Building new stroke systems

Now that endovascular therapy has been officially endorsed by experts, how should hospitals respond?

The 2015 International Stroke Conference can be considered a watershed moment in the world of stroke care. At (or shortly before) the February meeting in Nashville, researchers reported positive results from 3 major clinical trials of endovascular therapy (ET).

The trials showed that when delivered within 6 hours of symptom onset, ET was superior to usual care for patients with acute ischemic stroke with large vessel occlusions. After 2 other major trials reported similarly positive results, the American Heart Association/American Stroke Association updated clinical guidelines, recommending that patients who meet certain criteria receive ET in addition to tissue plasminogen activator (tPA) following a severe stroke.

Photo by Thinkstock
Photo by Thinkstock

To provide such care, the guidelines further state, hospitals should develop regional systems of stroke care to ensure that potential candidates for ET have rapid access to advanced imaging and qualified specialists.

“Since the studies and updated guidelines came out, endovascular therapy has gone from something not everyone agrees with to the standard of care for acute stroke,” said William J. Powers, MD, professor of neurology at the University of North Carolina in Chapel Hill and lead author of the AHA/ASA updated guidelines, published in the December 2015 Stroke. “Hospitals that can't provide this treatment need to contact the hospitals that can and come up with a system to expeditiously move patients when they need to be moved.”

In the wake of the new recommendations, some large stroke centers are considering hiring more specialists or adding space. Meanwhile, many smaller hospitals are revamping how they evaluate stroke patients and developing new procedures for efficiently triaging and routing patients to the most appropriate level of care.

“All hospitals should continue to concentrate on giving patients tPA as quickly as possible,” said S. Andrew Josephson, MD, medical director of inpatient neurology and head of the neurohospitalist program at the University of California San Francisco. “But providing endovascular care is a change in resources, and many hospitals will have to figure out how to deliver that kind of care.”

Impact on practice

The 5 studies underlying the updated guidelines—MR CLEAN, ESCAPE, EXTEND-IA, SWIFT PRIME, and REVASCAT—appear to have ended uncertainty about the potential benefits of ET. While earlier trials had failed to report any significant benefit of ET over standard care with intravenous tPA, these studies achieved better results by using advanced imaging to select patients and retrievable stents to remove clots.

“When the trials came out and demonstrated who would most likely benefit, it completely changed the aggressiveness with which we took people to ET,” said Elisabeth Marsh, MD, director of the stroke center at Johns Hopkins Bayview, part of the Johns Hopkins Health System in Baltimore. “Whereas we did about 5 cases in 2014, since last February we've already done 20 at Bayview and another 20 at our main downtown campus.”

Rather than an elective procedure, ET is now viewed as best practice for eligible patients, prompting emergency medical services (EMS) and smaller hospitals to reroute more patients to major stroke centers, said James Grotta, MD, director of stroke research in the Clinical Institute for Research and Innovation at Memorial Hermann Hospital-Texas Medical Center in Houston, a Joint Commission-certified comprehensive stroke center. The center connects with about 20 smaller hospitals in the region via telemedicine networks to assist with stroke care.

“EMS understands that they might need to send more patients to experienced stroke centers, and once they arrive we have to have our systems in place to treat them faster than ever before,” he said. “The whole system has been juiced as a result of these guidelines.”

The latest studies emphasize the importance of using advanced imaging techniques, including CT angiography (CTA) and magnetic resonance angiography (MRA), in the initial assessment of stroke patients. The tests are critical to selecting patients for ET as they provide a more detailed view of blood vessels than non-contrast CT, allowing physicians to assess whether a patient has enough salvageable brain tissue to benefit from reperfusion.

That represents a change in practice for many smaller hospitals where non-contrast CT alone has been the standard of care, said David Likosky, MD, FACP, director of the stroke and neurohospitalist programs at EvergreenHealth Medical Center in Kirkland, Wash., a Joint Commission-certified primary stroke center.

“Before all this data came out, we had considered stopping CT angiograms because it wasn't clear whether we could intervene based on them,” he said. “Now it is very important to figure out which patients may benefit from endovascular intervention and have a defined protocol to deliver that care in as expeditious a way as possible.”

Working out the logistics

The recent data on ET underscore the importance of speed in achieving positive patient outcomes. But getting patients to the procedure room within 6 hours of symptom onset is a formidable challenge, especially when patients must be moved between facilities.

Key steps must occur simultaneously in order to meet that time window, said Dr. Likosky. At Evergreen Hospital, ED physicians receive an alert ahead of time from EMS, prompting them to prepare to administer tPA and perform CT and CTA as soon as the patient arrives. At the same time, protocols must be in place to transfer patients identified as candidates for ET to a nearby comprehensive stroke center.

