Closure Device May Prevent Some Strokes



Mr. Susman is a freelance medical writer based in Florida, USA. He travels worldwide to report from medical conferences, writing regularly for wire services, internet websites, and medical journals such as the Journal of the National Cancer Institute and AIDS.

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HOUSTON, Texas – After more than a decade of following patients, it appears that a device used to close patent foramen ovale (PFO) – a common anatomical anomaly in the heart – will prevent strokes in patients who have already experienced a brain attack, researchers said here at the 2017 International Stroke Conference.

The Amplatzer PFO Occluder device approval had been on hold by the U.S. Food and Drug Administration until last year when it became apparent that over the long-haul implantation of the device reduced the incidents of stroke and transient ischemic attacks.

In the final analysis of the Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment (RESPECT) trial, 18 events occurred among the 499 patients assigned to be implanted with the device compared with 28 events in the 481 patients treated medically, a relative risk reduction of 45 percent which was statistically significant (P=0.046).

David Thaler, MD, PhD, chairman of neurology at Tufts University School of Medicine, Boston, Massachusetts, who reported the results said, “These analyses support the hypothesis that PFO closure is preventing PFO-related recurrent strokes. PFO closure cannot prevent strokes from non-PFO related causes.”

The data which was first collected in 2003 was locked in 2015. Dr. Thaler trial said the low rate of events required longer follow-up. The researchers enrolled patients from 69 sites in the United States and Canada from 2003 to 2011. Patients who were believed to have PFO-related strokes were randomized between having the device implants and guideline-driven medical management. Patients were eligible if they experienced cryptogenic strokes within the last nine months and were found to have a PFO and were between the ages of 18 to 60.

The composite endpoint was the occurrence of non-fatal ischemic stroke, fatal ischemic stroke or death within 45 days of randomization. The definition of stroke for the study was neurological deficit due to cerebral ischemia observed on imaging scans or stroke symptoms that lasted longer than 24 hours.

“In the RESPECT trial, PFO-closure with the Amplatzer PFO Occluder was more beneficial than medical management alone in the intention-to-treat population for the primary outcome,” Dr. Thaler said.

Pipeline stops aneurysm

In another study at the meeting, researchers suggested a new stent device might prevent the rupture of aneurysm in the brain – providing a minimally invasive procedure for occluding small to medium-sized wide-mouth aneurysms,

After one year, complete occlusion of the aneurysm without significant restenosis or retreatment was achieved in 83.5 percent of 138 patients who were implanted with the Pipeline stent device, reported Ricardo Hanel, MD, PhD, director of the Baptist Neurological Institute, Baptist Health System, Jacksonville, Florida.

The device creates a stented flow diversion that seals off the ballooning blood vessel until it occludes, he explained in his late-breaker oral presentation.

Dr. Hanel said that 11 patients had a residual aneurysm, eight had residual neck, two developed stenosis of greater than 50 percent and three patients required retreatment. One patient in the study suffered a fatal stroke in the periprocedural period, another patient experienced a major stroke within 30 days of the treatment and a third patient experienced a major stroke after stopping dual anti-platelet therapy 169 days after the treatment.

The device is indicated for use in the United States for large aneurysms, but the current study focused on treatment of unruptured small aneurysms located in the internal carotid artery or the vertebral artery, including the posterior inferior cerebellar artery. These aneurysms often are left untreated but they still can rupture with devastating effects.

“The treatment of unruptured wide-necked, small/medium aneurysms located in the internal carotid artery with Pipeline results in high occlusion rates at one year; low morbidity; low mortality; no aneurysm recurrence at one year and no aneurysm ruptures at one year,” Dr. Hanel said. The 2.1 percent rate of complications, he said, is acceptable when considering that patients with these small to medium aneurysm have a 0.5 percent per year risk of having those aneurysms rupture.

The mean age of the patients in the study was 54.6 years; about 80 percent of the patients were women. Dr. Hanel said that most of the patients were diagnosed because of symptoms such as headaches.

Neuroprotection agent fails

An attempt to use an antibody to protect against nerve damage and improve stroke patients walking ability did not appear to improve outcomes, researchers reported.

Neuroprotective agents have been sought for decades, but their success stories are elusive in this field. In this study, researchers tested the investigative compound known as GSK249320. They tried to determine if the agent would be better than placebo in improving motor function among patients diagnosed with acute stroke, as measured by the 90-day National Institutes of Health Stroke Scale (NIHSS) score.

Steven Cramer, MD, professor of neurology at the University of California at Irvine, California, found that the results of the trial were neutral. The NIHSS score among the 65 patients assigned to GSK249320 was four compared the average score of four among the 68 patients in the trial who were assigned to receive placebo, he said.

The researchers did note that GSK249320 did slowly reduce the levels of myelin-associated glycoprotein, a substance believed to inhibit the protective effect of myelin on nerves that affect motor function but that did not appear to translate into physical improvement.

“GSK249320, administered intravenously and initiated within 72 hours of stroke onset, demonstrated no improvement on gait velocity compared with placebo,” he said. The study had been stopped early for futility upon the recommendation of the Data Safety and Monitoring Board.

While failing to improve walking ability among the stroke patients, Dr. Cramer said he was hopeful that the study might be helpful in future studies of neuroprotective agent. He said there were no signs that the treatment produced high levels of immunogenicity. It was also well-tolerated, he said.

Dr. Cramer suggested there were a number of possibilities that GSK249320 failed to produce its desired effect including using too low a dose, reliance on pharmacokinetics of animal species, and that the drug just doesn’t work in the arena of acute stroke.

The patients were selected after being diagnosed with radiology confirmed supratentorial ischemic stroke and had been treated within 24 hours to 72 hour; they had NIHSS scores of three to 21 and had impaired gait or less than 0.8 meters per second.

The trial was sponsored by GlaxoSmithKline.

3 is not better than 2

Intensive treatment with anti-platelets for patients with acute stroke or transient ischemic attacks did not provide any addition benefit to patients over treatment based on current guidelines, said researchers reporting the results of the TARDIS (Triple Anti-platelets for Reducing Dependency in Ischemic Stroke) trial.

Closure Device May Prevent Some Strokes 2

However, adding a third anti-platelet drug to clopidogrel or aspirin plus dipyridamole therapy did increase bleeding risks, said Philip Bath, MBBS, MD, head of clinical neuroscience at the University of Nottingham, England, United Kingdom.

“This was a neutral trial. Any tendency for less recurrent cerebral ischemic events was offset by increase in major bleeding,” he said. “There was no difference in net risk versus benefit in deaths, serious adverse events, stroke plus major bleeding, major adverse cardiovascular events plus major bleeding.”

When compared with United Kingdom guideline recommendations for one or two anti-platelets, the use of a three-drug combination did not significantly reduce the risk of stroke or transient ischemic attacks (P=0.47).

The message for clinical practice, Dr. Bath said, “Intensive anti-platelet therapy is not recommended.”

Intensive therapy with aspirin, clopidogrel and dipyridamole had similar outcomes as less intensive therapy at 90 days in terms of stroke or transient ischemic attack recurrence and severity as indicated by score shifting on an ordinal modified Rankin Scale analysis, he reported.

The researchers recruited 3,096 patients in the trial, 2,143 of whom were diagnosed with ischemic strokes and 953 were diagnosed with transient ischemic attacks. Their average age was 69 and about 63 percent were men. About 11 percent of the cohort had previous stroke history. About 26 percent of the patients had previously been on aspirin therapy. The patients were recruited from 100 sites in the United Kingdom and other sites in Denmark, Georgia and New Zealand.

April 2017 Health and Lifestyle

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