The predictive value of compression rate on residual leak after left atrial appendage occlusion with watchman FLX

Abstract

Abstract Background Incomplete left atrial appendage (LAA) occlusion due to residual leaks may occur after percutaneous closure procedure with Watchman FLX. Before release of device PASS (position, anchor, size and seal) criteria must be verified. Optimal compression rate for watchman FLX device is between 10-30% according to company recommendations. Purpose The aim of this study is to evaluate the correlation between compression rate and leak presence after left atrial appendage closure. Methods This is an observational retrospective study including patients that underwent LAA closure under transesophageal echocardiography (TEE) with at least one follow-up where complete LAA closure was assessed by TEE in our center between January 2021 and August 2022. TEE images were reviewed by the first author. Compression rate was calculated based on intraprocedural TEE images using the following formula: (original device size—size after deployment)/original device size*100. Patients were divided into 2 groups based on the compression rate: group 1: 10-30%; group 2: >30%. The rate of leak between groups was compared using the Chi-square test. Results 203 patients (mean age 79± 8 years) were included in the study. The implanted device size was 20 mm in 7 (3.4%), 24 mm in 30 (14.8%), 27 mm in 49 (24.1%), 31 mm in 75 (36.9%) and 35 mm in 42 (20.7%) patients. Based on the compression rate, patients were classified into group 1: >30% [n=37 (18.2%)] and group 2: ≤30% [n=166 (81.8%)]. Mean compression rate was 38.5% and 21.3% in group 1 and 2 respectively. At follow-up TEE, 1 (2.7%) patient in group 1 and 32 (19.3%) patients in group 2 were found to have a residual leak of >1 mm. When comparing leaks between the two groups, there was 1 leak in group 1 whereas in group 2 there were 32 leaks (1/37 vs 32/166, p value 0.01, RR 0.14, 95% CI, 0.02-0.74). Conclusion Devices with compression rate ≤30% were associated with significantly higher risk of residual leak.