title: Coronary flow reserve is impaired in young men with familial hypercholesterolemia.
abstract: OBJECTIVE
  We sought to investigate whether functional abnormalities in coronary vasomotion exist in young adults by studying 15 men (age 31 +/- 8 years [mean +/- SD]) with familial hypercholesterolemia (FH) and a matched group of 20 healthy control subjects.
  
  
  BACKGROUND
  Precursors of morphologic coronary artery disease are known to be present in adolescents and young adults with a high risk factor profile.
  
  
  METHODS
  Myocardial blood flow was measured at the basal state and during dipyridamole-induced hyperemia using positron emission tomography and oxygen-15-labeled water.
  
  
  RESULTS
  Serum total and low density lipoprotein cholesterol concentrations were higher in the patients than in the control subjects (mean +/- SD): 7.7 +/- 1.9 versus 5.3 +/- 1.5 mmol/liter (298 +/- 73 vs. 205 +/- 58 mg/dl) and 6.1 +/- 1.8 versus 3.5 +/- 1.4 mmol/liter (236 +/- 70 vs. 135 +/- 54 mg/dl), respectively (both p < 0.001). The baseline myocardial blood flow was similar in the patients and control subjects: 0.92 +/- 0.24 versus 0.83 +/- 0.13 ml/g per min, respectively (p = 0.21). A significant increase in flow was observed in both groups after dipyridamole infusion, but the flow at maximal vasodilation was 29% lower in the patients: 3.19 +/- 1.59 versus 4.49 +/- 1.27 ml/g per min (p = 0.011). Consequently, coronary flow reserve (the ratio of hyperemia flow to basal flow) was 35% lower in the patients than in the control subjects: 3.5 +/- 1.6 versus 5.4 +/- 1.5 (p = 0.0008). Total coronary resistance during hyperemia was higher in the patients than in the control subjects: 36 +/- 25 versus 21 +/- 10 mm Hg/min per g per ml (p = 0.045). Coronary flow reserve was inversely associated with serum total cholesterol concentration: r = -0.43 (p = 0.009).
  
  
  CONCLUSIONS
  Coronary flow reserve is reduced in young men with FH, and, consequently, coronary resistance during hyperemia is increased. The results demonstrate very early impairment of coronary vasomotion in hypercholesterolemic patients.
authors.affiliation: Department of Medicine, Turku University, Finland.
authors.forename: O P
authors.initials: OP
authors.lastname: Pitkänen
authors.forename: O T
authors.initials: OT
authors.lastname: Raitakari
authors.forename: H
authors.initials: H
authors.lastname: Niinikoski
authors.forename: P
authors.initials: P
authors.lastname: Nuutila
authors.forename: H
authors.initials: H
authors.lastname: Iida
authors.forename: L M
authors.initials: LM
authors.lastname: Voipio-Pulkki
authors.forename: R
authors.initials: R
authors.lastname: Härkönen
authors.forename: U
authors.initials: U
authors.lastname: Wegelius
authors.forename: T
authors.initials: T
authors.lastname: Rönnemaa
authors.forename: J
authors.initials: J
authors.lastname: Viikari
authors.forename: J
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000328:Adult; D000367:Age Factors; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000209:etiology; D004176:Dipyridamole; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D014055:Tomography, Emission-Computed; D014655:Vascular Resistance; D014665:Vasodilator Agents
chemical_list: D008078:Cholesterol, LDL; D014665:Vasodilator Agents; D004176:Dipyridamole; D002784:Cholesterol