Figure 1
The Clinical Trial Outline.
Table 1
A. Characteristics of patients included in the retrospective phase of the study (n = 13); B. Characteristics of patients included in the prospective phase of the study (n = 18); C. General characteristics of all patients (n = 31). Mean ± standard deviation or frequency (%).
| Parameter | A. Retrospective group (n = 13) | B. Prospective group (n = 18) | C. Joint patient group (n = 31) |
|---|---|---|---|
| Age, years | 61.07 ± 9.70 | 65.44 ± 2.14 | 63.61 ± 1.65 |
| Men, n (%) | 9 (69) | 12 (66.67) | 22 (70.97) |
| Height, sm | 170.00 ± 2.14 | 171.33 ± 2.33 | 170.74 ± 1.52 |
| Weight, kg | 86.69 ± 2.64 | 77.89 ± 2.91 | 81.58 ± 2.05 |
| BMI, kg/m2 | 30.02 ± 0.83 | 26.64 ± 1.02 | 28.06 ± 0.71 |
| Smoking, n (%) | – | 5 (27.78) | – |
| Type 2 DiabetesMellitus, n (%) | – | 1 (5.56) | – |
| Arterial hypertension*, n (%) | – | 18 (100) | – |
| Angina clinic, n (%) | 13 (100) | 16 (88.89) | 29 (93.55) |
| A history of MI, n (%) | 1 (7.69) | 3 (16.67) | 4 (12,9) |
| A history of PCI, n (%) | 0 | 2 (11.11) | 2 (6.45) |
| LV EF, % | – | 62.78 ± 1.80 | – |
| Serum creatinine, μmol/l | – | 83.57 ± 7.36 | – |
| GFR (ml/min/1.73m2)1 | – | 82.44 ± 4.52 | – |
| SBP2, mm Hg | 135.00 ± 3.00 | 132.22 ± 2.17 | 133.39 ± 1.68 |
| DBP3, mm Hg | 86.15 ± 1.34 | 82.50 ± 1.33 | 84.03 ± 0.95 |
| HR4, bpm | 64.92 ± 0.68 | 65.39 ± 1.56 | 65.19 ± 0.90 |
[i] 1 Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) formula.
* Arterial hypertension was diagnosed if arterial blood pressure ≥ 140/90 mm Hg was detected in at least two outpatient measurements.
2 Systolic blood pressure measured at the time of CTCA scan.
3 Diastolic blood pressure measured at the time of CTCA scan.
4 Heart rate measured at the time of CTCA scan.
BMI – body mass index; MI – myocardial infarction; PCI – percutaneous coronary intervention; LV EF – left ventricular ejection fraction; GFR – glomerular filtration rate; SBP – systolic blood pressure; DBP –diastolic blood pressure; HR – heart rate.
Figure 2
ROC curve analysis (per-vessel). A. For the retrospective group (n = 16) data, p < 0.001. B. For the prospective group (n = 28) data, p = 0.019. C. For the overall group (n = 44) data, p < 0.0001.
Figure 3
Bland–Altman analysis. A. Bland–Altman plot for the retrospective group (n = 16). B. Bland–Altman plot for the prospective group (n = 28). C. Bland–Altman plot for the overall group (n = 44).
Table 2
Comparison of the diagnostic efficiency for the CT FFRc 1D method with over non-invasive technics of the fractional flow reserve assessment described in the literature.
| Study | DISCOVER–FLOW [1] | DeFACTO [2] | NXT [3] | Renker et al. [13] | Coenen et al. [14] | Ko et al. [15] | Kruk et al. [16] | Yang et al. [17] | CT FFRc 1D Method |
|---|---|---|---|---|---|---|---|---|---|
| Year | 2011 | 2013 | 2013 | 2014 | 2015 | 2016 | 2016 | 2016 | 2019 |
| Patients number (n) | 103 | 252 | 254 | 53 | 106 | 42 | 90 | 72 | 31 |
| Vessels number (n) | 159 | 407 | 484 | 67 | 189 | 78 | 96 | 138 | 44 |
| Software | HeartFlow v1.1 | HeartFlow v1.1 | HeartFlow v1.3 | Siemens v1.4 | Siemens v1.4 | Toshiba Medical | Siemens v1.4 | Siemens v1.4 | CT FFRc 1D |
| Sensitivity per vessels | 0.88 (0.77–0.95) | 0.80 (0.73–0.86) | 0.84 (0.75–0.89) | 0.85 (0.62–0.97) | 0.88 (0.78–0.91) | 0.78 (0.51–92.6) | 75.6 | 87 (75–94) | 66.67 (47–82) |
| Specificity per vessels | 0.82 (0.73–0.89) | 0.61 (0.54–0.67) | 0.86 (0.82–0.89) | 0.85 (0.72–0.94) | 0.65 (0.55–0.74) | 0.87 (0.71–0.95) | 72.3 | 77 (66–85) | 78.95 (57–91) |
| Sensitivity per patients | 0.93 (0.82–0.98) | 0.90 (0.83–0.95) | 0.86 (0.77–0.92) | 0.94 (0.70–0.99) | N/A | N/A | 75.6 | N/A | 69.57 (49–84) |
| Specificity per patients | 0.82 (0.68–0.91) | 0.54 (0.45–0.63) | 0.79 (0.72–0.84) | 0.84 (0.68–0.94) | N/A | N/A | 71.4 | N/A | 88 (53–99) |
| PPV per vessels | 0.74 (0.62–0.84) | 0.56 (0.49–0.62) | 0.61 (0.53–0.69) | 0.71 (0.49–0.87) | 0.66 (0.55–0.74) | 0.74 (0.49–0.90) | 67.4 | 71 (58–81) | 80 (58–92) |
| NPV per vessels | 0.92 (0.85–0.97) | 0.84 (0.78–0.89) | 0.95 (0.93–0.97) | 0.93 (0.81–0.98) | 0.88 (0.79–0.94) | 0.89 (0.74–0.96) | 80.0 | 90 (80–96) | 65.22 (45–81) |
| AUC per patients | 0.92 | 0.81 | 0.90 | 0.91 | N/A | N/A | N/A | N/A | N/A |
| AUC per per vessels | 0.90 | N/A | 0.93 | 0.92 | 0.83 | 0.88 | 0.835 | 0.893 | 66.25 (47.82–84.67) |
| Accuracy | 84.3 (77.7–90.0) | – | 86 (83–89) | 74.6 (68,4–80,8) | 83.9 | 74.0 | 81 (74–88) | – | |
| Correlation coefficient Pearson’s/Spearman’s1 | 0.678 | 0.63 | 0.82 | 0.66 | 0.59 | 0.57 | 0.671 | 0.671 | 0.65911 |
[i] PPV – positive predictive value; NPV – negative predictive value; N/A– not available.
Figure 4
A. Native-phase CT images in DICOM format. Considerable calcification of the left circumflex artery (LCX). B. 3D reconstruction of coronary vessels. Segmented veins and the gap in segmentation of the left circumflex artery are visible (RCA – right coronary artery; LCA – left coronary artery; LAD – left anterior descending artery; LCX – left circumflex artery). C. 3D reconstruction of coronary vessels. CTCA showed 65% stenosis in the proximal segment of the left anterior descending artery (LAD – left anterior descending artery; LCX – left circumflex artery). D. Invasive coronary angiography. Stenosis in the proximal segment of the left anterior descending artery up to 35% (LAD – left anterior descending artery).