Viability, prognosis, revascularization, and Pascal.

The presence and severity of ischemic left ventricular (LV) systolic dysfunction is an important predictor of prognosis. There are ample data demonstrating that for patients with coronary artery disease and ischemic LV dysfunction, revascularization is associated with a better prognosis compared with medical therapy alone. In addition, varying degrees of recovery of LV dysfunction can be observed after revascularization. To predict which patients will benefit most from surgical revascularization (and possibly which patients may not benefit at all), attempts have been made to prospectively assess the extent of myocardium that is dysfunctional but viable. However, the published literature on testing for myocardial viability is complicated, with conclusions that are sometimes contradictory. To a large degree, this is due to the disparate clinical scenarios in which myocardial viability is evaluated, the different noninvasive techniques used for its assessment, the vagaries of revascularization, and the variety of outcomes measured.