Heart Failure: A Review

Heart failure is a chronic condition that develops when the heart muscle is unable to pump enough blood to meet the body's needs for oxygen and nutrients1. This can lead to a variety of symptoms, such as shortness of breath, fatigue, and swelling in the legs and ankles2. Heart failure is a serious condition that can damage the liver or kidneys3. While there is usually no cure, early diagnosis and treatment are essential for improving quality of life and potentially slowing disease progression1.

Types of Heart Failure

Heart failure is often a progressive condition, meaning it gradually worsens over time1. Initially, the body attempts to compensate for the heart's reduced pumping ability. The heart may enlarge, develop more muscle mass, and pump faster in an effort to maintain adequate blood flow1. However, these compensatory mechanisms can eventually contribute to further heart damage and worsening symptoms.

Heart failure can be classified in several ways:

• Acute vs. Chronic: Heart failure can be acute, developing suddenly, or chronic, developing gradually over time3.
• Left-sided vs. Right-sided: Heart failure can affect the left side of the heart, the right side, or both. Left-sided heart failure, where the left ventricle cannot pump enough blood to the body, is more common4. In right-sided heart failure, the right ventricle cannot pump enough blood to the lungs5. Heart failure often begins with the lower left heart chamber, called the left ventricle5.

Symptoms of Heart Failure

Common symptoms of heart failure include: 2

• Shortness of breath during daily activities
• Trouble breathing when lying down
• Weight gain with swelling in the feet, legs, ankles, or stomach
• Generally feeling tired or weak

Medications Used to Treat Heart Failure

A variety of medications are used to manage heart failure and improve the heart's ability to pump blood. These medications work in different ways and are often used in combination.

Angiotensin-Converting Enzyme (ACE) Inhibitors and Angiotensin II Receptor Blockers (ARBs)

ACE inhibitors and ARBs are common medications for heart failure. They work by blocking the renin-angiotensin-aldosterone system (RAAS), a hormone system that regulates blood pressure and fluid balance6. By blocking the RAAS, these medications help to lower blood pressure and reduce fluid buildup in the body.

ACE inhibitors include: 7

• Enalapril
• Lisinopril
• Captopril

ARBs include: 7

• Losartan
• Valsartan
• Candesartan

Angiotensin Receptor-Neprilysin Inhibitors (ARNIs)

ARNIs are a newer class of heart failure medications that combine an ARB with a neprilysin inhibitor. Sacubitril-valsartan (Entresto) is an example of an ARNI7. It is used to treat certain types of heart failure and may help prevent hospitalizations.

Beta Blockers

Beta blockers work by blocking the effects of adrenaline and noradrenaline, hormones that can increase heart rate and blood pressure6. By blocking these hormones, beta blockers help to slow the heart rate and reduce the workload on the heart.

Examples of beta blockers used in heart failure include: 7

• Carvedilol
• Metoprolol
• Bisoprolol

Diuretics

Diuretics, often called water pills, help the body get rid of excess fluid by increasing urine production6. This can reduce swelling and shortness of breath. Diuretics are often used in combination with other heart failure medications7.

An example of a diuretic commonly used in heart failure is furosemide7.

SGLT2 Inhibitors

SGLT2 inhibitors are a newer class of medications that were initially developed to treat type 2 diabetes. However, they have also been shown to be effective in treating heart failure, even in people without diabetes7. SGLT2 inhibitors help lower blood sugar and have been shown to reduce the risk of hospitalization and death in individuals with heart failure.

Examples of SGLT2 inhibitors include: 7

• Canagliflozin
• Dapagliflozin
• Empagliflozin

Other Medications

Other medications that may be used to treat heart failure include: 7

• Digoxin (Lanoxin): This medication helps the heart squeeze better to pump blood and also tends to slow the heartbeat.
• Hydralazine and isosorbide dinitrate (BiDil): This combination of medicines helps relax blood vessels and may be used in people with severe heart failure symptoms when ACE inhibitors or beta blockers haven't been effective.
• Vericiguat (Verquvo): This medication is taken once a day and has been shown to reduce hospitalizations for heart failure.

Contraindications of Heart Failure Medications

Heart failure medications can have contraindications, which are situations where the medication should not be used due to potential risks. It's crucial to discuss your medical history and any other medications you are taking with your doctor to ensure the safe and appropriate use of heart failure medications.

Some common contraindications include:

• ACE inhibitors and ARBs: A history of angioedema (swelling of the face, lips, tongue, or throat), kidney problems, or high potassium levels8.
• Beta blockers: A slow heart rate, low blood pressure, or asthma9.
• Diuretics: While diuretics can be helpful for fluid management in some individuals with kidney problems, careful monitoring and selection of the appropriate type of diuretic are essential7.

Potential Drug Interactions

It's important to be aware of potential drug interactions when taking heart failure medications. These interactions can occur between different heart failure medications, as well as with other drugs and supplements.

Some potential drug interactions include: 10

• ACE inhibitors and ARBs: Should not be taken together.
• NSAIDs (e.g., ibuprofen): Can reduce the effectiveness of some heart failure medications and increase the risk of side effects.
• Grapefruit juice: Can interfere with the metabolism of some heart failure medications, potentially leading to increased drug levels and side effects.
• Certain supplements (e.g., St. John's Wort, ginseng): May interact with heart failure medications.

Side Effects of Heart Failure Medications

Heart failure medications can cause side effects, although not everyone experiences them. It's important to discuss any side effects with your doctor, as they may be able to adjust your medication or offer strategies to manage them.