What is heart failure?

From the Guidelines

Heart failure is a complex clinical syndrome that results from structural or functional impairment of ventricular filling or ejection of blood, leading to symptoms such as dyspnea, fatigue, and fluid retention. This condition may result from disorders of the pericardium, myocardium, endocardium, heart valves, or great vessels, or from metabolic abnormalities, but most patients have symptoms resulting from impaired left ventricular myocardial function 1.

Key Characteristics of Heart Failure

• It is a chronic condition that typically worsens over time
• It can lead to reduced exercise tolerance and quality of life if not properly managed
• The main symptoms include shortness of breath, fatigue, swelling in the legs and ankles, and rapid or irregular heartbeat
• It is typically managed with medications and lifestyle changes, such as limiting salt intake, restricting fluid intake, and regular exercise

Stages of Heart Failure

The American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) have developed guidelines on the diagnosis and treatment of heart failure, which are based on four progressive stages of heart failure 1.

• Stage A includes patients at risk of heart failure who are asymptomatic and do not have structural heart disease
• Stage B describes those with structural heart disease who do not have signs or symptoms of heart failure
• Stage C describes patients with structural heart disease who are currently symptomatic or have a history of heart failure symptoms
• Stage D describes patients with refractory heart failure who require specialized interventions Treatment of heart failure should focus on reducing modifiable risk factors, such as management of hypertension and hyperlipidemia, and using medications like ACE inhibitors and beta blockers in patients with stage B or C heart failure who have a reduced ejection fraction 1.

Management of Heart Failure

• Patients with stage C heart failure and fluid retention should be treated with diuretics in addition to ACE inhibitors and beta blockers
• Lifestyle changes, such as limiting salt intake to less than 2,000mg daily, restricting fluid intake, and regular moderate exercise, are crucial in managing heart failure
• Regular follow-up with healthcare providers is essential to adjust treatment as needed and improve symptoms and quality of life 1.

From the FDA Drug Label

PARADIGM-HF was a multinational, randomized, double-blind trial comparing sacubitril and valsartan and enalapril in 8,442 adult patients with symptomatic chronic heart failure (NYHA class II to IV) and systolic dysfunction (left ventricular ejection fraction ≤40%) The FDA drug label describes heart failure as a condition characterized by:

• Symptomatic chronic heart failure
• NYHA class II to IV
• Systolic dysfunction (left ventricular ejection fraction ≤40%) 2 2

From the Research

Definition of Heart Failure

• Heart failure is a clinical condition with high mortality and morbidity that occurs when the heart is unable to pump enough blood to meet the metabolic demands of the body 3.
• It is a syndrome requiring urgent, life-saving treatment, with multiple specific pathophysiologic mechanisms involved, including congestion, inflammation, and neurohormonal activation 4.
• Heart failure can be caused by various factors, including myocardial infarction, increased preload or afterload, and can lead to cellular, structural, and neurohumoral modulations that affect the phenotype of the disease 5.

Types of Heart Failure

• Heart failure can be classified into different types, including heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) 4.
• HFrEF is characterized by left ventricular systolic dysfunction, while HFpEF is characterized by preserved left ventricular systolic function 4.

Pathophysiology of Heart Failure

• The pathophysiology of heart failure involves the activation of the sympathoadrenergic and renin-angiotensin-aldosterone-system, leading to adaptive mechanisms that can worsen the condition 5.
• The activation of these systems can lead to volume overload, tachycardia, dyspnea, and further deterioration of cellular function, creating a vicious circle 5.
• The level of neurohormones, such as norepinephrine, and natriuretic peptides, such as NT-pro BNP, can increase as a measure of cellular dysfunction 5.

Diagnosis and Treatment of Heart Failure

• The diagnosis of heart failure can be made using noninvasive and invasive diagnostic procedures, including echocardiography, NMR, NT-proBNP, heart catheterization, and biopsy 5.
• The treatment of heart failure can involve pharmacologic agents, such as ACE inhibitors, beta blockers, and ARNI, which can improve outcome and symptoms in patients with left ventricular dysfunction 6, 5.
• Interventional and surgical therapy options may also be performed in some cases 5.
• The use of beta blockers has been shown to reduce morbidity and mortality in patients with heart failure when used with an angiotensin converting enzyme inhibitor (ACEI) and a diuretic 7.