A High Ratio of D-1 Dimer to Brain Natriuretic Peptide and Large Right-to-Left Shunt by Contrast-Enhanced Transthoracic Echocardiography as Risk Factors for Cryptogenic Stroke in Patent Foramen Ovale

The study investigated the relationship between ratio of D-dimer to brain natriuretic peptide (BNP), large right-to-left shunt (RLS) by contrast-enhanced transthoracic echocardiography (c-TTE), and cryptogenic stroke (CS) in patent foramen ovale (PFO). The study populations were composed of 61 patients with PFO who had been scheduled for transcatheter closure for CS (n = 20) or migraine (n = 41). Large RLS was defined as more than 20 microbubbles at rest and during the Valsalva maneuver by c-TTE. The PFO/CS group exhibited a higher proportion of large RLS at rest (3 vs. 0, P = 0.032) and during the Valsalva maneuver (14 vs. 11, P = 0.002) than the PFO/migraine group. More specifically about PFO characteristics, the height of PFO in the PFO/CS group was higher than that in the PFO/migraine group, and the proportion of atrial septal aneurysm in the PFO/CS group was higher than that in the PFO/migraine group (8 vs. 4, P = 0.013). The ratio of D-dimer to BNP was found to be significantly higher in the PFO/CS group than the PFO/migraine group (P = 0.010). The multiple logistic regression analysis showed that a large RLS during Valsalva maneuver and a high ratio of D-dimer to BNP were independent factors associated with CS in PFO. The study demonstrates that a high ratio of D-dimer to BNP and large RLS by c-TTE as risk factors for CS in PFO.