Association of Cerebral Microbleeds and Risk of Stroke and Mortality in Posterior Circulation Cerebral Infarction

Abstract Objective This study was investigated to determine whether CMBs were associated with the risk of recurrent stroke or all-cause death in patients with acute posterior circulation cerebral infarction. Methods A retrospective analysis was conducted on 323 patients with acute posterior circulation cerebral infarction who aged ≥ 45 years and were hospitalized at Qingdao University Affiliated Hospital from January 1, 2016 to December 31, 2020. Patients were divided into different CMBs groups according to the presence, number and distribution of CMBs. Occurrence of stroke and death was recorded during follow-up. We drew Kaplan Meier survival curves and constructed Cox proportional hazards regression models based on different CMBs groups and clinical outcomes. Results A total of 323 patients were enrolled in our study, and 138 (42.72%) had CMBs. During a median follow-up of 1357 days, 87 (26.94%) experienced recurrent stroke or death. ≥5 CMBs (HR 1.723; 95% CI 1.021-2.907; P=0.041) and lobar CMBs (HR 2.312; 95% CI 1.204-4.441; P=0.012) were independent predictors associated with the composite risk of recurrent stroke and all-cause death. All CMBs statuses were not significantly correlated with the risk of recurrent stroke. The presence of CMBs (HR 3.358; 95% CI 1.259-8.954; P=0.015), ≥ 5 CMBs (HR 5.290; 95% CI 1.599-17.499; P=0.006) and deep CMBs (HR 3.265; 95% CI 1.003-10.628; P=0.049) were all independent factors associated with all-cause death. Conclusions In patients with acute posterior circulation cerebral infarction, ≥5 CMBs and lobar CMBs may increase the risk of poor clinical outcome (the composite of recurrent stroke and all-cause death). Furthermore, the presence CMBs, ≥ 5 CMBs and deep CMBs all independently may increase the risk of all-cause death.