By Matthew E. Fink, MD

Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital

Dr. Fink reports he is a retained consultant for Procter & Gamble and Pfizer.

SOURCE: Tsivgoulis G, Zand R, Katsanos AH, et al. Risk of symptomatic intracerebral hemorrhage after intravenous thrombolysis in patients with acute ischemic stroke and high cerebral microbleed burden. A meta-analysis. JAMA Neurol 2016;73:675-683.

Cerebral microbleeds (CMBs), as visualized on gradient-echo or susceptibility-weighted MRI, are considered markers of bleeding-prone cerebral microvessels and constitute a significant and independent predictor of future intracerebral hemorrhage. However, the risk of these abnormalities in patients undergoing thrombolysis is uncertain, and observational studies have shown conflicting results. The authors undertook a literature review and meta-analysis to investigate the association of a high cerebral microbleed burden (> 10 CMBs on pre-IV thrombolysis MRI) and the risk of symptomatic intracranial hemorrhage following thrombolysis for acute ischemic stroke. Symptomatic hemorrhage was defined as any intracranial bleed with neurological worsening 4 points on the NIH stroke scale score. After a comprehensive literature review, nine studies were identified comprising 2,479 patients with acute ischemic stroke. The risk of symptomatic intracranial hemorrhage after thrombolysis was found to be higher in patients who had CMBs compared to patients without CMBs (risk ratio = 2.36). A higher risk for hemorrhage was detected in patients with a high CMB burden (> 10 CMBs) when compared with patients who had 0 to 10 CMBs (risk ratio = 12.10). The presence of cerebral microbleeds and a high CMB burden on pretreatment MRI were independently associated with symptomatic intracranial hemorrhage in patients treated for acute ischemic stroke with thrombolysis. CMB burden should be included as part of the individual risk stratification formula for patients when the decision is being made to administer IV thrombolysis.