International Study in NEJM Shows Benefits of Stenting for Stroke

Patients who receive both treatments have a much better chance of surviving and returning to normal function, the study found.

“This is exactly a game-changer,” says study co-author Elad I. Levy, MD, professor and chair of neurosurgery.

The international SWIFT PRIME trial compared outcomes for ischemic stroke patients treated with either the clot-busting drug tissue Plasminogen Activator (tPA) alone or tPA in conjunction with Solitaire, a wire-mesh stent device.

The study found that 88 percent of patients receiving the dual treatment experienced successful revascularization — much higher than the 35 percent rate with tPA alone. 

Of those patients in the Solitaire group, 60 percent regained final independent function, higher than what has been seen with other endovascular interventions.

Levy says some patients who were treated with tPA plus the wire-mesh stent were able to leave the hospital after just a few days. This is in stark contrast to what has been standard of care, where patients spend several days in the intensive care unit then additional time at a rehabilitation facility.

“We’re at the dawn of a new era in stroke,” says L. Nelson Hopkins, MD, SUNY Distinguished Professor and former chair of neurosurgery.

Patients at select hospitals and stroke centers, like Buffalo’s Gates Vascular Institute (GVI), will benefit, Levy adds.

“These results were achieved at the very best centers in the United States and Canada,” says Levy, “and much of it has to do with workflow systems and how we move stroke patients through the emergency room (ER).”

The trial aimed to progress from acquisition of a qualifying image — where the occlusion is confirmed — to groin puncture in 70 minutes or less. 

Of all 36 study centers in the trial, the UB/GVI team had the fastest pace and received a certificate for that achievement. In one case, the Buffalo team achieved the feat in just 18 minutes.

Stroke treatments fail because patients sit in the ER, Levy explains. “So here in Buffalo, we don’t let stroke patients sit anywhere; we keep them constantly moving through the ER.”

While Levy says stroke treatment shouldn’t be viewed only as a race against time, he notes that speed is a key factor. 

Under Hopkins’ direction, Levy and other UB neurosurgeons — including study co-author Adnan Siddiqui, MD, PhD, — pioneered minimally invasive stroke treatments in the 1990s.

Hopkins and his colleagues explored treatments that take advantage of the circulation system by threading micro-thin devices through an artery in the groin to reach blocked vessels in the brain.

At first, the neurosurgeon community was less than enthused. “They ridiculed us, they called us ‘cowboys,’ ” says Levy, recalling the response to a presentation he made on stenting for strokes. 

“Physicians in the audience got up out of their seats to tell us how absurd it was to think that we could use stents for acute stroke. They called it unproven, untested and dangerous.”

But Hopkins and his colleagues forged ahead, in part inspired by the successful use of stents to treat coronary heart disease.

The UB/GVI team also helped pioneer the use of CT perfusion imaging. This allows physicians to visualize where the clot is located and what portion of the brain is not receiving blood. 

“About 10 or 15 years ago, people thought CT perfusion imaging was of no value and that time was the only parameter in treating acute stroke,” says Siddiqui, professor and vice chair of neurosurgery at UB and site principal investigator for the trial at GVI. “Now we wouldn’t think of doing a stroke treatment without this kind of imaging.”

“CT perfusion along with CT angiography allowed for critical assessments to be made for clinical decision-making, reserving MRI for patients who did not need immediate intravenous tPA or mechanical thrombectomy,” he explains.

The study demonstrates the advantage of collaborations enabled by the building that houses both the UB Clinical and Translational Science Institute and GVI. 

“The SWIFT PRIME trial is a big win for this building,” says Levy. “It proves the value of having UB research upstairs and the operating rooms downstairs. You can take the elevator from research and translation to innovation and the clinical forum.”

Opened in 2012, the building was designed to help researchers bridge the gap between basic biomedical discoveries and clinical treatments. The collaborative environment was expected to reduce barriers between academic disciplines and between institutions, resulting in exceptional clinical and translational advances.

First authors on the paper, “Stent-Retriever Thrombectomy After Intravenous t-PA vs. t-PA Alone in Stroke,” are Jeffrey Saver of UCLA and Mayank Goyal of the University of Calgary.