CCTA and LAAC
PDL is a common phenomenon post LAAC. TEE used to be the most common used method for the preoperative and postoperative evaluation of LAAC, including the detection of post procedure PDL. In recent years, studies demonstrated that CCTA could be a promising alternative to TEE on the preoperative and postoperative evaluation of LAAC[9]. The high spatial resolution and multi-planar reconstruction capability of CCTA can therefore effectively evaluate the relevant preoperative indicators, and the postoperative complications post LAAC.
CCTA examination before LAAC can assist the three-dimensional electrophysiological mapping system to construct the LA model during catheter ablation [10]. In addition, preoperative CCTA can measure the maximum diameter of LAA orifice to select the appropriate size of the Watchman device. In our study, the preoperative TEE defined average value of the maximum diameter of LAA orifice was 22.6 ± 3.2 mm, while the value defined by CCTA was 27.8 ± 5.2 mm(P < 0.001), suggesting that the maximum diameter of LAA orifice measured by TEE was underestimated. Previous study also showed comparable measurement results of LAA orifice derived either form CCTA with DSA or intracardiac echocardiography (ICE), while there was poor consistence on measurement results of LAA orifice derived from TEE and other modalities[11]. In line with previous report[12], smaller LAA orifice was also demonstrated in our study. Above results thus suggest that there is a potential risk to select smaller LAAC device, if the choice was made surely on preoperative TEE measurement, which might evidently increase the risk of postoperative PDL. Thus, preoperative CCTA should be integrated into the preoperative algorithm to reduce the risk of PDL.
In our study, postoperative CCTA was done to evaluate the presence of PDL and device endothelialization at 6 months post LAAC. Previous study found that the detection efficacy on detecting post LAAC PDL was higher by CCTA than by TEE (51.0% vs. 34.3%, P = 0.016)[13].