SPC365

Not a cold success – efficacy of cryoablation

Session: Prémio Jovem Investigador
Speaker: Beatriz Valente Silva

Congress: CPC 2021
Topic: C. Arrhythmias and Device Therapy
Theme: 05. Atrial Fibrillation
Subtheme: 05.4 Atrial Fibrillation - Treatment
Session Type: Prémios
FP Number: ---
Authors: Beatriz Silva ; Tiago Rodrigues; Nelson Cunha; Pedro Silvério António; Sara Couto Pereira; Pedro Alves da Silva; Joana Brito; Catarina Oliveira; Beatriz Garcia; Margarida Martins; Afonso Ferreira; Nuno Cortez-Dias; Fausto J.Pinto; João de Sousa
<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><strong>Introduction:&nbsp;</strong></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">Atrial fibrillation (AF) is the most common supraventricular arrhythmia with a considerable burden in healthcare. Evidence supporting rhythm control is growing and cryoablation has been gaining ground over traditional point-to-point (PtP) ablation procedures. Predictors of relapse after cryoablation are not completely established.</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><strong>Purpose:</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">To evaluate the efficacy of cryoablation and determine factors that might explain the risk of relapse.</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><strong>Methods:</strong></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">Single centre prospective study evaluating AF patients (pts) refractory to antiarrhythmic therapy who performed the first AF ablation procedure. The ablation strategy consisted of pulmonary vein isolation (PVI), complemented with ablation of the cavo-tricuspid isthmus in patients with a history of concomitant flutter. Pts were monitored with Holter/7-day event loop recorders (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (&gt; 30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation.</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><strong>Results:</strong></span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">We analyzed 232 pts submitted to cryoablation (68.1% male, 59.57&plusmn;12.39 years old) with a mean follow-up 927,9 &plusmn; 847,3 days.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">Hypertension was present in 65.9% pts, 15.5% had structural cardiomyopathy and 24.8% had a history of obstructive sleep apnea (OSA). Mean CHADsVAsc was 2 and mean left atrium indexed volume was 41,02 &plusmn; 2,67mL</span></span></span><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><sup>2</sup></span></span></span><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">.&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">The success rate at one year and three years were 89.6% and 87.6%, respectively. Twenty-one patients had supraventricular arrhythmia relapse after one year and 25 after three years of follow-up. In those who underwent additional REDO procedures, the success rate rose to 95.5% and only 9 patients had relapsed after one year.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">After the procedure, 30.2% patients suspended anti-arrhythmic drugs, and it is noteworthy that it was not a factor contributing to relapse. In the general population, hypertension was linked to increased risk of relapse (p=0.043), though other factors, such as diabetes, obesity or OSA, did not seem to increase the risk.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">A group sub-analysis to determine the risk of relapse showed that CHADsVASc score, age, sex and left atrium indexed volume were non-predictors of supraventricular arrhythmia relapse rate.&nbsp;</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000"><strong>Conclusions:</strong></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Cambria,serif"><span style="color:#000000">Our analysis showed that cryoablation is an effective procedure with very high rates of success after one and three years. Regarding the risk of relapse, hypertension was identified as increasing the risk, unlike other factors, supporting the importance of cardiovascular risk factors control after the procedure.&nbsp;</span></span></span></p>