PVAC for AF patients linked to higher risk for embolic events
MedWire News: The multielectrode phased conventional radiofrequency (RF) pulmonary vein ablation catheter (PVAC) is associated with a significantly higher rate of subclinical intracranial embolic events than alternative ablation techniques, say researchers.
"Improvement in PVAC technology and further studies to clarify the origin of these embolic lesions are mandatory to reduce the rate of silent embolisms during ablation procedures in the left atrium," write Claudia Siklódy (Herz-Zentrum, Bad Krozingen, Germany) and co-authors.
The technique of performing pulmonary vein isolation (PVI) with a conventional RF ablation catheter is effective but technically demanding, they say. Recently, two new techniques have been approved as an alternative: the cryoballoon and PVAC.
Following the publication of data comparing the efficacy of the new techniques with the conventional method, Siklódy and team decided to compare their relative safeties.
The multicenter study included 74 patients: 27 in the conventional RF group, 23 in the cryoballoon group (Arctic Front; Medtronic, Minneapolis, Minnesota, USA), and 24 in the PVAC group (Medtronic Ablation Frontiers, Carlsbad, California, USA).
Overall, the conventional RF procedure was the longest, at 198 minutes versus 174 min for the cryoballoon, and 124 min for the PVAC procedure (p<0.001 for PVAC vs the cryoballoon and RF groups).
Magnetic resonance imaging conducted 1 day before ablation and 1-2 days afterwards detected a single new embolic lesion in two (7.4%) of the patients in the conventional RF group, and in one (4.3%) of the cryoballoon patients.
However, the number of new embolic lesions was much higher in the PVAC group, with an average of 2.7 new lesions each detected in nine (37.5%) patients (p=0.003 for presence of new embolic events among the three groups).
"Further study of the causes and significance of these emboli is required to determine the safety of the PVAC," conclude the authors.
In a related commentary, editorialists Jonathan Steinberg and Suneet Mittal (Columbia University, New York, USA) said, "the findings in this study are startling."
They added: "The inequality of distribution of events among the different ablation techniques strongly suggests that testing be part of the regulatory process before a new device or system reaches the market."
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By Piriya Mahendra