SPC365

Reducing Recurrence, Enhancing Success: The Role of Substrate Modification in Atrial Fibrillation Redo Procedures

Session: SESSÃO DE POSTERS 41 - ABLAÇÃO DE FIBRILHAÇÃO AURICULAR
Speaker: Nuno Alexandre Dias Madruga

Congress: CPC 2025
Topic: C. Arrhythmias and Device Therapy
Theme: 05. Atrial Fibrillation
Subtheme: 05.4 Atrial Fibrillation - Treatment
Session Type: Cartazes
FP Number: ---
Authors: Nuno Madruga; Miguel Azaredo Raposo; João Fonseca; Ana Abrantes; Rita Leal; Joana Brito; Afonso Nunes Ferreira; Gustavo Lima da Silva; Luís Carpinteiro; Nuno Cortez-Dias; Fausto J. Pinto; João de Sousa

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><strong>Introduction</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">:&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">Strategies for increasing atrial fibrillation (AF) redo procedures success are a matter of ongoing debate. Although pulmonary vein isolation (PVI) remains the cornerstone of AF ablation its long-term efficacy is unsatisfactory. In patients with extensive left atrium low-voltage areas (LVA) performing ablation targeting substrate areas may be of added value.</span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><strong>Purpose</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">:&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">To characterize a population with left atrium LVA and investigate the effectiveness of additional substrate modification in AF redo procedures.&nbsp;</span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><strong>Methods</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">:&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">Retrospective, single-center, study with patients were submitted to AF redo ablation from 2015 to 2024, with evidence of left atrium LVA beyond PVs. High-density electroanatomic systems were used to collect substrate and activation mapping (Ensite, Rhythmia, Carto). Substrate modification through linear lesions or scar homogenization were performed based on operator discretion. Survival analysis with Kaplan-Meier curves and log-rank test were performed to evaluate the time to AF recurrence.</span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><strong>Results</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">:&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">From a total of 231 patients submitted to AF redo, 79 had evidence of LVA. Patients had median age of 70 years (y), 54% male and 57% had paroxysmal AF. The majority of patients did not have structural heart disease and the median left atrial (LA) indexed volume and left ventricular ejection fraction were 39mL/m</span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><sup>2</sup></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"> and 57%, respectively. Considering the entire study population, LVA was more frequent in females (47% vs 25%, odds ratio 2.662, 95% confidence interval [CI]: 1.530-4.630, p&lt;0.001) and older patients (67 vs 59y, p&lt;0.001). In the redo procedure, 32% of patients had persistence of PVI. LVA were most commonly identified in the anterior wall (63%), followed by posterior wall (38%) and roof (35%) of LA. Substrate modification beyond PVI was performed in 64/79 patients (81%). During a mean follow-up time of 3.4y, the recurrence rate of AF was 49%. Patients who were submitted to additional substrate modification had a longer time to AF recurrence, although it did not reach statistical significance (hazard ratio 0.547, 95% CI: 0.271-1.103, p=0.09).&nbsp;&nbsp;</span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000"><strong>Conclusion</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">:&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos"><span style="color:#000000">In this population submitted to AF redo ablation, the presence of LVA was common, particularly in older and female patients. Performing additional substrate modification showed a trend towards higher procedural success, with longer time to AF recurrence. Further research is needed to determine the role of LVA-targeted interventions in improving long-term outcomes in AF patients</span></span></span></p>