The impact of cerebral microbleeds on intracerebral hemorrhage and poor functional outcome of acute ischemic stroke patients treated with intravenous thrombolysis: a systematic review and meta-analysis

Abstract

It is still controversial whether pre-existing cerebral microbleeds (CMBs) increase the risks of intracranial hemorrhage (ICH) and poor functional outcome (PFO) in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT). Therefore, we performed a systematic review and meta-analysis to determine the impact of CMBs on ICH and PFO of AIS patients with IVT. We searched PubMed, EMBASE and Web of Science from inception to August 3, 2016, with language restriction in English. We included studies that reported the relationship between CMBs and ICH or PFO after thrombolysis. Two retrospective and nine prospective studies met inclusion criteria (total 2702 patients). The overall prevalence of CMBs on pre-IVT MRI scans was 24.0%. Pre-existing CMBs on MRI scans were not significantly associated with a higher risk of early sICH (OR 1.74; 95% CI 0.91-3.33; I = 44.5%). Subgroup analyses did not substantially influence these associations. The presence of CMBs was associated with the increased risk of 3-month PFO (OR 1.58; 95% CI 1.08-2.31; I = 54.2%), PH (OR 2.14; 95% CI 1.34-3.42; I = 11.0%) and any ICH (OR 1.42; 95% CI 1.04-1.95; I = 0.0%), respectively. This meta-analysis showed that CMBs presence was not significantly associated with the increased risk of early sICH after IVT. However, the results also demonstrated that CMBs presence increased the risks of 3-month PFO, PH and any ICH after IVT. Due to a small number of included studies and methodological limitations, the results of this meta-analysis should be interpreted cautiously. CMBs presence should not be a contraindication to IVT for AIS patients based on the existing evidence.

Intravenous Thrombolytic Therapy in Acute Stroke: Problems and Solutions

“…Having CMH causes 2.5 times more symptomatic intracerebral hemorrhage risk following IV tPA (43). However, this statistically significant risk increase was not shown in other studies (44).…”

“…Although CMH causes a mild increase in bleeding rates, to make general and clear decisions, the efficacy of IV tPA in patients with CMH should be evaluated in randomized and controlled studies. There is an important point: the presence of CMH decreases the rate of good outcomes in patients both with and without bleeding following IV tPA (42,44,45). This could be related with small vessel dysfunction and insufficient control of risk factors.…”

Computed tomography-negative symptomatic intracerebral hemorrhage in a patient with cerebral small vessel disease

“…Although a recent meta-analysis concluded that cerebral microbleeds were not associated with symptomatic intracerebral hemorrhage (ICH) after intravenous thrombolysis, they were associated with poor functional outcome and various types of ICH. [ 3 ] Thus, patients with ICH without a prominent high density on NCCT, as in this case, should be treated with great care.…”

The risk of symptomatic intracranial hemorrhage after thrombolysis for acute stroke: Current concepts and perspectives

“…Preexisting cerebral microbleeds have been considered a risk factor for BH after thrombolysis, and it was confirmed in three meta-analyses from pooled data of medical literature with 2702,[17] 1704,[18] and 2479[19] patients. According to three meta-analyses from 15/11/11 trials with a similar number of treated patients (6967/6912/7194), the presence of leukoaraiosis was associated with an increased risk of SICH and poor outcomes.…”