Co-existence of COPD and bronchiectasis: a risk factor for a high ratio of main pulmonary artery to aorta diameter (PA:A) from computed tomography in COPD patients

Figures & data

Table 1 Characteristics of COPD patients

Variables	n=480
Age, years	69.5±9.6
Male (%)	365 (76.0)
Smokers (%)	339 (70.6)
Smoking, pack-years	28.2±27.9
BMI, kg/m^2	23.7±4.4
PFT
FVC, L	2.2±0.7
FEV1, L	1.1±0.5
FEV1 % predicted	42.1±19.2
FEV1/FVC%	50.0±13.4
Comorbidities (%)
Bronchiectasis	168 (35)
Ischemic heart disease	129 (26.9)
Hypertension	156 (32.5)
Diabetes mellitus	54 (11.3)
Arrhythmia	45 (9.4)
Chronic kidney disease	10 (2.1)

Note: Data are presented as mean ± SD for continuous variables and as a percentage for categorical variables.

Abbreviations: BMI, body mass index; PFT, pulmonary function testing; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Table 2 Characteristics of COPD patients with high and low PA:A ratios

Variables	PA:A ≤1 (n=385)	PA:A >1 (n=95)	P-value
Age, years	70.1±9.5	66.8±9.5	0.003b
Male (%)	306 (79.5)	59 (62.1)	<0.001c
Smokers (%)	279 (75)	60 (67.4)	0.145c
Smoking, pack-years	29.5±27.7	22.8±28.6	0.016b
BMI, kg/m^2	23.5±4.2	24.5±5.3	0.171a
Blood tests
PH	7.4±0.05	7.3±0.06	0.002b
PaO2, mmHg	81.3±25.4	74.4±34.5	<0.001b
PaCO2, mmHg	45.0±10.7	58.5±17.7	<0.001b
ALB, g/L	38.3±4.9	35.6±5.1	<0.001b
WBC, 10^9/L	7.9±3.2	7.2±2.7	0.017b
EOS, %	1.8±3.4	1.5±2.1	0.528b
ESR, mm/h	21.1±20.8	20.6±20.8	0.785b
Fib, g/L	3.4±1.2	3.3±1.5	0.292b
PFT
FVC, L	2.3±0.7	1.9±0.6	0.003a
FEV1.0, L	1.1±0.6	0.9±0.5	0.004b
FEV1 % predicted	43.1±18.9	37.4±19.7	0.008b
FEV1/FVC%	50.2±13.2	48.8±14.7	0.456a
Underlying disease (%)
Ischemic heart disease	105 (27.3)	24 (25.3)	0.692c
Hypertension	129 (34.4)	27 (28.4)	0.269c
Arrhythmia	40 (10.4)	5 (5.3)	0.125c
Bronchiectasis	111 (28.8)	57 (60)	<0.001c
Diabetes mellitus	32 (8.6)	22 (23.2)	<0.001c
PA, mm	29.1±4.5	38.0±4.7	<0.001a
A, mm	36.2±4.2	33.9±3.4	<0.001a
PA:A	0.8±0.1	1.1±0.1	<0.001a

Notes: Data are presented as mean ± SD for continuous variables and as a percentage for categorical variables.

a Analysis of Student’s t-test.

b Analysis of Mann–Whitney U-test.

c Analysis of chi-square test.

Abbreviations: BMI, body mass index; EOS, eosinophils; PH, pulmonary hypertension; ALB, albumin; ESR, erythrocyte sedimentation rate; Fib, fibrinogen; PFT, pulmonary function test; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 s; PA, pulmonary artery diameter; A, aorta diameter; WBC, white blood cell.

