The double-disc transcatheter PFO closure device, which is comprised of Nitinol mesh and polyester fabric, is designed to close all types of patent foramen ovale (PFOs) with an easy-to-perform deployment procedure.

The 980-patient based prospective, controlled trial was designed to determine if PFO closure with the Amplatzer device plus medical management was superior over medical management alone in the prevention of recurrent cryptogenic (unknown cause) stroke.

The trial, which had randomized the patients in 1:1 ratio, treated them with either the device or the antiplatelet medications such as aspirin, warfarin, clopidogrel and aspirin combined with extended release dipyridamole.

The primary efficacy endpoint of the study includes composite rate of recurrent nonfatal stroke, fatal ischemic stroke or death after randomization.

University of Colorado Hospital Interventional Cardiology and Cardiac and Vascular Center director Dr John Carroll said the data showed that the device closure with the AMPLATZER is safe, effective in closing the PFO and lowers the risk of recurrent stroke in two of the three patient cohorts.

"The reduction in stroke achieved in the PFO-closure group exceeds that of several well-established pharmacologic treatments for the prevention of secondary strokes," Carroll added.

According to the company, a difference in the dropout rate between the medical therapy group and the device group challenged the validity of the primary intent-to-treat raw count analysis, which did not meet statistical significance.

The study protocol also prespecified that if dropout rates differed significantly between the medication and device groups that analyses of two additional cohorts including Per-protocol cohort and As-treated cohort will be evaluated.

St. Jude Medical cardiovascular and ablation technologies division president Frank Callaghan said, "The analysis of the data from patients in the per-protocol group and the as-treated group provide compelling evidence that PFO closure with the AMPLATZER PFO Occluder is superior to medical management from both clinical and statistical perspectives."