title: Histopathology of the great vessels in patients with pulmonary arterial hypertension in association with congenital heart disease: large pulmonary arteries matter too.
abstract: BACKGROUND
  Pulmonary arterial hypertension (PAH) is considered primarily a disease of the distal pulmonary arteries whereas little is known on the effect of long-standing pulmonary hypertension on the larger proximal pulmonary arteries. This study aims to investigate the structural changes in the great arteries of adults who developed PAH in association with congenital heart disease (CHD), with severe cases termed Eisenmenger syndrome.
  
  
  METHODS
  We performed macroscopic and light microscopy analyses on the great arteries of 10 formalin-fixed human hearts from patients with PAH/CHD and compared them to age-matched healthy controls. A detailed histology grading score was used to assess the severity of medial wall abnormalities.
  
  
  RESULTS
  Severe atherosclerotic lesions were found macroscopically in the elastic pulmonary arteries of 4 PAH/CHD specimens and organised thrombi in 3; none were present in the controls. Significant medial wall abnormalities were present in the pulmonary trunk (PT), including fibrosis (80%), and atypical elastic pattern (80%). Cyst-like formations were present in less than one third of patients and were severe in a single case leading to wall rupture. The cumulative PT histology grading score was significantly higher in PAH/CHD cases compared to controls (p<0.0001) and correlated positively with larger PT diameters (ρ=0.812, p<0.0001) and the degree of medial wall hypertrophy (ρ=0.749, p<0.0001).
  
  
  CONCLUSIONS
  Chronic PAH in association with CHD results in marked macroscopic and histological abnormalities in the large pulmonary arteries. These abnormalities are likely to affect haemodynamics and contribute to morbidity and mortality in this cohort.
authors: Adult Congenital Heart Disease Centre and Centre for Pulmonary Hypertension, Royal Brompton Hospital and National Heart Lung Institute, Imperial College School of Medicine, London, United Kingdom. Electronic address: m.prapa@rbht.nhs.uk.
authors: Matina
authors: M
authors: Prapa
authors: Karen P
authors: KP
authors: McCarthy
authors: Konstantinos
authors: K
authors: Dimopoulos
authors: Mary N
authors: MN
authors: Sheppard
authors: Dimitra
authors: D
authors: Krexi
authors: Lorna
authors: L
authors: Swan
authors: S John
authors: SJ
authors: Wort
authors: Michael A
authors: MA
authors: Gatzoulis
authors: Siew Yen
authors: SY
authors: Ho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000473:pathology*; D004541:Eisenmenger Complex / Q000150:complications* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000473:pathology* / Q000503:physiopathology; D012189:Retrospective Studies; D055815:Young Adult
keywords: Arteries; CHD; Congenital heart disease; ETC; HGS; LPA; PA; PAH; PT; PT/Ao MT; Pulmonary arterial hypertension; RPA; STJ; Structure; Tissue; congenital heart disease; elastic tissue configuration; histology grading score; left pulmonary artery; pulmonary arterial hypertension; pulmonary artery; pulmonary trunk; pulmonary trunk-to-aortic media thickness; right pulmonary artery; sinutubular junction