Impact of Computed Tomography-Quantified Emphysema Score on Clinical Outcome in Patients with COVID-19

Figures & data

Table 1 Comparison of Clinical and Laboratory Findings and Clinical Outcomes in Patients with COVID-19 According to Quantitative Emphysema Scores by Computed Tomography

Variable			Emphysema Score		P value
	Total (n=146)	≤1% (n = 80)	>1% & ≤5% (n = 55)	>5% (n = 11)
Age, y	64 (54–77)	60 (50–72)	66 (59–78)	79 (70–81)	<0.001
Male sex	70 (48)	31 (39)	28 (51)	11 (100)	0.001
BMI, kg/m^2	23.6 (21.5–25.4)	24.1 (21.4–26.2)	23.3 (21.3–25.8)	22.3 (20.7–24.6)	0.352
Current smoker	19 (13)	7 (9)	9 (16)	3 (27)	0.107
Comorbidities	79 (54)	39 (49)	32 (58)	8 (73)	0.243
Hypertension	54 (37)	28 (35)	20 (36)	6 (55)	0.499
Diabetes mellitus	32 (22)	16 (20)	13 (24)	3 (27)	0.780
COPD	8 (6)	1 (4)	6 (11)	1 (9)	0.033
Ischemic heart disease	13 (9)	5 (6)	7 (13)	1 (9)	0.335
Chronic kidney disease	2 (1)	2 (3)	0 (0)	0 (0)	0.584
Chronic liver disease	6 (4)	3 (4)	3 (6)	0 (0)	0.806
Initial symptoms
Fever	136 (93)	74 (93)	52 (95)	10 (91)	0.782
Dyspnea	57 (39)	33 (42)	19 (35)	5 (46)	0.650
Laboratory findings
WBC counts, cells/μL	5,600 (4,368–7,700)	5,385 (4,015–7,360)	6,100 (4,480–7,700)	7,740 (3,730–10,040)	0.525
Lymphocyte, %	25(13–35)	27 (12–35)	27 (14–35)	16 (10–20)	0.123
Albumin, g/dL	3.8 (3.3–4.1)	3.9 (3.4–4.1)	3.8 (3.4–4.2)	3.3 (3.1–3.5)	0.023
Lactate dehydrogenase, U/L	475 (361–660)	519 (384–667)	422 (317–557)	640 (499–784)	0.006
C-reactive protein, mg/dL	2.4 (0.3–13.1)	2.1 (0.3–12.8)	1.2 (0.2–16.6)	7.5 (2.9–14.2)	0.377
NT-pro-BNP, pg/mL	110 (52–437)	90 (43–225)	131 (59–570)	567 (103–5,155)	0.028
Emphysema score, %	1.0 (0.5–1.8)	0.5 (0.2–0.9)	1.8 (1.2–2.0)	8.0 (5.0–13.0)	<0.001
O2 therapy	59 (40)	32 (40)	19 (35)	8 (73)	0.064
ICU admission	18 (12)	9 (11)	5 (9)	4 (36)	0.057
Death	14 (10)	7 (9)	4 (7)	3 (27)	0.155

Notes: Numerical data are expressed as median (interquartile range), and categorical data as frequency (percentage).

Abbreviations: COVID-19, coronavirus disease 2019; BMI, body mass index; COPD, chronic obstructive pulmonary disease; WBC, white blood cells; NT-pro-BNP, NT-pro-brain natriuretic peptide; CT, computed tomography; ICU, intensive care unit.

Figure 1 Representative images of emphysema quantification: Emphysema area (green color) was automatically calculated under thresholds of –950 HU on computed tomography axial images. Application of quantification software revealed that the percentage of emphysema was 1.0% of the entire lung tissue in a 53-year-old woman (A), 6.0% in an 82-year-old man (B), and 13.0% in a 73-year-old man (C).

Figure 2 The proportion of patients who received oxygen therapy during hospitalization in the groups with different emphysema scores *p < 0.05.

Table 2 Univariate and Multivariate Analyses for Factors Associated with in-Hospital Mortality of Patients with COVID-19

Variable	Univariate Analysis		Multivariate Analysis
	OR (95% CI)	P value	OR (95% CI)	P value
Age, y	1.078 (1.024–1.136)	0.005	1.069 (1.001–1.141)	0.046
Male sex	4.537 (1.210–17.015)	0.025	─	─
BMI, kg/m^2	1.091 (0.927–1.284)	0.294
Current smoker	3.500 (0.635–19.281)	0.150
Hypertension	1.312 (0.430–4.008)	0.633
Diabetes mellitus	4.280 (1.376–13.309)	0.012	─	─
Chronic obstructive lung disease	12.800 (2.777–58.997)	0.001	8.068 (1.195–54.486)	0.032
Ischemic heart disease	3.327 (0.796–13.906)	0.099	─	─
Chronic kidney disease	10.077 (0.595–170.723)	0.110
Chronic liver disease	1.9618 (0.707–3.703)	0.254
WBC counts, cells/μL (Log)	1.210 (0.228–6.433)	0.823
Lymphocyte, %	1.004 (1.001–1.007)	0.017	─	─
Albumin, g/dL	0.126 (0.038–0.413)	0.001	─	─
Lactate dehydrogenase, U/L	1.002 (1.000–1.004)	0.015	1.002 (1.001–1.004)	0.006
C-reactive protein, mg/dL	1.014 (1.001–1.027)	0.032	─	─
NT-pro-BNP, pg/mL (Log)	4.309 (1.741–10.661)	0.002	─	─
CT Emphysema score >5%	4.277 (0.979–18.260)	0.053	─	─

Abbreviations: COVID-19, coronavirus disease 2019; OR, odds ratio; CI, confidence interval; BMI, body mass index; WBC, white blood cells; NT-pro-BNP, NT-pro-brain natriuretic peptide; CT, computed tomography.