Baseline characteristics
Baseline characteristics are displayed in Table 1. The average age was 66.6±9.1 with 89.5% of patients’ male. The mean body mass index (BMI) was 27.5 kg/m2, and 26.3% of patients had diabetes mellitus, but only one patient was insulin dependent. The mean LVEF was 55.9±7.8%.
Table 1. Baseline patient characteristics
Characteristics
|
N= 57
|
Age, mean ± SD
|
66.6 ± 9.1
|
Male
|
89.5 (51/57)
|
Current smoking (%, n)
|
17.5 (10/57)
|
Diabetes mellitus (%, n)
|
26.3 (15/57)
|
On insulin use (%, n)
|
1.8 (1/57)
|
Hypertension (%, n)
|
89.5 (51/57)
|
Hyperlipidemia (%, n)
|
75.4 (43/57)
|
Family history of CAD (%, n)
|
29.8 (17/57)
|
Previous stroke (%, n)
|
3.5 (2/57)
|
Previous myocardial infarction (%, n)
|
10.5 (6/57)
|
Previous heart failure (%, n)
|
3.5 (2/57)
|
COPD (%, n)
|
8.8 (5/57)
|
PVD (%, n)
|
8.8 (5/57)
|
Creatinine clearance (ml/min) mean ± SD
|
79.9 ± 17.5
|
BMI (kg/m2), mean ± SD
|
27.5 ± 4.4
|
LVEF (%), mean ± SD
|
55.9 ± 7.8
|
Euro Score II, mean ± SD
|
1.05 ± 0.49
|
BMI: body mass index, CAD: coronary artery disease, COPD: chronic obstructive pulmonary disease, LVEF: left ventricular ejection fraction, PVD: peripheral vascular disease, SD: standard deviation
Lesion characteristics and SS-2020 calculation
Lesion characteristics and the results of SS-2020 calculations between ICA and CCTA are shown in Table 2. The mean anatomical SYNTAX scores derived from ICA and CCTA were comparable (35.1±11.5 and 35.6±11.5, respectively P=0.751), despite the total number of lesions per patient being significantly higher with CCTA (5.0±1.5 vs. 6.0±1.7, P<0.001). The presence of a trifurcation lesion was significantly higher in ICA than CCTA (8.2% vs 1.7%, P<0.005). The number of heavily calcified lesions was comparable among the two modalities (22.5% vs. 23.5%, P=0.758), however the presence of severe tortuosity (7.1% vs. 0.0%, P<0.001) and the frequency of lesions >20mm long (37.3% vs. 24.0%, P<0.001) were both significantly higher with ICA than CCTA. Despite the above-mentioned individual differences, the global average anatomical SYNTAX scores were similar. Furthermore, the incorporation of clinical characteristics to construct the SS-2020 confirmed the comparability of the SS-2020 and the predicted risk of MACE/all-cause mortality following surgical or percutaneous treatment.
Table 2. Comparison of lesion characteristics and SYNTAX score 2020 calculations between two modalities.
Characteristics
|
Assessment based on ICA
|
Assessment based on CCTA
|
P-value
|
Anatomical SYNTAX score, per patient
|
35.1 ± 11.5
|
35.6 ± 11.5
|
0.751
|
Lesion numbers, per patient
|
5.0 ± 1.5
|
6.0 ± 1.7
|
<0.001
|
Left main disease
|
5.4 (15/280)
|
2.4 (9/280)
|
0.074
|
Components anatomical SYNTAX score
|
|
|
|
Total occlusion
|
12.9% (36/280)
|
12.8% (44/344)
|
0.652
|
Trifurcation
|
8.2% (23/280)
|
1.7% (6/344)
|
<0.001
|
Bifurcation
|
34.3% (96/280)
|
27.0% (93/344)
|
0.050
|
Medina 1,0,0
|
4.6% (13/280)
|
2.3% (8/344)
|
|
Medina 0,1,0
|
5.0% (14/280)
|
4.7% (16/344)
|
|
Medina 1,1,0
|
4.3% (12/280)
|
5.2% (18/344)
|
|
Medina 1,1,1
|
7.1% (20/280)
|
3.8% (13/344)
|
|
Medina 0,0,1
|
6.8% (19/280)
|
5.5% (19/344)
|
|
Medina 1,0,1
|
2.5% (7/280)
|
1.7% (6/344)
|
|
Medina 0,1,1
|
3.9% (11/280)
|
3.8% (13/344)
|
|
Bifurcation angulation <70°
|
13.9% (39/280)
|
10.5% (36/344)
|
0.186
|
Aorto-ostial lesion
|
3.9% (11/280)
|
3.2% (11/344)
|
0.622
|
Severe tortuosity*
|
7.1% (20/280)
|
0% (0/344)
|
<0.001
|
Lesion length >20 mm†
|
37.3% (91/244)
|
24.0% (72/300)
|
<0.001
|
Heavy calcification‡
|
22.5% (63/280)
|
23.5% (81/344)
|
0.758
|
Thrombus
|
0% (0/280)
|
0% (0/344)
|
NA
|
SYNTAX score 2020§
|
|
|
|
Predicted MACE for 5 years (%)
|
|
|
|
PCI
|
23.6 ± 13.6
|
23.8 ± 12.0
|
0.771
|
CABG
|
16.2 ± 9.4
|
15.4 ± 8.4
|
0.040
|
Absolute risk difference
|
7.4 ± 6.8
|
8.4 ± 5.9
|
0.192
|
Predicted mortality for 5 years (%)
|
|
|
|
PCI
|
15.7 ± 12.6
|
15.4 ±11.0
|
0.595
|
CABG
|
11.0 ± 8.8
|
10.5 ± 8.0
|
0.048
|
Absolute risk difference
|
4.7 ± 4.9
|
4.9 ± 4.1
|
0.597
|
Predicted mortality for 10 years (%)
|
|
|
|
PCI
|
31.3 ± 20.1
|
31.4 ± 18.5
|
0.953
|
CABG
|
23.3 ± 16.0
|
22.4 ± 15.0
|
0.042
|
Absolute risk difference
|
8.0 ± 6.4
|
8.9 ± 6.0
|
0.186
|
CABG: coronary artery bypass graft, CCTA: coronary computed tomography angiography, MACE: major adverse cardiac events, PCI: percutaneous coronary intervention
*≥1 bend of ≥90 degrees, or ≥3 bends of 45-90 degrees proximal to the diseased segment.
