 Previous studies show inconsistent results on the role of innervation imaging (with I-123-mIBG) and perfusion imaging in predicting appropriate ICD therapy (aICDth). These studies included patients with both dilated and ischemic cardiomyopathy. This study compared the ability of 123I-mIBG imaging along with perfusion imaging (using thallium-199) to predict aICDth in patients with ischemic heart failure (IHF) in relation to indication for ICD implantation (primary vs. secondary prevention of sudden cardiac death (SCD)).