1) Lack of viability data on all patients; patients represent a subpopulation of STICH 2) Analysis limited to SPECT and DE, not PET or cardiac MRI 3) Fundamental differences in viability information provided by SPECT and DE, and differences in analytic methods between the two methods 4) Revascularization was not guided by the presence of viability 5) Optional viability testing was done upon clinical decision 6) Acceptable viability tests do not have high sensitivity or negative predictive value for identifying patients with viable myocardium