The Relevance of Preventive Implantable Cardioverter-Defibrillators (ICDs) in Non-Ischemic Cardiomyopathy in the Presence of Effective Quadruple Therapy for Heart Failure: A Review of Contemporary Medical Literature

• Published in: Curēus (Palo Alto, CA) Vol. 15; no. 4; p. e38268
• Main Authors: Obi, Mukosolu F, Namireddy, Vikhyath, Reinberg Palmar, Maria A, Sharma, Manjari, Gulas, Jennifer A
• Format: Journal Article
• Language: English
• Published: United States Cureus Inc 28-04-2023; Cureus
• Subjects: Beta blockers; Cardiac arrhythmia; Cardiology; Cardiomyopathy; Cardiovascular disease; Classification; Comorbidity; Disease prevention; Ejection fraction; Enzymes; Health Policy; Heart failure; Internal Medicine; Literature reviews; Medical prognosis; Mortality; Pacemakers; Patients; New York; United States > US; heart failure; ischemic dilated cardiomyopathy; cardiac sudden death; guideline directed medical therapy; implantable cardioverter-defibrillator (icd)
• ISSN: 2168-8184; 2168-8184
• DOI: 10.7759/cureus.38268

Cardiomyopathy is a disease of the cardiomyocytes that affects their structural function, leading to heart failure (HF). Non-ischemic cardiomyopathy (NICM) includes a subtype of dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), and hypertrophic cardiomyopathy (HCM). These types of cardiomyopathies have no coronary artery vessel involvement. The most common cause of NICM is DCM. In the ischemic cardiomyopathy (ICM) subtype, the utilization of implantable cardioverter-defibrillators (ICDs) has been effective in the prevention of sudden cardiac death (SCD). However, the relevance of ICDs in patients with NICM having an ejection fraction (EF) ≤35%, who are also receiving effective quadruple therapy (i.e., angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 (SGLT2) inhibitors) for HF has been a topic of debate. The purpose of this review is to analyze the benefits of preventive ICDs in NICM patients on adequate quadruple therapy for HF. The current guidelines recommend ICD implantation in patients with NICM who have a left ventricular ejection fraction of ≤35%, come under the New York Heart Association (NYHA) class II or III, and are in sinus rhythm with optimal medical therapy. The evidence supporting this recommendation is limited. Numerous clinical studies and meta-analyses have been conducted to look into this issue. While some have discovered a substantial decrease in mortality with the implantation of an ICD in patients with NICM, others have not found significant changes. Thereby, further investigations are required to define the function of ICDs in this population.