Carotid plaque morphological and compositional characteristics
| Mean±SD, n (%) or median | P value* | ||
| Northern subjects (n=63) | Southern subjects (n=56) | ||
| Carotid morphology | |||
| Mean lumen area, mm2 | 57.7±14.9 | 50.4±18.3 | 0.009 |
| Mean wall area, mm2 | 38.4±13.1 | 31.9±11.7 | <0.001 |
| Mean total vessel area, mm2 | 96.1±20.2 | 82.4±22.7 | 0.001 |
| Mean wall thickness, mm | 1.25±0.43 | 1.13±0.40 | 0.019 |
| Mean normalised wall index, % | 40.7±9.5 | 40.2±10.4 | 0.489 |
| Luminal stenosis ≥50% | 5 (7.9) | 5 (8.9) | >0.99 |
| Presence of plaque components | |||
| Calcification | 24 (38.1) | 23 (41.1) | 0.740 |
| Lipid-rich necrotic core | 38 (60.3) | 31 (55.4) | 0.584 |
| Intraplaque haemorrhage | 9 (14.3) | 3 (5.4) | 0.106 |
| Luminal surface disruption | 7 (11.1) | 4 (7.1) | 0.456 |
| High-risk plaque | 13 (20.6) | 6 (10.7) | 0.140 |
| Volume of plaque components† | |||
| Calcification, mm3 | 19.9 | 8.0 | 0.050 |
| Lipid-rich necrotic core, mm3 | 29.4 | 36.2 | 0.629 |
*P values are Mann-Whitney U test or χ2 test between northern and southern subjects.
†Only subjects with the corresponding component present were included in the comparison.