title: Reduced systemic microvascular density and reactivity in individuals with early onset coronary artery disease.
abstract: OBJECTIVE
  This study sought to test whether patients with early-onset coronary artery disease (EOCAD, n=30) showed systemic microvascular rarefaction and endothelial dysfunction in comparison to age- and sex-matched healthy controls (CTL, n=30), as evaluated by skin video-capillaroscopy.
  
  
  METHODS
  Functional capillary density (FCD) was defined as the number of spontaneously perfused capillaries per square millimeter of skin area and assessed by high-resolution intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using post-occlusive reactive hyperemia (PORH) after arm ischemia for 3min.
  
  
  RESULTS
  The mean capillary density at rest was significantly reduced in patients with EOCAD compared to controls (CTL 95±20 and EOCAD 80±18capillaries/mm(2), P=0.0040). During PORH, capillary density was also markedly reduced in EOCAD patients (CTL 96±18 and EOCAD 71±20capillaries/mm(2), P<0.0001). Moreover, the capillary density in EOCAD patients was significantly reduced during PORH (EOCAD at rest 80±19 and EOCAD during PORH 71±20capillaries/mm(2), P=0.0073).
  
  
  CONCLUSIONS
  Patients with EOCAD presented systemic capillary rarefaction and impaired microvascular endothelial function. Thus, the early detection of these microvascular alterations in young adults at an increased risk of coronary artery disease could be useful as a surrogate marker of subclinical atherosclerosis.
authors.affiliation: National Institute of Cardiology (INC), Rio de Janeiro, Brazil; Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, Rio de Janeiro, Brazil. Electronic address: etibi@ioc.fiocruz.br.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tibirica
authors.affiliation: National Institute of Cardiology (INC), Rio de Janeiro, Brazil; Federal University of Rio de Janeiro, Brazil.
authors.forename: Elaine G
authors.initials: EG
authors.lastname: Souza
authors.affiliation: National Institute of Cardiology (INC), Rio de Janeiro, Brazil; Federal University of Rio de Janeiro, Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: De Lorenzo
authors.affiliation: Federal University of Rio de Janeiro, Brazil.
authors.forename: Glaucia M M
authors.initials: GM
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D017668:Age of Onset; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D042241:Early Diagnosis; D004730:Endothelium, Vascular / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D008833:Microcirculation; D020678:Microscopic Angioscopy / Q000379:methods; D018715:Microscopy, Video; D055806:Microvessels / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D011237:Predictive Value of Tests; D012867:Skin / Q000098:blood supply*
keywords: Capillary rarefaction; Cardiovascular risk; Coronary artery disease; Microvascular endothelial dysfunction; Skin microvascular reactivity