The PC T rial (Clinical Trial Comparing Percutaneous Closure of PatentForamenOvale Using the Amplatzer PFO Occluder with Medical Treatment in Patients with Cryptogenic Embolism) randomized 414 patients with PFO who had had an ischemic stroke, TIA, or a peripheral thromboembolic event to either medical therapy or PFO closure with the Amplatzer PFO Occluder.