In 2017, roughly 3 years after evidence from several studies made endovascular thrombectomy first-line treatment for selected acute ischemic stroke patients, the treatment was available at barely more than one-third of all U.S. stroke centers, available within 30-minute access to just over 30% of Americans, and available within 15-minute access to one-fifth of U.S. residents, based on information in a comprehensive U.S. database.

These numbers showed that “current direct EVT [endovascular thrombectomy] access in the United States is suboptimal under predominate EMS routing protocols,” Amrou Sarraj, MD, and his associates wrote in an article published online in Stroke on Feb. 12. “Only in eight states did the coverage exceed 25% of the population, and nine states had coverage for less than 10% of the population. These results reflect limited access to an effective treatment modality that would improve clinical outcomes in patients with large strokes and prevent potentially devastating disability,” wrote Dr. Sarraj, chief of the general neurology service at Memorial-Hermann Hospital in Houston and coauthors.

Their analysis of data collected in 2017 by the Medicare Provider Analysis and Review (MEDPAR) database, maintained by the Centers for Medicare & Medicaid Services, identified two apparently effective ways to improve EVT access for acute ischemic stroke patients: First, systematically divert patients to a nearby center that offers EVT even when it means bypassing a closer stroke center that does not perform EVT when the added travel time is less than 15 minutes. Second, convert selected stroke centers that currently do not perform EVT into centers that do. Between these two approaches, the strategy of having ambulances bypass stroke centers that do not perform EVT and continuing to ones that do generally has the greater potential to boost access, the authors found. They based their analysis exclusively on their calculations of expected consequences rather than actual experience.

The calculations showed that bypassing non-EVT centers when the added bypass time computed to less than 15 minutes linked with an anticipated overall U.S. gain in access of about 17%, or 52 million people, extending the ability of acute ischemic stroke patients able to quickly reach an EVT center to about 37% of the American public. The second approach to boost access, converting the top 10% of stroke centers based on case volume that currently do not provide EVT to centers that do offer it, would result in expanded access for about 23 million additional Americans, raising the total with access to about 27% of the public, the new report said.

As part of this analysis, the MEDPAR data identified 1,941 U.S. centers providing stroke services during 2017, of which 713 (37%) had performed at least one EVT procedure. By comparison, 2015 MEDPAR data showed 577 U.S. stroke centers performing EVT, indicating that during the 2-3 years following several reports in early 2015 on the net benefits of EVT for acute ischemic stroke patients, the number of U.S. stroke centers offering this treatment had grown by a relative 24%. Based on the locations of the stroke centers that made EVT available in 2017, Dr. Sarraj and coauthors calculated that the 713 EVT-capable stroke centers provided emergency access within a 15-minute ground-ambulance trip for 61 million Americans (20% of the U.S. population), and within a 30-minute ground-transport trip to 95 million residents (31%).

Boosting these numbers by implementing a systematic bypass of stroke patients past non-EVT stroke centers to nearby centers that are EVT capable “has the benefit of ease of implementation and requires less time and resources,” the authors said. However, they also noted the heterogeneity of circumstances based on variables like population density and stroke center distribution, which means that in some locations the most effective way to boost access would be by increasing the number of stroke centers that provide EVT.

In 2018, Dr. Sarraj and associates reported results from a similar analysis of MEDPAR data that used 30-minute and 60-minute ground-transport times as the criteria for their calculations.

The study received no commercial funding. Dr. Sarraj reported receiving research funding from Stryker Neurovascular outside of this work. One coauthor reported serving in roles for the University of Texas Health System for which the institution has been funded via various industry and government grants, and another coauthor reported receiving research funding from the Patient-Centered Outcomes Research Institute, the National Institutes of Health, Genentech, and CSL Behring, as well as consulting fees from Frazer Ltd.

mzoler@mdedge.com

SOURCE: Sarraj A et al. Stroke. 2020 Feb 12. doi: 10.1161/STROKEAHA.120.028850.

Thrombectomy access lags for U.S. stroke patients