November 15, 2010 - A catheter procedure that closes a hole in patients’ hearts appears to be no more effective than drug therapy in preventing recurrent strokes, according to trial results presented at the American Heart Association’s Scientific Sessions.
The CLOSURE I trial compared a catheter procedure plus medical therapy with medications alone to prevent new strokes in patients with unexplained stroke and a hole between the heart’s two upper chambers.
Researchers expected the trial to show the superiority of the STARFlex Septal Closure System followed by clopidogrel over drug therapies alone. Instead, results showed no statistically significant differences between the system and aspirin or warfarin therapy.
“It is possible the procedure has a slight benefit, but you would need thousands of patients to find it in a randomized trial,” said Anthony J. Furlan, M.D., lead investigator of the study and chairman of the neurology department at the Case Western Reserve University School of Medicine and University Hospitals Case Medical Center in Cleveland.
Strokes of unknown origin have several causes, including a patent foremen ovale (PFO), a hole between the heart’s two upper chambers. The hole is vital to fetal survival but normally closes after birth. In roughly 20 percent of adults, remnants of the hole remain, Furlan said. If a blood clot develops in a vein, passes through the hole and reaches the brain a stroke occurs.
No medical device is approved by the U.S. Food and Drug Administration for sealing PFOs. However, physicians use devices approved for closing other types of heart holes to seal the opening between the right and left atria, usually in hopes of preventing a stroke. The STARFlex Septal Closure System, attached to a catheter and threaded into the upper heart, applies a “clamshell”-type patch on both sides of the hole.
The study found a slight, but not statistically significant, decrease in the stroke rate for the PFO-treatment group.
Furlan said possible alternative explanations for the strokes and transient ischemic attacks (TIA) that occurred were found for the majority of patients in both groups.
“Based on the trial results, even though a patient has a PFO and a recurrent stroke, the hole may be totally coincidental to the second stroke,” Furlan said. “The undeniable message here is that too many of these holes are being closed with an off-label procedure, but that’s partly because we’ve never had a randomized trial to guide us.”