The Trevo retriever registry showed the overwhelming benefits of stent retrievers to treat acute ischaemic stroke. It found that a final postprocedure TICI score of 2b or 3 was achieved in 93% of patients. At 90 days 55.3% of patients had a mRS of 0–2. The data indicated that results after six hours last known well are similar to results before six hours, and that late window thrombectomy use is of real benefit to patients.
The Trevo registry was designed to assess the real-world outcomes of the Trevo Retriever (Stryker) in patients with ischaemic stroke. It was the largest prospective study for acute stroke intervention and enrolled 2,008 patients. Revascularisation status based on post-procedure TICI scores was the primary endpoint and the secondary endpoint were 90-day mRS, 90-day mortality, neurological deterioration at 24 hours and device-or procedure-related adverse events.
The only requirement for enrolment was that patients needed to have confirmed large vessel occlusion (LVO) and the Trevo retriever needed to be used as the first device. This meant that there was no upper age limit of patients, a pre stroke mRS of 0–5 was included, there was no lower or upper NIHSS. The thrombectomy could be performed without tPA and there was no time limit to groin puncture.
From symptom onset to groin puncture, 68.1% received treatment in under six hours, 9.6% received treatment between six to eight hours, 8.9% received treatment in 8–12 hours and 13.4% received treatment after more than 12 hours. The study was started before the DAWN trial results were published but it showed the real-world application of thrombectomy beyond the six hour time window and the effectiveness of these interventions.
The registry evaluated all clot locations. M1 was the most common location for clot (54.7%), with 18.7% being M2 and 17.8% were internal carotid artery (ICA). The average patient was 68.3±14.4 years old and the most common comorbidity was hypertension, which occurred in 74.2% of patients. The group was 51.8% female, 36.1% had atrial fibrillation and the baseline NIHSS score median was 16(11–20). Out of the cohort, 52.3% received IV tPA prior to thrombectomy.
At first pass 62.3% achieved mTICI 2b/3 revascularisation and post procedure 92.8% had achieved this. Long-term outcomes were good. Of those treated in less than six hours from onset 57.2% achieved functional independence (mRS of 0–2) at 90 days. Patients treated after six hours achieved a good functional outcome in 51.3% of cases.
The safety endpoint was reached within 48 hours in a small percentage of cases. In 1.7% of the cohort the safety endpoint was reached because of symptomatic intracranial haemorrhage, 4.8% experienced neurological deterioration within 24 hours. The mortality rate within 48 hours was 0.6% and 2.4% of the cohort experienced procedure or device related serious adverse events.
The results were presented by Mandy Binding (Global Neurosciences Institute, Philadelphia, USA) at the International Stroke Conference (ISC; 24–26 January 2018, Los Angeles, USA).