title: Usefulness of Hyperemic Microvascular Resistance Index as a Predictor of Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction.
abstract: OBJECTIVE
  Microvascular function is a useful predictor of left ventricular functional changes in patients with ST-segment elevation myocardial infarction (STEMI). We evaluated the usefulness of the hyperemic microvascular resistance index (hMVRI) for predicting long-term major adverse cardiovascular events (MACEs) in patients with STEMI assessed immediately after primary percutaneous coronary intervention (PCI).
  
  
  METHODS
  hMVRI were evaluated in 145 patients with first acute STEMI treated with primary PCI using an intracoronary Doppler wire. hMVRI was defined as the ratio of mean aortic pressure over hyperemic averaged peak velocity of infarct-related artery. Major adverse cardiovascular events (MACEs) included cardiac death and re-hospitalization for congestive heart failure.
  
  
  RESULTS
  During the mean follow-up of 85±43 months, MACEs occurred in 17.2% of patients. Using a receiver-operating characteristics analysis, hMVRI >2.82 mm Hg·cm-1·sec (sensitivity: 87%; specificity: 69%; and area under curve: 0.818) was the best cut-off values for predicting future cardiac events. The Cox proportional hazard analysis showed that hMVRI was an independent predictor for long-term MACEs (hazard ratio 1.741, 95% confidence interval 1.348-2.264, p<0.001). The Kaplan-Meier survival analysis showed a higher incidence of MACEs in patients with hMVRI >2.82 mm Hg·cm-1·sec (p<0.001).
  
  
  CONCLUSIONS
  hMVRI was a strong predictor of long-term MACEs in patients with STEMI treated with primary PCI.
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: XiongJie
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Myeong-Ho
authors.initials: MH
authors.lastname: Yoon
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Kyoung-Woo
authors.initials: KW
authors.lastname: Seo
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Seung-Jea
authors.initials: SJ
authors.lastname: Tahk
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Lim
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hyoung-Mo
authors.initials: HM
authors.lastname: Yang
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Byoung-Joo
authors.initials: BJ
authors.lastname: Choi
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Gyo-Seung
authors.initials: GS
authors.lastname: Hwang
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Joon-Han
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jin-Sun
authors.initials: JS
authors.lastname: Park
keywords: Microcirculation; Myocardial infarction; Percutaneous coronary intervention