Right to left shunt and cryptogenic stroke in patients over 60 years old

Objective: To determine the possible role of patent foramen ovale (PFO) as indicated by a right to left
shunt and cryptogenic stroke in patients aged ≥ 60 years and to compare the prevalence of patent foramen
ovale with stroke of known cause.
Methods: We prospectively examined the prevalence of PFO using contrast enhanced colour Transcranial
Doppler ultrasonography (bubble-cTCD) in 86 consecutive patients aged ≥60 years with transient ischaemic
attack (TIA) or stroke and 86 consecutive patients aged <60 years with TIA/stroke as a control group.
Patients with cryptogenic stroke were compared to stroke patients with known cause.
Results: A significantly higher prevalence of PFO in patients with cryptogenic compared to patients with
stroke of known cause was registered in the patients aged < 60 years (56.6% vs.18.8%) and in patients
aged ≥ 60 years (37.14% vs.11.76%), respectively. Multivariate analysis adjusted for age, hypertension
and coronary disease showed that the existence of R-to-L shunt (RLS) was independently associated with
cryptogenic stroke in both, in the younger group (odds ratio 4.012; 95% CI1.323 to 12.171, p =0.0143.70)
and in the older group (odds ratio 3.197; 95% CI 1.140 to 10.877, p=0.037).
Conclusion: Our findings suggest that PFO is strongly associated with cryptogenic stroke in patients aged
≥ 60 years. Bubble – cTCD was feasible and suitable as a first-line method for the detection of PFO in
older patients.
Keywords: patent foramen ovale; cyptogenic stroke; transcranial Doppler ultrasonography