Background: Although pulmonary vein isolation (PVI) is an effective treatment strategy for patients with paroxysmal atrial fibrillation (AF), it is associated with limited success rates in patients with persistent AF (PersAF). In this context the left atrial appendage (LAA) was recently identified as a target of catheter ablation especially in PVI non-responders. Although effective, this strategy may cause electromechanical dissociation and was therefore assumed to be associated with an increased risk of thromboembolism despite oral anticoagulation (OAC). Since RF based LAAI showed increased rates of thromboembolism and stable LAAI is difficult to achieve in some cases, Cryoballoon- (CB) based LAAI might offer a valuable option to achieve safe and durable LAAI.

Objective: To assess safety, efficacy and one year follow-up on CB-based LAAI.

Methods: Cryoballoon based PVI and LAAI was performed in 31 patients with PersAF and long-standing PersAF. LAAI was performed by utilizing a bonus freeze protocol (freezing time 300 seconds + another 300 seconds after LAAI). After LAAI all patients received endocardial LAA closure to prevent LAA thrombus formation.

Results: The median procedure time was 81.3 (68, 89) minutes. Stable LAAI was achieved after a mean of 2.1 +/- 1.4 CB applications with a mean minimal temperature of -55 (-49, -55) °C. Unless one phrenic nerve palsy (3.2%) of the left phrenic nerve and one hematoma of the puncture site (3.2%) no further periprocedural complications occurred. Successful LAAI was performed in 28/31 (90%). The median freezing time was 600 (600, 900) seconds. Transesophageal echocardiography was performed after a median of 49 (47, 56) days and detected LAA thrombus in 6/31 (19.3%) patients. Successful LAA-closure was performed in all patients after a median of 50 (47, 91) days. The LAA was durable isolated in 22/31 patients (71%). Complete PVI of all PVs was detected in 21/31 (68%) of patients. One ischemic stroke occurred 6 months after LAA-closure. After a follow-up of 12.5+/-3.6 months 68% of patients showed stable Sinusrhyhtm.

Conclusions: LAAI was successfully isolated in the majority of patients. However, a relatively high rate of LAA-Thrombus was detected after LAAI. Therefore, LAA closure is mandatory in this population.