4.7 | Clinical safety
Assessing safety endpoints is a challenge for some complications occur
rarely. Thermal ablation modalities may cause injury in neighboring
tissues.1 Optimizing the safety of AF ablation remains
necessary in clinical practice. Our study exhibited a favorable safety
outcome.
In our series, vagal responses and diaphragmatic contractions were
common during the procedure. However, we did not observe persistent
diaphragmatic weakening or obvious heart rate variability indicative of
nerve injury after ablation. Some studies demonstrated that PFA does not
induce nerve injury during the PFA procedure.5,6 So we
concluded that the vagal responses and phrenic activation are
neurological stress responses due to electrical stimulation, but not
nerve damage. However, the cardiac autonomic nerve may participate in
the initiation and maintenance of AF, and some researchers hypothesize
that thermal ablation is advantageous for its ability to destroy the
ganglionic plexi simultaneously.24 Therefore, whether
ganglionated plexus ablation is required in addition to PFA remains
unknown.
The incidence of SCLs was relatively low in the present study. The
mechanism of SCLs formation is multifactorial, which may be due to the
air or thrombus entry via sheaths, coagulum form on catheter or ablation
lesions, and bubble formation during ablation.25Current evidence suggests that the majority of cerebral lesions are
asymptomatic and resolve over a short period.8,26,27Echogenic microbubbles were common with intracardiac echocardiography
during the application of PFA, however, this was not the main cause of
cerebral injury. Careful management of sheaths, continuation of
anticoagulation, and maintenance of ACT >300 s may help
reduce the risk of cerebral lesions.
Overall, our study’s safety findings should largely alleviate safety
concerns regarding PFA. However, larger studies will be needed to reveal
rare unanticipated safety issues.