Abstract 16465: Mode of Death and Outcomes of Implantable Cardioverter Defibrillators in Transthyretin Cardiac Amyloidosis

Abstract

Introduction: Patients with transthyretin cardiac amyloidosis (ATTR-CM) may have higher risk of sudden cardiac death yet the role of implantable cardioverter defibrillators (ICD) remains poorly defined. We report our experience with ICDs in a cohort with ATTR-CM. Methods: A single center observational cohort study of patients who had been seen at our Amyloidosis Center with either wild-type or hereditary ATTR-CM diagnosed between 2005-2019. ICD implant was at discretion of treating cardiologists. Device data was obtained from record review. Results: Ninety-seven patients with ATTR-CM (mean age 71.4±11 years, 89.7% male) had mean follow-up 2.2±1.9 years. Twenty-one patients (21.6%) got ICD - 19 for primary prevention and 2 for secondary prevention - with cumulative 137 interrogations over mean 2.0±2.7 years of device follow-up. In patients with primary prevention ICD, 1 patient got 2 inappropriate shocks - both for 1 episode of atrial flutter in the VT therapy zone; 1 patient got appropriate ATP on 3 occasions. In those with secondary prevention ICD, 1 patient got 15 appropriate shocks for 3 discrete episodes of VT storm; the other got ATP for 1 episode of monomorphic VT. In patients without ICD, 101 ambulatory monitors were reviewed (cumulative 12,313 hours) without sustained ventricular arrhythmia. In this group, 13/76 met at least a class IIB criterion for ICD per current guidelines. EF was higher in those without ICD versus with primary prevention ICD (45.0±13.9 vs 33.4±15.1 %, p=<0.01). Death was seen with similar frequency in those with primary prevention ICD and those without ICD (p=0.60) and mode of death did not vary between them (Table 1). Conclusions: Patients with ATTR-CM and primary prevention ICD have low rates of appropriate device therapy without differing in mode of death compared to those with no ICD. Use of ICD for secondary prevention was uncommon but all patients got appropriate device therapy. Further study on ICDs in ATTR-CM is needed to inform best care.