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.