The STICH study affords a unique opportunity to specifically evaluate the mechanism and prognosis of functional MR in a large group of patients with HF due to ischemic cardiomyopathy. The study design of STICH allows exploring the interactions between the mechanism of functional MR, therapy, and prognosis. For example, it is not known whether all patients with functional MR have an adverse prognosis or whether their prognosis is related to specific mechanisms or severity. In patients undergoing CABG, it is not known which patients with functional MR will require valve repair or which ones will do well without it. It is also not known whether SVR reduces MR severity more than medical therapy and by what mechanism. It is possible that improvement in functional MR is a consequence of reversed LV remodeling, which is known to be related to myocardial viability, independent of specific therapy. These important questions are addressed by the TEE STICH study, an ancillary study to the STICH study.