Primary Prevention of SCD in Patients With NICM Recommendations for Primary Prevention of SCD in Patients With NICM References that support the recommendations are summarized in Online Data Supplements 27 and 28. COR LOE Recommendations I A In patients with NICM, HF with NYHA class II III symptoms and an LVEF of 35% or less, despite GDMT, an ICD is recommended if meaningful survival of greater than 1 year is IIa B-NR In patients with NICM due to a Lamin A/C mutation who have 2 or more risk factors (NSVT, LVEF <45%, nonmissense mutation, and male sex), an ICD can be beneficial if meaningful survival of greater than 1 year is IIb B-R In patients with NICM, HF with NYHA class I symptoms and an LVEF of 35% or less, despite GDMT, an ICD may be considered if meaningful survival of greater than 1 year is III: No Benefit C-EO In patients with medication-refractory NYHA class IV HF who are not also candidates for cardiac transplantation, an LVAD, or a CRT defibrillator that incorporates both pacing and defibrillation capabilities, an ICD should not be implanted. Recommendation-Specific Supportive Text 1. For all patients with NICM, it is imperative that patients be on GDMT for HF for at least 3 months before a primary prevention ICD is offered. Four initially evaluated ICDs for primary prevention of SCD in patients with NICM. TwoS7.2.2-2,S7.2.2-6 were small studies that were terminated early due to a low event rate. In DEFINITE,S7.2.2-5 an ICD reduced the risk of SCD, with a trend toward reduced all- cause mortality. SCD-HeFT included 792 NICM Total mortality at 5 years was 27% in the placebo group and 21% in the ICD group (P=0.06). 