title: In vivo assessment of pulmonary arterial wall fibrosis by intravascular optical coherence tomography in pulmonary arterial hypertension: a new prognostic marker of adverse clinical follow-up.
abstract: BACKGROUND
  The aim is to correlate pulmonary arterial (PA) remodeling estimated by PA fibrosis in PA hypertension (PAH) with clinical follow-up. Histology of PA specimens is also performed.
  
  
  METHODS
  19 patients, aged 54±16 (4 men), functional class II-III were studied with right heart catheterization, PA Intravascular Ultrasound and optical coherence tomography (OCT) in inferior lobe segment. PA wall fibrosis was obtained by OCT ( area of fibrosis/PA cross sectional area × 100). Patients follow-up was blind to OCT. Events were defined as mortality, lung transplantation, need of intravenous prostaglandins or onset of right ventricular failure.
  
  
  RESULTS
  OCT measurements showed high intra- and interobserver agreement. There was a good correlation between OCT and histology in PA fibrosis from explanted lungs. Area of fibrosis was 1.4±0.8 mm(2), % fibrosis was 22.3±8. Follow-up was 3.5 years (2.5-4.5). OCT %Fib was significantly correlated with PA capacitance (r=-0.536) and with pulmonary vascular rsistance (r=0.55). Patients were divided according to the median value of PA fibrosis. There were 10 patients with a high (≥ 22%) and 9 with a low fibrosis (<22%). Events occurred in 6 (1 death, 1 lung transplantation, 2 intravenous prostaglandins, 2 right heart failure) out of 10 patients with high and in 0 out of 9 patients with low fibrosis (p<0.01).
  
  
  CONCLUSIONS
  In PAH, the severity of PA remodeling assessed by OCT wall fibrosis was significantly predictive of severely unfavorable clinical outcome. In vivo assessment of pulmonary arterial wall fibrosis by intravascular OCT in PAH is a promising new prognostic marker of adverse clinical outcome.
authors.affiliation: Area del Cor, Hospital Universitari Vall d'Hebron, Spain ; Dept Fisiología Universitat Autonoma Barcelona, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Domingo
authors.forename: Juan C
authors.initials: JC
authors.lastname: Grignola
authors.forename: Rio
authors.initials: R
authors.lastname: Aguilar
authors.forename: María Angeles
authors.initials: MA
authors.lastname: Montero
authors.forename: Christian
authors.initials: C
authors.lastname: Arredondo
authors.forename: Manuel
authors.initials: M
authors.lastname: Vázquez
authors.forename: Manuel
authors.initials: M
authors.lastname: López-Messeguer
authors.forename: Carlos
authors.initials: C
authors.lastname: Bravo
authors.forename: Nadia
authors.initials: N
authors.lastname: Bouteldja
authors.forename: Cristina
authors.initials: C
authors.lastname: Hidalgo
authors.forename: Antonio
authors.initials: A
authors.lastname: Roman
keywords: Catheterization; prognosis; pulmonary heart disease; remodeling.