PO-03-232 PROGNOSTIC IMPACT OF NON-SUSTAINED VENTRICULAR TACHYCARDIA IN WILD-TYPE TRANSTHYRETIN CARDIAC AMYLOIDOSIS

Abstract

Non-sustained ventricular tachycardia (NSVT) detected on rhythm monitoring is common in AL amyloidosis, but data on its prevalence and prognostic impact in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) are sparse. To investigate the prevalence of NSVT detected during clinically-indicated ambulatory Holter monitoring and its association with incident sustained VT and ventricular fibrillation (VF) in ATTRwt-CA patients. A single-center retrospective cohort of ATTRwt-CA patients without known history of sustained VT/VF was included (2011-2022). The presence and characteristics of NSVT (≥3 beats) at the first Holter after the ATTRwt-CA diagnosis at our institution were documented. The endpoint was the first occurrence of sustained VT or VF recorded by an implantable cardioverter-defibrillator (ICD) or other methods (in patients without ICD), and it was comparatively assessed in patients with and without NSVT with Kaplan-Meier analysis. Multivariate Cox regression analyses using stepwise variable selection were also performed to identify predictors of incident VT/VF. A total of 219 patients with ATTRwt-CA were included (mean age 74.9 years; 95% males; mean LVEF 52%). Of them, 8 had an ICD at baseline while 14 underwent ICD implantation within a 6-month window from baseline. Mean Holter monitoring duration was 25.6 hours and 53% of patients had at least one NSVT run at index Holter monitor with mean total ventricular ectopy burden 3.8%. After mean follow up 35.2 months, 17 patients experienced the primary outcome. Patients with NSVT had a lower survival free of VT/VF compared to those without NSVT (log-rank p=0.01; figure). In multivariable analysis, the presence of NSVT (HR 3.95, 95% CI 1.10-14.0) and the number of NSVT runs (HR 1.003, 95% 1.00-1.01, per run) were significant predictors of future VT/VF. NSVT is highly prevalent among patients with ATTRwt-CA and confers an increased risk of incident sustained ventricular arrhythmias. This finding has implications in the risk stratification and decision-making for the prevention of sudden cardiac death in these patients.