title: Relation between door-to-balloon time and microvascular perfusion as evaluated by myocardial blush grade, corrected TIMI frame count, and ST-segment resolution in treatment of acute myocardial infarction.
abstract: BACKGROUND
  The role of microvascular perfusion in relation to door-to-balloon time and mortality remains unknown. We sought to compare microvascular perfusion in patients who had undergone primary percutaneous coronary intervention with door-to-balloon time < or =90 minute versus >90 minutes.
  
  
  METHODS
  Using myocardial blush grade (MBG), corrected TIMI frame count (CTFC), and ST-segment resolution, microvascular perfusion was assessed in 297 patients who underwent successful primary percutaneous coronary intervention between January 2007 and April 2008.
  
  
  RESULTS
  Door-to-balloon time was < or =90 minutes in 199 (67%) patients and >90 minutes in 98 (33%) patients. Univariate analysis showed that door-to-treatment >90 minutes was associated with MBG 0/1 and CTFC >28. However, it was not associated with ST-segment resolution < or =70%. After adjustment for baseline confounding factors, door-to-balloon time >90 minutes was still associated with MBG 0/1 (adjusted OR 3.20, 95% CI 1.87 to 5.49, P < 0.001) and CTFC >28 (adjusted OR 6.30, 95% CI 3.56 to 11.17, P < 0.001). Thirty-day mortality was higher in patients with longer door-to-balloon time (adjusted OR 2.87, 95% CI 0.94 to 8.77, P = 0.064).
  
  
  CONCLUSIONS
  We found that door-to-balloon time >90 minutes, compared with < or =90 minutes, was independently associated with MBG 01/2 and CTFC >28, both suggesting microvascular obstruction. However, such association was not found in ST-segment resolution. Patients with door-to-balloon time >90 minutes also had higher 30-day mortality.
authors.affiliation: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. mdclchr@nus.edu.sg
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Lee
authors.forename: Bee-Choo
authors.initials: BC
authors.lastname: Tai
authors.forename: Cindy
authors.initials: C
authors.lastname: Lau
authors.forename: Zhaojin
authors.initials: Z
authors.lastname: Chen
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Low
authors.forename: Swee-Guan
authors.initials: SG
authors.lastname: Teo
authors.forename: Huay-Cheem
authors.initials: HC
authors.lastname: Tan
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D006328:Cardiac Catheterization / Q000379:methods*; D003331:Coronary Vessels / Q000601:surgery; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000601:surgery; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000601:surgery*; D015425:Myocardial Reperfusion / Q000379:methods*; D010477:Perfusion; D011446:Prospective Studies; D012039:Regional Blood Flow; D016896:Treatment Outcome