Baseline characteristics, assessability, and diagnostic accuracy of multislice computed tomographic (MSCT) angiography in detecting ≥ 50% coronary artery stenoses
| Groups | |||||
|---|---|---|---|---|---|
| All (n=78) | Group 1 (n=26) | Group 2 (n=26) | Group 3 (n=26) | ||
| *The number of lesions including non-assessable segments given in brackets. | |||||
| †All ≥2.0 mm segments, but excluding segments containing stents. | |||||
| ‡Percentages of the (relevant) ≥2.0 mm segments given in brackets. | |||||
| ¶Other causes include: respiratory motion, blending with adjacent contrast filled structures (vein, right ventricle), artefacts from pacemaker wire. | |||||
| §Sensitivity including undetected lesions in non-assessable segments as false-negative. | |||||
| **Percentage of patients with completely true positive or true negative diagnoses, including undetected lesions in non-assessable segments as false negative. | |||||
| CI, confidence interval. | |||||
| Baseline characteristics | |||||
| Heart rate (beats/min) | Mean (SD) | 68.0 (12.1) | 55.8 (4.1) | 66.6 (2.8) | 81.7 (8.8) |
| Range | 49 to 103 | 49 to 62 | 63 to 72 | 73 to 104 | |
| Age (mean (SD)) | 56.9 (10.1) | 58.3 (9.7) | 58.9 (9.7) | 53.4 (10.2) | |
| Sex (male/female) | 57/21 | 18/8 | 23/3 | 16/10 | |
| ≥50% stenotic lesions* | 57 (76) | 29 (34) | 19 (23) | 9 (19) | |
| Stents | 31 | 9 | 15 | 7 | |
| Assessability | |||||
| Relevant segments† | 741 | 244 | 251 | 246 | |
| Assessable segments‡ | 505 (68%) | 191 (78%) | 182 (73%) | 132 (54%) | |
| Causes of non-assessability‡ | Cardiac motion | 73 (10%) | 10 (4%) | 15 (6%) | 48 (20%) |
| Calcifications | 40 (5%) | 17 (7%) | 15 (6%) | 8 (3%) | |
| Other causes¶ | 35 (5%) | 5 (2%) | 4 (2%) | 26 (11%) | |
| Non-specific | 88 (12%) | 21 (9%) | 35 (14%) | 32 (13%) | |
| Diagnostic accuracy (95% CI) | |||||
| Assessable coronary segments | Sensitivity | 84% (74% to 92%) | 97% (84% to 100%) | 74% (52% to 89%) | 67% (33% to 90%) |
| Specificity | 95% (93% to 96%) | 96% (94% to 97%) | 94% (91% to 96%) | 94% (91% to 95%) | |
| Positive predictive value | 67% (58% to 73%) | 82% (71% to 85%) | 58% (41% to 70%) | 43% (21% to 58%) | |
| Negative predictive value | 98% (97% to 99%) | 99% (97% to 100%) | 97% (94% to 99%) | 97% (95% to 99%) | |
| Sensitivity including non-assessable segments (95% CI)§ | 63% (54% to 71%) | 82% (69% to 91%) | 61% (42% to 77%) | 32% (15% to 50%) | |
| Accuracy at patient level** | 56% | 73% | 54% | 42% | |
| Causes of misinterpretation | Total misinterpretations | 33 | 7 | 15 | 11 |
| Calcification | 17 | 5 | 8 | 4 | |
| Cardiac motion | 11 | – | 5 | 6 | |
| Other causes | 5 | 2 | 2 | 1 | |