Predictors and clinical outcomes of residual shunt in patients undergoing percutaneous transcatheter closure of patent foramen ovale.

OBJECTIVE

To determine echocardiographic characteristics that may identify patients likely to have residual right-to-left shunt after percutaneous closure of a patent foramen ovale (PFO).

BACKGROUND

Characteristics of the atrial septum and PFO may identify patients who are likely to have residual shunt following percutaneous closure.

METHODS

We reviewed 76 consecutive patients (42 women; 34 men) who underwent percutaneous PFO closure (AGA Amplatzer PFO occluder) for hypoxemia or paradoxical embolization who failed or were unable to receive systemic anticoagulation. Saline contrast echocardiography with and without the Valsalva maneuver was performed within 24 hours and after 6 months to assess for residual shunt.

RESULTS

48 patients (63%) had early closure of the PFO with total elimination of the shunt. Residual shunt was detected in 28 patients (37%), although the severity had diminished significantly compared to baseline. All patients with atrial septal aneurysm (n = 7), and all but 1 patient with a redundant atrial septum (n = 6) before percutaneous closure had residual shunts (p < 0.001). The patient's age, device size and PFO dimensions did not predict procedural success. At 6-month follow up, residual shunt had resolved in all but 3 patients. One of these 3 patients had a recurrent nonfatal transient ischemic event.

CONCLUSIONS

A percutaneous transcatheter approach confers early closure of PFO and elimination of the shunt in a majority of patients. Residual shunts are seen in patients with a redundant atrial septum and atrial septum aneurysm in the early post-closure period, but resolve without major clinical sequelae by 6 months.