IJCS | Volume 33, Nº4, July and August 2020

DOI: https://doi.org/10.36660/ijcs.20190075 307 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2020; 33(4):307-317 Mailing Address: Sónia P. P. Pereira Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernani Monteiro. Postal Code: 4200-319, Porto - Portugal. E-mail: sonia_1995@live.com.pt The Role of Patent Foramen Ovale Closure in the Secondary Prevention of Cryptogenic Stroke: a Meta-Analysis Report Sónia P. Pinto Pereira, 1 A lzira Nunes, 2 C ristina Santos, 1 S cott E. Kasner, 3 J osé P. L. Nunes 1 Faculdade de Medicina da Universidade do Porto, 1 Porto – Portugal Centro Hospitalar Universitário São João, 2 Porto – Portugal University of Pennsylvania, 3 Philadelphia – USA Manuscript received on April 12, 2019; reviewed on July 20,2019; accepted on August 07,2019. Abstract Background: Patent foramen ovale (PFO) closure has been compared to medical therapy for secondary prevention of recurrent cryptogenic stroke. Objectives: To produce an updated meta-analysis including only data from the primary analyses of clinical trials and to evaluate the role of PFO closure in the secondary prevention of recurrent stroke. Methods: Search in Medline (PubMed) and in ISI Web of Knowledge. Parameters under analysis and meta-analyses were: stroke, transient ischemic attack (TIA) and atrial fibrillation (AF). Comprehensive Meta-analysis Software V.2.0 (Biostat) was used. Random-effects analyses were carried out. A level of significance of 5% was used. Results: In this study six, randomized trials enrolling 3,750 patients were included. Unlike other published meta- analyses on the same topic, in this case, only clinical trial data, and not follow-up data, were used. PFO closure, as compared with medical therapy alone, demonstrated superiority in reducing the rate of recurrent stroke (risk ratio with PFO closure vs. medical therapy, 0.37; 95% confidence interval [CI], 0.17 to 0.78; p = 0.01). PFO closure did not offer a significant benefit in prevention of TIA (risk ratio with PFO closure vs. medical therapy, 0.96; 95% CI, 0.64 to 1.44; p = 0.85). Among patients assigned to closure group, an increased risk of atrial fibrillation was seen (risk ratio with PFO closure vs. medical therapy, 4.64; 95% CI, 2.38 to 9.01; p < 0.01). Conclusions: In patients with cryptogenic stroke who had a patent foramen ovale, a protective effect of closure was seen concerning the risk of recurrent stroke, but not regarding the prevention of TIA. (Int J Cardiovasc Sci. 2020; 33(4):307-317) Keywords: Foramen Ovale Patent/Diagnosis; Stroke; Isquemic Attack, Transient; Atrial Fibrillation; Risk Factors; Stroke/Prevention and control. Introduction Stroke remains one of the most important causes of death and morbidity worldwide. 1 Between 20% and 30% of ischemic strokes have no identifiable cause after exclusion of all potential causes, and they are denominated cryptogenic strokes. 2 Forty to fifty percent of patients who suffer a cryptogenic stroke also have a patent foramen ovale (PFO). This association suggests that some cryptogenic strokes, particularly in younger patients, may be due to paradoxical embolism, which consists in the passage of a thrombus from the venous to the atrial system through a patent foramen ovale. 3,4 The options to implement secondary prevention of recurrent stroke for patients with a patent foramen ovale who have had a cryptogenic stroke have been the administration of antithrombotic medications or percutaneous closure of PFO. However, it was not initially clear whether percutaneous closure is superior to medical therapy. 5,6 The results of early studies gave