Table 3 Characteristics of COPD patients with and without bronchiectasis

Characteristics	COPD without bronchiectasis (n=312)	COPD with bronchiectasis (n=168)	P-value
Age, years	69.8±9.2	68.8±10.2	0.188b
Male (%)	246 (78.8)	119 (70.8)	0.050c
Smokers (%)	235 (76.8)	104 (67.1)	0.026c
Smoking, pack-years	29.1±26.7	26.5±30.3	0.098b
BMI, kg/m^2	23.7±4.4	23.4±4.6	0.562a
PFT
FVC, L	2.2±0.7	2.1±0.7	0.130a
FEV1, L	1.1±0.6	1.1±0.5	0.381b
FEV1% predicted	42.8±19.9	40.5±17.0	0.676b
FEV1/FVC%	50.0±13.4	49.9±13.5	0.955a
Blood tests
PH	7.4±0.05	7.4±0.06	0.045b
PaO2, mmHg	80.6±27.0	78.2±28.9	0.185b
PaCO2, mmHg	45.6±11.5	52.5±16.3	<0.001b
ALB, g/L	38.4±4.6	36.6±5.5	<0.001a
EOS, %	1.4±2.0	2.3±4.7	0.092b
ESR, mm/h	18.2±19.2	27±22.4	<0.001b
Fib, g/L	3.3±1.2	3.7±1.3	0.006b
PA, mm	30.0±5.6	32.5±5.7	<0.001a
A, mm	36.3±4.2	34.6±3.9	<0.001a
PA/A	0.83±0.15	0.95±0.17	<0.001a

Notes: Data are presented as mean ± SD or median (interquartile range) for continuous variables and as a percentage for categorical variables.

a Analysis of Student’s t-test.

b Analysis of Mann–Whitney U-test.

c Analysis of chi-square test.

Abbreviations: BMI, body mass index; EOS, eosinophils; PFT, pulmonary function test; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 s; PH, pulmonary hypertension; ALB, albumin; ESR, erythrocyte sedimentation rate; Fib, fibrinogen; PA, pulmonary artery diameter; A, aorta diameter.

Table 4 Comparison of NT-proBNP and pulmonary artery pressure between COPD patients with and without bronchiectasis

Variables	COPD without bronchiectasis (n =312)		COPD with bronchiectasis (n =168)		P-value
	PA:A ≤1 (n=274)	PA:A >1 (n=38)	PA:A ≤1 (n=111)	PA:A >1 (n=57)
NT-proBNP, pg/mL	181.5 (69.8–494.3)	269.8 (134.9–586.8)	221.5 (63.8–718.7)	821.7 (202.7–2,801.0)	<0.001*
Pulmonary artery pressure, mmHg	37.6±12.2	48.8±20.2	35.9±12.9	52.5±24.8	<0.001*

Notes: Data are presented as mean ± SD or median (interquartile range) for continuous variables.

* Analysis of Kruskal–Wallis test.

Abbreviations: PA, pulmonary artery diameter; A, aorta diameter.

Figure 1 The association between the severity of bronchiectasis and PA:A ratio in COPD-bronchiectasis co-existence patients.

Abbreviations: PA, pulmonary artery diameter; A, aorta diameter.

Table 5 Logistic regression analysis for predictors of high PA:A ratio in COPD patients

Variables	Unadjusted analysis		Adjusted multivariate analysis
	OR (95% CI)	P-value	OR (95% CI)	P-value
Age (per 10 years increase)	0.731 (0.583–0.917)	0.007	0.718 (0.508–1.014)	0.060
Male	2.363 (1.459–3.830)	<0.001	2.047 (0.971–4.313)	0.060
ALB, g/L	0.904 (0.864–0.945)	<0.001	0.886 (0.828–0.947)	<0.001
PaO2 (per 10 mmHg decrease)	1.258 (1.098–1.440)	0.001	1.190 (0.990–1.431)	0.064
FEV1 % predicted (per 10% decrease)	1.207 (1.022–1.425)	0.027	1.195 (0.965–1.479)	0.102
Bronchiectasis	3.703 (2.324–5.900)	<0.001	3.707 (1.888–7.278)	<0.001
Diabetes mellitus	3.221 (1.770–5.862)	<0.001	3.721 (1.490–9.289)	0.005

Abbreviations: PA, pulmonary artery diameter; A, aorta diameter; ALB, albumin; FEV₁, forced expiratory volume in 1 s.