The myocardial salvage index was assessed by single photon emission computed tomography with ( 123 - ) I -- methyl-iodophenylpentadecanoic acid ( ischemic area-at-risk at onset of STEMI : AAR ) and ( 201 - ) thallium scintigraphy ( area-at-infarction at 6 months : AAI ) [ myocardial salvage index = ( AAR-AAI ) 100/AAR ( % ) ] .