title: The relationship of intracoronary stent placement following thrombolytic therapy to tissue level perfusion.
abstract: BACKGROUND
  Stenting has been shown to improve lumen diameters and thereby improve epicardial blood flow, but the impact of stent placement on tissue level perfusion has not been well characterized.
  
  
  METHODS
  Data were drawn from the LIMIT trial of rhuMAb CD18 (anti WBC antibody) in acute myocardial infarction (AMI). Adjunctive/rescue stenting was performed at the discretion of the investigator. The TIMI Myocardial Perfusion Grade (TMPG) was assessed and digital subtraction angiography (DSA) was used to quantify brightness of the myocardial blush.
  
  
  RESULTS
  TIMI 3 flow was 54.2% (64/118) before stent placement, and improved to 87.2% (102/117, p < 0.001) following stent placement. Likewise, Corrected TIMI Frame Counts (CTFCs) improved from medians of 37.6 to 21 (p < 0.001). By DSA, the rate of growth in brightness also tended to be greater after stenting (2.3 +/- 0.4 Gray/sec, n = 54 vs 3.1 +/- 0.3, n = 54, p = 0.07). The incidence of TMPG 0 decreased following stent placement (25.2% (29/118) vs 14.3% (16/118), p = 0.03) and the incidence of a stain in the myocardium (TMPG 1) increased (13.5% (16/118) vs 28.6% (34/118), p = 0.004).
  
  
  CONCLUSIONS
  Adjunctive stenting following thrombolytic administration in AMI improves epicardial TIMI 3 flow and TIMI frame counts as well as dye inflow into the myocardium: TMPG 0 is reduced and myocardial blush measured quantitatively by DSA tends to be brighter. However, more TMPG 1 or dye staining was present on next injection, suggesting dye outflow may be impaired.
authors.affiliation: Harvard Clinical Research Institute, Boston, MA 02215, USA.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Gibson
authors.forename: Daniel
authors.initials: D
authors.lastname: Frisch
authors.forename: Sabina A
authors.initials: SA
authors.lastname: Murphy
authors.forename: Steven G
authors.initials: SG
authors.lastname: Gourlay
authors.forename: Raymond
authors.initials: R
authors.lastname: Gibbons
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Baran
authors.forename: Michel
authors.initials: M
authors.lastname: Nguyen
authors.forename: Sebastian
authors.initials: S
authors.lastname: Palmeri
authors.forename: Hal V
authors.initials: HV
authors.lastname: Barron
mesh_terms: D001783:Blood Flow Velocity; D017023:Coronary Angiography / Q000379:methods; D003326:Coronary Circulation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015425:Myocardial Reperfusion / Q000379:methods*; D015607:Stents; D015912:Thrombolytic Therapy; D016896:Treatment Outcome