Although time is of the essence, bypassing the closest hospital and transporting patients who are potentially eligible for ET directly to a major stroke center is not always the best strategy. That's especially true in more remote areas where it might take an hour or more to reach the center.

“You have to be careful not to divert patients too far away, considering that the bulk of patients are not candidates for endovascular therapy and would benefit more from faster access to IV tPA,” said Dr. Likosky. “At the same time, picking the right patients for ET and transporting them as quickly as possible has huge potential benefit.”

EMS personnel can get a fairly good idea of who might be eligible for ET by using validated clinical scoring systems, said Dr. Marsh. Studies have shown that the Los Angeles Motor Scale (LAMS) and the Rapid Arterial Occlusion Evaluation (RACE), for example, can be effective screening tools for predicting large vessel occlusions.

“The factors that we are most interested in are whether the patient has a very small core of ischemia and a much larger area that we can potentially save,” she said. “Based on these scales and talking to EMS, we can make a good guess about whether a large artery is blocked.”

Telemedicine units that link ambulances with ED physicians via television monitors facilitate that communication and could be a key part of a hospital's stroke care strategy, Dr. Marsh added. An alternative is a mobile stroke unit with advanced imaging and a specialist on board.

“A mobile stroke unit is one of best solutions for triaging patients and providing upfront evaluation,” said Peter Rasmussen, MD, director of the cerebrovascular center at Cleveland Clinic in Ohio, which launched a mobile stroke service last year. “You can evaluate and triage patients at their home and then transport them to the closest facility that meets their needs, whether that's the local community hospital or a major stroke center.”

However, mobile units are expensive—about $400,000 excluding personnel and basic vehicle costs—which may be a significant cost hurdle for many hospitals, said Dr. Grotta, who directs the Mobile Stroke Unit Consortium in Houston. However, the investment may be worthwhile from a health system standpoint considering the long-term costs of caring for survivors of severe stroke.

“Without treatment, patients with large vessel blockages suffer substantial disabilities that require extensive long-term care,” he said. “If you can reverse one of these or move someone from totally dependent or bedridden to walking and looking after themselves, that's a big savings to the health care system.”

Telestroke networks are emerging as a cost-effective option for many regions, said Dr. Rasmussen. Under such hub-and-spoke systems, specialists at major stroke centers assist ED physicians at a network of smaller hospitals in evaluating stroke patients via telemedicine connections.

A key point to remember when developing new protocols is that most patients with ischemic stroke do not qualify for ET because they do not have a large vessel occlusion or because they fall outside the 6-hour treatment window, said Dr. Josephson. As a result, hospitals should continue to prioritize administering tPA as quickly as possible.

“All patients with ischemic stroke should get tPA while you are making plans about whether they also need embolectomy,” he said. “The best way to maximize resources and minimize transfers is for all hospitals to also perform rapid vessel imaging to identify patients who might be eligible for endovascular therapy.”

Cost implications

The stir created by advances in ET has been likened to the sea change in cardiovascular care that was triggered by cardiac catheterization and angioplasty. Just as hospitals reacted to the latter by hiring interventional cardiologists, major stroke centers are now enhancing stroke care, experts said.

Texas Medical Center, for example, has added endovascular suites and hired 2 additional endovascular specialists over the past year, said Dr. Grotta. The changes have been instrumental in speeding patients to treatment, which the stroke team now achieves in under an hour.

“Transferring the patient from the ED to the endovascular suite can constitute the biggest delay in our process,” he said. “If no room is available or the interventionalist is busy doing another case, it can potentially delay a procedure for up to an hour.”

However, it's harder to make a financial case for new hires at smaller hospitals, since the frequency of stroke is much lower than heart attack. In most areas, it makes more sense for smaller hospitals to join a regional network that includes at least 1 major stroke center and to concentrate on developing protocols for transferring eligible patients, said Dr. Josephson.

“If a smaller hospital only has 2 ET cases a month, it may not be cost-effective to hire a specialist,” he said. “One needs to balance the need to provide this specialty care with the volume that any one hospital would generate.”

Endovascular specialists—typically neurointerventional radiologists, neurosurgeons, and neurologists—command high salaries, noted Dr. Powers. And a hospital would need to hire at least 3 specialists to provide round-the-clock coverage, with 1 specialist on call every third night.

“The volume of severe stroke patients that you see in most places won't generate enough income to cover those salaries,” he said. The exception might be a hospital that sees a significant number of other neurological issues—such as aneurysms, arteriovenous malformations, and carotid artery stenting—that could be handled by the same specialists.

Overall, the new emphasis on endovascular care is likely to increase demand for hospitalists at both smaller and larger centers, said Dr. Grotta.

“One of the ripple effects is that there will be a greater need for neurohospitalists at stroke centers and at community hospitals that decide to develop their endovascular programs,” he said. “They will all need hospitalists to take care of these patients before and after their procedures.”