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

J, Benbassat; Baumal, Reuben

doi:10.1111/j.1468-1331.2008.02237.x

Cited by 7 publications

(7 citation statements)

References 88 publications

(174 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the benefits of closure may become apparent only with longer follow-up, because this intervention has an increased risk of periprocedural complications and is expected to prevent the occurrence of relatively infrequent outcome events. 82 The 2-year follow-up of CLOSURE I may be inadequate to fully capture the benefit of the intervention and reassessment after additional person-time has accumulated may be warranted.…”

Section: Discussionmentioning

confidence: 99%

Patent Foramen Ovale Closure and Medical Treatments for Secondary Stroke Prevention

Kitsios

Dahabreh

Dabrh

et al. 2012

Stroke

128

View full text Add to dashboard Cite

Background and Purpose Patients discovered to have a patent foramen ovale in the setting of a cryptogenic stroke may be treated with percutaneous closure, antiplatelet therapy, or anticoagulants. A recent randomized trial (CLOSURE I) did not detect any benefit of closure over medical treatment alone; the optimal medical therapy is also unknown. We synthesized the available evidence on secondary stroke prevention in patients with patent foramen ovale and cryptogenic stroke. Methods A MEDLINE search was performed for finding longitudinal studies investigating medical treatment or closure, meta-analysis of incidence rates (IR), and IR ratios of recurrent cerebrovascular events. Results Fifty-two single-arm studies and 7 comparative nonrandomized studies and the CLOSURE I trial were reviewed. The summary IR of recurrent stroke was 0.36 events (95% CI, 0.24–0.56) per 100 person-years with closure versus 2.53 events (95% CI, 1.91–3.35) per 100 person-years with medical therapy. In comparative observational studies, closure was superior to medical therapy (IR ratio=0.19; 95% CI, 0.07–0.54). The IR for the closure arm of the CLOSURE I trial was higher than the summary estimate from observational studies; there was no significant benefit of closure over medical treatment (P=0.002 comparing efficacy estimates between observational studies and the trial). Observational and randomized data (9 studies) comparing medical therapies were consistent and suggested that anticoagulants are superior to antiplatelets for preventing stroke recurrence (IR ratio=0.42; 95% CI, 0.18–0.98). Conclusions Although further randomized trial data are needed to precisely determine the effects of closure on stroke recurrence, the results of CLOSURE I challenge the credibility of a substantial body of observational evidence strongly favoring mechanical closure over medical therapy.

show abstract

Section: Discussionmentioning

confidence: 99%

Patent Foramen Ovale Closure and Medical Treatments for Secondary Stroke Prevention

Kitsios

Dahabreh

Dabrh

et al. 2012

Stroke

128

View full text Add to dashboard Cite

show abstract

“…Analyzed studies were highly heterogenous in entry criteria, duration of follow up and definition of end points and these data cannot be regarded as a reliable guide to treatment. Another potential confounding issue is the prolonged duration between index event and device closure in some studies that could potentially bias in favor of device closure [34].…”

