In patients treated with pulsed field ablation (PFA) for symptomatic paroxysmal atrial fibrillation (AF), the incidence of asymptomatic thromboembolic cerebral events or lesions detected by magnetic resonance imaging (MRI) was as low as 3%. This is according to the authors of a study published in Heart Rhythm, looking at cerebral safety after PFA for paroxysmal AF.
The study’s authors, Nico Reinsch (Alfried Krupp Hospital, Essen, Germany) et al, also report that there were no neurological deficits in any of the patients.
Writing in Heart Rhythm, the study’s authors note that safety and efficacy studies have shown that PFA is capable of creating significant lesions to perform cardiac ablation effectively with no adverse effects, such as coronary artery stenosis, persistent phrenic nerve palsy, or oesophageal damage.
However, they add that procedure-associated stroke is among the most severe disabling complications of AF ablation, and while symptomatic thromboembolic events are rare, recent studies on magnetic resonance imaging (MRI) highlighted the occurrence of silent cerebral lesions and/or events using thermal ablation techniques and have increased awareness of possible cerebral complications.
Their study investigated the occurrence of neurological deficits and silent cerebral lesions and/or events after PFA in paroxysmal AF using cerebral MRI and National Institutes of Health Stroke Scale (NIHSS) scores to objectively quantify the impairment caused by a stroke.
The study investigators enrolled consecutive patients with symptomatic paroxysmal AF undergoing pulmonary vein isolation (PVI) at the Alfried Krupp Hospital in Essen between April and June 2021. Exclusion criteria were the incidence of previous left atrial (LA) ablation procedure, persistent AF, known pregnancy, life expectancy of less than two years, severe mitral valvular heart disease, and contraindications to post-interventional oral anticoagulation, computed tomography (CT) or MRI.
One day after PVI, all patients underwent cerebral 1.5 Tesla MRI-scanning using diffusion-weighted imaging (DWI) and T2-weighted axial fluid-attenuated inversion recovery (FLAIR) sequences to document the occurrence of silent cerebral lesions and/or events.
In the 30 patients (age 63±10 years) who underwent PFA during the study period, Reinsch et al report that none showed neurological deficits. All obtained NIHSS scores showing the minimum value of 0. Cerebral MRI scans were normal in 29/30 (97%) patients, while in 1 (3%) patient, a single 7mm cerebellar lesion was observed. Forty days after the procedure, a follow-up cerebral MRI scan showed complete regression of the lesion, the study team reports.
The authors note that their study comes with some limitations, including its non-randomised design and inclusion of a limited, consecutive number of relatively young patients. Furthermore, they note that the present study protocol did not incorporate a detailed neurological examination by a trained neurologist and therefore, occurrence of very discrete asymptomatic neurological deficits cannot be ruled out.
In conclusion, the study investigators write: “In patients treated with PFA for symptomatic paroxysmal AF, the incidence of MRI-detected asymptomatic thromboembolic cerebral events or lesions was as low as 3%. There were no neurological deficits in any of the patients. Future studies have to confirm these findings.”