Next-generation sequencing increases the diagnostic yield in aborted sudden cardiac death caused by hereditary heart disease   Brøndberg AK1, Christiansen MK1, Thorsen K2 Pedersen LN2, Jensen HK1 1 Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark 2 Department of Molecular Medicine (MOMA), Aarhus University Hospital, Denmark Methods Purpose Sudden cardiac death (SCD) in young adults is often caused by inherited heart disease. Until now the genetic diagnostic tools in patients with SCD or survivors after cardiac arrest have targeted the presumed phenotype which often can be difficult to define. We aimed to overcome these limitations by applying next-generation sequencing (NGS) to a cohort of non-ischemic aborted SCD victims. Patient selection We identified all patients ≤50 years of age with an Implantable cardioverter defibrillator (ICD) received at Aarhus University Hospital from 1999 to 2013 (n=433). Data was extracted from the Danish Pacemaker and ICD registry. All patients with unexplained ventricular tachycardia (VT), ventricular fibrillation (VF) or recurrent malignant syncope were study candidates. Eighty (78%) of eligible patients participated in the study. Figure 1, Flow diagram showing patient selection. Figure 2, Diagram showing genetic analysis work flow. Results Median age (IQR) at the time of ICD implantation was 38 (30:43). The most frequent symptom at disease onset was VF, followed by VT and recurrent malignant syncope of which 7 were inducible to ventricular arrhythmia with an electro-physiological study (EPS) (table 1). Seventeen (21%) participants were found to have a possible rare pathogenic gene variant. In 63 (79%) participants we did not find any significant genetic variants. Conclusion NGS considerably increases the number of molecular-genetic diagnoses in patients with aborted SCD. However, a great number of VUS complicates the clinical interpretation. Correspondence: Anders Krogh Brøndberg, MD, anders.kragh@clin.au.dk