RESUMEN
Background The assessment of myocardial viability has been used to identify patients withcoronary artery disease and left ventricular dysfunction in whom coronary-arterybypass grafting (CABG) will provide a survival benefit. However, the efficacy of thisapproach is uncertain. Methods In a substudy of patients with coronary artery disease and left ventricular dysfunctionwho were enrolled in a randomized trial of medical therapy with or withoutCABG, we used single-photon-emission computed tomography (SPECT), dobutamineechocardiography, or both to assess myocardial viability on the basis of prespecifiedthresholds.ResultsAmong the 1212 patients enrolled in the randomized trial, 601 underwent assessmentof myocardial viability. Of these patients, we randomly assigned 298 to receivemedical therapy plus CABG and 303 to receive medical therapy alone. A total of 178of 487 patients with viable myocardium (37%) and 58 of 114 patients without viablemyocardium (51%) died (hazard ratio for death among patients with viable myocardium,0.64; 95% confidence interval [CI], 0.48 to 0.86; P = 0.003). However, afteradjustment for other baseline variables, this association with mortality was notsignificant (P = 0.21). There was no significant interaction between viability statusand treatment assignment with respect to mortality (P = 0.53).ConclusionsThe presence of viable myocardium was associated with a greater likelihood ofsurvival in patients with coronary artery disease and left ventricular dysfunction,but this relationship was not significant after adjustment for other baseline variables.The assessment of myocardial viability did not identify patients with a differentialsurvival benefit from CABG, as compared with medical therapy alone.(Funded by the National Heart, Lung, and Blood Institute; STICH ClinicalTrials.govnumber, NCT00023595.)