Primary prevention implantable cardioverter-defibrillator use in non-ischemic dilated cardiomyopathy based on arrhythmic risk stratification and left ventricular reverse remodeling prediction

Abstract

Sudden cardiac death (SCD) and significant ventricular arrhythmias in patients with dilated cardiomyopathy (DCM) have been markedly reduced over the last couple of decades as a result of the advances in pharmacological and non-pharmacological treatment. Primary prevention implantable cardioverter-defibrillator (ICD) plays an important role in the treatment of patients at risk of SCD caused by ventricular arrhythmias. However, the arrhythmic risk stratification in patients with DCM remains extremely challenging, and the decision for primary prevention ICD implantation based on left ventricular ejection fraction (LVEF) solely appears to be insufficient. This review provides an update on current evidence for primary prevention ICD implantation, arrhythmic risk stratification, and left ventricular reverse remodeling (LVRR) prediction in patients with DCM in addition to most recent guideline recommendations for primary prevention ICD implantation in DCM patients and a proposed multiparametric algorithm based on arrhythmic risk stratification and left ventricular reverse remodeling (LVRR) prediction to better identify patients who are likely to benefit from primary prevention ICD.

Keywords: Implantable cardioverter defibrillator; Non-ischemic dilated cardiomyopathy; Sudden cardiac death.

Fig. 1

Parameters that have been shown to predict arrhythmic risk in patients with DCM

Fig. 2

Integrated LVEF- and LGE-based algorithm proposed by Di Marco and his colleagues for arrhythmic risk stratification ⁴⁴. LGE − : LGE negative; LGE + : LGE-positive. High risk LGE distribution: epicardial LGE, transmural LGE, or combined septal and free-wall LGE

Fig. 3

Proposed algorithm for timing and patient selection for primary prevention ICD implantation among patients with DCM. a Special population: advanced renal dysfunction/dialysis, elderly/pediatric, class I/IV heart failure, and adult congenital heart. b GDMT: ACEI/ARNI, BB, MRA, and SGLT2i. c High-risk features: positive LGE with high-risk LGE distributions on CMR, confirmed LMNA, RBM20, PLN, and FLN mutation with two or more risk factors (NSVT during ambulatory ECG monitoring, LVEF < 45% at first evaluation, male sex, and non-missense mutations (insertion, deletion, truncations, or mutations affecting splicing)). d Predictors of LVRR: narrow QRS complex, absence of LGE, hypertension, absence of FH of DCM, absence of symptoms or symptom duration of less than 3 months, and absence of LMNA gene variants. e Regular follow-up (clinical + ECG + Holter + Echo) is recommended during this waiting period