Association of residual shunts after PFO closure with recurrent stroke risk: Single-center experience.

BACKGROUND

Literature on residual right-to-left shunts after patent foramen ovale (PFO) closure shows conflicting results regarding stroke recurrence risk, although recent data suggest increased risk with moderate and large residual shunts.

AIMS: To evaluate the effect of the presence and grade of residual shunt on the risk of stroke/transient ischemic attack (TIA) after PFO closure.

MATERIAL AND

METHODS

We retrospectively analyzed data from a prospectively maintained registry of 498 patients who underwent PFO closure following cryptogenic stroke/TIA between 2004 and 2022. Residual shunts (RS) were classified as grade 0 (none), grade I (<10 microbubbles), grade II (10-20), or grade III (>20) using transesophageal echocardiography and transcranial Doppler at 6 and 12 months. Recurrent ischemic events during 7-year follow-up (mean 5.24 ± 2.0 years) were assessed via medical records. Risk ratios with 95% confidence intervals adjusted for follow-up duration were calculated.

RESULTS

In the study population (median age 52 years), RS was present in 35% of patients at 6 months, decreasing to 19% at 12 months (grade II or III: 13%). The annual risk of TIA/stroke was significantly higher in patients with any RS compared to those without (risk ratio [RR], 3.57; 95% confidence interval [CI], 1.52-8.43), particularly driven by grade III shunts (RR, 3.71; 95% CI, 1.21-11.39).

CONCLUSIONS

Although the incidence of residual shunting decreases over time, residual right-to-left shunting following PFO closure is associated with a significantly increased risk of recurrent ischemic stroke or TIA.