Baseline characteristics
A total of 157 patients underwent LAAC with Watchman device from March 2018 to November 2020 in Jiangsu Taizhou People's Hospital were enrolled. All patients had contraindications to long-term OAC.The median age was 67 years. Persistent and permanent AF was present in 114 patients (72.6%), whereas 38 (24.2%) had a history of stroke/transient ischemic attack(TIA).The mean CHA2DS2-VASc score was 4 (3-6) and HAS-BLED score was 3 (2-5). The baseline demographics and clinical parameters were detailed in Table 1.
LAAC procedures and parameter analysis
The procedural details were shown in Table 2. Deep intravenous anesthesia was used in 101(63.7%) patients and general anaesthesia in 56 (36.3%) cases. All procedures were performed under TEE guidance. Primary technical success of LAAC was achieved in all cases with the Watchman device. The device was deployed at the first attempt in142/157 cases (90.4%). After successful device release, mild leak (<3 mm) was observed in 14 cases and moderate leak (3-5 mm) in 4 cases. The perioperative adverse event occurred in 5 cases (3.2%). including 2 pericardial effusions (1.3%) and 3 vascular complications (1.9%). Pericardial effusion requiring pericardiocentesis was happened in 1 case.
The ostium diameters of LAA measured by CTA, TEE, and DSA
There was no significant difference in the diameter measurement of the LAA ostium between DSA and TEE[(22.9±3.7)mm vs.(22.5±3.6) mm, q =0.92, p =0.16]. Meanwhile, The diameter of the LAA ostium obtained by CTA [(24.6±3.7) mm] was greater than that of DSA and TEE(q =3.92, p<0.01;q =4.58, p<0.01,respectively).
For the measurements of the LAA ostium ,there were reasonably good correlations among the three modalities, with r=0.78 and p<0.001 between TEE/CTA, r=0.85 and p<0.01 between TEE/DSA, r=0.77 and p<0.001 between CTA/DSA (Figure 4:A-C ).There were also good correlations between the LAA ostium measured by TEE, CTA, DSA and the Watchman device, with r=0.85 and p<0.01, r=0.92 and p<0.01, r=0.79 and p<0.01, respectively(Figur 4:D-F). Among which, the relevance of CTA measurements was the best.
Bland Altman diagram was used to analyze the consistency. The results showed that the p values of CTA versus DSA, CTA versus TEE, TEE versus DSA were 0.0855, 0.0663 and 0.9916 respectively (p > 0.05), that is, the difference and mean value were independent, and the consistency limit could be calculated. Compared with DSA, 6.25% (5 / 80) of CTA was outside the consistency limit, and the maximum difference / mean value within the limit was 38.68% (8.8 / 22.75). Compared with TEE, 7.5% (6 / 80) of CTA were outside the consistency limit, and the maximum difference / mean value within the limit was 35.6% (8.1 / 22.75). The error of comparison between CTA and TEE was beyond the clinically acceptable range (± 25%). Compared with DSA, 3.75% (3 / 80) of TEE were outside the consistency limit, the maximum difference / mean value within the limit was 22.52% (5 / 22.20), the error was within the clinical allowable range (± 25%) (Figure 5: A-C ). Combined with correlation analysis, the correlation coefficient of TEE and DSA was r = 0.86, so it can be considered that the results measured by the two methods have good consistency, and the two methods can be used instead of each other in clinic.
DSA measurements and the actual device size were the widest limits of agreement (-9.3120mm, 0.2395mm), followed by TEE (-9.4445 mm, -1.0205 mm), and CTA measurements were the narrowest limits of agreement(-8.7912mm, -1.8724 mm). The p-values of the regression analysis of DSA,TEE and CTA with occluder were 0.0003, 0.008 and 0.3102 , the p-values of TEE and DSA were statistically significant (Figure5:D-F).Therefore, the CTA measurements more closely to the actual Watchman device size.
For the LAA depth measurements, mean CTA measurements (25.1±3.9mm) was higher than that of TEE (24.6±3.7mm) and DSA (23.9±3.6mm).There was no significant difference in the depth measurement between CTA and DSA, CTA and TEE, TEE and DSA (p > 0.05). The correlations between TEE and CTA (r=0,66, p<0.01), TEE and DSA (r=0.75, p<0.01), CTA and DSA (r=0.59, p< 0.01) were good and statistically significant (Figure6:A-C).