The Tortuosity of Middle Cerebral Artery is Associated with Ipsilateral Recurrence of Ischemic Events.

Abstract

Aim: To investigate whether the tortuosity of the culprit middle cerebral artery (MCA) is correlated with the recurrence of ipsilateral ischemic events in patients with ischemic stroke caused by intracranial atherosclerotic disease (ICAD) on M₁ segment of MCA.

Methods: A total of 279 patients with first-ever M₁-ICAD-related stroke were enrolled. The morphology of the culprit M₁ segment was measured using MR or CT angiography, including the arc and chord length. The tortuosity index was calculated as (arc length / chord length - 1) × 100%. During the follow-up, the primary endpoints included recurrent transient ischemic attack and ischemic stroke attributable to culprit M₁-ICAD. The participants were stratified into subgroups according to the tertiles of the tortuosity index: Q₁ (＜9.98%), Q₂ (9.98%-19.17%), and Q₃ (＞19.17%). Multivariate Cox regression was performed to identify the factors associated with recurrence and the recurrence rates of subgroups was analyzed by log-rank test.

Results: The recurrence rates (group Q₁, 20.4%, group Q₂, 10.6%, group Q₃, 4.3%, p = 0.003) are statically different. The tortuosity index (HR[hazard ratios] = 0.96, 95% CI[confidence intervals] = 0.92-0.997, p = 0.037) is inversely associated with the recurrence. The Q₁ group exhibits a higher risk of recurrence (HR = 5.39, 95% CI: 1.66-17.48, p = 0.005) than the Q3 group, with the rate difference of 16.1% (95% CI: 6.9%-25.3%, p = 0.002).

Conclusion: In patients with M₁-ICAD-related stroke, lower tortuosity index of culprit MCA is associated with a higher risk of recurrent ipsilateral ischemic events.