National trends in patient characteristics, interventional techniques and outcomes of endovascular treatment for acute ischaemic stroke: Final results of the MR CLEAN Registry (2014–2018)

Introduction: Endovascular thrombectomy (EVT) procedures and workflow have evolved over the years. We examined trends in patient characteristics, EVT techniques and outcomes over 5 years in the Netherlands. Patients and methods: Data from the MR CLEAN Registry (2014–2018) were analysed, including patients treated with EVT for anterior circulation acute ischaemic stroke (AIS). Patients were grouped by year of inclusion except for the linear regression analysis where the inclusion date was used. Baseline predicted probability of poor outcome (modified Rankin Scale (mRS) score 3–6) was calculated using a validated prediction model. Primary outcome was mRS score at 90 days. Secondary outcomes included workflow times, EVT techniques, successful reperfusion (eTICI ⩾ 2B) and symptomatic intracranial haemorrhage (sICH). Time trends were analysed using multivariable regression models (adjusted common odds ratios (acOR) per year). Results: 5193 patients were included. Median age increased (from 66 in 2014 to 74 years in 2018 [p < 0.001]). Proportion of patients with pre-stroke dependence (mRS ⩾ 3) increased from 2014 through 2018 (9% to 16%, p < 0.001). Baseline predicted probability of poor outcome did not change (60% vs 66%, p = 0.06). Over time, functional outcomes improved (acOR 1.14 per year, 95%CI: 1.09–1.20); mortality decreased (aOR 0.88 per year, 95%CI: 0.83–0.94). EVT under local anaesthesia increased (from 46% in 2014 to 70% in 2018; aOR 1.15, 95%CI: 1.10–1.22), as did use of direct aspiration (13%–36%; aOR 1.43, 95%CI: 1.35–1.53). Successful reperfusion became more frequent (aOR 1.32 per year, 95%CI: 1.25–1.40), despite needing more attempts (1 in 2014 vs 2 in 2018, aOR 0.93 per year, 95%CI: 0.89–0.98). Incidence of sICH remained unchanged (5% vs 5%, aOR 0.99 per year, 95%CI: 0.89–1.09). Time from emergency room to groin puncture reduced by 7 min per year (95%CI: 5–8). Discussion and conclusion: Enhanced workflow and increased EVT experience may have led to shorter time to treatment and more frequent successful reperfusion, with better functional outcomes over 5 years, despite treating older, more dependent patients.