title: Grade III ischemia on presentation with acute myocardial infarction predicts rapid progression of necrosis and less myocardial salvage with thrombolysis.
abstract: We assessed the relation between baseline electrocardiographic ischemia grades and initial myocardial area at risk (AR) and final infarct size (IS) in 49 patients who had undergone (99m)Tc sestamibi single-photon emission computed tomography before and 6 +/- 1 days after thrombolysis. Patients were classed as having grade III ischemia (ST segment elevation with terminal QRS distortion, n = 19) or grade II ischemia (ST elevation but no terminal QRS distortion, n = 30). We compared AR and IS by baseline ischemia grade and treatment (adenosine vs. placebo) and assessed relations of infarction index (IS/AR ratio x100) to time to thrombolysis, baseline ischemia grade, and adenosine therapy. Time to thrombolysis was similar for grade II and grade III. For placebo- treated patients, the median AR did not differ significantly between grade II (38%) and grade III patients (46%, p = 0.47), nor did median IS (16 vs. 40%, p = 0.096), but the median infarction index was 66 vs. 90% (p = 0.006). For adenosine-treated patients, median AR (21 vs. 26%, p = 0.44), median IS (5 vs. 17%, p = 0.15), and their ratio (31 vs. 67%, p = 0.23) did not differ significantly between grade II and grade III patients. The infarction index independently related to grade III ischemia (p = 0.0121) and adenosine therapy (p = 0.045). Infarct size related to baseline ischemia grade and was reduced by adenosine treatment. Necrosis progressed slowlier with baseline grade II versus III ischemia, which could offer more time for myocardial salvage with reperfusion.
authors.affiliation: Division of Cardiology, University of Texas Medical Branch, Galveston, Tex. 77555-0553, USA. yobirnba@utmb.edu
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Criger
authors.forename: Kathy B
authors.initials: KB
authors.lastname: Gates
authors.forename: Gabriel I
authors.initials: GI
authors.lastname: Barbash
authors.forename: Alejandro
authors.initials: A
authors.lastname: Barbagelata
authors.forename: Peter
authors.initials: P
authors.lastname: Clemmensen
authors.forename: Elena B
authors.initials: EB
authors.lastname: Sgarbossa
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Gibbons
authors.forename: M Atiar
authors.initials: MA
authors.lastname: Rahman
authors.forename: Robert M
authors.initials: RM
authors.lastname: Califf
authors.forename: Chistopher B
authors.initials: CB
authors.lastname: Granger
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D017202:Myocardial Ischemia / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi; D015912:Thrombolytic Therapy; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi