Table 1.
Baseline patient characteristics and empirical diagnostic performance of computed tomography angiography to diagnose coronary artery disease, stratified by pretest probability category and scanner detector rows
| Overall (n=5332) | Pretest probability categories | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 to <10% (n=86) | 10 to <20% (n=530) | 20 to <30% (n=601) | 30 to <40% (n=727) | 40 to <50% (n=745) | 50 to <60% (n=752) | 60 to <70% (n=590) | 70 to <80% (n=535) | 80 to <90% (n=698) | 90 to 100% (n=68) | ||
| Demographic characteristics (median (range) or No (%)) | |||||||||||
| Median age (years) | 61 (18-96) | 47 (18-50) | 56 (23-70) | 59 (24-82) | 57 (37-89) | 55 (27-87) | 63 (30-91) | 70 (36-88) | 55 (47-92) | 66 (59-77) | 80 (78-89) |
| Men | 3473 (65) | 0 | 29 (5) | 211 (35) | 509 (70) | 576 (77) | 507 (67) | 391 (66) | 484 (90) | 698 (100) | 68 (100) |
| Women | 1859 (35) | 86 (100) | 501 (95) | 390 (65) | 218 (30) | 169 (23) | 245 (33) | 199 (34) | 51 (10) | 0 | 0 |
| Median body mass index | 26.3 (14.3-57.1) | 25.6 (17.9-39.3) | 26.2 (14.3-47.3) | 25.9 (16.1-44.8) | 26.2 (16.9-41.8) | 26.4 (17.5-45.2) | 26.5 (17.2-57.1) | 26.4 (15.5-56.2) | 27.0 (17.5-42.5) | 26.9 (16.9-56.7) | 25.9 (16.8-35.2) |
| Clinical presentation (No) | |||||||||||
| Typical angina | 1967 | 0 | 0 | 4 | 43 | 137 | 247 | 306 | 464 | 698 | 68 |
| Atypical angina | 1592 | 1 | 138 | 269 | 235 | 280 | 339 | 260 | 70 | 0 | 0 |
| Non-anginal chest pain | 796 | 38 | 162 | 157 | 188 | 158 | 80 | 12 | 1 | 0 | 0 |
| Other chest discomfort | 977 | 47 | 230 | 171 | 261 | 170 | 86 | 12 | 0 | 0 | 0 |
| Diagnostic performance (No or %) | |||||||||||
| CAD prevalence (%)* | 48.3 | 17.4 | 24.0 | 32.1 | 40.9 | 46.8 | 46.8 | 53.7 | 68.6 | 71.6 | 82.4 |
| TP | 2251 | 14 | 120 | 176 | 272 | 321 | 310 | 256 | 317 | 420 | 45 |
| TN | 2031 | 52 | 313 | 312 | 334 | 287 | 294 | 194 | 103 | 134 | 8 |
| FP | 728 | 19 | 90 | 96 | 96 | 109 | 106 | 79 | 65 | 64 | 4 |
| FN | 322 | 1 | 7 | 17 | 25 | 28 | 42 | 61 | 50 | 80 | 11 |
| NDX† | 554 | 13 | 58 | 50 | 54 | 67 | 76 | 79 | 60 | 85 | 12 |
| NDX rate (%)† | 10.4 | 15.1 | 10.9 | 8.3 | 7.4 | 9.0 | 10.1 | 13.4 | 11.2 | 12.2 | 17.6 |
| PPV (%) | 75.6 | 42.4 | 57.1 | 64.7 | 73.9 | 74.7 | 74.5 | 76.4 | 83.0 | 86.8 | 91.8 |
| NPV (%) | 86.3 | 98.1 | 97.8 | 94.8 | 93.0 | 91.1 | 87.5 | 76.1 | 67.3 | 62.6 | 42.1 |
| Sensitivity (%) | 87.5 | 93.3 | 94.5 | 91.2 | 91.6 | 92.0 | 88.1 | 80.8 | 86.4 | 84.0 | 80.4 |
| Specificity (%) | 73.6 | 73.2 | 77.7 | 76.5 | 77.7 | 72.5 | 73.5 | 71.1 | 61.3 | 67.7 | 66.7 |
| Diagnostic accuracy (%) | 80.3 | 76.7 | 81.7 | 81.2 | 83.4 | 81.6 | 80.3 | 76.3 | 78.5 | 79.4 | 77.9 |
| LR+ | 3.32 | 3.49 | 4.23 | 3.88 | 4.10 | 3.34 | 3.32 | 2.79 | 2.23 | 2.60 | 2.41 |
| LR− | 0.17 | 0.09 | 0.07 | 0.12 | 0.11 | 0.11 | 0.16 | 0.27 | 0.22 | 0.24 | 0.29 |
| CT scanners with ≤64 detector rows (No or %) | |||||||||||
| No of patients | 4666 | 80 | 452 | 529 | 651 | 634 | 637 | 530 | 472 | 619 | 62 |
