Introduction
Creating of sustainable ablation lesions is the key for successful chronic pulmonary vein isolation using RF-Ablation. For this purpose, different objective parameter like the impedance drop, reduction in unipolar und bipolar voltage, the force time integral or the ablation index (AI) were established 1,2. In this context, the ablation index (AI, Biosense Webster Inc), combining RF power, ablation-time, contact force, and catheter stability in a weighted, non-linear formula, was well validated in the close protocol in a prospective outcome trial 3,4. An ablation index between 400 and 550 in dependence of the anatomical location has been developed as standard of care, enabling reliable and reproducible pulmonary vein isolation (PVI) as described by Taghji and Duytschaever et al in the CLOSE protocol 4,5. However, there is an ongoing discussion regarding the optimal RF power to achieve the required AI in the most effective and safest way. While conventional PVI is commonly performed using 20-30W on the thin posterior atrial wall in proximity to the oesophagus to avoid thermal injury, 30-40W are used on the thicker anterior wall and atrial roof. However, there is growing evidence that high power short duration energy application (HPSD) relying on the ablation index might be as efficient, safe, and durable, whilst shortening procedure time 6,7.
Here, we thought to compare the standard energy delivery with an ablation protocol of fixed high power 50W setting, both for circumferential PVI as well as additional lesion sets, guided by AI and the close-protocol to achieve durable PVI.