Letter by Pristipino et al Regarding Article, 'Potentially Large yet Uncertain Benefits: A Meta-analysis of Patent Foramen Ovale Closure Trials

A meta-analysis of published randomized trials performed by Kitsios et al1 failed to resolve current uncertainties regarding the optimum secondary prevention strategy against cryptogenic stroke in patients with a patent foramen ovale. The results of their analysis are enticing. All 3 individual randomized studies in their analysis exhibited major limitations that rendered their interpretation problematic. First, despite broad definitions of composite primary end points, all 3 studies were underpowered because the a priori risk estimate was far from the actual outcome incidence observed in each study. Therefore, both positive and negative results could have been because of chance. Second, the enrollment of patients with transient ischemic attacks—a diagnosis that is difficult to confirm—and the inclusion of transient …