Table 1.
Incidence of stroke across major studies of symptomatic and asymptomatic carotid artery stenosis comparing carotid revascularization and medical therapy
| Study name | Clinical presentation | Luminal stenosis (%) | Number of patients | Medical treatment (%) | Carotid revascularisation (%) | NNT |
|---|---|---|---|---|---|---|
| ACAS[26] | Asymptomatic | ≥60 | 1659 | 6.2* | 4* | 45 |
| ACST[27] | Asymptomatic | ≥60 | 3120 | 6.7 | 1.9 | 21 |
| <80 | 1284 | 7 | 1.4 | 18 | ||
| ≥80 | 1836 | 6.5 | 2.3 | 24 | ||
| ECST[16] | Symptomatic | 0-100 | 3018 | 17.8 | 17.4 | 250 |
| <50 | 1070 | 12 | 18.4 | - | ||
| 50-69 | 959 | 15.6 | 17.9 | 43 | ||
| ≥70 | 989 | 26.4 | 16 | 10 | ||
| NASCET[17] | Symptomatic | <70 | 2226 | 32.6 | 29.6 | 33 |
| <50 | 1368 | 26.2 | 25.7 | 200 | ||
| 50-69 | 858 | 32.3 | 23.9 | 12 | ||
| VA cooperative[25] | Symptomatic | 0-100 | 444 | 24.5 | 12.8 | 9 |
| 50-69¶ | 58 | 6.7 | 7.1* | - | ||
| ≥70¶ | 129 | 25.6 | 7.9* | 6 |
*Including death, ¶Early report of results stratified according to luminal stenosis. ACAS: Asymptomatic Carotid Artery Study, ACST: Asymptomatic Carotid Surgery Trial, ECST: European Carotid Surgery Trial, NASCET: North American Symptomatic Carotid Endarterectomy Trial, VA: Veterans affairs