Pediatric Neurology 50 (2014) 203e204
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Making Sense of Patent Nonsense
See related article on page 213.
The foramen ovale is a normal fetal connection between the right and left atria; it persists as a patent foramen ovale (PFO) in about 25% of individuals.1 Although a PFO is usually harmless, it represents a potential route through which venous clots can enter the systemic circulation (a “paradoxical” embolus) and cause ischemic stroke. Some reports also suggest an association between PFO and ischemic stroke and with migraine with aura.2-4 Whether to close a PFO in stroke patients has long been a point of controversy, and the development of percutaneous PFO closure devices in recent years has only honed the debate. Although it may seem intuitive that PFO closure should reduce the risk of recurrent ischemic stroke, common sense is sometimes a ﬁckle friend. PFOs are common in the general population, and many individuals with an ischemic stroke have additional risk factors, making it difﬁcult to pinpoint a role for PFO. A 2004 American Academy of Neurology Practice Parameter concluded that PFO does not carry a meaningful risk of recurrent ischemic stroke unless it is associated with an atrial septal aneurysm.5 But even if we conclude that PFO increases the risk of stroke or migraine, it is not a given that closing the defect will lower either risk. One study of adults with ischemic stroke and PFO found that recurrent stroke occurred just less than 2% per year, making it more difﬁcult to demonstrate a beneﬁcial effect from PFO closure even if it exists.2 Any beneﬁt from PFO closure would need to offset any procedural risk and exceed any beneﬁt from medical therapy. Recent reports underscore the need to replace common sense with data. In a multicenter trial, Furlan and colleagues randomly assigned 909 adults who had a PFO and cryptogenic stroke or transient ischemic attacks to either percutaneous closure of the PFO or to continued medical therapy.6 After a 2-year follow-up interval, percutaneous closure of the PFO was not superior to medical therapy alone for the prevention of recurrent stroke or transient ischemic attack. Similarly, Meier and colleagues randomized 414 patients * Communications should be addressed to: Dr. E. Steve Roach; Nationwide Children’s Hospital; Ohio State University College of Medicine; Division of Child Neurology E583; 700 Children’s Drive; Columbus, OH 43245. E-mail address: [email protected]
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with ischemic stroke, transient ischemic attacks, or peripheral thromboembolism to undergo percutaneous closure or continued medical therapy.7 During the 4-year follow-up period, no beneﬁt was apparent from the PFO closure. Similar robust data do not exist for children, but the few existing pediatric studies offer little reason to suppose that such procedures would beneﬁt children more than adults. Candee and colleagues found no relationship between the presence of PFO and the type of migraine or the occurrence of white matter lesions on magnetic resonance imaging.8 In this issue of Pediatric Neurology, Menon and colleagues analyzed 153 individuals younger than age 20 years who underwent percutaneous closure of a PFO.9 Members of this cohort had migraine, transient ischemic attacks, or strokelike symptoms. Although 143 of these 153 individuals reported beneﬁt from the PFO closure, 29 of the 143 had a residual intracardiac shunt, leading the authors to question the existence of a placebo effect for PTO closure. That idiopathic strokes often do not recur and that the severity of migraine often varies widely over time adds to the difﬁculty. Large-scale randomized trials like those recently reported in adults are not feasible in children, even assuming there is any reason to do them. But if we are to continue closing PTOs in children, it is time to agree on the indications. The procedure might be justiﬁed, for example, when there is a strong clinical suspicion of a stroke because of paradoxical embolism, as in a child whose symptoms began in conjunction with a Valsalva maneuver. Patients known to have a venous thrombosis might also be reasonable candidates. But given the available data, we can no longer trust intuition. References 1. Calvert PA, Rana BS, Kydd AC, Shapiro LM. Patent foramen ovale: anatomy, outcomes, and closure. Nat Rev Cardiol. 2011;8: 148-160. 2. Bogousslavsky J, Garazi S, Jeanrenaud X, Aebischer N, van MG. Stroke recurrence in patients with patent foramen ovale: the Lausanne Study. Lausanne Stroke with Paradoxal Embolism Study Group. Neurology. 1996;46:1301-1305. 3. Carod-Artal FJ, da Silveira RL, Braga H, Kummer W, Mesquita HM, Vargas AP. Prevalence of patent foramen ovale in migraine patients with and without aura compared with stroke patients. A transcranial Doppler study. Cephalalgia. 2006;26:934-939. 4. Agnetti A, Carano N, Sani E, et al. Cryptogenic stroke in children: possible role of patent foramen ovale. Neuropediatrics. 2006;37:53-56. 5. Messe SR, Silverman IE, Kizer JR, et al. Practice parameter: recurrent stroke with patent foramen ovale and atrial septal aneurysm: report
Editorial / Pediatric Neurology 50 (2014) 203e204
of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2004;62:1042-1050. 6. Furlan AJ, Reisman M, Massaro J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med. 2012; 366:991-999. 7. Meier B, Kalesan B, Mattle HP, et al. Percutaneous closure of patent foramen ovale in cryptogenic embolism. N Engl J Med. 2013;368: 1083-1091. 8. Candee MS, McCandless RT, Moore KR, Arrington CB, Minich LL, Bale JF Jr. White matter lesions in children and adolescents with migraine. Pediatr Neurol. 2013;49:393-396.
9. Menon SC, Grove A, McFadden M, Korgenski KE, Cowley CG. Clinical practice, resource utilization and outcomes of device closure of patent foramen ovale in pediatrics. Pediatr Neurol. 2014; 50:213-217.
E. Steve Roach, MD* Nationwide Children’s Hospital Ohio State University College of Medicine Division of Child Neurology Columbus, Ohio