The clinical relevance of cerebral microbleeds in patients with cerebral ischemia and atrial fibrillation

Abstract

The clinical significance of cerebral microbleeds (CMB) in patients hospitalized with atrial fibrillation (AF) and cerebral ischemia is unclear. We aimed to determine the prevalence of CMB in this population and determine the future risk of intracerebral hemorrhage (ICH) and cerebral infarction (CI). The medical records and brain imaging of patients hospitalized with cerebral ischemia due to AF between 2008 and 2011 were reviewed. Followup was obtained through medical record review, mailed survey, and acquisition of death certificates. Prevalence was calculated from those patients with a hemosiderin-sensitive MRI sequence. Recurrent CI and ICH were calculated using Kaplan-Meier curves censored at 3 years. Among 426 patients hospitalized with cerebral ischemia due to AF, 134 had an MRI with hemosiderin-sensitive sequences. The prevalence of CMB was 27.6%. At 3 years, 90.6% of CMB-negative patients were overall stroke free (ICH and CI) compared to 78.6% CMB-positive patients (p = 0.0591). Only one patient in the CMB-positive group had an ICH distant to the CMB. There was a nonsignificant trend toward higher recurrent CI, recurrent overall stroke rate, and mortality in patients with 5 or more CMB compared to 0-4 CMB. The rate of prospective CI in patients with prior cerebral ischemia due to AF is higher than the rate of ICH in patients with CMB. Further study is warranted to assess larger numbers of patients to determine appropriate antithrombotic use in this high-risk population.

Cerebral Microbleeds and Cortical Superficial Siderosis in Patients Presenting With Minor Cerebrovascular Events

“…Other studies have found that the presence of CMB, and especially multiple CMB, was associated with an increased risk of stroke, including first-ever ischemic stroke. 23,24 Presumably, the follow-up period in our study period was too short to detect an increase in stroke recurrence. Likewise, our …”

Antithrombotic therapy in patients with cerebral microbleeds

“…A small study in 134 patients with TIA or IS associated with AF (65% treated with anticoagulants) over a median follow-up of 2.4 years (39), found that CMBs were associated with an increased unadjusted risk of all stroke (21% vs 9%, p = 0.06) but there was only 1 ICH. A study from Korea in 504 patients with IS or TIA (97% discharged on anticoagulation) (29) found that strictly lobar CMBs were associated with ICH mortality (HR 5.91; 95% CI 1.58 to 22.11) whilst increasing CMB burden was associated with all cause (HR 1.99; 95% CI 1.03 to 3.85) and IS mortality (HR 3.39; 95% CI 1.39 to 8.28) but did not report on non-fatal IS or ICH.…”

Prior Antithrombotic Therapy Is Associated With Cerebral Microbleeds in Ischemic Stroke Patients With Atrial Fibrillation and/or Rheumatic Heart Disease

“…The frequency of CMBs in stroke patients with AF/RHD was 56.3% in the present study, which fell broadly within the range of 18% to 68% in patients with ischemic stroke (23). When focusing on stroke patients with AF, the prevalence of CMBs was reported to be around 30% (11, 12, 24, 25). The higher prevalence of CMBs in our study might be related to ethnic differences or different imaging protocol.…”

“…The presence of CMBs has been reported to increase the risk of ICH up to 8-fold in a pooled cohort of ischemic stroke or transient ischemic attack (TIA) (10). This is more clinically relevant in AF/RHD patients with anticoagulation needs (11). Prior studies showed that CMBs appear to be more prevalent in patients with AF (12) and ≥5 CMBs powerfully predict future ICH risk in ischemic stroke patients with AF taking oral anticoagulants (13).…”