Mechanical thrombectomy vs intravenous rt-PA in medium vessel occlusions: real-world data from the Italian SITS registry

Background Recent randomized trials have questioned the benefit of endovascular therapy (EVT) for medium vessel occlusion (MeVO) stroke, but data from clinical practice are limited. This study aimed to assess the effectiveness and safety of EVT, with or without intravenous thrombolysis (IVT), versus IVT alone in MeVO stroke using registry-based real-world data.

This retrospective multicenter study included patients from 82 Italian centers in the SITS registry (January 2020–December 2023). Adults with acute ischemic stroke due to MeVO (ACA A1/A2, MCA M2/M3 or more distal, or PCA P1/P2), treated with IVT or EVT±IVT, and with available 90-day modified Rankin Scale (mRS) scores were included. Patients with tandem occlusions were excluded. Propensity score matching (1:1) was used to balance baseline variables. Primary outcome was functional independence (mRS 0–2) at 90 days. Secondary outcomes included in-hospital mortality, intracranial hemorrhage incidence, and recanalization status.

Among 1375 total patients, 780 were included and matched (390 per group) by propensity score. Baseline characteristics were balanced. Functional independence at 90 days was achieved in 57.7% of EVT±IVT patients versus 59.2% in the IVT-only group (OR 0.939, 95% CI 0.706–1.248, p=0.663). In-hospital mortality was non significantly lower in the EVT±IVT group (5.4% vs 8.7%, p=0.069). Symptomatic intracranial hemorrhage rates were comparable between groups, although overall hemorrhagic complications were higher with EVT (18.4% vs 11.2%, p<0.0001). Successful recanalization occurred in 81.0% of EVT cases. Stratified analyses by stroke severity and treatment timing showed consistent lack of benefit across all subgroups (all interaction p-values >0.05).

EVT did not improve long-term functional outcomes compared to IVT alone in MeVO stroke but was associated with higher hemorrhagic risk. These findings support a cautious approach to EVT in this setting, in line with recent trial evidence. Competing Interest Statement AZ declares consulting and speaker fees from Bayer, Boehringer-Ingelheim, Alexion, Daiichi Sankyo, Pfizer, PIAM, Amgen, fees for Advisory Board from Boehringer-Ingelheim, Daiichi Sankyo, Bayer and Astra Zeneca, not related to this study. Funding Statement This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The coordinating center (Fondazione IRCCS San Gerardo dei Tintori, Monza) determined that this study is exempt from full review as it involves secondary analysis of de-identified data from the SITS registry. Participating sites confirmed that no additional local approval was required for use of de-identified registry data, per local regulations. Informed consent was [waived/not required] due to use of de-identified data. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data availability The study protocol and additional supplementary information are available from the corresponding author upon reasonable request.