title: Relationship between myocardial reperfusion, infarct size, and mortality: the INFUSE-AMI (Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction) trial.
abstract: OBJECTIVE
  This study sought to compare infarct size (IS) measured by magnetic resonance imaging in patients with successful (myocardial blush grade [MBG] 2/3) versus unsuccessful (MBG 0/1) microcirculatory reperfusion in the INFUSE-AMI (Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction) trial.
  
  
  BACKGROUND
  Successful microcirculatory reperfusion, defined angiographically by MBG 2 or 3, is associated with improved outcomes in patients with ST-segment elevation myocardial infarction. The precise mechanism underlying this association is not well defined.
  
  
  METHODS
  The INFUSE-AMI trial randomized 452 patients with anterior ST-segment elevation myocardial infarction to intracoronary bolus abciximab delivered locally at the infarct lesion versus no abciximab, and to manual thrombus aspiration versus no aspiration. The primary endpoint was IS (percentage of left ventricular mass) at 30 days.
  
  
  RESULTS
  MBG 2/3 was achieved in 367 patients (81.4%). IS was significantly lower in patients with MBG 2/3 than in those with MBG 0/1 (median: 16.7% [interquartile range (IQR): 7.0 to 22.7] vs. 19.5% [IQR: 11.1 to 29.2]; p = 0.002). Intracoronary abciximab further reduced IS in patients with MBG 2/3 (median: 14.4% [IQR: 5.4 to 20.9] vs. 17.4% [IQR: 10.5 to 23.8]; p = 0.01). MBG 2/3 was associated with ∼30% reduction in infarct mass (p = 0.002) and ∼90% reduction in microvascular obstruction on day 5. Ejection fraction was higher with MBG 2/3 at 30 days: median: 50.3% (IQR: 43.8 to 57.8) versus 46.9% (IQR: 37.5 to 54.0); p = 0.004. At 30 days, the rate of death was significantly lower (1.7% vs. 8.3%; p = 0.0008) in the MBG 2/3 group.
  
  
  CONCLUSIONS
  MBG 2/3 occurs in 80% of ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention and is associated with smaller infarct size, less microvascular obstruction, improved ejection fraction, and significantly lower 30-day mortality. (Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction [INFUSE-AMI]; NCT00976521).
authors.affiliation: Department of Medicine, New York Methodist Hospital, Brooklyn, New York 11215, USA. sjb9005@nyp.org
authors.forename: Sorin J
authors.initials: SJ
authors.lastname: Brener
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.forename: Jose M
authors.initials: JM
authors.lastname: Dizon
authors.forename: Martin
authors.initials: M
authors.lastname: Fahy
authors.forename: Bernhard
authors.initials: B
authors.lastname: Witzenbichler
authors.forename: Helen
authors.initials: H
authors.lastname: Parise
authors.forename: Magdi
authors.initials: M
authors.lastname: El-Omar
authors.forename: Jan-Henk
authors.initials: JH
authors.lastname: Dambrink
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Keith
authors.initials: K
authors.lastname: Oldroyd
authors.forename: C Michael
authors.initials: CM
authors.lastname: Gibson
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
mesh_terms: D000077284:Abciximab; D000368:Aged; D056988:Anterior Wall Myocardial Infarction / Q000401:mortality / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000008:administration & dosage* / Q000009:adverse effects; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000401:mortality; D020127:Recovery of Function; D012307:Risk Factors; D013396:Suction; D017131:Thrombectomy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D000925:Anticoagulants; D007140:Immunoglobulin Fab Fragments; D000077284:Abciximab
keywords: CMR; IC; IQR; IS; LV; MBG; MI; MVO; PCI; ST-segment elevation myocardial infarction; STEMI; TIMI; Thrombolysis In Myocardial Infarction; cardiac magnetic resonance; infarct size; interquartile range; intracoronary; left ventricular; microvascular obstruction; myocardial blush grade; myocardial infarction; percutaneous coronary intervention; thrombus aspiration