Resetting the Clock: Stent Retrievers & the Race to Stop Stroke

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“Time is brain,” physicians say. As they ponder new data on acute stroke intervention with stent retrievers, many are advocating for new systems and a team-based approach modeled after the successful door-to-balloon time protocols that have vastly improved heart attack outcomes. Others note the healthcare dollar is stretched thin and wonder if the formidable costs of endovascular stroke intervention will prohibit nationwide implementation. 

In addition to the personal toll on patients and families, stroke has had a similarly crippling effect on the U.S. healthcare system. According to the Centers for Disease Control and Prevention, stroke costs the United States $34 billion annually in healthcare services, medications and lost productivity. It is the leading cause of serious long-term disability and is responsible for 1 in 20 deaths, or 130,000 deaths per year.

With such harrowing statistics, the results of five trials published in 2015 in The New England Journal of Medicine (NEJM)—MR CLEAN, EXTEND-IA, ESCAPE, REVASCAT and SWIFT PRIME—become all the more remarkable. In the studies, stent retrievers—a catheter-based approach for mechanical thrombectomy—plus intravenous tissue-type plasminogen activator (IV tPA) improved outcomes compared with standard of care IV tPA in patients with acute ischemic stroke.

“Up until these recent five trials, data were really not conclusive that stroke reperfusion, other than tPA … was beneficial,” says Christopher J. White, MD, chair of medicine at Ochsner Clinical School of Medicine, University of Queensland, New Orleans. “We knew from the beginning that opening occluded arteries would benefit patients. We just had a heck of a time proving it.”

White says that the major struggle came because the preceding trials did not select the right patients. “Part of [the issue] was understanding how to bring this therapy to the right patient,” he says. “We say, ‘the right patient, the right device at the right time.’ And now it’s the perfect storm. Five trials all of a sudden say open arteries are better than closed arteries.”

Early endovascular treatment stressed

Shortly after the publication of these data, the American Heart Association (AHA) and the American Stroke Association (ASA) released the “2015 AHA/ASA Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment.”

Authored by AHA Stroke Council members, the new document emphasizes the endovascular approach among patients similar to those examined in the five clinical trials, stating that patients should receive endovascular therapy with a stent retriever if they meet all of seven criteria (see sidebar at right).

Yet, according to William J. Powers, MD, chair of the guidelines and H. Houston Merritt Distinguished Professor and chair of the Department of Neurology at the University of North Carolina at Chapel Hill, what has been even more telling than the speed at which the revisions were made is the change to his daily practice.

“Recently, during a one-week period, we evaluated five people for this treatment … and treated three, which were as many [intra-arterial interventions] as we used to do in a year,” Powers says. “And of the three, one of the patients got dramatically better. This patient was completely paralyzed on one side and semi-comatose when he went to treatment. He walked home two days later.”

The catch: Timeliness is money

Although the data and early reports of patient experience have been encouraging, not many regions in the United States are currently set up to handle this time-sensitive procedure.

According to the AHA, although all 90 comprehensive stroke centers certified by the association and the Joint Commission perform mechanical thrombectomy, many states in the Midwest don’t have a single accredited comprehensive stroke facility (see “Stents for Strokes” map). The AHA added that the procedure is offered at some of the more than 1,000 AHA/Joint Commission certified primary stroke centers.

David J. Cohen, MD, MSc, director of cardiovascular research at St. Luke’s Mid America Heart Institute in Kansas City, Mo., and investigator in the SWIFT PRIME trial, speculates that the biggest challenge to providing this therapy is transporting patients to stroke centers and delivering these therapies in a timely fashion.

“These therapies only work within the first few hours of a stroke, and we continue to have challenges in recognizing the symptoms in these