title: Coronary flow reserve during coronary angioplasty in patients with a recent myocardial infarction: relation to stenosis and myocardial viability.
abstract: OBJECTIVE
  In the present study, we examined post-stenotic coronary flow before and after percutaneous transluminal coronary angioplasty (PTCA) in patients with and without a recent myocardial infarction (MI) and related it to stenosis severity and residual viability.
  
  
  BACKGROUND
  Post-stenotic coronary blood flow velocity reserve (CFVR) has been used with success to estimate functional stenosis severity in patients with stable angina. However, in patients with a recent MI, the impaired coronary vasodilator response of the reperfused myocardium may substantially alter the flow dynamics of the infarct-related artery.
  
  
  METHODS
  Distal coronary flow velocities were recorded before and after PTCA in 36 patients at day 13 +/- 7 (mean +/- SD) after acute MI and in 38 patients without MI. The CFVR was assessed by the ratio of distal hyperemic to baseline average peak velocity, using a 0.014-in. Doppler guide wire. Stenosis severity was analyzed by quantitative coronary angiography, and infarct size was assessed scintigraphically.
  
  
  RESULTS
  For similar angiographic stenosis severity, pre- and post-PTCA values of CFVR were significantly lower in patients with than without MI: 1.22 +/- 0.26 versus 1.50 +/- 0.45 before PTCA (p < 0.05) and 1.72 +/- 0.43 versus 2.21 +/- 0.74 after PTCA, respectively (p < 0.01). Although CFVR increased significantly (p < 0.0001) after angiographically successful PTCA in both study groups, abnormal CFVR (< or = 2.0) was still observed in 80% of patients with MI and in 44% of those without MI (MI vs. no MI, p = 0.001). Patients with an extensive infarction (relative infarct size > or = 50%) and those with a small infarction (relative infarct size < 50%) had comparable levels of post-PTCA CFVR (1.6 +/- 0.3 vs. 1.8 +/- 0.5, p = NS). Among a variety of factors, angiographic stenosis severity was the most important determinant of CFVR in both study groups.
  
  
  CONCLUSIONS
  In patients with a recent MI, CFVR was significantly lower than in those without MI, both before and after PTCA. Besides the presence of this postreperfusion-related impairment of the coronary vasodilating response, CFVR was mainly influenced by stenosis severity and not by residual viability.
authors.affiliation: Department of Cardiology, University Hospital Antwerp, Edegem, Belgium.
authors.forename: M J
authors.initials: MJ
authors.lastname: Claeys
authors.forename: C J
authors.initials: CJ
authors.lastname: Vrints
authors.forename: J
authors.initials: J
authors.lastname: Bosmans
authors.forename: B
authors.initials: B
authors.lastname: Krug
authors.forename: P P
authors.initials: PP
authors.lastname: Blockx
authors.forename: J P
authors.initials: JP
authors.lastname: Snoeck
mesh_terms: D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003326:Coronary Circulation; D003327:Coronary Disease / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D012008:Recurrence; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D017256:Technetium Tc 99m Sestamibi