Clinical/imaging features associated with an increased risk of late stroke in patients with 50%–99% asymptomatic carotid stenosis treated medically in the 2017 European Society for Vascular Surgery carotid guidelines16
| Imaging/clinical parameter | OR/HR (95% CI); P value |
| Spontaneous embolisation on TCD | 7.46 (2.24 to 24.89); P=0.001 |
| Plaque echolucency (vs echogenic) on Duplex US | 2.61 (1.47 to 4.63); P=0.001 |
| Spontaneous embolisation on TCD+uniformly or predominantly echolucent plaque (70%–99% stenoses) | 10.61 (2.98 to 37.82); P=0.0003 |
| Stenosis progression (50%–99% stenoses) | 1.92 (1.14 to 3.25); P=0.05 |
| Stenosis progression (70%–99% stenoses) | 4.7 (2.3 to 9.6) |
| Silent infarction on CT (60%–99% stenoses) | 3.0 (1.46 to 6.29); P=0.002 |
| Impaired cerebrovascular reserve (70%–99% stenoses) | 6.14 (2.77 to 4.95); P<0.01 |
| Juxtaluminal black area on computerised plaque analysis (<4 mm2, 4–8 mm2, 8–10 mm2, >10 mm2) | Trend P<0.001 |
| Intraplaque haemorrhage on MRI | 3.66 (2.77 to 4.95); P<0.01 |
| Contralateral stroke/TIA | 3.0 (1.9 to 4.73); P=0.0001 |
TCD, transcranial Doppler; TIA, transient ischaemic attack; US, ultrasound.