| CAD prevalence (%) | 48.2 | 17.5 | 24.1 | 31.2 | 41.8 | 45.5 | 46.0 | 54.0 | 67.4 | 72.5 | 85.5 |
| TP | 1943 | 13 | 102 | 150 | 248 | 264 | 256 | 226 | 270 | 372 | 42 |
| TN | 1757 | 47 | 265 | 273 | 295 | 247 | 246 | 170 | 95 | 114 | 5 |
| FP | 662 | 19 | 78 | 91 | 84 | 99 | 98 | 74 | 59 | 56 | 4 |
| FN | 304 | 1 | 7 | 15 | 24 | 24 | 37 | 60 | 48 | 77 | 11 |
| NDX† | 538 | 13 | 54 | 50 | 50 | 65 | 75 | 77 | 58 | 84 | 12 |
| NDX rate (%)† | 11.5 | 16.3 | 11.9 | 9.5 | 7.7 | 10.3 | 11.8 | 14.5 | 12.3 | 13.6 | 19.4 |
| PPV (%) | 74.6 | 40.6 | 56.7 | 62.2 | 74.7 | 72.7 | 72.3 | 75.3 | 82.1 | 86.9 | 91.3 |
| NPV (%) | 85.2 | 97.9 | 97.4 | 94.8 | 92.5 | 91.1 | 86.9 | 79.9 | 66.4 | 59.7 | 31.3 |
| Sensitivity (%) | 86.5 | 92.9 | 93.6 | 90.9 | 91.2 | 91.7 | 87.4 | 79.0 | 84.9 | 82.9 | 79.2 |
| Specificity (%) | 72.6 | 71.2 | 77.3 | 75.0 | 77.8 | 71.4 | 71.5 | 69.7 | 61.7 | 67.1 | 55.6 |
| Diagnostic accuracy (%) | 79.3 | 75.0 | 81.2 | 80.0 | 83.4 | 80.6 | 78.8 | 74.7 | 77.3 | 78.5 | 75.8 |
| LR+ | 3.16 | 3.23 | 4.12 | 3.64 | 4.11 | 3.20 | 3.07 | 2.61 | 2.22 | 2.52 | 1.78 |
| LR− | 0.19 | 0.10 | 0.08 | 0.12 | 0.11 | 0.12 | 0.18 | 0.30 | 0.24 | 0.26 | 0.37 |
| CT scanners with >64 detector rows (No or %) | |||||||||||
| No of patients | 558 | 6 | 73 | 62 | 66 | 87 | 103 | 55 | 41 | 59 | 6 |
| CAD prevalence (%)* | 46.1 | 16.7 | 21.9 | 37.1 | 30.3 | 54.0 | 49.5 | 50.9 | 75.6 | 62.7 | 50.0 |
| TP | 240 | 1 | 16 | 21 | 19 | 44 | 46 | 27 | 29 | 34 | 3 |
| TN | 254 | 5 | 46 | 36 | 39 | 33 | 47 | 22 | 6 | 17 | 3 |
| FP | 47 | 0 | 11 | 3 | 7 | 7 | 5 | 5 | 4 | 5 | 0 |
| FN | 17 | 0 | 0 | 2 | 1 | 3 | 5 | 1 | 2 | 3 | 0 |
| NDX† | 16 | 0 | 4 | 0 | 4 | 2 | 1 | 2 | 2 | 1 | 0 |
| NDX rate (%)† | 2.9 | 0.0 | 5.5 | 0.0 | 6.1 | 2.3 | 1.0 | 3.6 | 4.9 | 1.7 | 0.0 |
| PPV (%) | 83.6 | 100 | 59.3 | 87.5 | 73.1 | 86.3 | 90.2 | 84.4 | 87.9 | 87.2 | 100 |
| NPV (%) | 93.7 | 100 | 100 | 94.7 | 97.5 | 91.7 | 90.4 | 95.7 | 75.0 | 85.0 | 100 |
| Sensitivity (%) | 93.4 | 100 | 100 | 91.3 | 95.0 | 93.6 | 90.2 | 96.4 | 93.5 | 91.9 | 100 |
| Specificity (%) | 84.4 | 100 | 80.7 | 92.3 | 84.8 | 82.5 | 90.4 | 81.5 | 60.0 | 77.3 | 100 |
| Diagnostic accuracy (%) | 88.5 | 100 | 84.9 | 91.9 | 87.9 | 88.5 | 90.3 | 89.1 | 85.4 | 86.4 | 100 |
| LR+ | 5.98 | ∞ | 5.18 | 11.87 | 6.24 | 5.35 | 9.38 | 5.21 | 2.34 | 4.04 | ∞ |
| LR− | 0.08 | 0 | 0 | 0.09 | 0.06 | 0.08 | 0.11 | 0.04 | 0.11 | 0.10 | 0 |
TP=true positives; TN=true negatives; FP=false positives; FN=false negatives; PPV=positive predictive value; NPV=negative predictive value; LR+=positive likelihood ratio; LR−=negative likelihood ratio; NDX=non-diagnostic results.
The empirical results were derived from raw data and thus differ from the results of the statistical model.
*
CAD prevalence was defined by coronary angiography.
†
Non-diagnostic results were included in the estimation of diagnostic accuracy as false positives if the reference standard was negative, and as false negative if the reference standard was positive.