SPC365

Long term prognosis of idiopathic ventricular arrhythmias: an eighteen-year experience from a tertiary center

Session: Sessão Melhores Comunicações Orais
Speaker: Cátia Oliveira

Congress: CPC 2024
Topic: P. Other
Theme: 37. Miscellanea
Subtheme: 08.3 Ventricular Arrhythmias and SCD - Diagnostic Methods
Session Type: Comunicações Orais
FP Number: ---
Authors: Cátia Oliveira; Ana Pinho; Luís Santos; Ricardo Pinto; Sílvia Oliveira; Helena Moreira; Miguel Rocha; Pedro Palma; Gonçalo Pestana; Marta Madeira; Ana Lebreiro; Luís Adão
<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><strong><span style="font-size:11.0pt">Introduction:&nbsp;</span></strong><span style="font-size:11.0pt">Idiopathic ventricular arrhythmia&nbsp;(IVA) <span style="background-color:white">is diagnosed in patients (pts) who survived sudden cardiac death (SCD) due to&nbsp;ventricular fibrillation (VF) or&nbsp;</span></span></span></span><span style="color:#000000; font-size:11pt">pulseless ventricular tachycardia (pVT)</span><span style="color:#000000"><span style="font-size:12pt"><span style="font-size:11.0pt"><span style="background-color:white">&nbsp;without any identifiable structural or electrical cause after extensive investigation. </span>The exact incidence of IVA&nbsp;is unknown but is declining with the advance of diagnostic testing and identification of primary arrhythmic&nbsp;syndromes, but current evidence still provides limited guidance on the diagnosis and follow-up of these pts.&nbsp;</span></span></span><span style="color:#000000; font-size:11pt">Our aim was to assess the clinical outcomes of survivors of an aborted&nbsp;SCD&nbsp;attributed to IVA.</span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><strong><span style="font-size:11.0pt">Methods: </span></strong><span style="font-size:11.0pt">We retrospectively collected clinical and technical data of a&nbsp;sample of pts who survived IVA and implanted a&nbsp;cardiac defibrillator (ICD)&nbsp;between 2005 and 2023. Median&nbsp;follow-up time was 5 years.</span></span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><strong><span style="font-size:11.0pt">Results:</span></strong><span style="font-size:11.0pt"> A total of 38 pts, 36.8% female, with a mean age of 44&plusmn;14&nbsp;years-old at the time of&nbsp;aborted SCD were included. The type of ICD implanted was:&nbsp;64.9% transvenous single chamber, 21.6% dual chamber and 13.5% subcutaneous. Upon medical arrival, the initial&nbsp;rhythm was VF in 73.7%&nbsp;and pVT in 26.3%. SCD ocurred during daily life activities in&nbsp;52.9%, 17.6% at rest, 11.8% during emotional stress, 11.8% during exercise and 5.9% while asleep. Of note, 13.9% of&nbsp;pts&nbsp;had a previous history of syncope and 15.8% had family history of SCD. Normal ECG was present in 72.2% of pts. </span></span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><span style="font-size:11.0pt">All&nbsp;pts underwent a comprehensive diagnostic evaluation, including invasive/noninvasive coronary angiogram and echocardiogram (all pts), cardiac magnetic resonance (78.6%), genetic testing (37.2%), electrophysiology study (18.4%), pharmacological provocative test (13.5%)&nbsp;and endomyocardial biopsy (2.6%).</span></span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><span style="font-size:11.0pt">During long-term follow-up, a diagnosis was established in 34.2% of pts. Specifically, 3 events were attributed to coronary vasospasm,&nbsp;3 to short coupled polymorphic VT, 3 to long QT syndrome, 2 with Brugada syndrome, 1 to&nbsp;arrhythmogenic cardiomyopathy, and in 1 patient an ANK2 mutation was identified. Genetic testing improved the diagnosis and allowed identification of a clinical entity in 47.1% of pts&nbsp;(p=0.04, OR=4.7).</span></span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><span style="font-size:11.0pt">Concerning clinical outcomes, 5.3% pts died (all due to non-arrhythmic causes) and 36.4% received appropriate therapies (Fig&nbsp;1) with a median&nbsp;time to first shock of 33&nbsp;(IQR 11.4-43.2)&nbsp;months. Also, 13,9% experienced inappropriate shocks (60%&nbsp;sinus tachycardia&nbsp;and&nbsp;40%&nbsp;supraventricular tachycardias).</span></span></span></span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="color:#000000"><span style="font-size:12pt"><strong><span style="font-size:11.0pt">Conclusion: </span></strong><span style="font-size:11.0pt">Etiological diagnosis and&nbsp;recurrence prediction in pts with IVA&nbsp;poses considerable challenges, even with extensive diagnostic evaluation and&nbsp;long-term follow-up. Our study reveals that genetic testing played a crucial role in enhancing the diagnostic yield. Consistent with previous findings, our cohort experienced a notable&nbsp;arrhythmic recurrence&nbsp;in about&nbsp;one-third of pts, with no&nbsp;cardiac deaths. These results underline&nbsp;the pivotal role of ICD implantation in&nbsp;these pts.</span></span></span></span></p>