Comparative Effectiveness of Prophylactic ICD Versus Non-ICD Therapy

Inclusion Criteria:

• Age ≥ 18 years (no upper limit)

• Class I or IIa indication for a primary prevention ICD15: Ischemic or non-ischemiccardiomyopathy and NYHA Class ≥ II if most recent LVEF is ≤ 35% OR ischemiccardiomyopathy with NYHA Class I if most recent LVEF is ≤ 30%

• Most recent LVEF (%) obtained per cardiac imaging obtained at any time prior toenrollment 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 studyrandomization:

receiving all 4 therapy classes (beta-blockers, ARNI/ARB/ACE, MRA and SGLT2i) OR GDMT Score ≥ 6 (per Figure 7)

• MADIT-ICD Benefit Score < 50 (per Figure 4)

Exclusion Criteria:

• Existing ICD/CRT-D

• • Planned CRT-P or CRT-D implant for any indications including Class I or IIaindication for CRT: Presence of left bundle branch block (LBBB) with QRS ≥ 120 msecOR QRS duration ≥ 150 msec regardless of QRS morphology OR decision for CRT implantby 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