Pulmonary hypertension and computed tomography measurement of small pulmonary vessels in severe emphysema.
BACKGROUND
Vascular alteration of small pulmonary vessels is one of the characteristic features of pulmonary hypertension in chronic obstructive pulmonary disease. The in vivo relationship between pulmonary hypertension and morphological alteration of the small pulmonary vessels has not been assessed in patients with severe emphysema.


OBJECTIVE
We evaluated the correlation of total cross-sectional area of small pulmonary vessels (CSA) assessed on computed tomography (CT) scans with the degree of pulmonary hypertension estimated by right heart catheterization.


METHODS
In 79 patients with severe emphysema enrolled in the National Emphysema Treatment Trial (NETT), we measured CSA less than 5 mm(2) (CSA(<5)) and 5 to 10 mm(2) (CSA(5-10)), and calculated the percentage of total CSA for the lung area (%CSA(<5) and %CSA(5-10), respectively). The correlations of %CSA(<5) and %CSA(5-10) with pulmonary arterial mean pressure (Ppa) obtained by right heart catheterization were evaluated. Multiple linear regression analysis using Ppa as the dependent outcome was also performed.


RESULTS
The %CSA(<5) had a significant negative correlation with Ppa (r = -0.512, P < 0.0001), whereas the correlation between %CSA(5-10) and Ppa did not reach statistical significance (r = -0.196, P = 0.083). Multiple linear regression analysis showed that %CSA(<5) and diffusing capacity of carbon monoxide (DL(CO)) % predicted were independent predictors of Ppa (r(2) = 0.541): %CSA (<5) (P < 0.0001), and DL(CO) % predicted (P = 0.022).


CONCLUSIONS
The %CSA(<5) measured on CT images is significantly correlated to Ppa in severe emphysema and can estimate the degree of pulmonary hypertension.
Matsuoka
Shin
S
Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan. shin4114@mac.com
Washko
George R
GR
Yamashiro
Tsuneo
T
Estepar
Raul San Jose
RS
Diaz
Alejandro
A
Silverman
Edwin K
EK
Hoffman
Eric
E
Fessler
Henry E
HE
Criner
Gerard J
GJ
Marchetti
Nathaniel
N
Scharf
Steven M
SM
Martinez
Fernando J
FJ
Reilly
John J
JJ
Hatabu
Hiroto
H
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy; D011379:Prognosis; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011656:Pulmonary Emphysema / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D011667:Pulmonary Veins / Q000000981:diagnostic imaging*; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*