Invasive risk stratification and implantable loop recorders in brugada syndrome: a single centre experience

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Risk stratification in Brugada syndrome (BrS) is challenging. Cardiogenic syncope, family history of sudden cardiac death and ECG markers are useful variables in determining patient risk. Invasive risk stratification is sometimes needed in those with an intermediate risk phenotype. Implantable loop recorders (ILR) may be considered in those patients with no inducible ventricular arrythmias during programmed ventricular stimulation (PVS). Objective The aim of this study was to retrospectively evaluate the outcome of BrS patients referred for PVS and ILR implantation. Methodology Demographic, clinical and follow-up data of BrS patients seen in clinic were retrospectively analysed from hospital databases. A p vale of <0.05 was considered significant. Results 129 patients have been diagnosed with BrS since launching the inherited arrhythmia clinic service (53.5% males). 15 (high risk patients) had an ICD (n=13, 10.1%) or PM (n=2, 1.6%) implanted because of a hospital cardiac arrest, ventricular arrhythmias, high grade AV Block or cardiogenic syncope. 26 (20.2%) were placed in the intermediate risk category, (65.4% males). Patients were offered an electrophysiology study (EPS/PVS) or an ILR depending on the clinical indication (Figure 1). Most were male (65.4%), with a mean age of 41.8±17.7 years at the time of risk stratification. 6 had a likely or definite pathogenic mutation (n=5 19.2% SCN5A, n=1 3.8% MYBPC3). This group had a median Shanghai score of 4.0±0.9. Gender (p=0.429), age (p=0.246), genotype (p=0.273) and shanghai score (p=0.746) did not differ between strategies. Most (n=12, 9.3%) were offered an EPS/PVS from the offset. Ventricular arrhythmias were induced in 1 (8.3%), an ICD was then implanted. The rest were implanted with an ILR on the day. Patients not offered an EPS (n=14, 10.9%) were initially implanted with an ILR because of insufficient grounds to proceed with an EP study. Patients with an ILR (n=25, 19.4%) were followed up for a median 39 ± 21 months. ILR monitoring identified actionable events in 3 (12.0%) patients. One (4.0%) needed a pacemaker for sick sinus syndrome. Two (8.0%) recorded non-sustained ventricular arrhythmias. Both were subjected to an EPS/PVS, one needed an ICD. None of the patients who had an EPS initially had any significant events during follow up. Conclusion ILR implantation has a role in risk stratifying intermediate risk patients who do not fulfil criteria for EPS referral. This may also be considered in intermediate risk patients who are not keen on an invasive risk assessment with EPS.