Basilar Artery Dolichosis Increases the Risk of Long-Term Recurrence in Patients With Pontine Infarction: A Prospective Cohort Study

Background and Purpose: Patients with basilar artery (BA) dolichosis are at high risk of acute pontine infarction (API), but the association between BA dolichosis and long-term stroke recurrence has received little attention. We aimed to identify the effect of BA dolichosis on the risk of long-term brainstem infarction recurrence in patients with API. Methods: In this prospective cohort study, we enrolled 113 patients with API admitted to our department. BA dolichosis was diagnosed by a BA curve length >29.5 mm or bending length (BL) >10 mm on magnetic resonance angiography. The primary outcome was the occurrence of diffusion-weighted imaging (DWI)-confirmed brainstem infarction. The Cox proportional hazard model was used to detect possible predictors of brainstem infarction recurrence. Results: Among 113 patients with API, 39 (34.5%) patients had BA dolichosis, and DWI-confirmed brainstem infarction recurred in 15 (13.3%) patients with a mean follow-up time of 31.2 months; the estimated 5-year incidence of brainstem infarction recurrence was 23.1% in patients with BA dolichosis, which was significantly higher than the incidence of 8.1% in patients without BA dolichosis. Cox proportional hazard analysis showed that age ≥65 years (hazard ratio (HR) = 3.341, 95% confidence interval (CI): 1.079-10.348, P = 0.036) and BA dolichosis (HR = 3.048, 95% CI: 1.069-8.693, P = 0.037) were significantly associated with a higher risk of brainstem infarction recurrence. In a subgroup analysis stratified by age, the patients aged ≥65 years with BA dolichosis had a higher risk of brainstem infarction recurrence (HR = 7.319, 95% CI: 1.525-35.123, P = 0.013). Conclusions: This study indicates that BA dolichosis may increase the risk of long-term brainstem infarction recurrence in patients with API, especially in elderly patients, and therefore warrants more attention in clinical practice.