Clinical characteristics of the study population are described in Table 1.
Table 1 Clinical characteristics of the subjects (n = 490)
Characteristics
|
Values (%)
|
Age,
years
|
35.2 ± 4.4
|
Male / Female
|
383 / 107
|
Symptom
|
|
Typical chest pain
|
6 (1.2%)
|
Atypical chest pain
|
35 (7.1%)
|
Non-anginal pain
|
180 (36.7%)
|
Asymptomatic
|
269 (54.9%)
|
Pretest probability
|
|
Intermediates
|
55 (11.2%)
|
Low
|
165 (33.7%)
|
Very low
|
270 (55.1%)
|
HR,
bpm
|
61.6 ± 11.6
|
Agatston calcium score
|
1.8 ± 19.5
|
Zero
|
462 (94.3%)
|
1-10
|
16 (3.3%)
|
10-100
|
11 (2.2%)
|
100-400
|
1 (0.2%)
|
Cardiovascular risk factors*
|
|
Hypertension (n = 441)
|
90 (20.4%)
|
Smoking (n = 362)
|
179 (49.4%)
|
Diabetes mellitus (n = 426)
|
12 (2.8%)
|
Hypercholesterolemia (n = 410)
|
132 (32.2%)
|
Low HDL cholesterol (n = 346)
|
62 (17.9%)
|
10 year CHD risk (n = 241)*†
|
|
Moderate (10-20%)
|
16 (6.6%)
|
Low (< 10%)
|
225 (93.4%)
|
CHD coronary heart disease,
HDL high-density lipoprotein,
HR heart rate
*Number is based on that recorded in the medical chart
†10-year CHD risk obtained using the Framingham risk score calculator
Fifty-five individuals had CT-detected CAD (11.2%,
53 males) composed of non-calcified plaques in 25 cases (45%),
mixed plaques in 11 cases (20%) and calcified plaques in 19 cases (35%).
All patients with CT-detected CAD showed non-significant stenosis (not > 50% of diameter).
The plaque severity score was 4 in one patient,
2 in 7 patients and 1 in 47 patients.
LVM measured by cardiac CT was 126.9 ± 30.0 g for males and 93.6 ± 20.9 g for females and correlated well (r = 0.498,
P < 0.001) with echocardiographic measurement (n = 158) (Table 2).
Table 2 Comparison of LV function between CT and echocardiography (n = 158)
|
CT
|
Echocardiography
|
Correlation coefficient
|
P value
|
Male
|
Female
|
Total
|
Male
|
Female
|
Total
|
LVEF (%)
|
69.4 ± 7.9
(16-89)
|
69.0 ± 7.0
(43-85)
|
69.5 ± 9.1
(16-89)
|
63.9 ± 6.5
(20-79)
|
66.5 ± 5.6
(50-76)
|
64.5 ± 6.4
(20-79)
|
0.558
|
< 0.001*
|
LVSV (mL)
|
92.1 ± 20.3
(33-161)
|
76.1 ± 15.9
(48-124)
|
71.7 ± 25.5
(33-161)
|
-
|
-
|
-
|
-
|
-
|
LVEDV (mL)
|
133.1 ± 27.0
(72-223)
|
110.3 ± 19.5
(67-167)
|
104.3 ± 33.5
(67-223)
|
-
|
-
|
-
|
-
|
-
|
LVESV (mL)
|
41.0 ± 14.8
(11-168)
|
34.2 ± 10.4
(18-94)
|
32.6 ± 18.4
(11-168)
|
-
|
-
|
-
|
-
|
-
|
LVM (g)
|
126.9 ± 30.0
(71-248)
|
93.6 ± 20.9
(53-164)
|
122.2 ± 31.9
(53-71)
|
168.0 ± 40.0
(43-278)
|
121.2 ± 33.0
(50-222)
|
156.7 ± 43.3
(43-278)
|
0.498
|
< 0.001*
|
LVMi (g/m2)
|
66.4 ± 15.4
(35-114)
|
58.4 ± 12.6
(34-102)
|
65.6 ± 15.0
(34-114)
|
87.2 ± 18.3
(23-145)
|
74.3 ± 18.6
(35-142)
|
84.1 ± 19.1
(23-145)
|
0.298
|
< 0.001*
|
LVEDV left ventricular end-diastolic volume,
LVEF left ventricle ejection fraction,
LVESV left ventricular end-systolic volume,
LVM left ventricular mass,
LVMi left ventricular mass index,
LVSV left ventricular stroke volume
LVM was higher (133.6 ± 33.1 g vs.
117.8 ± 30.8 g,
P < 0.001) in patients with CT-detected CAD compared to those without (Table 3).
