Response to letter regarding article, "Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association".

We think letter of Dr Saver et al raises 3 important questions. First, what is the evidence required for a class III no benefit classification? Second, does the current evidence for the effectiveness of patent foramen ovale (PFO) closure devices meet the criterion for class III no benefit. Third, what are the appropriate criteria for assigning a level of evidence (LOE) A rating for the class III no benefit classification? In assigning recommendation classes, the writing group was guided by the 2010 American Heart Association (AHA) methodology manual and policies from the American College of Cardiology Foundation/AHA Task Force on Practice Guidelines that includes the following advice: