CT Emphysema Predicts Thoracic Aortic Calcification in Smokers with and Without COPD

Figures & data

Figure 1.  Aortic calcification measurement. Shown is a representative screen image of the Aquarius Workstation highlighting areas of calcification within the thorax (>130 Hounsfield Units). The red arrow highlights an area of thoracic aortic calcification. The total aortic calcification score, or Agatston calcium score, was determined by obtaining the sum of each CT slice's area of calcification multiplied by a coefficient based on the peak CT number. Calcifications in the aortic valve and coronary arteries were excluded from analysis.

Table 1.  Subject characteristics

	Subjects with COPD (n = 159)	Subjects without COPD (n = 81)	p-value
Age, years	62.6 ± 5.0	60.7 ± 4.9	0.009
Sex,% male	69.8	51.9	0.006
Race,% Caucasian	89.3	93.8	0.36
Current smokers,%	56.6	51.9	0.57
Pack-years, No.	67 ± 32	54 ± 23	0.002
FEV1/FVC	0.58 ± 0.10	0.77 ± 0.05	< 0.001
FEV1,% predicted	66 ± 17	92 ± 8	< 0.001
WA%	78.1 ± 6.4	76.6 ± 5.4	0.08
LAA%	7.91 ± 6.95	3.34 ± 2.79	< 0.001
Calcium score	75.8 ± 109.7	47.6 ± 84.2	0.046

*Data are reported as mean ± SD unless otherwise indicated.

WA –wall area; LAA –low attenuation areas; FEV₁ –forced expiratory volume; FVC –forced vital capacity.

Table 2.  Univariate analyses between subject characteristics and calcium score

	Calcium Score Regression Coefficient (95% Confidence Interval)	p-value
Age	9.74 (7.45 to 12.0)	< 0.001
Sex, male	15.8 (−11.3 to 42.8)	0.25
Race, Caucasian	10.7 (−34.6 to 55.9)	0.64
Pack-years	0.66 (0.24 to 1.09)	0.002
Current smoking	8.91 (−17.3 to 35.1)	0.50
WA%	−2.29 (−4.41 to −0.17)	0.03
LAA%	3.89 (1.86 to 5.92)	< 0.001
COPD (FEV1/FVC < 0.70)	27.9 (0.50 to 55.3)	0.046
FEV1,% predicted	−1.00 (−1.67 to −0.34)	0.003

WA –wall area; LAA –low attenuation areas; FEV₁ –forced expiratory volume; FVC –forced vital capacity

Table 3.  Final multivariate model for predictors of calcium score

	Calcium Score Regression Coefficient (95% Confidence Interval)	p-value
Age	8.63 (6.18 to11.1)	< 0.001
Sex, Male	−14.6 (−40.4 to 11.1)	0.26
Race, Caucasian	2.44 (−37.7 to 42.6)	0.90
Pack-years	0.38 (−0.02 to 0.79)	0.06
Current smoking	2.68 (−20.5 to 25.8)	0.82
WA%	−0.92 (−2.90 to 1.06)	0.36
LAA%	2.16 (0.10 to 4.22)	0.04
COPD (FEV1/FVC < 0.70)	0.95 (−25.8 to 27.7)	0.94

WA –wall area; LAA –low attenuation areas; FEV₁ –forced expiratory volume; FVC –forced vital capacity.