title: Myocardial salvage is reduced in primary PCI-treated STEMI patients with microvascular obstruction, demonstrated by early and late CMR.
abstract: OBJECTIVE
  This study evaluates the association between microvascular obstruction and myocardial salvage, determined by cardiac magnetic resonance performed both in the acute stage of myocardial infarction and after 4 months.
  
  
  METHODS
  In patients with acute ST-elevation myocardial infarction treated by primary percutaneous coronary intervention, myocardial salvage, infarct size, left ventricular volumes, and ejection fraction were assessed by early (1-4 days) and follow-up (4 months) cardiac magnetic resonance. These variables were related to the presence or absence of microvascular obstruction at early investigation. Myocardial salvage was determined by: (1) myocardium at risk and infarct size measured in the acute stage and (2) myocardium at risk, measured acutely, and infarct size measured after 4 months. Multivariate analyses were performed, adjusting for clinical confounders at baseline.
  
  
  RESULTS
  Microvascular obstruction was present in 49 of 94 included patients, (52%). Myocardial salvage was significantly reduced in patients with microvascular obstruction, compared to those without: 23% vs. 38%, measured acutely, and 39.8% vs. 65.4%, after 4 months (p<0.001). The presence of microvascular obstruction was significantly and independently associated with large infarct size, lower left ventricular ejection fraction, and larger left ventricular end-systolic volume.
  
  
  CONCLUSIONS
  The presence of microvascular obstruction demonstrated by cardiac magnetic resonance early after infarction was associated with impaired myocardial salvage. This association was more marked when based on measurement of infarct size after 4 months compared to assessment in the acute stage.
authors: Department of Cardiology Oslo University Hospital Ullevål, Oslo, Norway ; Center for Heart Failure Research, University of Oslo, Norway.
authors: Shanmuganathan
authors: S
authors: Limalanathan
authors: Jan
authors: J
authors: Eritsland
authors: Geir Øystein
authors: GØ
authors: Andersen
authors: Nils-Einar
authors: NE
authors: Kløw
authors: Michael
authors: M
authors: Abdelnoor
authors: Pavel
authors: P
authors: Hoffmann
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D055806:Microvessels / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000628:therapy*; D009206:Myocardium / Q000473:pathology; D011446:Prospective Studies; D013318:Stroke Volume; D016896:Treatment Outcome
references: J Am Coll Cardiol. 2008 Feb 5;51(5):529-35
references: 18237680
references: J Am Coll Cardiol. 2010 Jun 1;55(22):2470-9
references: 20510214
references: J Clin Invest. 1974 Dec;54(6):1496-508
references: 4140198
references: Cardiology. 2010;116(2):103-9
references: 20588018
references: J Cardiovasc Magn Reson. 2004;6(4):917-25
references: 15646895
references: Eur Heart J Cardiovasc Imaging. 2012 May;13(5):433-43
references: 22207343
references: Eur Heart J. 2008 Dec;29(23):2909-45
references: 19004841
references: JACC Cardiovasc Imaging. 2010 Jan;3(1):45-51
references: 20129530
references: Eur Heart J. 2010 Nov;31(21):2660-8
references: 20675660
references: Circ Cardiovasc Imaging. 2009 Jan;2(1):47-55
references: 19808564
references: N Engl J Med. 2007 Sep 13;357(11):1121-35
references: 17855673
references: Radiology. 2007 Oct;245(1):95-102
references: 17885184
references: J Cardiovasc Magn Reson. 2011 Feb 18;13:13
references: 21332972
references: Trials. 2011 Sep 14;12:204
references: 21917147
references: J Clin Invest. 1985 Nov;76(5):1713-9
references: 4056048
references: Circulation. 2002 Feb 5;105(5):656-62
references: 11827935
references: BMJ. 2001 Nov 10;323(7321):1123-4
references: 11701584
references: Eur Heart J. 2005 Mar;26(6):549-57
references: 15713695
references: JACC Cardiovasc Imaging. 2009 May;2(5):569-76
references: 19442942
references: Catheter Cardiovasc Interv. 2009 Dec 1;74(7):1000-7
references: 19626683
references: Eur Heart J. 2009 Aug;30(16):1978-85
references: 19502624
references: J Am Coll Cardiol. 2010 Apr 20;55(16):1649-60
references: 20394867
references: Eur Radiol. 2007 Oct;17(10):2572-80
references: 17361420
references: J Am Coll Cardiol. 2008 Jul 15;52(3):181-9
references: 18617066
references: Circulation. 1998 Mar 3;97(8):765-72
references: 9498540