Preliminary results of the CLOSURE I Trial, recently released by NMT Medical, indicate that treatment by patent foramen ovale (PFO) closure with the STARFlex device is not significantly superior to best medical therapy for preventing recurring stroke and transient ischemic attack (TIA). Immediately after the announcement, NMT Medical's share price dropped by over seventy-five percent. As yet, it is unknown whether these findings will affect other ongoing PFO trials such as Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment (RESPECT) study, which is a randomized trial using the Amplatzer closure device.
PFO closure devices are approved for stroke prevention in Europe and Canada, yet they have never been approved by the FDA, which was awaiting the results of trial. While CLOSURE I was unable to meet its primary endpoint, the preliminary results do indicate a small, but not statistically significant, benefit of PFO closure over best medical therapy. The results also showed that complications rates were on par with current best medical therapy and other transcatheter closure devices. NMT Medical and other stakeholders are in the process of analyzing the full data set to determine if sub-populations of patients could benefit from treatment. The full results of the trial are expected to be presented at the American Heart Association's 2010 Scientific Sessions this November. (theheart.org, 6/18/10; NMT Medical Press Release, 6/17/10)