title: The effects of enhanced external counterpulsation on myocardial perfusion in patients with stable angina: a multicenter radionuclide study.
abstract: BACKGROUND
  Enhanced external counterpulsation (EECP) reduces angina and extends time to exercise-induced ischemia in patients with symptomatic coronary disease. One- and two-center studies and a retrospective case series reported that EECP improves myocardial perfusion in stable angina pectoris. We sought to critically evaluate and quantify the effect of EECP on myocardial perfusion.
  
  
  METHODS
  In 6 US university hospitals, EECP was performed for 35 hours in patients with class II to IV angina who had exercise-induced myocardial ischemia. Symptom-limited quantitative gated technetium Tc 99m sestamibi single photon emission computed tomography exercise perfusion imaging was performed at baseline and 1 month post-EECP. Sestamibi was injected at the same heart rate in both stress tests. Single photon emission computed tomography images were read at a blinded core laboratory.
  
  
  RESULTS
  Thirty-seven patients were enrolled, 34 of whom completed pre- and post-EECP stress testing. The mean age was 61 +/- 10 years, 81% were male, 78% had prior revascularization, and 68% had 3-vessel disease. The mean angina class decreased from 2.7 +/- 0.7 at baseline to 1.7 +/- 0.7 after EECP (P < .001). Exercise duration increased from 9.1 +/- 3.7 minutes at baseline to 10.2 +/- 3.6 minutes post-EECP (P = .03). The average percentage of tracer uptake, magnitude of reversibility, average thickening fraction, and the left ventricular ejection fraction remained unchanged after EECP.
  
  
  CONCLUSIONS
  We confirm previous report that EECP reduces angina and improves exercise capacity. There were no significant changes in mean defect magnitude, amount of reversibility, thickening fraction, and ejection fraction measured using myocardial quantitative single photon emission computed tomography imaging when compared at identical pre- and post-EECP heart rates.
authors.affiliation: Division of Cardiology, University of California, San Francisco Medical Center, San Francisco, California 94143-0124, USA. andrewm@itsa.ucsf.edu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Michaels
authors.forename: Ajit
authors.initials: A
authors.lastname: Raisinghani
authors.forename: Ozlem
authors.initials: O
authors.lastname: Soran
authors.forename: Paul-Andre
authors.initials: PA
authors.lastname: de Lame
authors.forename: Michele L
authors.initials: ML
authors.lastname: Lemaire
authors.forename: Paul
authors.initials: P
authors.lastname: Kligfield
authors.forename: Denny D
authors.initials: DD
authors.lastname: Watson
authors.forename: C Richard
authors.initials: CR
authors.lastname: Conti
authors.forename: George
authors.initials: G
authors.lastname: Beller
mesh_terms: D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D003326:Coronary Circulation; D015908:Counterpulsation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging