Occlusion of functional high-volume intra-atrial shunts in older patients after embolic stroke of undetermined source

Background: Intra-atrial shunts are associated with an elevated risk of embolic stroke of undetermined source (ESUS). Percutaneous occluder implantation is recommended as secondary prevention in younger patients. This study aims to compare the outcome after shunt occlusion between younger and older patients with a history of presumed paradox embolism and to evaluate the impact of high-volume shunting in an elderly population.

Methods: We conducted a single-center, retrospective, observational study, involving 187 patients who underwent interventional percutaneous PFO or ASD occlusion at our center between 2013 and 2023.

Results: The mean age of participants was 51.8 ± 11.8 years, with 76 patients aged ≤50 years and 111 patients aged >50 years. Older patients presented more cardiovascular risk factors. The presence of atrial septum aneurysm or large shunting was evenly distributed (ASA 26.3% vs. 28.8%, p = 0.833, mean shunt defect size 6.67 vs. 7.23 mm, p = 0.151). There were no significant differences in procedural or intrahospital complications. The event rate during the 6-month follow-up was low. Recurrence of arterial embolism occurred in 1.6% of the younger and 3.8% of the older patients (p = 0.817). Comparison of high-volume shunts (defect size ≥10 mm or passage ≥20 bubbles during bubble study) with low-volume shunts in this elderly cohort with a mean age ≥50 years showed no significant difference in outcomes. There was a statistically non-significant trend toward a higher rate of residual shunt at the end of the procedure in the high-volume shunt group (2.9% vs. 9.8%, p = 0.0894). This difference was not observed at the 6-month follow-up anymore (14.5 vs. 12.1%, p = 0.628). Two unsuccessful implantation attempts were reported in the high-volume shunt group, while none were observed in the low-volume shunt group (p = 0.372). No intervention-related deaths occurred in this patient cohort during follow-up.

Conclusion: Occlusion of relevant, intra-atrial shunting is a safe and effective option for secondary prevention of cryptogenic embolism in patients over 50 years of age. The beneficial outcome was irrespective of a high-volume shunting before implantation.