Incomplete endothelialization after LAAC
CCTA can not only display PDL but also incomplete endothelialization at
the distal site of LAA by signs of contrast enhancement post device
implantation, while TEE is not available.
Previous report showed that satisfactory endothelialization could be
achieved within 45 days after LAAC device implantation in the canine
model[17]. However, several clinical observation
studies found that delayed endothelialization or incomplete
endothelialization of LAAC device might occur in some patients, which
was linked with increased risk of DRT, stroke and
systemic embolic
events[18].
In our study, CCTA performed at 6 months post LAAC showed that among 51
patients without PDL, complete device endothelialization was achieved in
44 patients (86.3%) , while there were 7 patients with incomplete
device endothelialization (13.7%). This result is in line with a
previous study, which reported incomplete endothelialization in 7 out of
79 patients (8.9%) at 3 months post LAAC with Watchman
device[13].
The clinical implication of PDL and incomplete endothelialization
defined by CCTA in our patient remains to be determined during the
planned long-term follow-up. It sounds that both PDL and incomplete
endothelialization do not affect short-term outcome of patients post
LAAC, since adverse events were similar and rare post procedure between
patients with or without PDL and with or without incomplete
endothelialization during the 6 months follow-up post LAAC and AFCA.
Our patients will undergo long-term follow-up to see if the complete
endothelialization could be achieved or not in the 7 patients with
incomplete endothelialization, and to compare the outcome of patients
among various groups. Prospective long-term follow-up studies with large
patient cohort are definitively needed to validate the value of CTTA on
defining post LAAC PDL and incomplete endothelialization,
CCTA derived maximum diameter of LAA
orifice on predicting post LAAC PDL, and the clinical implication on
outcome including the incidence of stroke, DRT or systemic embolic
events of PDL and incomplete endothelialization post LAAC. Moreover,
future studies should also evaluate if the maximum diameter of LAA
orifice could be used as a screening index for AF patients before LAAC
on risk stratification of post LAAC PDL and incomplete
endothelialization and to see if this index could be integrated to other
parameters to establish a compressive coding system for individualized
decision making regarding the postoperative anticoagulation program.