Comparative Effectiveness of Prophylactic ICD Versus Non-ICD Therapy

Eligibility Criteria

• * Age ≥ 18 years (no upper limit)
• * Class I or IIa indication for a primary prevention ICD15: Ischemic or non-ischemic cardiomyopathy and NYHA Class ≥ II if most recent LVEF is ≤ 35% OR ischemic cardiomyopathy with NYHA Class I if most recent LVEF is ≤ 30%
• * Most recent LVEF (%) obtained per cardiac imaging obtained at any time prior to enrollment after being stable on optimal GDMT\*\* for at least one month
• * Stable optimal GDMT at least one calendar month prior to last cardiac imaging test, prespecified as one of the following for at least 1 calendar month prior to study randomization:
• * Existing ICD/CRT-D
• * • Planned CRT-P or CRT-D implant for any indications including Class I or IIa indication for CRT: Presence of left bundle branch block (LBBB) with QRS ≥ 120 msec OR QRS duration ≥ 150 msec regardless of QRS morphology OR decision for CRT implant by EP provider for other indications
• * Acute MI within the past 3 calendar months
• * Chronic renal failure requiring hemodialysis
• * Coronary revascularization within the past 3 calendar months
• * History of sustained VT or VF
• * Known genetic cause of cardiomyopathy
• * Life expectancy \< 1 year
• * Unable or unwilling to follow study protocol
• * Inability to consent