Reevaluating the role of heparin during mechanical thrombectomy for acute ischemic stroke: Increased risks without functional benefit.

Background: Heparin may be administered during mechanical thrombectomy (MT) for acute ischemic stroke due to large vessel occlusions (AIS-LVO), with the aim of enhancing reperfusion and improving patient outcomes. The uncertain balance between risks and benefits of administering heparin during MT prompted us to perform this systematic review and meta-analysis.

Methods: A comprehensive search was conducted in PubMed, Embase, and Scopus to find studies that report the safety or efficacy of administering heparin during MT for AIS-LVO. Meta-analysis was performed using the random effects model. In case of significant heterogeneity a subgroup analysis was performed.

Results: From 2398 screened records, we included 15 studies. Rate of favorable functional outcome (90 day modified Rankin Scale 0-2 (mRS 0-2)) was lower among patients who received heparin (OR, 0.88 [95 %CI 0.79-0.98]; p=.023). Risk of distal embolization was higher in patients who received heparin (OR, 1.25 [95 %CI 1.01-1.55]; p=.04). The subgroup analysis showed that patients who received intravenous thrombolysis (IVT) had higher risk of Symptomatic intracranial hemorrhage (sICH) (OR, 2.94 [95 %CI 1.30-6.63]; p=.009) and lower rate of mRS 0-2 (OR, 0.66 [95 %CI 0.50-0.87]; p=.004). Heparin use didn't affect successful reperfusion rate (Thrombolysis in cerebral infarction ≥2B), mortality or any ICH risk.

Conclusion: Overall, our analysis indicates that administering heparin during MT for AIS-LVO correlates with worse clinical outcomes and increased distal embolization rates. Moreover, it is linked to a higher risk of sICH in patients who receive IVT. Consequently, the routine utilization of heparin during MT should be reconsidered.