Table 1.

 Risk of recurrent brain infarction according to presence or absence of PFO and ASA in a registry of patients with a cryptogenic stroke. Adapted from Mas et al⁸

	1 year (95% CI)	2 years (95% CI)	3 years (95% CI)	4 years (95% CI)	Mean annual risk
No PFO no ASA	2.0 (0.4 to 3.6)	3.7 (1.6 to 5.8)	4.2 (1.8 to 6.6)	4.2 (1.8 to 6.6)	1.1
PFO only	1.8 (0.05 to 3.6)	1.8 (0.05 to 3.6)	2.3 (0.3 to 4.3)	2.3 (0.3 to 4.3)	0.6
ASA only	0	0	0	0	0
PFO + ASA	2.0 (0 to 5.8)	4.0 (0 to 9.4)	6.3 (0 to 13.2)	15.2 (1.8 to 28.5)	4.0

ASA, atrial septal aneurysm; CI, confidence interval; PFO, patent foramen ovale.