Applicability of the AHA/ACC/HRS guideline for implantable cardioverter defibrillator implantation in Japanese patients with cardiac sarcoidosis
Authors: Takenaka S , Kobayashi Y , Nagai T , Kato Y , Komoriyama H , Nagano N , Kamiya K , Konishi T , Sato T , Omote K , Tada A , Iwano H , Kusano K , Ishibashi-Ueda H , Anzai T 
Published: October 2021

Abstract

Background
Sarcoidosis is a systemic granulomatous disease that affects multiple organs. Cardiac involvement is a key determinant of poor clinical outcomes in the patients with sarcoidosis, as it causes congestive heart failure, conduction abnormalities, ventricular tachycardia and fibrillation (VT/VF), and sudden cardiac death (SCD). Although implantable cardioverter defibrillators (ICDs) are used to prevent SCD from VT/VF in patients with cardiac sarcoidosis (CS), the generalizability of the AHA/ACC/HRS guidelines for the Japanese CS patients remains unclear.

Purpose
We aimed to assess, among Japanese patients with CS, the ICD recommendations from the 2017 AHA/ACC/HRS Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death.

Methods
We examined 188 consecutive patients with CS in two tertiary hospitals between 1979 and 2020. The primary outcome was defined as a composite outcome involving SCD or ventricular arrhythmic events. Ventricular arrhythmic events were defined as either emergency treatment for VF or sustained VT, which included appropriate ICD therapy.

Results
During a median follow-up period of 5.68 (IQR: 4.87–6.70) years, the primary outcome occurred in 44 patients (23%), which included 6 cases of SCD and 38 cases of VT/VF. ICD implant was indicated based on left ventricular ejection fraction (LVEF) of ≤35% (class I recommendation) in 62 patients, with an annualized event rate of 3.93%. A LVEF of &gt;35% with a need for a permanent pacemaker (class IIa recommendation) was observed for 53 patients, with an annualized event rate of 2.54%. A LVEF of &gt;35% with late gadolinium enhancement (LGE) during cardiovascular magnetic resonance (class IIa recommendation) was observed for 62 patients, with an annualized event rate of 2.38% (Figure A). Kaplan-Meier analyses revealed that patients with a class I recommendation for ICD implantation had a significant higher incidence of the primary outcome, compared to patients with a class IIa recommendation and patients with no indication for ICD implantation (P=0.03). However, there were no significant differences in the incidence of the primary outcome between patients with a LVEF of &gt;35% and a need for a permanent pacemaker and patients with a class I recommendation (P=0.08) or patients with a LVEF of ≤35% (P=0.31). Moreover, there was no significant difference in the incidence of the primary outcome between patients with a LVEF of &gt;35% and LGE on cardiovascular magnetic resonance and patients with a class I recommendation (P=0.054) or patients with a LVEF of ≤35% (P=0.22) (Figure B).

Conclusions
The American guideline recommendations for ICD implantation might be applicable to Japanese patients with CS. Implantation of an ICD may need to be considered in these patients if they require a permanent pacemaker or have LGE, regardless of LVEF.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science