Prevalence, Risk Factors, and Clinical Outcomes of New Cerebral Microbleeds After Intravenous Thrombolysis in Acute Ischemic Stroke: a Systematic Review and Meta-analysis.

ABSTRACT

BACKGROUND: Cerebral microbleeds (CMBs) are common in the elderly population, and are associated with an increased risk of stroke and dementia. An acute ischemic stroke event can make CMBs develop rapidly. However, the progression of CMBs after intravenous thrombolysis is not well understood. METHODS: Following a previously registered protocol, PubMed, Web of Science, and Embase databases were systematically searched to identify relevant literature up to August 2022. Cohort studies that reported new CMBs in patients with acute ischemic stroke undergoing intravenous thrombolysis were included. Random effects models were used to calculate the pooled estimates. RESULTS: Seven studies with 1079 patients were included in the meta-analysis. The pooled new CMBs prevalence was 7.6% (95% CI 3.9-14.3%) and 63.6% new CMBs were located in the cerebral lobes. Compared with patients without new CMBs, those with new CMBs were older, had a higher proportion of hypertension, and had higher systolic blood pressure and baseline CMBs burden. The presence of new CMBs increased the likelihood of remote intracerebral hemorrhage (OR 28.75, 95% CI 8.58-96.38) and symptomatic intracerebral hemorrhage (OR 15.49, 95% CI 3.21-74.73) but was not related to functional outcomes or hemorrhagic transformation. CONCLUSIONS: The prevalence of new CMBs after intravenous thrombolysis was approximately 7.6%. The presence of new CMBs is associated with remote and symptomatic intracerebral hemorrhage following intravenous thrombolysis. Considering the potential long-term adverse effects of CMBs progression, patients at a high risk of developing new CMBs should be identified based on potential risk factors.