SPC365

Is PFA Ready for Atypical Atrial Flutter?

Session: Sessão de Posters 05 - Ablação por campo pulsado: da viabilidade à fisiologia
Speaker: Inês Coutinho dos Santos

Congress: CPC 2026
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Session Type: Posters Eletrónicos
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Authors: Samuel Azevedo; Inês Coutinho Santos; Daniel Gomes; Daniel Matos; Gustavo Rodrigues; João Carmo; Francisco Moscoso Costa; Pedro Galvão Santos; Pedro Carmo; Diogo Cavaco; Francisco Bello Morgado; Pedro Pulido Adragão
<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Background:</span></span></strong><br />
<span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Pulsed field ablation (PFA) has emerged as a non-thermal modality with high tissue selectivity and favorable acute safety in the treatment of atypical atrial flutter (AAF). Although PFA is hypothesized to improve acute procedural outcomes due to its rapid and homogeneous lesion formation, its long-term performance compared with radiofrequency (RF) ablation remains uncertain. </span></span><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Experimental and clinical observations suggest that reduced acute collateral and myocardial injury with PFA may paradoxically lead to incomplete substrate modification and higher arrhythmic recurrence over time.</span></span></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Methods:</span></span></strong><br />
<span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">We retrospectively analyzed 98 consecutive patients who underwent catheter ablation for AAF between January 2023 and September 2025. Baseline characteristics included age, sex, CHA2DS2-VASc score, LVEF, CT-derived left atrial volume index (LAV</span></span><span style="font-family:&quot;Times New Roman&quot;,serif">I<span style="color:black">), and history of prior AF ablation. Patients were treated with RF (n=60, 61%), PFA (n=35, 36%), or a combination of both (n=3, 3%). Acute success was defined as termination of the clinical flutter during ablation </span>and<span style="color:black"> non-inducibility of atrial arrhythmias at the end of the procedure. Long-term recurrence was defined as documented AAF or AF on ECG</span> or <span style="color:black">Holter monitoring</span> during follow-up<span style="color:black">. Median follow-up was 13 </span>(6-21)<span style="color:black"> months.</span></span></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Results:</span></span></strong><br />
<span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Mean age was 69 &plusmn; 13 years, 47% were female, the mean CHA2DS2-VASc score was 3 &plusmn; 1, and the CT-LAV</span></span><span style="font-family:&quot;Times New Roman&quot;,serif">I<span style="color:black"> was 67 &plusmn; 20 mL/m&sup2;. Regarding ablation lesion sets, 33% of lines were delivered for pulmonary vein isolation, </span>24<span style="color:black">% targeted the posterior wall, 27% corresponded to a mitral isthmus line, and </span>16<span style="color:black">% were performed at other atrial sites. Acute procedural success was numerically higher with PFA compared with RF (90% vs 83%), although this difference did not reach statistical significance (p = 0.397). Of t</span>he total procedures, 24 (24,5%) were redo radiofrequency ablations. During follow-up, the outcome of interest occurred in 34 (34,7%) patients. In the mid-term<span style="color:black">, PFA was independently associated with a significantly higher risk of arrhythmi</span>a<span style="color:black"> recurrence compared with RF </span>(<span style="color:black">HR 2.62, 95% CI 1.31&ndash;5.26, p = 0.007).</span></span></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Conclusions:</span></span></strong><br />
<span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">In this contemporary cohort of </span></span><span style="font-family:&quot;Times New Roman&quot;,serif">AAF<span style="color:black">, approximately one-third of patients experienced arrhythmia recurrence. Although acute success was numerically higher with PFA, mid-term recurrence rates were greater in th</span>is<span style="color:black"> group. This pattern may reflect the reversible or retractile characteristics of acute PFA lesions, which could limit long-term substrate modification. These results highlight the need to refine PFA lesion strategies in complex atrial arrhythmias and underscore the importance of prospective evaluation of long-term lesion durability.</span></span></span></span></span></p>