Pulmonary vein isolation lesions plus personalised methods shows promising results

PVI+ strategies, which use pulmonary vein isolation (PVI) with additional personalised methods, showed promising results in first single-centre studies for some of these methods [1]. Confirmation from randomised, multicentre studies is pending.

PVI is the standard of care for paroxysmal atrial fibrillation (AF). The innovation in this field mainly focuses on lesion durability and improved energy sources. Recent clinical trials have shown an >80% success rate at 1 year [2-4]. However, in persistent AF, PVI is not particularly effective and non-PV drivers as mechanisms for persistent AF are postulated.

To approach these non-PV targets, several PVI+ ablation strategies have been developed: an anatomical approach including linear lesions, ganglionic plexi ablation, and non-PV trigger ablation or isolation, and, with significant overlap, a targeted approach including ganglionic plexi ablation, non-PV trigger ablation or isolation, and locally-guided ablation. Dr Tom De Potter (Cardiovascular Research Center Aalst, Belgium) provided an overview of the clinical evidence of these approaches [1].

Linear lesions are the most well studied of these approaches and most of the related single-centre studies show a trend towards benefit. However, a recent, large, multicentre, randomised study showed that PVI alone was not inferior to PVI plus linear lesions [5]. More recently, ablation shifted towards posterior wall isolation, which is achievable in most cases with a low procedural risk and good 12-month outcomes as shown by a retrospective meta-analysis. However, statistical analysis of randomised clinical trials did not show superiority of PVI+ posterior wall isolation [6].

Percutaneous linear cryoablation is another strategy to facilitate Cox-maze-like lesions. To evaluate the safety and efficacy of this method, a first-in-man study (NCT02839304) has been conducted. Results showed an 84% success rate after 12 months in patients with paroxysmal AF and a similarly good efficacy of 82% success rate with a good safety profile in patients with persistent AF (n=60). Dr De Potter also introduced anatomical alcohol ablation, for which benefit over PVI has been suggested, and left atrial appendage isolation, for which no results are available yet [7-9].

Targeted ablation focuses on a leading circle concept with multiple or random re-entrant wavelets, which can be observed in real-time. Different approaches have been published for targeted ablation. For example, using atrial mapping, panoramic non-invasive and invasive mapping. Several mapping systems are currently being researched [10], confirmation of efficacy in a randomised trial is not available yet.

Dr de Potter emphasised the inter-patient variability in AF and significant inter-observer variability in target identification. Machine learning could be of high potential to enhance target identification, i.e. pattern recognition algorithms may overcome interpretation issues [11].

In conclusion, non-PV ablation targets are of significant interest not only for the very large persistent AF population but also for the heart failure population and in patients with recurrent AF after PVI. Randomised clinical trials are available, ongoing, or planned for anatomical and targeted PVI+ strategies [11].

1. 
   
   1. De Potter T. Strategies beyond pulmonary vein isolation lesions. EHRA 2021 Congress, 23-25 April.
   2. Nielsen JC, et al. Heart 2017:103(5):368-376.
   3. Kaba RA, et al. Clob Card Sci Pract 2014(2):53-55.
   4. Duytschaever M, et al. Eur Heart J 2018:39(16):1429-1437.
   5. Terricabras M, et al. JAMA Netw Open 2020: 3(12):e2025473.
   6. Thiyagarajah A, et al. Circ Arrhythm EP 2019:12:e007005.
   7. Derval N, et al. Hearth Rhythm 2021:18:529-537.
   8. Velderrabano M, et al. JAMA 2020:324:1620-1628.
   9. Romero J, et al. Europace 2018:20(8):1268-1278.
   10. Tomassoni G, JACC Clin EP 2017:3(3):217-219.
   11. De Potter T, et al. Hearth Rhythm 2017:14:5:173.

 

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Posted on 16 June, 2021