Late-Breaking Science: Sending patients from ambulance directly to angio suite improves outcomes

Two presenters reveal results for changing workflow and imaging and treating suspected ischemic stroke in the field.

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Findings from two late-breaking science abstracts were presented during Wednesday’s Opening Main Event. (Both of these late-breaking science presentation recordings will be available for registered ISC attendees through April 16.)

Researchers found that:

  • Changing workflow to send patients with suspected large vessel ischemic stroke directly from ambulance to angiography and treatment improves post-stroke outcomes.
  • Imaging and treating suspected ischemic stroke in the field before transport to hospital improves treatment times and reduces stroke-related disability.

Workflow changes for patients with suspected large vessel ischemic stroke directly from ambulance to angiography improves post-stroke outcomes

Delivering patients with suspected large vessel occlusions from the ambulance directly to the angiography suite improves both clinical and functional outcomes. The 20-month ANGIO-CAT trial randomized patients with suspected large vessel stroke to either direct transfer from ambulance to the angio suite or a conventional workflow from ambulance to CT suite to confirm a large vessel occlusion and then to the angio suite for treatment. Recruitment was stopped early after a planned 90-day interim analysis of the first 150 patients.

“Direct transfer to the angio suite reduced door-to-groin puncture time and improved patients’ functional scores at 90 days,” said Manuel Requena, MD, PhD, neurointerventional fellow at Vall d'Hebron University Hospital in Barcelona, Spain. “With the usual workflow, door-to-puncture was 42 minutes. By going directly to the angio suite, we are able to reduce door-to-puncture time to 18 minutes. 

“ANGIO-CAT was the first randomized clinical trial to compare direct transfer of patients with suspected large vessel occlusion from ambulance to the angio suite versus the conventional workflow,” Requena said. The trial followed a small observational study suggesting that direct transfer to the angio suite (DTAS) was both safe and could reduce door-to-puncture times.

A total of 174 patients with suspected large vessel occlusions were randomized to either DTAS or the conventional ambulance to CT suite to angio suite workflow. Patients averaged 73 years of age, the mean time from onset to door was 224.9 minutes, the median NIHSS was 18, and there were no significant baseline differences between the two groups.

Specific study results included: 

·      DTAS reduced the hospital arrival to reperfusion time from mean of 84 minutes with a conventional workflow to 57 minutes (p<0.001).

·      DTAS patients had an odds ratio of 2.2 for a one-point reduction in modified Rankin score 90 days post-stroke versus conventional workflow.

·      DTAS patients showed a numerical, but not statistically significant, advantage in symptomatic intracranial hemorrhage (1.4% versus 4.1%, p=0.39).

·      90- day mortality (20.2% versus 32.9%, p=0.07).

"Right now, we can do direct transfer in about one-third of our patients. We are building a dedicated angio suite for what we call 'one-step stroke' and plan to progressively cover longer shifts so we can do this one-step procedure more often,” Requena said.

Mobile stroke unit speeds tPA treatment, improves post-stroke disability outcomes

Starting thrombolysis treatment for ischemic stroke patients via a mobile stroke unit (MSU) before transport to the hospital improves 90-day disability outcomes compared to standard thrombolysis treatment starting after the patients arrive at the hospital. MSU management enables treatment with tissue plasminogen activator (tPA) more frequently and more quickly than standard management by emergency medical services and MSU-treated patients have better 90-day disability outcomes.

“The data suggest that if we can get patients treated within the first hour, there is a whole other physiology involved. Not only is the brain less damaged, but clots may be more dissolvable by tPA,” said James Grotta, MD, director of stroke research and director of the Mobile Stroke Unit Consortium at Memorial Hermann Hospital-Texas Medical Center in Houston.

Grotta presented the results of the BEST-MSU trial, which enrolled 1,515 patients with suspected ischemic stroke within 4.5 hours of last known normal at seven U.S. sites. Because it was not practical to randomize individual patients, researchers alternated weeks between standard EMS management and MSU management.

During EMS weeks, the MSU team responded to potential ischemic stroke calls and evaluated patients to determine whether they would have been eligible for tPA based on the MSU clinical criteria and prehospital timeframe. All patient charts were reviewed for tPA eligibility by an independent vascular neurologist who was blinded to both MSU or standard management status and tPA treatment status.

Within the cohort, 617 patients in the MSU group and 430 in the standard management group were adjudicated as tPA-eligible. There were no differences in baseline demographics between the two groups. The mean NIH Stroke Score was nine, Grotta reported, with a similar distribution across mild, moderate and severe scores. The patient population included 40% who were from the Black community and 17% who indicated their ethnicity was Hispanic.

Of tPA-eligible patients, 97.1% actually received tPA compared to 79.1% in the standard management group. Time from last known normal was shorter in the MSU group, a mean of 72 minutes versus 108 minutes in the standard management group. Within the MSU group, 33% of patients received tPA within 60 minutes of last known normal versus 3% in the standard management group.

Clinical outcomes 90 days post-stroke were evaluated for all tPA-eligible patients using the utility-weighted modified Rankin Scale (uw-mRS). The MSU group had a more favorable uw-mRS score: 0.726 versus 0.657. Within the MSU group, 55% of patients had mRS of 0 or 1 versus 44.4% in the standard management group. Patients in the MSU group had an odds ratio of 2.43 for a mRS of 0 or 1 compared to the standard management group (p<0.001).

“This is a very robust difference and consistent with earlier trials,” Grotta said. “We had 18 % more tPA-eligible patients treated in the MSU group and 10 times more treated within the first hour. MSU management reduced disability from stroke, and this is driven by earlier tPA treatment especially within the first hour from stroke onset.