Quantity of Cerebral Microbleeds, Antiplatelet Therapy, and Intracerebral Hemorrhage Outcomes: A Systematic Review and Meta-analysis.
OBJECTIVE
Cerebral microbleeds (CMBs) increase future intracerebral hemorrhage (ICH) risk after ischemic stroke (IS) or transient ischemic attack (TIA). However, whether CMB-related ICH risk depends on CMB quantity, CMB location, or antithrombotic agents is unclear. We performed a systematic review and meta-analysis to investigate CMB-related ICH risk, stratifying patients according to the quantity of CMB, the location of CMB, and the type of antithrombotic therapy used.


METHODS
Literature databases were searched for prospective cohorts reporting ICH outcomes in patients with IS or TIA with baseline CMB evaluation. We calculated pooled relative ratios (RRs) for ICH among patients with and without CMBs. Pooled RRs of CMB-related ICH were further calculated in subgroups stratified by CMB quantity, CMB location, and antithrombotic therapy.


RESULTS
Among the 10 included studies, the pooled RR of future ICH was 7.73 (95% confidence interval [CI], 4.07-14.70; P < .001) in CMB versus non-CMB patients. Subgroup analysis revealed that compared with non-CMB patients, multiple-CMB patients were at an increased risk for future ICH (RR = 8.02; 95% CI, 3.21-20.01; P < .001), whereas single-CMB patients did not incur this risk (RR = 2.33; 95% CI, .63-8.63; P = .205). A strong association was found between CMB presence and subsequent ICH in antiplatelet users (RR = 16.56; 95% CI, 3.68-74.42; P < .001). Studies on CMB-related ICH according to CMB locations and in anticoagulant users are lacking for subgroup analysis.


CONCLUSIONS
Our study revealed that patients with IS or TIA with multiple CMBs may incur a higher risk of future ICH, and the presence of CMBs in patients with IS or TIA using antiplatelet agents may significantly increase the subsequent ICH risk.
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, China.
Dan-Ni
DN
Wang
Department of Clinical Epidemiology, Institute of Cardiovascular Disease, The First Affiliated Hospital of China Medical University, China.
Xiao-Wen
XW
Hou
Department of Clinical Epidemiology, Institute of Cardiovascular Disease, The First Affiliated Hospital of China Medical University, China.
Bo-Wen
BW
Yang
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, China.
Yi
Y
Lin
Department of Clinical Epidemiology, Institute of Cardiovascular Disease, The First Affiliated Hospital of China Medical University, China. Electronic address: sjp562013@126.com.
Jing-Pu
JP
Shi
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, China; Fujian Key Laboratory of Molecular Neurology, China. Electronic address: ningwang@mail.fjmu.edu.cn.
Ning
N
Wang
D006801:Humans; D020300:Intracranial Hemorrhages / Q000209:etiology*; D002546:Ischemic Attack, Transient / Q000150:complications / Q000188:drug therapy*; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000150:complications / Q000188:drug therapy*; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors
Cerebral microbleeds; antiplatelet therapy; intracerebral hemorrhage; magnetic resonance imaging; secondary prevention; stroke