Table 1
Baseline Demographic Table of Study Participants.
| Clinical Variables | Total Population (n = 130) | Patients with significant stenosis on CTCA (n = 23) | p-value* |
|---|---|---|---|
| Age (years) | 55.79 ± 12.37 | 58 ± 9.54 | 0.347 |
| Male gender | 89 (61.38%) | 17 (73.91%) | 0.184 |
| Diabetes Mellitus | 37 (25.69%) | 10 (43.48%) | 0.065 |
| Hypertension | 89 (59.72%) | 15 (65.22%) | 0.531 |
| Hyperlipidemia | 107 (73.79%) | 20 (86.96%) | 0.285 |
| Family History of premature CAD | 60 (41.38%) | 12 (52.17%) | 0.255 |
| Current Smoker | 14 (9.66%) | 5 (21.74%) | 0.041 |
| Chest Pain | |||
| Typical Angina | 18 (12.41%) | 6 (26.09%) | 0.077 |
| Atypical Angina | 88 (60.69%) | 12 (52.17%) | 0.901 |
| Non cardiac chest pain | 39 (26.90%) | 5 (21.74%) | Ref |
| Duke Clinical Score (%) | 38.8 ± 13.7% | 31.7 ± 8.2% | 0.009 |
| Duke Treadmill Score | |||
| Low risk | 79 (67.52%) | 4 (21.05%) | Ref |
| Intermediate risk | 35 (29.91%) | 12 (63.16%) | 0.001 |
| High risk | 3 (2.56%) | 3 (15.79%) | 0.003 |
| CT Calcium Score | |||
| 0 | 37 (25.52%) | 0 | Ref |
| 1–99 | 51 (35.17%) | 2 (8.70%) | 0.395 |
| 100–400 | 32 (22.07%) | 4 (17.39%) | 0.102 |
| >400 | 25 (17.24%) | 17 (73.91%) | 0.001 |
| Moderate to severe ischemia on MPI | 15 (10.34%) | 11 (47.83%) | 0.001 |
| Cardiovascular Event and All Cause Death | 17 (11.72%) | 11 (47.83%) | 0.001 |
[i] * p-value compares the groups with and without significant stenosis on CTCA.
Table 2
Univariate and Multivariate Logistic Regressions for Outcome of Epicardial artery stenosis >70% on CTCA.
| Variables | Univarate | Model 1 (Duke Clinical score + TMX) | Model 2 (Duke Clinical score + TMX + CAC) | Model 3 (Duke Clinical Score + TMX + MPI) | ||||
|---|---|---|---|---|---|---|---|---|
| Odds Ratio (SE) | p-value | Odds Ratio (SE) | p-value | Odds Ratio (SE) | p-value | Odds Ratio (SE) | p-value | |
| Duke Clinical Score | 0.28 (0.13) | 0.010 | 1.31 (1.61) | 0.017 | 1.61 (2.41) | 0.211 | 1.44 (1.82) | 0.055 |
| Duke Treadmill Score | ||||||||
| Low Riskⱡ | 1.01.0 | 1.0 | 1.0 | 1.0 | ||||
| Intermediate Risk | 5.94 (1.62) | 0.001 | 7.11 (1.77) | 0.001 | 9.68 (3.25) | 0.003 | 6.80 (1.94) | 0.001 |
| High Risk | 12.85 (4.31) 3.52 (1.26)9 | 0.003 | 12.76 (4.32) | 0.003003 | 15.27 (5.36) | 0.0040. | 11.67 (4.75) | 0.0140 |
| Coronary Calcium Score (per unit) | 0.018 (0.003) | 0.001 | 0.018 (0.004) | 0.001 | ||||
| MPI ischemia | 7.57 (2.59) | 0.004 | ||||||
| None or mild ischemiaⱡ | 1.0 | |||||||
| Moderate to Severe | 8.66 (1.71) | 0.001 | ||||||
| Ischemia | ||||||||
| AUC C-statistic | 0.833 (0.710–0.956) | 0.974 (0.947–1.000) | 0.833 (0.686–0.980) | |||||
| Adjusted R2 | 0.257 | 0.670 | 0.336 | |||||
Diagram 1
ROC curve of Model 1, Model 2 and Model 3.
Table 3
Interpretation of Duke Treadmill Score with Calcium Score.
| Sensitivity | Specificity | Positive Predictive Value | Negative Predictive Value | |||
|---|---|---|---|---|---|---|
| Low risk Duke Treadmill Score | ||||||
| CAC < 100 | CAC ≥ 100 | |||||
| Presence of significant CAD | 0 | 4 | 100% | 77.3% | 19.0% | 100% |
| Absence of significant CAD | 58 | 17 | ||||
| CAC < 400 | CAC ≥ 400 | |||||
| Presence of significant CAD | 0 | 4 | 100% | 96% | 57.1% | 100.0% |
| Absence of significant CAD | 72 | 3 | ||||
| Intermediate to High risk Duke Treadmill Score | ||||||
| CAC < 100 | CAC ≥ 100 | |||||
| Presence of significant CAD | 2 | 13 | 86.7% | 65.2% | 61.9% | 88.2% |
| Absence of significant CAD | 15 | 8 | ||||
| CAC < 400 | CAC ≥ 400 | |||||
| Presence of significant CAD | 6 | 9 | 60.0% | 91.3% | 81.8% | 77.8% |
| Absence of significant CAD | 21 | 2 | ||||