Fibrinogen depletion and the risk of intracerebral hemorrhage following endovascular mechanical thrombectomy

BackgroundIntravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are the standard of care for select stroke patients with acute large vessel occlusion (LVO). Fibrinogen levels may drop after IVT, and a significant decrease in fibrinogen is associated with an increased risk of intracranial hemorrhage (ICH). Our pilot study aimed to explore the relationship between fibrinogen levels and the development of ICH in MT-treated patients and whether bridging with IVT further increases that risk.MethodsThis is a prospective pilot study that enrolled adults presenting with a diagnosis of LVO stroke and eligible to receive MT with or without IVT between April 2020 and May 2023. Fibrinogen levels were drawn before treatment with IVT or MT and immediately following MT.ResultsForty-one patients were enrolled. Median age was 68 years [interquartile range 56-79], 58.5% were females and 56.1% were black. Nineteen patients (46.3%) were treated with MT + IVT, and 22 (53.6%) were treated with MT-only. There was no difference in baseline characteristics between the two groups. Baseline fibrinogen levels were similar between MT + IVT and MT-only groups [391 vs. 352 mg/dL, p = 0.4]. Post MT, the MT + IVT group had lower fibrinogen levels compared to the MT-only group [224 vs. 303 mg/dL, p < 0.001]. Similarly, there was a significant change between baseline and follow-up levels in the MT + IVT vs. MT-only group [106 vs. 39.5 mg/dL, p = 0.001]. Eight patients (19.5%) developed ICH; 5 (26.3%) in the MT + IVT group and 3 (13.6%) in the MT-only group. No significant differences were seen in baseline, follow-up, or change in fibrinogen levels between patients who developed ICH and those who did not. However, when stratified by treatment group, postintervention fibrinogen levels were significantly lower in patients who developed an ICH in the MT + IVT group compared to those without ICH in the MT group (200 vs. 301 mg/dL, p = 0.006). There was also a negative correlation between the change in fibrinogen levels and the rate of first-pass recanalization (Spearman CC -0.33, p = 0.03).ConclusionThis pilot study's preliminary data showed an association between fibrinogen depletion and hemorrhagic transformation in MT-treated patients. Since intracerebral hemorrhage is the most dire side effect in stroke treatment, fibrinogen monitoring in patients undergoing MT after IVT may help identify patients with an increased risk of ICH. Larger, prospective, and multicenter studies are needed to confirm these findings and if fibrinogen repletion should be considered for dysfibrinogenemia.