Incidence of Asymptomatic Intracranial Embolic Events Following Pulmonary Vein Isolation: Comparison Between Different AF Ablation Technologies in a Multicentric Study
How safe are devices specifically designed to facilitate pulmonary vein isolation (PVI) with either conventional irrigated radiofrequency (RF) or cryoballoon or multi-electrode phased RF ablation (PVAC)?
This prospective, observational, multicenter study included patients with symptomatic atrial fibrillation referred for PVI. Ablation was performed using either one of the three catheters. Strict periprocedural anticoagulation, with intravenous heparin during ablation to achieve an activated clotting time >300 seconds, was ensured in all patients. Cerebral magnetic resonance imaging (MRI) was performed before and after ablation. Odds ratio was calculated using binary logistic regression, including parameters showing significant levels of correlation with the presence of new embolic lesions on univariate analysis.
Seventy-four patients were included in the study: 27 in the irrigated RF group, 23 in the cryoballoon group, and 24 in the PVAC group. Total procedure times were 198 ± 50 minutes, 174 ± 35 minutes, and 124 ± 32 minutes, respectively (p < 0.001 for PVAC against irrigated RF and cryoballoon). Neurological examination was normal in all patients before and after ablation. Postprocedural MRI detected a single new embolic lesion in 2 of 27 patients in the irrigated RF group (7.4%), and 1 out of 23 in the cryoballoon group (4.3%). However, in the PVAC group, 9 of 24 patients (37.5%) displayed 2.7 ± 1.3 new lesions each (p = 0.003 for the presence of new embolic events among the three groups).
The authors concluded that the PVAC catheter is associated with a significantly higher incidence of subclinical intracranial embolic events.
The current study aimed to assess whether the ablation technique (conventional open-irrigated RF, multielectrode phased RF, or cryoballoon ablation) impacts on the incidence of new embolic events detected by cerebral MRI. All three groups presented new subclinical embolic lesions after PVI. However, the incidence and number of new lesions was significantly higher in patients treated with PVAC, with a predilection for the vertebrobasilar territory, favoring a cardiac origin. Given the small sample size of the current study, it will be important to determine if the findings reported are reproducible with different investigators and centers, using larger samples. The PVAC technology appears to have substantially greater risk than competing energy delivery systems, and it is difficult to justify its clinical use until clarification regarding mechanism and long-term consequences of silent cerebral embolism are addressed.
Keywords: Incidence, Intracranial Embolism, Pulmonary Veins, Catheter Ablation, Ablation Techniques
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