F5 and Patent foramen ovale: In another study published in 2009 in Thrombosis and Haemostasis, that analyzed data from six eligible studies regarding the association of factor V Leiden with PFO, a trend toward an association for the FV(G1691A) mutation (OR 1.18; 95% CI 0.73 to 1.90, compared to control subjects was noticed; OR 1.14; 95% CI 0.62 to 2.09, compared to non–PFO–associated stroke patients).