The Efficacy of Stroke Prevention Devices

Clay Johnston, MD, PhD
Clay Johnston, MD, PhD

While several devices designed to prevent recurrent stroke are currently on the market, some are not approved by the Food and Drug Administration and remain available for off-label use.

In an editorial in the March 15, 2012, issue of The New England Journal of Medicine, S. Claiborne “Clay” Johnston, MD, PhD, associate vice chancellor of research at UCSF, comments on the pitfalls of this practice. He notes that evidence supporting the use of devices for patent foramen ovale, a well-established cause of stroke, has been limited to observational studies that were mostly small and poorly controlled.

Allowing use of devices before we have evidence they work just isn't good medicine.
Clay Johnston, MD, PhD

“It's getting harder and harder to bring devices to the public, and devices can really improve health,” said Johnston, who is also director of the Clinical and Translational Science Institute (CTSI) at UCSF. “However, allowing use of devices before we have evidence they work just isn't good medicine.”

Dr. Johnston’s editorial is in response to the CLOSURE I trial, a large-scale, randomized trial comparing device closure with the best medical therapy in patients with a patent foramen ovale who have had a stroke or a transient ischemic attack (TIA) of unclear etiology. The CLOSURE I trial is featured in the same issue of NEJM.

Johnston notes that “during the 9 years it took for the results of this trial to be reported, approximately 80,000 patients have had a patent foramen ovale closed with the use of a device at an average cost of $10,000 per procedure. Even if only half these patients were treated by this method for the purpose of preventing stroke, it would suggest that during that period of time $400 million was spent on a procedure that had no apparent benefit, to say nothing of the potential clinical risks involved.”

Read the full editorial: Patent Foramen Ovale Closure — Closing the Door Except for Trials

“We need to make it cheaper and easier to get trials done and harder to use expensive devices when there is no trial,” Johnston said.

Watch a related video featuring Dr. Johnston: “Does PFO Closure prevent stroke?(produced by

CTSI is a member of the National Institutes of Health-funded Clinical and Translational Science Awards network. Under the banner of Accelerating Research to Improve Health, it provides a wide range of services for researchers, and promotes online collaboration and networking through tools such as UCSF Profiles.