Section: Findings Recommendationsmentioning

confidence: 99%

Patent Foramen Ovale—Assessment and Treatment

Irwin

Ray

2011

Cardiovascular Therapeutics

View full text Add to dashboard Cite

SUMMARYA Patent Foramen Ovale (PFO) is detectable in 20-25% of the population. Some, but not all, case control studies have found an increased incidence of PFO in patients with cryptogenic stroke. Prospective cohort studies have failed to convincingly demonstrate a link between PFO and first stroke, and evidence linking PFO to recurrent stroke is far from compelling. The rate of recurrent stroke in medically treated patients is low, but the development of devices for PFO closure has lead to enthusiasm in some quarters to pursue a strategy of device closure. Nonrandomized studies have suggested a lower risk of recurrent events with device closure but the data are heterogeneous, and potentially prone to bias. Device implantation is associated with a risk of major adverse events of between 1.5% and 2.3%, and there is a significant rate of failure to close shunts. The results of randomized trials of device closure are keenly awaited. Migraine with aura has been linked with PFO. A recent metanalysis suggested an association, but the one prospective population study did not. The well-publicized and controversial MIST Trial is the only randomized trial of device closure in migraineurs yet published, and failed to demonstrate a convincing benefit from device closure. Other conditions such as platypnea-orthodeoxia syndrome and prevention of decompression sickness in divers, may justify device closure. Evidence for a role of PFO in the etiology of cryptogenic stroke and migraine is contradictory. It is possible that some patients might benefit from PFO closure but there is scant evidence of sufficient quality to justify routine PFO closure in either group. It is essential that ongoing randomized trials of device closure are completed. Prevalence and DetectionA patent foramen ovale (PFO) is a slit or tunnel like passage in the interatrial septum (IAS) formed by failure of postnatal fusion of the septum primum and septum secundum. Persistent PFO occurs in around 20-25% of the adult population, the exact frequency dependent on the method of detection. An autopsy based study suggested that the prevalence of PFO decreased with age implying either spontaneous closure or, intriguingly, a significant early death rate in those with PFOs [1]. However recent evidence from a large surgical series suggests that this is not the case and prevalence does not relate to age [2].Transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), and transcranial Doppler (TCD) can all be used to detect . TOE has traditionally been regarded as the gold standard but has some significant disadvantages. Whilst in some individuals a PFO is obvious on 2D echo or color flow on TOE, injection of bubble contrast is needed in many to clearly demonstrate a right to left shunt (see Figure 1). Patient sedation, positioning in the left decubitus position and the inability to perform a complete Valsalva may make it more difficult to visualize a shunt with bubbles on TOE than on TTE where the patient is semiupright and able to perform a good Vals...

show abstract

“…Surgical closure of PFO without stroke recurrence has been reported [44, 45], but others have not been so fortunate [46]. A minimally invasive alternative to surgery consists in transcatheter closure of the PFO.…”

Section: Patent Foramen Ovale (Pfo)mentioning

confidence: 99%

“…However long-term consequences of PFO closure are unknown. A review of 12 uncontrolled case series of more than 100 patients documented a rate of stroke recurrence during the first year after transcatheter PFO closure between 0 and 5% [46]; the percentages during the other years of follow-up varied considerably between the different studies. Current data suggest that transcatheter closure is at least effective as medical treatment, but further studies are necessary to investigate this issue.…”

Section: Patent Foramen Ovale (Pfo)mentioning

confidence: 99%

Prevention Strategies for Cardioembolic Stroke: Present and Future Perspectives~!2009-05-11~!2009-12-23~!2010-06-09~!

Giacalone¹,

Abbas²,

Corea³

2010

TONEUJ

View full text Add to dashboard Cite

Atrial fibrillation (AF) is the most common cause of cardioembolism. An update on secondary prevention strategies, used to protect patients from the risk of stroke in many common cardiac conditions, is presented in the paper. The main line of actions of stroke prevention in cardioembolism is mostly connected with antithrombotic drugs, but also other, more invasive, techniques are quickly emerging. Also the classic pharmacological prevention with coumarins may soon be overcome by new generation anticoagulants. Is an aggressive treatment of Patent Foramen Ovale (PFO) always recommended? One of the main challenges of the future years will be to understand competitiveness between old and new preventive strategies.

show abstract

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

Cited by 7 publications

References 88 publications

Patent Foramen Ovale Closure and Medical Treatments for Secondary Stroke Prevention

Patent Foramen Ovale Closure and Medical Treatments for Secondary Stroke Prevention

Patent Foramen Ovale—Assessment and Treatment

Prevention Strategies for Cardioembolic Stroke: Present and Future Perspectives~!2009-05-11~!2009-12-23~!2010-06-09~!

Contact Info

Product

Resources

About