Beta-Blockers For Heart Failure

Introduction

Heart Failure, also known as congestive heart failure, is a long-term condition that occurs when the heart cannot work properly and isn’t pumping blood as well as it should. When this happens, it means that you’re not getting enough oxygen which will affect how your body works by causing some intolerable symptoms including difficulty breathing.

Unfortunately, there is currently no cure for heart failure, but there are some treatments that your doctor can prescribe to help manage the symptoms and improve your quality of life. 

One of the treatments that your doctor may prescribe to you is called beta-blockers, sometimes written as β-blockers. It is usually given as a part of a treatment plan with other medications.

Understanding heart failure

Causes and risk factors

Heart failure occurs when the heart is weakened, stiffened, or damaged and can’t pump enough blood to the rest of the body. These changes can be caused by different reasons such as infections, heavy alcohol use and some medications, which means that most patients may be at risk if they have high blood pressure or other serious heart conditions.¹

Symptoms of heart failure

When heart failure occurs, it means that the body is not getting enough oxygen to let it work properly, which affects your breathing and other muscle-related activities that need oxygen to function.¹ This results in the symptoms seen in patients with heart failure such as:

• Breathlessness (when you’re active and sometimes even at rest)
• Feeling more tired, such that you find doing exercises becomes too hard
• Swelling on both ankles
• Fainting or feeling lightheaded
• Dizziness
• Feeling like your heart is racing
• Cough with phlegm that doesn’t clear by itself and has lasted more than 3 weeks.

Impact on quality of life

Patients with heart failure tend to experience serious symptoms which can limit daily physical and social activities and can lead to an increased risk of being hospitalised for a long time, or even worse, death.²

Role of beta-blockers

Mechanism of action

Beta-blockers, sometimes written as β-blockers, are one of the medications used to manage heart failure. 

They work by blocking the receptor sites that are responsible for part of the body's fight-or-flight response, thereby  suppressing the function of certain parts of the body or organs. Three types of beta-receptors (also spelt β-receptors) become activated in the fight-or-flight response to support the body’s functions– β1, β2 and β3 receptors.  β1-receptors are mainly found in the heart and the kidneys. β2-receptors are found mainly in the lungs, gastrointestinal tract, liver, and muscles. β3-receptors are found in fat cells.³

In heart failure, beta-blockers help by slowing the heart rate and reducing the oxygen demand of the heart.

Benefits of heart failure management

There is currently no cure for heart failure but the symptoms can be controlled for as long as possible.¹

Some of the benefits include:

• Improvement in your heart function
• Reducing the intolerable symptoms
• Improving your life expectancy
• Improved exercise tolerance
• Reducing the need for long hospitalisation.

Types of beta-blockers

Some beta-blockers work by blocking the activation of all types of β-receptors and others are more selective for one of the three known types of beta-receptors.

Selective vs. non-selective beta-blockers

Beta-blockers are classified as either non-selective or β1 selective. The non-selectives bind to both β1 and β2 receptors and cause a blocking effect via both receptors. Common non-selective beta-blockers include propranolol, carvedilol, sotalol, and labetalol. 

Selective beta-blockers like atenolol, bisoprolol, metoprolol, and nebivolol only bind to the β1 receptors which are mostly found in the heart and are therefore known as cardio-selective.⁴

Commonly prescribed beta-blockers for heart failure

There have been loads of studies that have shown the good effects of beta-blockers, particularly carvedilol, nebivolol, and bisoprolol, in congestive heart failure.⁵ Therefore, your GP will likely prescribe one of them according to the NICE guidelines as part of your management and treatment plan.

Initiating beta-blocker therapy

Patient evaluation and selection

Some studies found that beta-blockers may worsen the symptoms if not managed properly, therefore beta-blockers will likely only be started on patients whose conditions are stable.

However, you should speak to your doctor or heart failure team for advice if you experience a worsening of symptoms such as tiredness, weight gain, or breathlessness.⁶

Starting with low doses

If you’ll be taking beta-blockers, you will be started with low doses at first which will then be increased slowly until the target dose, or your highest tolerated dose is reached. 

You might experience a temporary worsening of your symptoms at the start, but these symptoms may likely improve slowly over 3–6 months. For further information, see Self-care Advice.

Therefore, it is important to know not to stop taking your beta-blockers without speaking to your doctor.⁷

Titration and monitoring

Table 1: Recommended doses of beta-blockers for heart failure

Considerations and precautions

Contraindications

NICE guidelines advised that beta-blockers should not be prescribed to people with:

• Asthma or Chronic Obstructive Pulmonary Disease (COPD). This is because the cardio-selective beta-blockers only act on β1-receptors which are not present in the lungs.⁹
• Acute or chronic bradycardia and/or hypotension. This means people with a heart rate of less than 60 beats per minute (bradycardia) and/or systolic blood pressure of less than 90 mmHg (hypotension).⁹
• Raynaud phenomenon should avoid beta-blockers due to the risk of making the symptoms worse.¹⁰

Specific beta-blockers can also be contraindicated depending on the patient's past medical history:

• Patients previously with Long QT syndrome should not use the drug Sotalol.¹¹
• Bisoprolol and carvedilol are not recommended during pregnancy and breastfeeding. If prescribed, it is advised that carvedilol treatment should be stopped 2–3 days before the expected birth if possible.⁹

Potential side effects

Beta-receptors are found all over the body, which means that the blockade of these receptors with beta-blocker medications can cause some side effects. 

Bradycardia and hypotension are the two most common side effects. Other side effects that have been reported by patients taking beta-blockers include fatigue, dizziness, nausea, constipation, and sexual dysfunction.⁹

Interactions with other medications

Some of the common drug interactions of beta-blockers include:

• Drugs used for high blood pressure such as amlodipine and nitrates due to the risk of causing hypotension which can worsen heart failure.
• Digoxin because it can reduce your heart rate
• Verapamil and Diltiazem because of the risk of causing bradycardia, severe hypotension, and heart failure. It is important to discuss this with your specialist if you are taking these tablets or if you will be prescribed these medications.
• Insulin and/or other oral antidiabetic drugs due to the risk of masking of symptoms of hypoglycaemia.⁹

Monitoring and follow-up

Regular check-ups with healthcare providers

The use of beta-blockers in heart failure offers a lot of benefits but they also carry the risk of causing serious side-effects if not monitored properly.

Therefore, they should only be started by your doctor or specialist team as they can monitor your titration regimen and identify what your maximum tolerated dose is. 

This explains the need for a mix of healthcare professionals including specialist consultants and nurses to prescribe, manage, and monitor the use of beta-blockers to ensure that they are safe and effective for you.

Some of the things they might examine include your heart rate and blood pressure to check for any signs of bradycardia and heart block, hypotension, and sudden death.¹⁰

Summary

Heart failure is a life-threatening condition that can affect your quality of life. Although there’s no cure for heart failure, there are treatments available to help reduce your symptoms and improve your quality of life. 

One of the treatments that your doctor may prescribe is beta-blockers, a group of medications that work by blocking the beta-receptors that are present all over the body. These blockade effects can in turn cause some side effects for patients taking beta-blockers, therefore your specialist team will have a monitoring plan with you after your diagnosis.

As such, beta-blockers are contraindicated in certain groups of patients as they might make the symptoms worse.

You must discuss any worsening of your symptoms or any concerns that you may have with your doctor and specialist team as they are well-suited to give you advice and support about your condition.