title: Effect of Ischemia Duration and Door-to-Balloon Time on Myocardial Perfusion in ST-Segment Elevation Myocardial Infarction: An Analysis From HORIZONS-AMI Trial (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction).
abstract: OBJECTIVE
  This study sought to investigate the effect of treatment delay on microvascular reperfusion in ST-segment elevation myocardial infarction (STEMI) patients from the large, multicenter, prospective HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction) trial.
  
  
  BACKGROUND
  Despite restoration of epicardial blood flow during primary percutaneous coronary intervention (PCI), one-third of patients do not obtain myocardial perfusion due to impairment in the microvascular circulation.
  
  
  METHODS
  We examined the effect of symptom onset-to-balloon time (SBT) and door-to-balloon time (DBT) on myocardial reperfusion during primary PCI in STEMI, utilizing resolution of ST-segment elevation (STR) and the myocardial blush grade (MBG). The primary analysis was the relationships between SBT ≤2, >2 to 4, and >4 h and DBT ≤1, >1 to 1.5, >1.5 to 2, and >2 h with MBG and STR. Clinical risk was assessed using a modified version of the Thrombolysis In Myocardial Infarction risk score for STEMI.
  
  
  RESULTS
  In 2,056 patients, absent microvascular perfusion (MBG 0/1) and STR (STR <30%) after primary PCI was significantly more common in patients with longer SBT, in patients with both low and high clinical risk profiles. By multivariable analysis, SBT (p < 0.0001), anterior infarction (p < 0.0001), reference vessel diameter (p = 0.005), lesion minimum lumen diameter (p < 0.0001), hyperlipidemia (p = 0.03), and current smoking (p = 0.001) were independent predictors of MBG 0/1, whereas SBT (p = 0.007), anterior infarction (p < 0.0001), and history of renal insufficiency (p = 0.0002) were independent predictors of absent STR. DBT (p < 0.0001) was an independent predictor of MBG 0/1. MBG 0/1 and STR<30% identified patients with increased 3-year mortality.
  
  
  CONCLUSIONS
  The present study suggests that delay in mechanical reperfusion therapy during STEMI is associated with greater injury to the microcirculation.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; St. George's, University of London, London, United Kingdom.
authors.forename: Abhiram
authors.initials: A
authors.lastname: Prasad
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
authors.affiliation: The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Clinical Trials Center, Cardiovascular Research Foundation, New York, New York. Electronic address: roxana.mehran@mssm.edu.
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.affiliation: LeBauer Cardiovascular Research Foundation/Cone Health, Greensboro, North Carolina.
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Brodie
authors.affiliation: Clinical Trials Center, Cardiovascular Research Foundation, New York, New York; New York Methodist Hospital, Brooklyn, New York.
authors.forename: Sorin J
authors.initials: SJ
authors.lastname: Brener
authors.affiliation: Center for Interventional Vascular Therapy, Division of Cardiology, Columbia University Medical Center, New York, New York.
authors.forename: José M
authors.initials: JM
authors.lastname: Dizon
authors.affiliation: Yale Cardiovascular Research Program, Yale University Medical Center, New Haven, Connecticut.
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Lansky
authors.affiliation: Department of Cardiology and Pneumology, Helios Amper-Klinikum, Dachau, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Witzenbichler
authors.affiliation: Cardiology Division, Rabin Medical Center, Petah-Tikva, Israel.
authors.forename: Ran
authors.initials: R
authors.lastname: Kornowski
authors.affiliation: Ospedale Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Guagliumi
authors.affiliation: Department of Interventional Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dudek
authors.affiliation: Clinical Trials Center, Cardiovascular Research Foundation, New York, New York; Center for Interventional Vascular Therapy, Division of Cardiology, Columbia University Medical Center, New York, New York.
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003326:Coronary Circulation; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D055414:Myocardial Perfusion Imaging; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D011446:Prospective Studies; D011474:Prosthesis Design; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D061665:Time-to-Treatment; D016896:Treatment Outcome
chemical_list: D008670:Metals
keywords: PCI; STEMI; ischemia duration; myocardial infarction; perfusion