Risk and fate of residual interatrial shunting after transcatheter closure of patent foramen ovale: a long term follow up study

BACKGROUND: Percutaneous transcatheter closure of patent foramen ovale (PFO) in cryptogenic stroke is an alternative to medical therapy. There is still debate on different outcome for each currently available device. The impact of residual shunting after PFO-clo- sure on recurrent arterial embolism is unknown. AIMS: (i) To evaluate the prevalence of residual interatrial shunting after device- closure of PFO, (ii) to identify risk factors predicting residual interatrial shunting after device implantation, and (iii) to investigate the outcome of patients after PFO-closure during long- term follow- up (FU). METHODS AND RESULTS: Between 2000- 2005 PFO-closure was performed in 124 patients using four different devices: Amplatzer PFO-(n = 52), CardioSeal (n = 33), Helex (n = 23) and Premere (n = 16) occluder. All patients underwent serial contrast-enhanced transesophageal echocardiography (TEE) for 24 months after PFO- closure; clinical FU was at minimum 5 years up to 9.75 years (mean 6.67 ± 1.31 years). Overall-closure rate was 87% at 2 years, device-specific closure time curves differed significantly (p-logrank = 0.003). Independent risk factors for residual-shunting were implantation of a Helex occluder (hazard ratio [HR] 12.6, 95% confidence interval [CI] 2.6- 57.4, p = 0.002), PFO- canal- lengths (HR 1.2, 95%CI 1.1- 1.3, p = 0.004) and extend of atrial-septal-aneurysm (HR 1.1, 95%CI 0.9- 1.3; p = 0.05). 4 (3.2%) arterial embolic events occurred during a FU-period of 817.2 patient-years, actuarial annual thromboembolic-risk was 0.49%. All ischemic events were not related to residual PFO-shunting or device-related thrombus- formation. CONCLUSION: Success rates of PFO- closure are mainly dependent on occluder-type, extend of concomitant atrial-septum-aneurysm and PFO-canal- length. Importantly, residual shunting after PFO-closure was not associated with recurrence of arterial embolism during long-term follow-up.