Clinical Implications of Preinterventional Thrombus Migration in Patients with Emergent Large Vessel Occlusion

Thrombus migration in ischemic stroke due to large vessel occlusion: a question of time

BACKGROUND

Thrombus migration (TM) is frequently observed in large vessel occlusion (LVO) ischemic stroke to be treated by endovascular thrombectomy (EVT). TM may impede complete recanalization and hereby worsen clinical outcomes. This study aimed to delineate factors associated with TM and clarify its impact on technical and functional outcome.

METHODS

All patients undergoing EVT due to LVO in the anterior circulation at two tertiary stroke centers between October 2015 and December 2020 were included. Source imaging data of all individuals were assessed regarding occurrence of TM by raters blinded to clinical data. Patient data were gathered as part of the German Stroke Registry, a multicenter, prospective registry assessing real-world outcomes. Technical outcome was assessed by modified Thrombolysis in Cerebral Infarction scale (mTICI). Functional outcome was assessed by modified Rankin Scale (mRS) at 3 months.

RESULTS

The study consisted of 512 individuals, of which 71 (13.8%) displayed TM. In adjusted analyses, TM was associated with longer time from primary imaging to reassessment in the angio suite (aOR 2.37 (1.47 to 3.84) per logarithmic step) and intravenous thrombolysis (IVT; aOR 4.07 (2.17 to 7.65)). In individuals with IVT, a needle-to-groin time >1 hour was associated with higher odds for TM (aOR 2.60 (1.20 to 5.99)). TM was associated with lack of complete recanalization (aORmTICI3 0.46 (0.24 to 0.90)) but TM did not worsen odds for good clinical outcome (aORmRS≤2_d90 0.89 (0.47 to 1.68)).

CONCLUSIONS

TM is associated with IVT and longer time between sequential assessments of thrombus location. Consequently, TM may be of high relevance in patients with drip-and-ship treatment.

Endovascular thrombectomy with or without intravenous alteplase in acute stroke: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND AND PURPOSE

This study investigated clinical outcomes after direct endovascular thrombectomy (EVT) compared to bridging therapy (EVT with prior intravenous alteplase) in acute stroke within 4.5 h after onset.

METHODS

PubMed and Embase were searched for eligible randomized controlled trials. The primary outcome was the rates of neurological functional independence defined as modified Rankin scale score 0-2 at 90 days, whose non-inferiority margin was set at - 15%, - 10%, - 6.5%, - 5%, and - 1.3% for its risk difference (RD).

RESULTS

We included six studies enrolling 2334 participants. The crude cumulative rates of functional independence were 49.0% with direct EVT vs 50.9% with bridging therapy, without significant difference (Odd ratio [OR] = 0.93, 95% confidence interval [CI] 0.79-1.09) between two groups, where the pooled RD was - 2% (95% CI - 6 to 2%) whose lower 95% CI bound fell within non-inferiority margins of - 15%, - 10%, -6.5%, but not - 5% and - 1.3%. Between the two groups, no significant difference was found in excellent function rate (30.2% vs 30.6%, OR = 0.99, 95% CI 0.82-1.18) with RD of 0% (95% CI - 3 to 4%), mortality rate (16.0% vs 15.0%, OR = 1.08, 95% CI 0.86-1.35) with RD of 1% (95% CI - 2 to 4%), and symptomatic intracranial hemorrhage rate (4.3% vs 5.0%, OR = 0.86, 95% CI 0.58-1.27) with RD of 0% (95% CI - 2 to 1%).

CONCLUSIONS

No statistical difference was found in functional and safety outcomes between direct EVT and bridging therapy groups in acute stroke within 4.5 h after symptom onset. EVT alone was non-inferior to bridging therapy for several, but not the more stringent, non-inferiority margins.