A large cohort study of 2160 patients from 1979 to 1998 noted that the risk of stroke after MI was dramatically higher in the first month after infarct and remained elevated for years afterward.510 In the percutaneous coro- nary angiography era, a multicenter study of 753 patients with ST-segment elevation MI identified LV thrombus in 3.5% and 7.1% of patients after ante- rior ST-segment elevation MI using cardiac MRI, although mural thrombus has been noted in as many as 26% of those studied in other series.504,505 In a meta-analysis of 8 studies encompassing 856 patients, Vaitkus and Barnathan506 noted an increased risk of stroke or systemic embolism in the presence of LV thrombus demonstrated on echocardiogram with an OR of 5.45. Moreover, the risk of embolism was substantially reduced in the presence of oral anticoagulation with a VKA with an OR of 0.14. A smaller single-center ret- rospective study of 33 patients with LV thrombus on cardiac MRI compared with 66 matched con- trols observed a short-term risk of stroke of 9.1%; another study of LV thrombus noted stroke or systemic embolism in 7.7% of patients with docu- Finally, a larger, more het- erogeneous single-center study of 155 patients with LV thrombus found on cardiac MRI compared with 400 matched patients over 3.3 years found an annualized rate of stroke or systemic embolism of 3.7% versus 0.8% in those without LV throm- bus, suggesting that an increased risk of embo- lism may persist.508 It is unclear whether events in the cohort with LV thrombus were caused by the thrombus or the LV thrombus was a marker of a higher-risk population. 2. Both administration of microbubble contrast with transthoracic echocardiography and cardiac MRI have been shown to be superior to echocardiog- raphy without contrast for the detection of LV thrombus. 