Long-Term Study Results Show that PFO Closure May Be Effective in Preventing Recurrent Cryptogenic Stroke, Particularly in Younger Patients

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Results from the RESPECT Trial Reported at TCT 2015

SAN FRANCISCO – October 15, 2015 – Long-term study results from the RESPECT trial found that closing a patent foramen ovale (PFO) with an AMPLATZER PFO Occluder was superior to medical management in the prevention of recurrent cryptogenic stroke in patients who previously had a cryptogenic stroke.

Findings were reported today at the 27th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. Sponsored by the Cardiovascular Research Foundation (CRF), TCT is the world’s premier educational meeting specializing in interventional cardiovascular medicine.

Patent foramen ovale (PFO) is a small flap of two tissue layers between the atria that fuses shut in two-thirds of patients after birth but in the one-third of patients in which it stays open can allow blood clots to travel to the brain causing a stroke. Current guidelines call for medical management with anti-coagulants for patients with PFO following a cryptogenic stroke. The RESPECT study examined the use of a device that closes the flap compared with medical management. A total of 980 subjects between 18 and 60 years of age were randomized to PFO Closure (N=499) or medical management (N=481). Original enrollment ended when 25 ischemic stroke events occurred; the present report details longer term follow-up from the trial.

The mean follow-up for the PFO group was 5.5 years and 4.9 years for the medical management group [total patient years: 2,769 (PFO) and 2,376 (medical management)]. The overall intent-to-treat analysis showed no statistically significant difference in the incidence of all-cause strokes, which included both cryptogenic and “other” strokes (p=0.16). When subsequent strokes were restricted to cryptogenic stroke, there was a 54% relative risk reduction in recurrent cryptogenic stroke for the PFO closure group (p=0.042), although the absolute number of strokes remained small. An additional sensitivity analysis of all-cause stroke in patients under the age of 60 (where a greater proportion of strokes are likely to be cryptogenic) showed a 52% relative risk reduction (p=0.035). Additional benefit was also seen within a subgroup in 2/3 of RESPECT patients who had PFO characteristics of substantial shunt or atrial septal aneurysm with a 75% reduction in cryptogenic stroke risk (p=0.007).

Analysis of PFO Closure procedure or device-related serious adverse events found no intra-procedure strokes, device embolization, device thrombosis or device erosion. There was a low rate of major vascular complications (0.9%) and device explants (0.4%).

“The long-term results of the RESPECT trial show that PFO closure is superior to medical management in reducing recurrent cryptogenic ischemic stroke,” said lead investigator John D. Carroll, MD. Dr. Carroll is Professor of Medicine at the University of Colorado School of Medicine and Director, Interventional Cardiology at the University of Colorado Hospital in Denver, Colorado. “The procedure and device have proven to be safe.”

RESPECT was funded by St. Jude Medical. Dr. Carroll reported receiving consulting fees as a member of the Steering Committee for the RESPECT trial from St. Jude Medical.