LOS ANGELES (FRONTLINE MEDICAL NEWS) – Evidence continues to mount that in the new era of thrombectomy treatment for selected acute ischemic stroke patients outcomes are better when patients go directly to the closest comprehensive stroke center that offers intravascular procedures rather than first being taken to a closer hospital and then needing transfer.

Nils H. Mueller-Kronast, MD , presented a modeled analysis of data collected in a registry on 236 real-world U.S. patients who underwent mechanical thrombectomy for an acute, large-vessel occlusion stroke following transfer from a hospital that could perform thrombolysis but couldn’t offer thrombectomy. The analysis showed that if the patients had instead gone directly to the closest thrombectomy center the result would have been a 16-percentage-point increase in patients with a modified Rankin Scale (mRS) score of 0-1 after 90 days, and a 9-percentage-point increase in mRS 0-2 outcomes, Dr. Mueller-Kronast said at the International Stroke Conference, sponsored by the American Heart Association.

The model also predicted a modest increase in the time until treatment with thrombolytic tissue plasminogen activator when ambulances with stroke patients bypass the closest hospital able to perform thrombolysis to head directly to the place able to do thrombectomy. Bypass to the closest thrombectomy hospital would have added an average of 2 minutes to the time until thrombolysis for patients transported by ground, and 33 minutes for air-transport patients. The results suggested that this “modest delay in thrombolysis is outweighed by the shortened time to thrombectomy,” said Dr. Mueller-Kronast, an interventional neurologist at Tenet Health in West Palm Beach, Fla. He conceded that ideally a randomized trial should confirm this conclusion.

The analysis he presented used data from the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke ( STRATIS ) registry, which included 984 acute ischemic stroke patients who underwent mechanical thrombectomy at any one of 55 participating U.S. sites ( Stroke. 2017 Oct;48[10]:2760-8 ). A previously-reported analysis of the STRATIS data showed that the 55% of patients taken directly to a center that performed thrombectomy had a 60% rate of mRS score 0-2 after 90 days, compared with 52% of patients taken first to a hospital unable to perform thrombectomy and then transferred ( Circulation. 2017 Dec 12;136[24]:2311-21 ).

The current analysis focused on 236 of the transferred patients with complete information on their location at the time of their stroke and subsequent time intervals during their transport and treatment, including 117 patients with ground transfer from their first hospital to the thrombectomy site, 114 with air transfer, and 5 with an unreported means of transport.

Dr. Mueller-Kronast and his associates calculated the time it would have taken each of the 117 ground transported patients to have gone directly to the closest thrombectomy center (adjusted by traffic conditions at the time of the stroke), and modeled the likely outcomes of these patients based on the data collected in the registry. This projected a 47% rate of mRS scores 0-1 (good outcomes) after 90 days, and a 60% rate of mRS 0-2 scores with a direct-to-thrombectomy strategy, compared with actual rates of 31% and 51%, respectively, among the patients who were transferred from their initial hospital.

“Bypass to an endovascular-capable center may be an option to improve rapid access to mechanical thrombectomy,” he concluded.

The STRATIS registry is sponsored by Medtronic. Dr. Mueller-Kronast has been a consultant to Medtronic.

SOURCE: Mueller-Kronast N et al. Abstract LB12 .