Vulnerable Carotid Plaque is Associated with an Increased Risk of Intracerebral Hemorrhage in Individuals at High Risk of Stroke: A Chinese Population-based Cohort Study.

Objectives: To assess the association between carotid artery plaques and the risk of incident intracerebral hemorrhage (ICH) event in high-risk individuals for stroke.

Methods: We conducted a population-based cohort study using the longitudinal participant-level data of a multicenter, cross-sectional survey in southwestern China. 2644 high-risk participants for stroke were enrolled in the year 2015. The primary outcome was new-onset ICH events during a five-year follow-up period. Multivariate logistic regression was performed to identify the association between carotid plaque and new-onset ICH. Stratified analyses and interaction tests were conducted to identify variables that might modify the association between vulnerable carotid plaque and ICH.

Results: Among 2644 high-risk individuals enrolled, carotid plaques were found in 904 (34.2%) subjects, including 479 (18.1%) with stable plaques and 425 (16.1%) with vulnerable plaques. During a five-year follow-up period, 22 (0.83%) participants developed ICH. Vulnerable carotid plaque was associated with an increased risk of new-onset ICH in multivariable analyses (adjusted RR 3.72, 95 % CI 1.32 to 10.46, p=0.013). Stratified analyses and interaction analyses demonstrated the association between vulnerable carotid plaque and ICH was not changed by age, family history of stroke, hemorrhagic stroke and chronic disease, smoking, drinking, physical activity, BMI, antihypertensives, and antithrombotic drugs (all p for interaction>0.05). However, among the female cohort, participants with vulnerable plaques had a significantly higher risk of ICH compared with participants without vulnerable plaques (crude RR=9.8; 95%CI: 3.1-31.3, p<0.001; adjusted RR=26.3, 95%CI: 5.5-124.5, p<0.001), but not in man (p>0.05).

Conclusion: In Chinese individuals at high risk of stroke, vulnerable carotid artery plaques are associated with an increased risk of intracerebral hemorrhage independent of classical vascular risk factors, especially in female individuals.