Table 3 Comparison of LV function between patients with and without CT-detected CAD
|
No CT-detected CAD (n = 435)
|
CT-detected CAD (n = 55)
|
P value
|
LVEF (%)
|
69.3 ± 7.7
|
70.0 ± 7.8
|
0.518
|
LVSV (mL)
|
73.0 ± 24.0
|
71.1 ± 25.2
|
0.580
|
LVEDV (mL)
|
105.9 ± 33.7
|
101.1 ± 33.0
|
0.321
|
LVESV (mL)
|
32.9 ± 15.2
|
30.0 ± 12.0
|
0.178
|
LVM (g)
|
117.8 ± 30.8
|
133.6 ± 33.1
|
< 0.001*
|
LVMi (g/m2)
|
64.1 ± 14.7
|
68.6 ± 16.2
|
0.034*
|
CAD coronary artery disease,
LVEDV left ventricular end-diastolic volume,
LVEF left ventricle ejection fraction,
LVESV left ventricular end-systolic volume,
LVM left ventricular mass,
LVMi left ventricular mass index,
LVSV left ventricular stroke volume
Plaque severity score was significantly correlated with LVM (r = 0.152,
P < 0.001) and LVMi (r = 0.096,
P = 0.033).
- Mean LVM (153.8 ± 36.3 g) in the group with a plaque severity score of 2 was higher (P = 0.005 and 0.002,
respectively) than in the groups scoring 0 (117.8 ± 30.8 g) or 1 (131.2 ± 32.0 g) (Fig.
2).
- Mean LVMi was higher (P = 0.019) in the group with a plaque severity score of 2 (77.3 ± 17.2 g/m2) than in the group scoring 0 (64.1 ± 14.7 g/m2) (Fig.
3).
All of the clinical CV risk factors except DBP and diabetes mellitus were significantly different (P = 0.047 – <0.001) between patients with and without CT-detected CAD (Table 4).
Table 4 Clinical characteristics of patients with and without CT-detected CAD
Characteristics
|
No CT-detected CAD (n = 435)
|
CT-detected CAD (n = 55)
|
P value
|
Age,
years
|
35.1 ± 4.5
|
36.4 ± 3.6
|
0.047*
|
Sex,
men
|
330 (75.9%)
|
53 (96.4%)
|
0.001*
|
BMI,
kg/m2
|
24.5 ± 4.0
|
26.1 ± 3.5
|
0.004*
|
Obesity (BMI > 25 kg/m2)
|
171 (39.3%)
|
36 (65.5%)
|
< 0.001*
|
SBP,
mmHg
|
119.8 ± 15.2
|
125.7 ± 16.6
|
0.012*
|
DBP,
mmHg
|
77.3 ± 11.7
|
80.5 ± 12.4
|
0.068
|
Hypertension (n = 441)
|
74 (18.9%)
|
16 (32.7%)
|
0.039*
|
Smoking (n = 362)
|
147 (46.7%)
|
32 (68.1%)
|
0.010*
|
Diabetes mellitus (n = 426)
|
10 (2.7%)
|
2 (3.8%)
|
0.995
|
Total cholesterol,
mg/dL (n = 410)
|
184.3 ± 38.8
|
206.4 ± 45.8
|
< 0.001*
|
Hypercholesterolemia (n = 410)
|
109 (30.1%)
|
23 (47.9%)
|
0.021*
|
HDL,
mg/dL (n = 346)
|
51.9 ± 14.0
|
46.9 ± 11.2
|
0.029*
|
10 year CHD risk (n = 241) †
|
|
|
|
Moderate (10-20%)
|
10 (4.8%)
|
6 (17.6%)
|
0.016*
|
Low (< 10%)
|
197 (95.2%)
|
28 (82.4%)
|
BMI body mass index,
CAD coronary artery disease,
CHD coronary heart disease,
DBP diastolic blood pressure,
HDL high-density lipoprotein,
SBP systolic blood pressure
*Statistically significant
†10-year CHD risk obtained using the Framingham risk score calculator
Obesity,
hypertension,
smoking,
hypercholesterolemia,
LVM and LVMi were predictors for CAD (Table 5).
BMI (r = 0.237,
P < 0.001) and SBP (r = 0.281,
P < 0.001) were positively correlated with LVM.
Table 5 Predictors of CT-detected CAD using univariate logistic regression analysis
|
OR
|
95% CI
|
P value
|
Age,
years
|
1.078
|
1.000-1.162
|
0.049*
|
Sex,
men
|
8.432
|
2.020-35.192
|
0.003*
|
BMI,
kg/m2
|
1.099
|
1.029-1.174
|
0.005*
|
Obesity (BMI > 25 kg/m2)
|
2.925
|
1.625-5.267
|
< 0.001*
|
SBP,
mmHg
|
1.024
|
1.005-1.044
|
0.013*
|
Hypertension
|
2.084
|
1.089-3.985
|
0.027*
|
Smoking
|
2.438
|
1.270-4.680
|
0.007*
|
Total cholesterol
|
1.012
|
1.005-1.019
|
< 0.001*
|
Hypercholesterolemia
|
2.135
|
1.161-3.927
|
0.015*
|
HDL cholesterol
|
0.966
|
0.938-0.996
|
0.026*
|
LVM
|
1.015
|
1.006-1.023
|
< 0.001*
|
LVMi
|
1.020
|
1.001-1.038
|
0.036*
|
BMI body mass index,
CAD coronary artery disease,
HDL high-density lipoprotein,
LVM left ventricular mass,
LVMi left ventricular mass index,
SBP systolic blood pressure
*Statistically significant
In the multivariate analysis,
LVM (OR = 1.016,
95% confidence interval [CI] = 1.006-1.026,
P = 0.003) and LVMi (OR = 1.026,
95% CI = 1.004-1.048,
P = 0.020) remained independent predictors of CAD.