week of appropriate antibi- otic therapy is not warranted. Prediction of individual patient risk for embolization is extremely difficult. Many studies have attempted to use echocardiography to identify a high-risk subset of IE patients who might benefit from early surgery to avoid embolization. Several studies with TTE have demonstrated a trend toward higher embolic rates with left-sided vegetations >1 cm in De Castro and colleagues276 compared TTE with multiplane TEE and found that neither technique was help- ful in defining embolic risk in patients with vegetations. In a based on TEE, mitral vegetations >1 cm in diameter were associated with the greatest frequency of embolism. The association was strengthened when the analysis was limited to those patients who had not yet experienced a clinical embolic event. 