Ischemic Cardiomyopathy (ICM) 

1. Definition

Ischemic cardiomyopathy (ICM) is a subtype of heart failure due to chronic myocardial ischemia or infarction leading to left ventricular systolic dysfunction (LVEF ≤40%), typically in the setting of coronary artery disease.

• It is not just prior MI, but a remodeling disease driven by:
• Repeated ischemia
• Infarct scar formation
• Hibernating myocardium

2. Epidemiology

• Most common cause of heart failure worldwide
• Responsible for:
• ~60–70% of HFrEF cases in developed countries
• High prevalence in:
• Diabetes
• Hypertension
• Elderly males

3. Pathophysiology 

A. Initial Trigger

• Atherosclerotic plaque → coronary stenosis → ↓ perfusion
• Acute plaque rupture → MI → myocardial necrosis

B. Myocardial Consequences

1. Infarction → Scar Formation

• Replacement fibrosis
• Non-contractile myocardium
• Regional wall motion abnormality

2. Hibernating Myocardium 

• Chronically underperfused myocardium
• Reduced function but viable
• Improves after revascularization

3. Stunning

• Transient LV dysfunction after ischemia despite reperfusion

C. Ventricular Remodeling

• LV dilation
• Spherical geometry
• Increased wall stress (Laplace law)
• Secondary MR

 Neurohormonal activation:

• RAAS
• SNS
• ADH

→ Leads to progressive HF

4. Structural & Functional Changes

5. Clinical Features

A. Symptoms

• Dyspnea (most common)
• Orthopnea, PND
• Fatigue
• Angina (may be absent in advanced disease)

B. Signs

• S3 gallop
• Displaced apex
• Pulmonary crepitations
• Peripheral edema

C. Red Flags

• Sudden cardiac death
• Ventricular arrhythmias

6. Diagnosis

A. Confirm HF + Reduced EF

• Echocardiography:
• EF ≤40%
• Regional wall motion abnormality → suggests ischemic cause

B. Demonstrate Ischemic Etiology

1. Coronary Imaging

• Gold standard: Coronary angiography
• CT coronary angiography in selected patients

2. Viability Assessment 

• Viable myocardium → benefit from revascularization

C. Differentiate from Non-Ischemic Cardiomyopathy

7. Management (ESC 2023 / AHA 2022)

“Management of ischemic cardiomyopathy includes guideline-directed medical therapy for HFrEF PLUS revascularization and anti-ischemic therapy where indicated.”

A. Foundational Quadruple Therapy

• ARNI (preferred) / ACEi / ARB
• Beta-blocker (Carvedilol, Bisoprolol, Metoprolol succinate)
• MRA (Spironolactone / Eplerenone)
• SGLT2 inhibitors (Dapagliflozin / Empagliflozin)

B. Revascularization  Indications:

• Significant CAD
• Viable myocardium
• Angina or large ischemic burden

Options:

• PCI
• CABG (preferred in multivessel disease)

 Evidence:STICH trial → CABG improves survival in ICM

 In non-ischemic cardiomyopathy → no role of revascularization

C. Anti-Ischemic Therapy

• Antiplatelets (aspirin ± P2Y12 if indicated)
• High-intensity statins
• Nitrates (for angina)
• Risk factor control (DM, HTN, smoking)

D. Viability-Guided Strategy

• If myocardium is viable → revascularize
• If scarred → focus on GDMT + devices