November 15th, 2010
Let’s Bring CLOSURE to This Debate About PFO Treatment
In this blog, Rick Lange tells us how he would answer FAQs about PFO closure to prevent stroke.
Based on retrospective and nonrandomized studies, many physicians are convinced that percutaneous patent foramen ovale closure can reduce rates of cryptogenic stroke and transient ischemic attack. Although PFO closure devices are approved for stroke prevention in Europe and Canada, the FDA has not approved them for this indication in the U.S. Despite the lack of trial evidence, the number of percutaneous PFO/atrial septal defect closures in the U.S. increased almost 50-fold from 1998 to 2004, according to a recent study, while the number of surgical PFO/ASD closures was unchanged. The estimated percentage of PFO/ASD closures performed percutaneously in the U.S. increased from 18.5% to 92.5%.
In about 100 sites in the U.S. and Canada, 909 patients with a stroke and/or TIA due to presumed paradoxical embolism through a PFO were randomized to receive medical therapy alone or PFO closure with the STARFlex Septal Closure System followed by medical therapy. The rate of the primary endpoint — stroke or TIA at 2 years — did not differ significantly between the two groups (5.5% in the PFO-treatment group vs. 7.7% in the control group). Stroke recurrence at 2 years was 3% in both groups.
Was there a problem with the device?
Not likely, since the rate of adverse events with the closure device was low, and it was used successfully to close more than 85% of PFOs.
Why wasn’t PFO closure more effective than medical therapy?
Although PFOs are present in as many as 30% of individuals, paradoxical embolism through a PFO is rarely the cause of cryptogenic stroke. Furthermore, medical therapy can be quite effective at preventing paradoxical emboli.
Does this bring closure to the issue?
It does for me. However, individuals who are convinced that PFO closure is important will likely want corroborative studies. Several ongoing trials using other closure devices are in progress: the Helex septal occluder (Gore Medical) is under investigation in the multinational REDUCE study; the Amplatzer closure device (AGA Medical) is under investigation in the North American RESPECT trial and the European and Australian PC Trial; and the CLOSE study , which does not specify a particular device, is underway in France.
Where do you stand? For which, if any, patients with PFO would you recommend percutaneous closure?