Thrombectomy: Equal Benefits With Pre-stroke Disability

New study fills gap in large trial enrollment, supports extending the treatment.

Results from a retrospective study presented at the annual American Academy of Neurology meeting in May suggest that patients with prior stroke-related disability who underwent thrombectomy experienced proportionately equal benefits to patients with no prior disability.

Eva Mistry, M.B.B.S., a neurologist at Vanderbilt University Medical Center, led a team that used Vanderbilt’s patient data to evaluate modified Rankin scores (mRS) before and after thrombectomy for large vessel occlusion in the anterior cerebral circulation. With encouraging results in hand, they are collaborating with a team at Rhode Island Hospital to compare data across different institutions.

“These procedures are so massively successful, but many institutions may take the guidelines at their face value and do not offer thrombectomy to this group of patients.”

This study is significant because current American Heart Association thrombectomy guidelines do not include patients with pre-stroke disability. “These procedures are so massively successful, but many institutions may take the guidelines at face value and do not offer thrombectomy to this group of patients,” Mistry says.

Functional and Procedural Success Rates

The study investigated how patients with and without pre-stroke disability compare on two counts: functional outcomes and procedural outcomes. “Based on our anecdotal experience, we hypothesized that patients with pre-stroke disabilities would see equal benefits,” Mistry says.

Researchers looked at patients’ pre-procedure mRS scores and dichotomized them into groups that scored either 0-1 (n=175) or 2-3 (n=124). They defined functional outcomes in terms of the accumulation of additional disabilities. While the gap in outcomes did not narrow between the two groups, patients with pre-stroke disability did not accumulate more disabilities than those without pre-stroke functional disabilities.

Mistry was also interested to find they had similar procedural success, assessed by looking at rates of symptomatic intracranial hemorrhage (that associated with a four point or greater increase in the National Institute of Health Stroke Scale), successful recanalization and in-hospital death.

Toward a Treatment Therapy Shift

 Mistry says approximately 30 percent of stroke patients have a prior disability. It is common for a hospital to factor their disabled status into treatment consideration and withhold mechanical thrombectomy, per the current guidelines.

“Endovascular therapy is a massively morbidity-saving procedure for a very large patient population. It was approved in 2015, and since then the indications have only expanded,” Mistry says. “We plan to corroborate our results with data from other institutions. My hope is that this group of patients will no longer be limited by the lack of clear treatment guidelines.”

Along with this study of a “forgotten population,” Mistry is working to address other gaps in the stroke care spectrum. She is leading a team to establish post-surgical hypertension control guidelines after thrombectomy to address widely disparate practices in setting blood pressure management objectives.