title: Clinical and Angiographic Predictors of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction.
abstract: OBJECTIVE
  We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI).
  
  
  METHODS
  We enrolled 113 patients with STEMI (age, 56±11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [<18 U (12.9±2.6 U), n=38], Mid IMR [18-31 U (23.9±4.0 U), n=38], and High IMR [>31 U (48.1±17.1 U), n=37].
  
  
  RESULTS
  The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively).
  
  
  CONCLUSIONS
  Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Yong-Soo
authors.initials: YS
authors.lastname: Baek
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Sang-Don
authors.initials: SD
authors.lastname: Park
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Soo-Han
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Man-Jong
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Dae-Hyeok
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Jun
authors.initials: J
authors.lastname: Kwan
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea.
authors.forename: Keum-Soo
authors.initials: KS
authors.lastname: Park
authors.affiliation: Division of Cardiology, Inha University Hospital, Incheon, Korea. siwoo@inha.ac.kr.
authors.forename: Seong-Ill
authors.initials: SI
authors.lastname: Woo
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000601:surgery*; D061646:Operative Time; D062645:Percutaneous Coronary Intervention; D012044:Regression Analysis
keywords: Microvascular dysfunction; ST-segment elevation myocardial infarction; doorto-balloon time; index of microcirculatory resistance; symptom-onset-to-balloon time