CRD summary

This review assessed transcatheter closure and medical therapy for patent foramen ovale. The authors concluded that transcatheter closure may prevent a substantial number of recurrent strokes, but definitive conclusions were not possible because of methodological limitations and a lack of comparability between the studies of these treatments. The authors' cautious conclusions correctly reflect the poor-quality studies on this topic.

Authors' objectives

To assess and compare transcatheter closure and medical therapy for patent foramen ovale.

Searching

MEDLINE was searched from 1985 to July 2003; the search terms were stated. Additional articles were searched for in the reference lists of retrieved studies. Articles published in English and foreign language journals were eligible. Unpublished studies were not sought.

Study selection

Assessment of study quality

The authors did not state that they assessed validity.

Data extraction

The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction. The extracted data included: the number of patients with major and minor complications of transcatheter closure; the number of patients with a recurrent event of TIA, stroke and noncerebrovascular systemic embolism; and the number of these events at 1-year for both transcatheter closure and medical therapy. Attempts were made to exclude duplicate data. Four studies with potentially overlapping populations were excluded.

Methods of synthesis

Results of the review

Sixteen studies (n=2,250) were included. There were 6 retrospective and 4 prospective studies of transcatheter closure (1,355 patients) and 3 retrospective and 3 prospective studies of medical therapy (895 patients).

Complications after transcatheter device closure.

Minor complications were reported in 7.9% of the patients and major complications in 1.5%. Major complications included death, haemorrhage requiring blood transfusion, cardiac tamponade, need for surgical intervention and massive fatal pulmonary emboli. Minor complications included bleeding not requiring transfusion, periprocedural atrial arrhythmias, transient atrioventricular node block, device arm fractures (25, 31), device embolisation with successful catheter retrieval, asymptomatic device thrombosis, need for recatheterisation, symptomatic air embolism, transient ST-segment elevation, arteriovenous fistula formation and femoral haematoma.

Recurrent events for transcatheter device closure and medical therapy.

The incidence of stroke or TIA ranged from 3.8 to 12% at 1 year with medical therapy, and from 0 to 4.9% after transcatheter closure. Seven of the 10 studies of transcatheter closure reported rates of 1.7% or less. There was a trend towards an increasing incidence of recurrent events with increasing mean age for both transcatheter closure and medical therapy studies. There was no apparent correlation between stroke or TIA and complete closure of patent foramen ovale at 6 months in studies of transcatheter device closure.

Authors' conclusions

Transcatheter closure may prevent a substantial number of recurrent strokes, but definitive conclusions could not be reached because of a lack of comparability between studies of transcatheter closure and medical therapy. Randomised controlled trials (RCTs) are required.

CRD commentary

The review question was clear in terms of the study design, intervention, participants and outcomes. The search strategy was limited to one electronic database and reference lists of identified studies, thus the possibility of publication bias is highly likely. Attempts were made to limit language bias. The methods used to select the studies and extract the data were not described, and it is not known whether any efforts were made to reduce errors and bias. Validity was not formally assessed, although some methodological limitations of the studies were discussed in the text.

Adequate details of the included studies were given. Given the considerable clinical heterogeneity among the studies identified, it was appropriate to report the range of event rates. The authors appropriately considered the limitations in study design and differences across the studies. Consequently, the authors' cautious conclusions correctly reflect the poor quality of studies on this topic.

One of the authors has participated in trials of transcatheter devices and medical therapy, and has received expenses from pharmaceutical and manufacturing companies.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that RCTs are required to examine the benefits of transcatheter closure of patent foramen ovale, to define the subgroups most likely to benefit, and to assess the cost-effectiveness of this technology.

Bibliographic details

Khairy P, O'Donnell C P, Landazberg M J. Transcatheter closure versus medical therapy of patent foramen ovale and presumed paradoxical thromboemboli. Annals of Internal Medicine 2003; 139(9): 753-760. [PubMed: 14597460]

Original Paper URL

http://www.annals.org/cgi/content/full/139/9/753

Indexing Status

Subject indexing assigned by NLM

MeSH

Cardiac Catheterization /instrumentation; Embolism, Paradoxical /complications /prevention & control; Heart Septal Defects, Atrial /complications /drug therapy /therapy; Humans; Platelet Aggregation Inhibitors /therapeutic use; Prostheses and Implants; Recurrence /prevention & control; Stroke /etiology /prevention & control

AccessionNumber

12003008701

Database entry date

30/06/2005

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.