+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Variability in duration of follow up may bias the conclusions of cohort studies of patients with patent foramen ovale

Variability in duration of follow up may bias the conclusions of cohort studies of patients with patent foramen ovale

European Journal of Neurology 15(9): 909-915

Closure of patent foramen ovale (PFO) is expected to prevent paradoxical emboli. In the absence of randomized trials, its efficacy has been assessed by comparing uncontrolled cohort studies of medically treated patients with those treated by PFO closure. The objective of this study was to highlight a confounder of such studies, namely, the variability in the duration of follow-up. We searched the literature for cohort studies of patients with ischaemic strokes, including those with PFO. During the first year of follow-up, recurrence hazards in patients younger than 55 years were 1-4% in those with any ischaemic stroke, 1-6% in medically treated patients with PFO and 0-5% in those after PFO closure. In most studies, the recurrence hazards were highest immediately after the index stroke and declined thereafter. Still, hazards were commonly reported in terms of annual averages over a wide range of follow-up periods for the various cohort studies, thereby ignoring the possibility that the duration of the follow-up may in and of itself affect the derived average recurrence hazards. A disregard of the time variance of stroke recurrence may confound the conclusions from comparisons between uncontrolled studies of patients with stroke and PFO.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 034181339

Download citation: RISBibTeXText

PMID: 18637821

DOI: 10.1111/j.1468-1331.2008.02237.x

Related references

Intermediate and long-term results of transcatheter closure of patent foramen ovale using the amplatzer patent foramen ovale occluder: one case of pulmonary embolism irrespective of patent foramen ovale closure. Korean Circulation Journal 41(7): 356-362, 2011

Percutaneous closure of patent foramen ovale in patients with paradoxical embolism Impact of patent foramen ovale dedicated devices on procedural complications and residual shunt. Journal of the American College of Cardiology 39(5 Suppl. A): 405A, March 6, 2002

Low cerebrovascular event rate in subjects with patent foramen ovale and different clinical presentations: results from a prospective non randomized study on a population including patients with and without patent foramen ovale closure. International Journal of Cardiology 156(1): 47-52, 2012

Rate of recurrent embolic events after paradoxic cerebral embolism in patients with patent foramen ovale Comparison of transvenous occlusion of patent foramen ovale versus medical therapy. Circulation 106(19 Suppl.): II-514, November 5, 2002

Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network meta-analysis incorporating complementary external evidence. BMJ Open 8(7): E023761, 2018

Predictors of recurrent events in patients with cryptogenic stroke and patent foramen ovale within the CLOSURE I (Evaluation of the STARFlex Septal Closure System in Patients With a Stroke and/or Transient Ischemic Attack Due to Presumed Paradoxical Embolism Through a Patent Foramen Ovale) trial. Jacc. Cardiovascular Interventions 7(8): 913-920, 2016

Effect of Medical Treatment in Stroke Patients With Patent Foramen Ovale: Patent Foramen Ovale in Cryptogenic Stroke Study. Circulation 105(22): 2625-2631, 2002

Effect of medical treatment in stroke patients with patent foramen ovale: Patent foramen ovale in cryptogenic stroke study. Circulation 105(22): 2625-2631, June 4, 2002

Closure of a coexisting ostium secundum atrial septal defect and patent foramen ovale using a single Amplatzer patent foramen ovale occluder device. Cardiovascular Revascularization Medicine 11(1): 63-66, 2010

Chronic outcome of percutaneous transcatheter patent foramen ovale closure with Left-disk-coated patent foramen ovale occluder. Zhonghua Xin Xue Guan Bing Za Zhi 37(12): 1132-1135, 2010

Results of US phase I clinical trial of closure of patent foramen ovale associated with stroke/transient ischemic attack of peripheral embolism using the Amplatzer patent foramen ovale device. Journal of the American College of Cardiology 41(6 Suppl. A): 75A, March 19, 2003

Three-dimensional imaging of the atrial septum and patent foramen ovale anatomy: defining the morphological phenotypes of patent foramen ovale. European Journal of Echocardiography 11(10): I19-I25, 2011

Transcatheter closure of patent foramen ovale with the Spider patent foramen ovale occluder: a prospective, single-center trial. Chinese Medical Journal 123(7): 834-837, 2010

Risk of recurrent cerebrovascular events in patients with cryptogenic stroke or transient ischemic attack and patent foramen ovale: the FORI (Foramen Ovale Registro Italiano) study. Cerebrovascular Diseases 31(2): 109-116, 2011

Residual shunt after patent foramen ovale closure: preliminary results from Italian patent foramen ovale survey. Journal of Stroke and Cerebrovascular Diseases 22(7): E219-E226, 2014