Heart Failure

Heart failure is a progressive condition that occurs when the heart is not able to fully fill with blood and/or pump blood effectively. It is also known as “congestive heart failure”. The American College of Cardiology and American Heart Association have jointly identified four stages of heart failure. Stage A (at risk for HF) and stage B (pre-HF) occur when the heart begins to structurally and functionally change without symptoms. Most people are diagnosed with heart failure when the disease has progressed to stages C (symptomatic HF), when symptoms start to occur, or D (advanced HF).^[1] The most common risk factors for heart failure are metabolic syndrome, obesity, coronary artery disease, and hypertension.

Heart failure symptoms occur at stages C and D, while heart failure stage A and B are asymptomatic.^[1] Symptoms in stages C and D can include:^[2]

• Shortness of breath/coughing when lying down or with activity
• Fatigue and weakness
• Frequent urination
• Chest pain and palpitations (rapid or irregular heartbeat)
• Swelling of the lower legs and fluid retention
• Nausea and poor appetite
• Anxiety

Heart failure is diagnosed when structural and functional changes to the heart are suspected due to risk factors, symptoms, physical exam, and medical history. The diagnosis is confirmed with an echocardiogram (ultrasound of the heart). Laboratory tests (e.g., serum B-type natriuretic peptide) and electrocardiogram can be used to characterize the degree of heart failure. After HF is diagnosed, it is then further classified based on severity and type. The two main types, which often have different causes, are: HF with reduced ejection fraction (HFrEF), in which the heart can’t squeeze with enough force to push out all the blood, and HF with preserved ejection fraction (HFpEF), in which the heart can’t fully relax to be filled with enough blood to supply the body.^[2][1]

In recent years, there have been some major advances in medical treatments which improve the trajectory and symptoms of heart failure. For example, treatments for HF with reduced ejection fraction include a combination of sodium-glucose cotransporter-2 inhibitors (SGLT2i - commonly used drugs for diabetes), angiotensin receptor/neprilysin inhibitors (ARNi), certain beta-blockers, mineralocorticoid receptor antagonists (MRA), and as needed diuretics. Treatments for HF with preserved ejection fraction involves ensuring that conditions such as hypertension, atrial fibrillation, and diabetes are well controlled.^{[2] [1]}

Depending on the cause of HF, implantation of electrical devices may be required to either synchronize the chambers of the heart (atria and ventricles) or to defibrillate (shock) the heart in the event of a ventricular arrhythmia. Although relatively uncommon, cardiac transplantation or the use of a mechanical pump for circulatory support may be considered in end-stage HF.

Some supplements studied for heart failure include coenzyme Q10, vitamin D, iron, L-carnitine, thiamine, and other B vitamins. For most supplements, evidence of benefit is very limited. However, for coenzyme Q10, a meta-analysis of 7 clinical studies in about 1800 participants with heart failure found that it may slightly reduce the risk of mortality compared to control.^[3] In contrast, taking vitamin E has been linked with increased heart failure hospitalizations compared to control.^[4]

For those at risk for heart failure (stage A), plant-based diets such as the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet — which emphasize the intake of whole grains, fruits, vegetables, and legumes — can help prevent the development of heart failure. Also, following a diet with reduced salt (sodium) intake can help to prevent the development of heart failure in those at risk, and may reduce mortality in people with stages B–D heart failure.^[3][4]

Maintaining normal body weight has been shown to be effective for preventing the development of heart failure. There is strong evidence that bariatric surgery in severely obese persons is beneficial for prevention of HF, as well as reducing symptoms and hospitalizations in those with existing heart failure. There is strong evidence showing the benefit of exercise for heart failure, while only weak evidence suggests that mind-body modalities like mindfulness and tai chi are beneficial.^[4]

Chronic congestive heart failure is caused by abnormal structural and functional changes to the heart and a number of triggering factors. Most commonly, heart failure is caused by coronary artery disease (CAD) and heart attack,^[2] which lead to an initial injury to the heart and numerous downstream effects. Other triggering factors of heart failure include:^[2]

• Arrhythmia (uncontrolled)
• Myocarditis (inflammation of the heart caused by infection or autoimmune disease)
• Cardiomyopathy
• Chronic obstructive pulmonary disease (COPD)
• Congenital heart disease
• Diabetes
• Endocarditis
• Heart valve diseases
• Hypertension
• Obesity
• Pulmonary embolism (blood clot in the lungs)