title: Changes in myocardial perfusion abnormalities by positron emission tomography after long-term, intense risk factor modification.
abstract: OBJECTIVE
  To quantify changes in size and severity of myocardial perfusion abnormalities by positron emission tomography (PET) in patients with coronary artery disease after 5 years of risk factor modification.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Outpatient community setting.
  
  
  METHODS
  Randomization of patients to risk factor modification consisting of very low-fat vegetarian diet, mild to moderate exercise, stress management, and group support (experimental group, n = 20) or to usual care by their own physicians, consisting principally of antianginal therapy (control group, n = 15).
  
  
  METHODS
  Quantitative coronary arteriography and PET at baseline and 5 years after randomization. Automated, objective measures of size and severity of perfusion abnormalities on rest-dipyridamole PET images and of stenosis severity on arteriograms were made by computer algorithms.
  
  
  RESULTS
  Size and severity of perfusion abnormalities on dipyridamole PET images decreased (improved) after risk factor modification in the experimental group compared with an increase (worsening) of size and severity in controls. The percentage of left ventricle perfusion abnormalities outside 2.5 SDs of those of normal persons (based on 20 disease-free individuals) on the dipyridamole PET image of normalized counts worsened in controls (mean +/- SE, + 10.3% +/- 5.6%) and improved in the experimental group (mean +/- SE, -5.1% +/- 4.8%) (P = .02); the percentage of left ventricle with activity less than 60% of the maximum activity on the dipyridamole PET image of normalized counts worsened in controls (+13.5% +/- 3.8%) and improved in the experimental group (-4.2% +/- 3.8%) (P = .002); and the myocardial quadrant on the PET image with the lowest average activity expressed as a percentage of maximum activity worsened in controls (-8.8% +/- 2.3%) and improved in the experimental group (+4.9% +/- 3.3%) (P = .001). The size and severity of perfusion abnormalities on resting PET images were also significantly improved in the experimental group as compared with controls. The relative magnitude of changes in size and severity of PET perfusion abnormalities was comparable to or greater than the magnitude of changes in percent diameter stenosis, absolute stenosis lumen area, or stenosis flow reserve documented by quantitative coronary arteriography.
  
  
  CONCLUSIONS
  Modest regression of coronary artery stenoses after risk factor modification is associated with decreased size and severity of perfusion abnormalities on rest-dipyridamole PET images. Progression or regression of coronary artery disease can be followed noninvasively by dipyridamole PET reflecting the integrated flow capacity of the entire coronary arterial circulation.
authors.affiliation: Department of Medicine, University of Texas Medical School at Houston 77030, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Gould
authors.forename: D
authors.initials: D
authors.lastname: Ornish
authors.forename: L
authors.initials: L
authors.lastname: Scherwitz
authors.forename: S
authors.initials: S
authors.lastname: Brown
authors.forename: R P
authors.initials: RP
authors.lastname: Edens
authors.forename: M J
authors.initials: MJ
authors.lastname: Hess
authors.forename: N
authors.initials: N
authors.lastname: Mullani
authors.forename: L
authors.initials: L
authors.lastname: Bolomey
authors.forename: F
authors.initials: F
authors.lastname: Dobbs
authors.forename: W T
authors.initials: WT
authors.lastname: Armstrong
mesh_terms: D000328:Adult; D000368:Aged; D001521:Behavior Therapy; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D018752:Diet, Fat-Restricted; D014676:Diet, Vegetarian; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012657:Self-Help Groups; D013312:Stress, Physiological / Q000628:therapy; D014055:Tomography, Emission-Computed
chemical_list: D000960:Hypolipidemic Agents