Background: Rarely, hypoxaemia is associated with shunt reversal at the atrial level. Closure by interventional catheterization is the treatment of choice but indications and results have been studied insufficiently.
Purpose: To describe our experience with interventional closure of atrial right-to-left shunts described as hypoxaemic and the impact on patient oxygenation and clinical status.
Method: Retrospective study in two referral centres, including all patients undergoing closure of interatrial right-to-left shunt associated with hypoxaemia.
Results: Since 2001, 21 consecutive patients underwent interventional shunt closure using the "Amplatzer((R)) device"; two patients had atrial septal defect and 19 had patent foramen ovale. Three patients had minor adverse events; two patients have a tiny residual shunt. Transcutaneous oxygen saturation and partial oxygen pressure increased significantly from 86+/-5 to 95+/-3% (p<0.001) and from 49.8+/-6.8 to 82.9+/-30.4mmHg (p=0.001), respectively. Seventeen (80%) patients reported clinical improvement. However, patients with chronic respiratory insufficiency remained more symptomatic, with three deaths after a median follow-up of 35 (6-97) months and 89% remaining in New York Heart Association class III/IV (vs 29% of patients without chronic respiratory insufficiency; p=0.035).
Conclusion: Hypoxaemic shunts are treated effectively by transcatheter closure, resulting in functional improvement in patients without respiratory insufficiency. When associated with chronic respiratory insufficiency, hypoxaemia often persists after shunt closure. In such cases, the right-to-left atrial shunt does not seem to be the main cause of hypoxaemia and the indication for closure is questionable.