Moreover, the study with the largest number of patients (n=176) that assessed the value of TEE and included silent embolism detected by CT scanning demonstrated that the risk of embolic events was highly related to vegetation size and mobility but not to other known risk factors associated with embolism in IE.283 The conflicting results on the relationship between echocardiography and embolic risk can be explained at least partially by the poor standardization of diagnostic cri- teria for IE in older series, inclusion or not of silent embolism, inclusion or not of previous embolism, echocardiographic method used, lack of focus on future embolic events after TEE, and sample size. An increase in vegetation size over 4 to 8 weeks of therapy as documented by TEE appears to predict embolic events.282 In addition, a second, albeit infrequent, peak of late embolic events has been observed to occur 15 to 30 weeks after the diagnosis of IE and has been associated with nonhealing veg- etations (failure of a vegetation to stabilize or diminish in size) as defined by echocardiography.63 The traditional indication for valvular surgery for IE to avoid embolization has been 2 major embolic events.284 This criterion is arbitrary and excludes cutaneous embolization, which is common, or embolism occurring before the insti- tution of therapy, which is common among IE patients who develop embolic events. Because of the observed decreases in embolic risk during the first 2 weeks of antibiotic therapy, the benefit of surgery in avoiding catastrophic embolic events is greatest early in the treatment course of IE. Early surgi- cal intervention may preclude a primary or recurrent major embolic event but exposes the patient to both immediate and lifelong risks of valve replacement if the valve cannot be pri- marily repaired. 