†Total occlusions were excluded in the overall assessment of the length of the lesions.
‡For computed tomography angiography defined as the presence of calcium that encompasses more than 50% of the cross-sectional area of the vessel at any location within the specific lesion. For invasive coronary angiography defined as multiple persisting opacifications of the coronary wall visible in more than one projection surrounding the complete lumen of the coronary artery at the site of the lesion.[17]
§Absolute risk difference is calculated by subtracting predicted CABG mortality from PCI mortality.
Predicted mortality according to SS-2020
The predicted mortality with PCI or CABG according to the SS-2020, as well as the predicted individual ARD in all-cause mortality at 5- and 10-year, ranked in order of magnitude based on CCTA and ICA, is shown in a scatter plot indicating 5-year (Figure 2A, B) and 10-year mortality (Figure 2C, D). Patients on the left side have a low ARD, and hence these patients have equipoise between PCI and CABG. In contrast, those on the right side have a large ARD, such that the treatment benefit of CABG is higher than PCI, and hence CABG is recommended for these patients. Using the ARD cut-off of 4.5% results in CABG being the recommended treatment to lower 5-year mortality in 43.9% of patients when using CCTA (Figure 2A) versus 35.1% when using ICA (Figure 2B). Similarly, for 10-year mortality CABG is safer than PCI for 73.7% of the population on CCTA (Figure 2C) compared to 64.9% on ICA (Figure 2D). Bland-Altman analysis for the predicted mortality according to SS-2020 derived from ICA and CCTA are shown in Supplementary figure 2.
Agreement in treatment recommendation between predicted absolute risk difference derived from ICA and CCTA
The correlation of ARD for predicting 5- and 10-year all-cause mortalities between ICA and CCTA are shown in Figure 3. According to the individual ARD cut-off of 4.5%, agreement in the recommended treatment was observed in 48 (84.2%) and 46 (80.7%) patients for 5- and 10-year all-cause mortality, respectively. The Pearson correlation coefficient between the ARD derived from CCTA and ICA demonstrated high positive correlations for predicting 5- and 10-year all-cause mortality. Bland-Altman analyses (anatomic or 2020) between the ARD derived from ICA and CCTA demonstrated a mean difference of -0.26 and standard deviation of 3.69 for 5-year mortality, and a mean difference of -0.93 and standard deviation of 5.23 for 10-year mortality (Figure 4). The scatter plot and Bland-Altman analysis for 5-year risk of MACE is shown in Supplementary figure 3 and Supplementary figure 4.
The agreements in revascularization recommendations according to individual ARDs between PCI and CABG are summarized in Table 3. Substantial and moderate agreements were confirmed with Cohens’ kappa of 0.672 (95% CI: 0.574-0.770) and 0.551 (95% CI: 0.433-0.668) for 5- and 10-year all-cause mortality, respectively.
Table 3. Agreement on treatment recommendation between coronary computed tomography angiography and invasive coronary angiography.
Treatment recommendation for predicting 5-year (A) and 10-year mortality (B).
(A)
|
|
|
|
Treatment recommendation based on CCTA
|
|
CABG
|
Equipoise CABG and PCI
|
Treatment recommendation based on ICA
|
|
|
CABG
|
31.6% (18/57)
|
3.5% (2/57)
|
Equipoise CABG and PCI
|
12.3% (7/57)
|
52.6% (30/57)
|
Cohen's Kappa 0.672 (95% CI: 0.574-0.770)
The agreement of revascularization treatment: 84.2%
|
(B)
|
|
|
|
Treatment recommendation based on CCTA
|
|
CABG
|
Equipoise CABG and PCI
|
Treatment recommendation based on ICA
|
|
|
CABG
|
59.6% (34/57)
|
5.3% (3/57)
|
Equipoise CABG and PCI
|
14.0% (8/57)
|
21.1% (12/57)
|
Cohen's Kappa 0.551 (95% CI: 0.434-0.668)
The agreement of revascularization treatment: 80.7%
|
Abbreviations:
CABG: coronary artery bypass graft, CCTA; coronary computed tomography angiography,
ICA; invasive coronary angiography, PCI; percutaneous coronary intervention