Lobe-based computed tomography assessment of airway diameter, airway or vessel number, and emphysema extent in relation to the clinical outcomes of COPD

Figures & data

Table 1 Demographic data of the subjects stratified for presence of airway-lumen obliterated emphysema

	Total	ALOE, yes	ALOE, no	P
Number	65	26	39
Age	70.8 (6.4)	70.5 (5.9)	71.0 (6.9)	NS
Pack-years	76.2 (34.7)	76.1 (33.0)	76.3 (36.3)	NS
Body mass index	20.5 (3.6)	18.9 (3.1)	21.5 (3.5)	P=0.006
FVC, % predicted	83.7 (21.0)	75.4 (14.1)	89.3 (23.1)	P=0.009
FEV1, % predicted	62.9 (30.7)	43.4 (18.3)	76.0 (30.6)	P<0.001
FEV1, change, mL/yr	−34.3 (38.7)	−32.0 (36.6)	−35.7 (40.5)	NS
FEV1, reversibility, %	4.9 (7.3)	5.8 (7.0)	4.4 (7.6)	NS
Treatments
Inhaled corticosteroids	50.8%	69.2%	38.5%	P=0.023
Long-acting β-agonist	56.9%	73.1%	48.7%	NS
Long-acting muscarinic antagonists	73.8%	84.6%	66.7%	P=0.018
Treatments for exacerbations
Antibiotics	100%	100%	100%	NS
Systemic	20.8%	29.2%	12.5%	NS
Corticosteroids

Notes: P, significance of difference between groups with or without ALOE was analyzed by Mann–Whitney U-test. Means (standard deviation) are expressed for number, age, body mass index, FVC, FEV₁, changes of FEV₁ and reversibility of FEV₁. Percentages of the drugs used are expressed for the daily treatments and treatments for exacerbations.

Abbreviations: ALOE, airway lumen-obliterated emphysema; FVC, forced expiratory volume; FEV₁, forced expiratory volume in 1 second; yr, year; NS, not significant.

Figure 1 Percentages of low attenuation area (%LAA) and frequency of COPD exacerbation.

Notes: Panels (A–C) demonstrate the relationship between frequency of COPD exacerbation and %LAA in total lobe (right B1–B10, [A]), upper lobe (right B1–B3, [B]) and lower lobe (right B6–B10, [C]). Each %LAA value shows mean value of 3 cm circle images exactly perpendicular to the axis of the airways at central zone (2 cm from the entrance of segmental bronchus), peripheral zone (2 cm from the pleura), and middle zone (halfway point of central and peripheral points) of each bronchus.
Abbreviation: COPD, chronic obstructive pulmonary disease.

Figure 2 Two phenotypes of emphysema in relation to the numbers of airways and vessels.

Notes: Two phenotypes of emphysema are shown. Right B9 bronchi were traced from entrance of segmental bronchi to the peripheral bronchi by curved multi-planar reconstruction images. Both cases had a similar percentage predicted diffusion capacity to carbon monoxide (%DLco: 56.5% versus 53.0%, respectively), but patient (A) has fewer lung structures around airways and patient (B) has more lung structures around airways. Case (A) had a lower %FEV₁ value (62.9% versus 129.0%, respectively) and demonstrated a rapid annual decline in FEV₁ (−104 mL per year versus −55 mL per year, respectively) compared to case (B).

Abbreviation: FEV₁, forced expiratory volume in 1 second.

Figure 3 The numbers of airways and vessels and the extent of emphysema.

Notes: The mean numbers of vessels (A) and airways (B) in 3 cm circles along right B1 to B10 airways were plotted to the mean percentage of low attenuation areas (%LAA). Segments (a) are under and (b) are above/on the linear regression lines. The subgroup of patients in (Aa) (n=36) who had less vessels along airways had larger annual decline of FEV₁ (−43.8 mL per year) compared to that of (Ab) (n=29) (−21.7 mL per year; P=0.015). The annual declines of FEV₁ in patients (a) and (b) in (B) were −40.6 mL per year (n=36) versus −26.4 mL per year (n=29), respectively (P=0.062).
Abbreviation: FEV₁, forced expiratory volume in 1 second.

Figure 4 Numbers of airway lumen-obliterated emphysema (ALOE) and %FEV₁ and annual change in FEV₁.

Notes: (A) Shows numbers of ALOE observed in right lung and predicted %FEV₁. (B) Shows numbers of ALOE observed in right lung and annual changes in FEV₁.

Abbreviation: FEV₁, forced expiratory volume in 1 second.

Figure 5 Frequency of COPD exacerbation and presence of airway lumen-obliterated emphysema (ALOE).

Notes: Frequencies of COPD exacerbation are compared in patients with or without ALOE. Horizontal bars represent mean values.
Abbreviation: COPD, chronic obstructive pulmonary disease.