Delayed left atrial appendage contrast filling in computed tomograms after percutaneous left atrial appendage occlusion

Background The gold standard for the follow-up of left atrial appendage occlusion (LAAO) is performing transesophageal echocardiogram (TEE) at 45 days after LAAO; however, the duration for complete LAA seal-off after percutaneous LAAO is unknown in humans. We retrospectively evaluated the LAA contrast-filling (CF) rate in follow-up cardiac computed tomography (CT) scans after LAAO. Methods We included 35 patients (age 67.5 ± 10.9 years, CHA₂DS₂VASc 4.2 ± 1.6, HAS-BLED 3.7 ± 1.5) who underwent LAAO [16 WATCHMAN, 19 Amplatzer cardiac plug (ACP)] and follow-up cardiac CT within 6 months after LAAO, and evaluated the LAA-CF rates. Eighteen patients (51.4%) underwent multiple episodes of CT follow-up. Results 1. The proportions of patients with LAA-CF were 54.2% (19/35) at 6 months, 55.5% (5/9) at 6–18 months, and 33.3% (3/9) at >18 months after LAAO. 2. Among 23 patients with no peridevice leak at the 2 months TEE, LAA-CFs were found in 12 patients at 2.8 ± 1.5 months (66.6% in WATCHMAN and 36.3% in ACP; p = 0.158). 3. Among eight patients with consecutive follow-up CT (≥3 times), LAA-CFs were partially reduced in three; however, there was no complete LAA seal-off at 19.0 ± 11.3 months. 4. A larger LAA landing zone diameter was independently associated with LAA-CF in follow-up CT [OR 1.45 (1.08–1.96), p = 0.013, adjusted for age, sex, and device type]. Conclusions Delayed LAA-CF is common after LAAO, with considerable discrepancies between cardiac CT and TEE findings. Although the clinical significance of LAA-CF is unclear, 45 days seem to be insufficient for complete LAA seal-off after LAAO.