Ablation vs Medication for Atrial Fibrillation: what is the gold standard?

Atrial Fibrillation (AF) is the most common abnormal rhythm with over a million people being affected in the UK. AF remains undiagnosed in some as it has not been ‘caught’ on an ECG or does not cause symptoms in some.

AF is characterised by irregular activity at the top of the heart and there is good evidence that this arises from the pulmonary veins, close to where they enter the heart. The pulmonary veins carry blood from the lungs to the top left chamber of the heart, the left atrium. We do not know why AF occurs but we do recognise associations and are good at treating it.

AF is not a dangerous, life-threatening rhythm. However, symptoms can be problematic in some and there is the associated risk of stroke in some.

Symptoms can include palpitations, breathlessness and lethargy. Some people can feel dizzy and rarely, some may ‘pass out’.

There are a variety of options and these are considered as management of both:

• Heart rate or rhythm
• Stroke risk

Treatment of AF also includes to ‘do nothing’.

In addition, any reversible causes should be addressed. These are rarer but may include an overactive thyroid, consumption of alcohol or energy drinks.

Control of associated conditions warrant attention too. Examples are high blood pressure, increased weight (specifically raised body mass index which considers weight and height) and valve disease.

It is important to discuss the best personalised approach for you with your consultant.

Let us consider each in turn.

Heart Rate

Atrial fibrillation is an abnormal heart rhythm. With this rhythm, the heart rate may be normal, fast or even slow.

A sustained fast heart rate is not desirable. In order to control this, medication can be considered and these are beta blockers or calcium channel blockers. Sometimes additional medication is required to control heart rate in AF.

These medications are well tolerated and act to slow overall heart rate. Beta blockers and calcium channel blockers can also control blood pressure.

Where this approach is adopted, AF remains and a faster heart rate is controlled.

Heart Rhythm

This involves restoration of a normal rhythm and its maintenance (hopefully)

• Medication
• Catheter ablation
• Direct current cardioversion (DCCV or ‘cardioversion’)

Medication

The medications to control heart rhythm act to:

1. Prevent episodes of AF where this comes and goes (paroxysmal AF). This is often combined with a rate slowing medication. For paroxysmal AF, medication can be advised regularly or ‘Pill in pocket’ where it is taken as needed.
2. Maintain sinus rhythm in those with AF all of the time (persistent AF) where sinus rhythm is being restored. The most common medication used in this scenario is not recommended for a younger population indefinitely due to side effects that occur years after it has been commenced. Long term side effects can include liver and lung scarring, thyroid dysfunction, small deposits on the cornea of the eye, rashes in the sunlight. It is useful and acceptable in these scenarios:

• In persistent AF, for a few months, around the time of ablation to maintain a normal rhythm
• Following DCCV (cardioversion) in the octogenarian population indefinitely to maintain sinus rhythm

Catheter Ablation

Catheter Ablation is a definitive treatment for AF meaning that it allows long-term restoration of sinus rhythm.

Catheter ablation is generally for symptoms, although there may be other scenarios where we advise this.

This is a procedure whereby we enter the heart from the groin and commonly freeze (cryoablation) or burn (radiofrequency ablation) a region of the heart, close to the pulmonary veins that trigger AF. Ablation causes scar tissue to form thus providing a barrier preventing electrical impulses (that is, AF) entering the heart from the pulmonary veins.

It can be performed as a day case with local anaesthetic and sedation or indeed a general anaesthetic.

As with all procedures, it does come with a risk profile, albeit small. These include bruising or bleeding at the top of the leg, blood into the sac around the heart that requires draining, stroke and heart attack, temporary damage to the phrenic nerve. There are also some rarer risks. Great care is taken to avoid or mitigate such risks. For more information on the risks of ablation, read this article.

There is a chance of needing more than one procedure dependent of a variety of factors.

DCCV (Direct Current Cardioversion)

This is a shock delivered to the heart where AF is present all of the time to restore sinus rhythm. On its own, it is not a treatment. It is used in the following scenarios:

• To understand if there is symptom improvement in a normal rhythm with a view to performing catheter ablation if there is. Some symptoms associated with AF can be insidious and so a DCCV acts as a test.
• Together with amiodarone in an older population for long term maintenance of sinus rhythm.

AF contributes 1 in 5 strokes in the UK and may be the first presentation of AF.

Stroke risk is managed with a blood thinner, otherwise known as anticoagulation. Direct Oral Anticoagulants (DOACs) are used of which there are many. An alternative anticoagulant is utilised if there is increased weight.

There is a scoring system, the CHA2DS2VASc score, which helps us to understand whether anticoagulation is warranted. The CHA2DS2VASc score considers:

• C - Congestive heart failure; this is where the heart muscle does not pump effectively
• H - Hypertension or high blood pressure
• A2 - Age over 75 years
• D - Type II diabetes mellitus
• S2 - Stroke/TIA (transient ischaemic attack or ