title: Long-term impact of postconditioning on infarct size and left ventricular ejection fraction in patients with ST-elevation myocardial infarction.
abstract: BACKGROUND
  Ischemic postconditioning (PostC), reperfusion in brief cycles, is known to induce short-term reduction in infarct size in patients with ST elevation myocardial infarction (STEMI), especially among those with large myocardium at risk (MaR). The aim of the present study was to investigate the long-term effect of PostC on infarct size and left ventricular ejection fraction (LVEF).
  
  
  METHODS
  Sixty-eight patients with a first STEMI were randomised to primary percutaneous coronary intervention (PCI) (n = 35) or PCI followed by PostC (n = 33). MaR was determined as abnormally contracting segments on left ventricular angiogram. Cardiac magnetic resonance was performed at 3 and 12 months for the determination of infarct size and LVEF.
  
  
  RESULTS
  Overall there was no difference in infarct size expressed in percentage of MaR between patients randomised to the control (31%; 23, 41) and PostC (31%; 23, 43) groups at 12 months. Likewise there was no difference in LVEF between control (49%; 41, 55) and PostC (52%; 45, 55). In contrast, patients in the PostC group with MaR in the upper quartile had a significantly smaller infarct size (29%; 18, 38) than those in the control group (40%; 34, 48; p < 0.05) at 12 months. In these patients LVEF was higher in the PostC (47%; 43, 50) compared to the control group (38%; 34, 42; p < 0.01).
  
  
  CONCLUSIONS
  In this long-term follow-up study PostC did not reduce infarct size in relation to MaR or improved LVEF in the overall study population. However, the present data suggest that PostC exerts long-term beneficial effects in patients with large MaR thereby extending previously published short-term observations.
  
  
  BACKGROUND
  Karolinska Clinical Trial Registration (http://www.kctr.se). Unique identifier: CT20080014.
authors.affiliation: Karolinska Institutet, Department of Medicine, Unit of Cardiology, Karolinska University Hospital, Stockholm, Sweden. peder.sorensson@karolinska.se
authors.forename: Peder
authors.initials: P
authors.lastname: Sörensson
authors.forename: Lars
authors.initials: L
authors.lastname: Rydén
authors.forename: Nawsad
authors.initials: N
authors.lastname: Saleh
authors.forename: Per
authors.initials: P
authors.lastname: Tornvall
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
authors.forename: John
authors.initials: J
authors.lastname: Pernow
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D057775:Ischemic Postconditioning; D016014:Linear Models; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000473:pathology*; D062645:Percutaneous Coronary Intervention; D011237:Predictive Value of Tests; D020127:Recovery of Function; D013318:Stroke Volume; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left