Cardiologist/Physician Royal Columbian Hospital Royal Columbian Hospital Vancouver, British Columbia, Canada
Background: Detection of right-to-left shunting (RLS) after patent foramen ovale (PFO) closure is typically assessed using Intracardiac echocardiography (ICE) or transthoracic echocardiography with agitated saline (TTE-S). The presence of residual RLS on TTE-S is associated with recurrent stroke or transient ischemic attack (TIA). However, the sensitivity of TTE-S for assessment of RLS pre-closure has been noted to be inferior to that of robotic transcranial doppler (r-TCD). The efficacy of r-TCD for the evaluation of RLS has not been studied after PFO closure. The aim of this study was to assess the accuracy of r-TCD for detecting RLS after PFO closure compared with ICE-S peri-procedurally and with TTE-S 4-8 weeks after procedure.
METHODS AND RESULTS: Patients undergoing PFO closure for stoke or TIA between 2023-2025 in the Fraser Health Authority were examined. All patients had periprocedural assessment of residual RLS post-closure using r-TCD and ICE-S. Repeat evaluation of RLS was performed at 4-8 weeks post-closure with both r-TCD and TTE-S. All RLS assessments were performed at baseline and with Valsalva maneuver. A total of 52 patients underwent PFO Closure and assessment by r-TCD. In the periprocedural setting after PFO Closure, r-TCD noted residual RLS in 81% (n=42) of patients compared with 27% (n=14) noted by ICE-S (p=0.0001). Of the RLS detected by r-TCD, 37% were deemed Foster Grade ≥3 shunts. On ICE-S, 64% (n=9) residual RLS detected were noted in patients with TCD-associated Foster Grade ≥3 residual shunts. In outpatient follow-up after PFO closure, r-TCD detected residual RLS in 81% (n=17) of patients compared with 24% (n=5) noted with TTE-S (p=0.0005). All 5 cases of RLS detected with TTE-S had Foster Grade ≥3 shunts on TCD.
Conclusion: r-TCD maybe highly sensitive for detecting any RLS with accurate grading after PFO closure compared with both ICE-S and TTE-S. The prognostic impact of residual RLS remains unclear and needs determination.
