The effect of two different methods of planning landing zone for left atrial appendage closure by cardiac computed tomography angiography: a comparative study.

Background:To explore the value of 2 different methods for planning landing zone for left atrial appendage closure (LAAC) by cardiac computed tomography angiography (CCTA). Methods:A retrospective analysis was performed on the clinical data of patients who successfully underwent LAAC with the Watchman device at The Affiliated Taizhou People's Hospital of Nanjing Medical University from August 2020 to February 2022. Two different methods were used to plan the landing zone and measure the longest diameter, average diameter, depth, and perimeter of the landing zone. The difference between the 2 methods and the correlation between their measurements and occluder size were analyzed. Results:A total of 66 patients undergoing LAAC were included, with an average age of 69.35±7.1 years, of whom 30 (45.5%) were women. The mean error between the longest diameter measured by the traditional method and the actual value was 2.90±2.83 mm, and the mean absolute error (MAE) was 2.71 (1.17, 4.38) mm. The mean error between the longest diameter measured by the new method and the actual value was 0.9 (-0.13, 2.50) mm, and its MAE was 1.4 (0.40, 2.53) mm. The error of the longest diameter measured by the traditional method was larger than that measured by the new method (P<0.001). The mean error between the depth measured by the traditional method and the actual value was 1.40±3.45 mm, and the MAE was 2.36 (0.74, 4.58) mm. The mean error between the depth measured by the new method and the actual value was 0.10 (-1.33, 1.95) mm, and the MAE was 1.55 (0.60, 3.10) mm. Likewise, the depth error measured by the traditional method was larger than that measured by the new method (P<0.05). The correlation between the perimeter and the size of the occluder was the strongest (r=0.919, P<0.001). Conclusions:With CCTA, the new method is more accurate in planning landing zone than the traditional method. It is particularly important to select the occluder size for the patients with flat oval landing zone ostium.