Pre-treatment cerebral microbleeds and intracranial hemorrhage in patients with ischemic stroke receiving endovascular therapy: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Predicting the risk of intracranial hemorrhage (ICH) is an important aspect for improving the efficacy and safety of endovascular therapy (EVT). We intended to perform a systematic review and meta-analysis to show whether pre-treatment cerebral microbleeds (CMBs) were associated with an increased incidence of ICH in patients with ischemic stroke receiving EVT. METHODS: We searched PubMed, EMBASE, Web of Science and Cochrane Library from their dates of inception to December 18, 2018, and also manually searched reference lists of relevant articles. Cumulative prevalence of CMBs and ICH was calculated. Relative risk and 95% confidence interval (CI) were calculated for the incidence of ICH in patients with CMBs versus those without after EVT. RESULTS: Four studies involving 598 patients were included. The pooled prevalence of CMBs was 18% (95% CI 15-21%) and the pooled prevalence of ≥ 5 CMBs was 1% (95% CI 0-2%). The pooled incidence of ICH was 29% (95% CI 8-49%) in all patients, 25% (95% CI 5-45%) in those with CMBs and 29% (95% CI 8-50%) in those without CMBs. The pooled relative risk of ICH was 0.90 (95% CI 0.65-1.25, P = 0.528; I2 = 0%, P = 0.949) in patients with CMBs versus those without CMBs. CONCLUSIONS: There is no evidence that pre-treatment CMBs were associated with an increased incidence of ICH in patients with ischemic stroke receiving EVT.

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.

Completeness of circle of Willis and white matter hyperintensities in patients with severe internal carotid artery stenosis.

BACKGROUND: We investigated whether completeness of the circle of Willis (CoW) protected patients with severe internal carotid artery (ICA) stenosis against white matter hyperintensities (WMHs). METHODS: We included 115 patients with unilateral ICA stenosis ≥ 70%. The completeness of CoW was assessed and WMHs were rated on a visual scale. The score of deep and periventricular WMHs was compared between patients with complete and incomplete CoW and between the two hemispheres, ipsilateral and contralateral to stenosed ICA. RESULTS: We included 115 patients with severe ICA stenosis, 60 patients had a complete CoW (52.17%) and 55 had an incomplete CoW (47.83%). The patients with incomplete CoW had higher score of deep WMHs (OR = 1.82, 95% CI 1.08-3.06, P = 0.023) and periventricular WMHs (OR = 4.53, 95% CI 2.09-9.81, P = 0.000) than those with complete CoW. In the patients with incomplete CoW, the score of deep WMHs (OR = 4.14, 95% CI 1.33-12.93, P = 0.014) and periventricular WMHs (OR = 5.46, 95% CI 1.16-25.62, P = 0.032) was higher in the hemisphere ipsilateral to stenosed ICA than that in the contralateral hemisphere. In the patients with complete CoW, there was no significant difference in the score of deep WMHs (OR = 2.10, 95% CI 0.37-11.91, P = 0.401) and periventricular WMHs (OR = 2.83, 95% CI 0.99-8.05, P = 0.051) between the ipsilateral and contralateral hemispheres to stenosed ICA. CONCLUSION: The completeness of CoW protected patients with severe ICA stenosis against WMHs.

Antiplatelet Therapy, Cerebral Microbleeds, and Intracerebral Hemorrhage: A Meta-Analysis.

BACKGROUND AND PURPOSE: Antiplatelet therapy is associated with the presence of cerebral microbleeds (CMBs) with limited studies. We further investigate the topic focusing on different effects of antiplatelet therapy on strict lobar and deep/infratentorial MBs. METHODS: We searched PubMed and EMBASE from January 1, 1997 to December 1, 2017, for relevant studies, calculated the pooled odds ratios (OR) for CMB incidence and distribution (strictly lobar, deep/infratentorial) in antiplatelet users versus nonantiplatelet users and calculated the OR for the incidence of intracerebral hemorrhage in antiplatelet users with CMBs versus those without. RESULTS: We included 20 988 participants from 37 studies. CMBs were more frequent in antiplatelet users than those in nonantiplatelet users (pooled OR, 1.21; 95% confidence interval, 1.07-1.36; P=0.002). There was a significant association of antiplatelet therapy with strictly lobar MBs (OR, 1.45; 95% confidence interval, 1.15-1.84; P=0.002) rather than deep/infratentorial MBs (OR, 1.37; 95% confidence interval, 0.98-1.90; P=0.062). Intracerebral hemorrhage incidence was higher in participants with CMBs than those without CMBs (OR, 3.40; 95% confidence interval, 2.00-5.78; P=0.000) in antiplatelet users. CONCLUSIONS: Antiplatelet drug use was associated with increased risk of strictly lobar MBs and increased the intracerebral hemorrhage incidence in participants with CMBs.