CT measurements of central pulmonary vasculature as predictors of severe exacerbation in COPD

Abstract

To identify a predictive value for the exacerbation status of chronic obstructive pulmonary disease (COPD) subjects, we evaluated the relationship between pulmonary vascular measurements on chest CT and severe COPD exacerbation.Six hundred three subjects enrolled in the COPDGene population were included and divided into nonexacerbator (n = 313) and severe exacerbator (n = 290) groups, based on whether they had an emergency room visit and/or hospitalization for COPD exacerbation. We measured the diameter of the main pulmonary artery (MPA) and ascending aorta (AA) at 2 different sites of the MPA (the tubular midportion and bifurcation) on both axial images and multiplanar reconstructions. Using multiple logistic regression analyses, we evaluated the relationship between each CT-measured pulmonary vasculature and exacerbation status.Axial and multiplanar MPA to AA diameter ratios (PA:AA ratios) at the tubular midportion and the axial PA:AA ratios at the bifurcation indicated significant association with severe exacerbation. The strongest association was found with the axial PA:mean AA ratio at the bifurcation (adjusted odds ratio [OR] = 12.53, 95% confidence interval [CI] = 2.35–66.74, P = .003) and the axial PA:major AA ratio at the tubular midportion (adjusted OR = 10.72, 95% CI = 1.99–57.86, P = .006). No differences were observed in the MPA diameter. Receiver operating characteristic analysis of these variables indicates that they may serve as a good predictive value for severe exacerbation (area under the curve, 0.77–0.78). The range of cut-off value for PA:AA ratio was 0.8 to 0.87.CT-measured PA:AA ratios at either the bifurcation or the tubular site, measured either on axial or multiplanar images, are useful for identification of the risk of severe exacerbation, and consequently can be helpful in guiding the management of COPD. Although CT measurement was used at the level of pulmonary bifurcation in previous studies, we suggest that future studies should monitor the tubular site of the MPA for maximum diagnostic value of CT in pulmonary hypertension or severe COPD exacerbation, as the tubular site of the MPA remains relatively constant on CT images.

Main pulmonary artery enlargement predicts 90-day readmissions in Chinese COPD patients

“…Other researches which aimed to study relation between pulmonary artery diameter and PHT (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) and those researches which studied pulmonary artery enlargement and acute exacerbations of COPD (30,32,33) failed to address and take the pathobiologic difference between pAECOPD and npAECOPD as explained above. We encourage future researchers to consider this aspect and strongly believe this approach will produce a more reliable result.…”

“…We encourage future researchers to consider this aspect and strongly believe this approach will produce a more reliable result. Many researchers have measured the widest MPAD diameter on the axial image at the bifurcation site [method 2 mentioned in Mahammedi et al (15)] while MPAD diameter at the tubular site have been only considered by few researchers (21,32). It is difficult to determine the bifurcation site due to the morphologically complex shape and axis of the MPAD and its branches.…”

“…Main pulmonary artery diameter (MPAD) enlargement has been proven to correlate with invasive measurements of mPAP obtained by RHC (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31). Moreover, pulmonary artery enlargement is associated with increased risk of exacerbations of COPD (17,30,32,33) and this particular phenomenon has not been studied thoroughly.…”

Pulmonary trunk to ascending aorta ratio and reference values for diameters of pulmonary arteries and main bronchi in healthy adults

“…[17] Different values have been reported regarding the normal range of PT:AA ratio in various studies (to be less than 0.9, 1 or 1.4). [4,5,[7][8][9][10] An elevated PT:AA ratio was important since it was associated with an increased risk of all-cause mortality (>0.9). [4] The mean PT:AA ratio was found higher in females than in males for all age groups, but this ratio found to decrease with increasing age in both genders.…”

“…[6] The normal value of PT:AA ratio have been reported in a wide range in recent studies (as less than 0.9, 1 or 1.4). [4,5,[7][8][9][10] The trachea bifurcates into RMB and LMB at the level of the fourth thoracic vertebra. [2] Knowing the exact localization of this bifurcation is important for anesthesiologists and thoracic surgeons.…”