What is the primary treatment for a patient with dilated cardiomyopathy?

Primary Treatment for Dilated Cardiomyopathy

All patients with dilated cardiomyopathy and reduced ejection fraction should immediately receive quadruple guideline-directed medical therapy consisting of ACE inhibitors (or ARBs), beta-blockers, mineralocorticoid receptor antagonists, and SGLT2 inhibitors, which together can reduce mortality by up to 73% over 2 years. 1, 2

Foundational Pharmacological Therapy

ACE Inhibitors or Angiotensin Receptor Blockers

• ACE inhibitors are recommended as first-line therapy for all patients with current or prior symptoms of heart failure and reduced left ventricular ejection fraction (LVEF), unless contraindicated. 3
• Start at low doses and uptitrate every 2 weeks to target or maximally tolerated doses. 1, 4
• ARBs are recommended for patients who are ACE inhibitor-intolerant. 3
• The American Heart Association emphasizes that ACE inhibitors/ARBs significantly reduce mortality and morbidity in DCM patients. 1

Beta-Blockers

• One of three beta-blockers proven to reduce mortality (bisoprolol, carvedilol, or sustained-release metoprolol succinate) is recommended for all stable patients with current or prior symptoms of heart failure and reduced LVEF. 3
• Start at very low doses and uptitrate gradually to avoid initial decompensation. 4
• Beta-blockers should be used in conjunction with ACE inhibitors/ARBs for optimal neurohormonal antagonism. 1

Mineralocorticoid Receptor Antagonists (MRAs)

• MRAs are indicated in all symptomatic heart failure patients with LVEF ≤35%. 4
• These agents are beneficial in patients with symptomatic heart failure and reduced ejection fraction. 1
• MRAs are an essential component of triple therapy that significantly reduces mortality. 2

SGLT2 Inhibitors

• SGLT2 inhibitors should be included as the fourth agent in quadruple therapy regimen for all heart failure with reduced ejection fraction patients, regardless of diabetes status. 1, 4, 2
• These provide additional mortality benefit beyond traditional triple therapy. 2

Diuretic Therapy for Volume Management

• Diuretics and salt restriction are indicated in patients with current or prior symptoms of heart failure and reduced LVEF who have evidence of fluid retention. 3
• Loop diuretics (furosemide 20-40 mg once or twice daily, bumetanide 0.5-1.0 mg once or twice, or torsemide 10-20 mg once) are preferred for volume overload. 3
• Thiazide diuretics or sequential nephron blockade (combining metolazone with loop diuretics) may be used for refractory fluid retention. 3

Device Therapy Considerations

Implantable Cardioverter-Defibrillator (ICD)

• An ICD is recommended as secondary prevention in patients with current or prior symptoms of heart failure and reduced LVEF who have a history of cardiac arrest, ventricular fibrillation, or hemodynamically destabilizing ventricular tachycardia. 3
• ICD therapy is recommended for primary prevention of sudden cardiac death in patients with non-ischemic dilated cardiomyopathy who have symptomatic heart failure (NYHA class II-III) and ejection fraction ≤35% despite ≥3 months of optimal pharmacological therapy, with reasonable expectation of survival with good functional status for more than 1 year. 3
• Pooled analysis demonstrates a 31% reduction in all-cause mortality with ICD therapy relative to medical therapy alone. 3
• ICD should be considered in patients with DCM and confirmed disease-causing LMNA mutation with clinical risk factors. 3, 1

Cardiac Resynchronization Therapy (CRT)

• CRT should be considered in DCM patients with left bundle branch block (LBBB) and LVEF <50%, especially when LBBB may be contributing to cardiomyopathy. 1, 2
• CRT is particularly beneficial in patients with LVEF ≤35%, NYHA class II-IV symptoms, and LBBB with QRS ≥150 ms. 4

Medications to Avoid

Drugs known to adversely affect clinical status should be avoided or withdrawn whenever possible, including: 3

• Nonsteroidal anti-inflammatory drugs
• Most antiarrhythmic drugs (except amiodarone in specific circumstances)
• Most calcium channel blocking drugs (particularly dihydropyridines)
• Cardiac myosin inhibitors in patients who develop persistent systolic dysfunction (LVEF <50%). 1

Management of Arrhythmias

• Catheter ablation is recommended for bundle branch re-entry ventricular tachycardia refractory to medical therapy. 3, 1, 2
• Amiodarone should be considered in patients with an ICD who experience recurrent appropriate shocks despite optimal device programming. 3, 1, 2
• Amiodarone is NOT recommended for treatment of asymptomatic non-sustained ventricular tachycardia in DCM patients. 3
• Sodium channel blockers and dronedarone are NOT recommended due to potential pro-arrhythmic effects. 3

Exercise and Lifestyle Modifications

• Exercise training is beneficial as an adjunctive approach to improve clinical status in ambulatory patients with current or prior symptoms of heart failure and reduced LVEF. 3
• Salt restriction should be implemented in all patients with evidence of fluid retention. 3

Monitoring Strategy

• Regular assessment of cardiac function is essential, including clinical assessment every 3-6 months, repeat echocardiography at 3-6 months to assess response to therapy, and BNP monitoring to assess disease progression. 1, 4
• Parameters to monitor include symptoms, volume status, vital signs, laboratory results (electrolytes, renal function), and cardiac function. 4

Advanced Heart Failure Management

• Patients with nonobstructive DCM and advanced heart failure should be assessed for heart transplantation or mechanical circulatory support. 1, 2
• Continuous-flow left ventricular assist device therapy is reasonable as a bridge to heart transplantation in appropriate candidates. 1, 2
• Heart transplantation is recommended for children with severe end-stage heart failure from DCM refractory to treatment. 3

Critical Pitfalls to Avoid

The most significant gap in DCM management is underuse and underdosing of guideline-directed medical therapy—less than one-quarter of eligible patients receive all components of therapy concurrently. 1

• Medications should be uptitrated in small increments to target doses unless contraindicated, not stopped at low doses. 1, 2
• Avoid excessive diuresis leading to hypotension and hypovolemia. 3
• Do not delay device therapy in eligible patients—ICD placement should occur after at least 3 months of optimal medical therapy if LVEF remains ≤35%. 3

Poor Prognostic Indicators Requiring Aggressive Management

Patients with the following features require intensified monitoring and consideration for advanced therapies: 1, 2

• Severe LV and RV enlargement and dysfunction
• Persistent S3 gallop or right-sided heart failure
• Moderate to severe mitral regurgitation
• Pulmonary hypertension
• Left bundle branch block on ECG
• Recurrent ventricular tachycardia
• Elevated BNP levels
• Peak oxygen consumption <10-12 mL·kg⁻¹·min⁻¹
• Serum sodium <137 mmol/L