title: Morphological changes in small pulmonary vessels are associated with severe acute exacerbation in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Pulmonary vascular remodeling is essential for understanding the pathogenesis of chronic obstructive pulmonary disease (COPD). The total cross-sectional area (CSA) of small pulmonary vessels has been reported to correlate with the pulmonary artery pressure, and this technique has enabled the assessment of pulmonary vascular involvements. We investigated the contribution of morphological alterations in the pulmonary vessels to severe acute exacerbation of COPD (AE-COPD).
  
  
  METHODS
  This study enrolled 81 patients with COPD and 28 non-COPD subjects as control and assessed the percentage of CSA (%CSA) less than 5 mm(2) (%CSA<5) and %CSA in the range of 5-10 mm(2) (%CSA5-10) on high-resolution computed tomography images.
  
  
  RESULTS
  Compared with the non-COPD subjects, the COPD patients had lower %CSA<5. %CSA<5 was positively correlated with airflow limitation and negatively correlated with the extent of emphysema. COPD patients with lower %CSA<5 showed significantly increased incidences of severe AE-COPD (Gray's test; P=0.011). Furthermore, lower %CSA<5 was significantly associated with severe AE-COPD (hazard ratio, 2.668; 95% confidence interval, 1.225-5.636; P=0.010).
  
  
  CONCLUSIONS
  %CSA<5 was associated with an increased risk of severe AE-COPD. The distal pruning of the small pulmonary vessels is a part of the risk associated with AE-COPD, and %CSA<5 might be a surrogate marker for predicting AE-COPD.
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan; Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan; Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uto
authors.affiliation: Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Sato
authors.affiliation: Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Imokawa
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072226:Computed Tomography Angiography / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000098:blood supply* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011667:Pulmonary Veins / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D066253:Vascular Remodeling; D014797:Vital Capacity
keywords: acute exacerbation; chronic obstructive pulmonary disease (COPD); computed tomography; cross-sectional area (CSA); pulmonary vessels