Long-Term Outcomes of Acute Endovascular Thrombectomy: Tokyo/tama-Registry of Acute Endovascular Thrombectomy (TREAT)

Abstract

Mechanical thrombectomy (MT) is the recommended treatment for patients with acute ischemic stroke due to large cerebral vessel occlusion (LVO). However, few studies have investigated long-term outcomes after MT. The aim of this study was to investigate functional outcomes at long-term follow-up (1 year after MT) in patients undergoing MT for anterior circulation LVO in real-world clinical practice. This was a retrospective and prospective observational study using data from TREAT (Tokyo/tama-Registry of Acute Endovascular Thrombectomy), a multicenter registry of MT for acute LVO in the Tokyo metropolitan area. All subjects emergently transferred and treated with MT from January 2015 to December 2018 were selected. Patients' baseline characteristics and stroke-related parameters were evaluated. The primary outcome was the modified Rankin Scale (mRS) score 1 year after MT. The secondary outcomes were risk factors for long-term good outcomes (mRS score 0-2); transfer system (stroke bypass vs. secondary transfer) was also evaluated as a potential factor associated with good long-term outcomes. A total of 162 cases (mean age 73.0 years, age range 30-97 years; 59.9% male) whose mRS scores at 1 year were obtained were analyzed. The median admission National Institutes of Health Stroke Scale (NIHSS) score was 17. Overall, 42.6% of the patients achieved functional independence at 1-year follow-up. Lower initial NIHSS score and mRS score 0-2 at 90 days were the independent predictors for good long-term outcomes. Stroke bypass was associated with a higher initial NIHSS score and mRS score 0 at 1 year. A significant number of patients experience a good long-term outcome after MT.