You're right, the trial looked at a 70% stenosis, but more studies have been done since then, specifically the ACAS trial—asymptomatic carotid atherosclerosis study—and it suggested that there is significant benefit, though not as significant as the other study, in doing carotid endarterectomy on patients who are asymptomatic.
Comme vous le disiez, l'essai portait sur les cas de sténose supérieure à 70 p. 100, mais d'autres études ont été menées depuis, dont notamment sur l'athérosclérose carotidienne asymptomatique.