Myocardial viability testing and the effect of early intervention in patients with advanced left ventricular systolic dysfunction

Background - The clinical value of revascularization and other procedures in patients with severe systolic heart failure is unclear. It has been suggested that assessing ischemia and viability by positron emission tomography ( PET) with fluorodeoxyglucose (FDG) imaging may identify patients for whom revascularization may lead to improved survival. We performed a propensity analysis to determine whether there might be a survival advantage from revascularization. Methods and Results - We analyzed the survival of 765 consecutive patients ( age 64 +/- 11 years, 80% men) with advanced left ventricular systolic dysfunction ( ejection fraction <= 35%) and without significant valvular heart disease who underwent PET/FDG study at the Cleveland Clinic between 1997 and 2002. Early intervention was defined as any cardiac intervention ( surgical or percutaneous) within the first 6 months of the PET/FDG study. In the entire cohort, 230 patients (30%) underwent early intervention (188 [25%] had open heart surgery, most commonly coronary artery bypass grafting, and 42 [5%] had percutaneous revascularization); 535 (70%) were treated medically. Using 39 demographic, clinical and PET/FDG variables, we were able to propensity-match 153 of the 230 patients with 153 patients who did not undergo early intervention. Among the propensity-matched group, there were 84 deaths during a median of 3 years follow-up. Early intervention was associated with a markedly lower risk of death (3-year mortality rate of 15% versus 35%, propensity adjusted hazard ratio 0.52, 95% CI 0.33 to 0.81, P = 0.0004). Conclusions - Among systolic heart failure patients referred for PET/FDG, early intervention may be associated with improved survival irrespective of the degree of viability.