PHOENIX — Thrombectomy is generally beneficial for patients from a low-income population who have a large vessel occlusion stroke presenting in the later time window and who can be identified as suitable for treatment without the need for advanced and costly imaging, a new Brazilian trial has shown.
“The RESILIENT-Extend trial is the first major study of thrombectomy in the late time window (8-24 h) conducted outside first-world countries and shows the procedure also has benefit in a lower socioeconomic status population without the need for costly imaging equipment,” said lead investigator Raul G. Nogueira, MD.
“The trial expands the treatment window for thrombectomy globally with simplified selection criteria based on non-contrast CT, potentially altering current guidelines,” Dr. Nogueira said.
However, there were some caveats that need to be considered; in particular, a lack of benefit with thrombectomy in older patients (over 68 years of age), which Dr. Nogueira believes is a reflection of the particular population enrolled in this study. Specifically, he suggested that older age in this low socioeconomic status population is a surrogate for frailty, and the study may have identified frailty as a factor that correlates with reduced or lack of benefit of thrombectomy.
Dr. Nogueira, who is a professor of neurology and neurosurgery at the University of Pittsburgh, and Sheila Martins, MD, a professor of neurology at Hospital de Clinicas Porto Alegre in Brazil, presented the RESILIENT-Extend results at the International Stroke Conference presented by the American Stroke Association, a division of the American Heart Association.
Dr. Nogueira explained that the lack of available advanced imaging techniques is a major challenge for implementing endovascular therapy in an extended time window, especially in lower-income countries.
“Our main objective was to see if we could remove the need for advanced imaging to select patients with large vessel occlusion stroke in the late time window (8-24 h) for thrombectomy,” he said. “In this way, our trial overlaps somewhat with the MR CLEAN-LATE Trial conducted in the Netherlands, although the two trials were conducted in very different socioeconomic populations.”
The RESILIENT-Extend trial was conducted in the public health service of Brazil and involved a different population of people than have been included in other thrombectomy trials, which have mostly been conducted in first-world countries.
“The public health system in Brazil is not well-resourced and tends to care for patients at lower socioeconomic levels. These patients are fundamentally different from the average patients in the first-world recruited into most other thrombectomy trials,” Dr. Nogueira noted.
The trial enrolled 245 patients with a large vessel occlusion stroke within 8-24 hours of last known well. Patients were included who had a mismatch between the clinical severity as shown by the National Institutes of Health Stroke Scale (NIHSS) score and the stroke burden on imaging as measured by ASPECTS scores.
They had to have relatively high NIHSS scores (8 or more) showing more severe strokes but also a high ASPECTS score (5-10) excluding patients with large areas of ischemic brain. There was also a sliding scale that adjusted for age to avoid enrolling elderly patients with large strokes.
These patients were identified exclusively using non-contrast CT and CT angiography imaging.
The median age of patients included was 62-63 years. Dr. Nogueira pointed out that patients were slightly younger than seen in other thrombectomy trials, perhaps because in lower-middle-income countries strokes occur at a younger age. They also have a higher case fatality rate.
The median baseline NIHSS score was 16, and the median ASPECTS score was 7-8.
The median time to treatment was 12.5 hours, which is similar to other late window thrombectomy trials.