Pretreatment cerebral microbleeds and symptomatic intracerebral hemorrhage post-thrombolysis: a systematic review and meta-analysis.

Background And Purpose: Cerebral microbleeds (CMBs) are a possible predictor of symptomatic intracranial hemorrhage (sICH) and poor function outcome (PFO). We aimed to investigate the presence of CMBs on increased incidence of sICH and PFO in acute ischemic stroke patients receiving intravenous thrombolysis (IVT) treatment.

Methods: We searched PubMed, EMBASE, and Cochrane Library from 1 January 1997 to 13 May 2018, for relevant studies and calculated the pooled relative risk (RR) for the incidence of sICH and PFO in patients with CMBs versus those without after IVT.

Results: We included 2407 participants from nine studies. The cumulative sICH incidence was higher in patients with CMBs (6%, 95% CI 4-8%) than that in patients without CMBs (4%, 95% CI 2-6%) with pooled RR 1.51 (95% CI, 1.04-2.21; P = 0.031). Four studies including 1550 patients reported data on 3- to 6-month PFO. The cumulative PFO incidence was higher in patients with CMBs (53%, 95% CI 47-59%) than that in patients without CMBs (41%, 95% CI 36-46%) with pooled RR 1.25 (95% CI 1.11-1.41; P = 0.000).

Conclusions: The pretreatment CMBs were associated with increased incidence of sICH and PFO in acute ischemic stroke patients receiving IVT. However, it was not convincing enough to set the presence of CMBs as contraindication to IVT.