How many patients with ischemic cardiomyopathy exhibit viable myocardium?

Severe left ventricular (LV) dysfunction secondary to chronic coronary artery disease is a major problem in clinical cardiology.(1) Incidence is increasing and the severity of LV dysfunction is related to clinical outcome.(1,2) Current options of treatment include medical therapy and heart transplantation. Transplantation is associated with excellent survival, but the number of donor hearts is limited, and medical therapy is still suboptimal.(1-3) Coronary revascularization can be an alternative treatment in selected patients. However, surgery in these patients is associated with higher morbidity and mortality, and thus a careful selection of patients who may benefit from revascularization is necessary to offset this higher risk. It has been demonstrated that in the presence of viable myocardium, revascularization may improve LV function, heart failure symptoms, and prognosis.(4,5) In view of the rapidly increasing number of patients with ischemic cardiomyopathy and the suboptimal therapeutic options, it is of interest to know how many patients may be eligible (based on viability assessment) for coronary revascularization. This information is currently not available. To establish the prevalence of myocardial viability, consecutive patients who had ischemic cardiomyopathy were studied with dobutamine stress echocardiography.