Online Measurement of Microembolic Signal Burden by Transcranial Doppler during Catheter Ablation for Atrial Fibrillation-Results of a Multicenter Trial.

Christian Von Bary,Dobri Baldaranov,Anja Schade,Lars Maier,Sabine Fredersdorf,Thomas Deneke,Heiko Lehrmann,Felix Schlachetzki,Thomas Arentz

doi:10.3389/fneur.2017.00131

Abstract

Left atrial pulmonary vein isolation (PVI) is an accepted treatment option for patients with symptomatic atrial fibrillation (AF). This procedure can be complicated by stroke or silent cerebral embolism. Online measurement of microembolic signals (MESs) by transcranial Doppler (TCD) may be useful for characterizing thromboembolic burden during PVI. In this prospective multicenter trial, we investigated the burden, characteristics, and composition of MES during left atrial catheter ablation using a variety of catheter technologies. PVI was performed in a total of 42 patients using the circular-shaped multielectrode pulmonary vein ablation catheter (PVAC) technology in 23, an irrigated radiofrequency (IRF) in 14, and the cryoballoon (CB) technology in 5 patients. TCD was used to detect the total MES burden and sustained thromboembolic showers (TESs) of >30 s. During TES, the site of ablation within the left atrium was registered. MES composition was classified manually into "solid," "gaseous," or "equivocal" by off-line expert assessment. The total MES burden was higher when using IRF compared to CB (2,336 ± 1,654 vs. 593 ± 231; p = 0.007) and showed a tendency toward a higher burden when using IRF compared to PVAC (2,336 ± 1,654 vs. 1,685 ± 2,255; p = 0.08). TES occurred more often when using PVAC compared to IRF (1.5 ± 2 vs. 0.4 ± 1.3; p = 0.04) and most frequently when ablation was performed close to the left superior pulmonary vein (LSPV). Of the MES, 17.004 (23%) were characterized as definitely solid, 13.204 (18%) as clearly gaseous, and 44.366 (59%) as equivocal. We investigated the burden and characteristics of MES during left atrial catheter ablation for AF. All ablation techniques applied in this study generated a relevant number of MES. There was a significant difference in total MES burden using IRF compared to CB and a tendency toward a higher burden using IRF compared to PVAC. The highest TES burden was found in the PVAC group, particularly during ablation close to the LSPV. The composition of thromboembolic particles was balanced. The impact of MES, TES, and composition of thromboembolic particles on neurological outcome needs to be evaluated further. (Clinical Trial Registration: Deutsches Register Klinischer Studien, https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003465. DRKS00003465.).

Highlights

Left atrial catheter ablation leading to electrical pulmonary vein isolation (PVI) is a corner stone therapy for patients with symptomatic atrial fibrillation (AF)
Observing the occurrence of thromboembolic showers (TESs) pertaining to the ablation site, we found a significantly higher rate of TES when ablating the left superior pulmonary vein (LSPV) compared to the left inferior pulmonary vein and right inferior pulmonary vein (Figure 4)
The total microembolic signals (MESs) burden was significantly higher in the irrigated radiofrequency (IRF) group compared to the CB group and showed a tendency toward a higher burden in the IRF group compared to the pulmonary vein ablation catheter (PVAC) group. (ii) TESs occurred more often in the PVAC group compared to the IRF group

Summary

Introduction

Left atrial catheter ablation leading to electrical pulmonary vein isolation (PVI) is a corner stone therapy for patients with symptomatic atrial fibrillation (AF). PVI targets and eliminates potential electrical triggers of AF located inside the pulmonary veins (PVs). Clinically apparent stroke is a fatal complication of this procedure with an incidence of up to 1% [1]. Silent cerebral embolism (SCE) measured by diffusion-weighted MRI (DWIMRI) has been shown to be a clinically unapparent thromboembolic complication following PVI [2,3,4]. Occurrence of SCE has been linked to different ablation strategies, whereby the pulmonary vein ablation catheter (PVAC) technology seemed to provoke the highest incidence of new DWI lesions [2,3,4,5,6]

Methods

Discussion

Conclusion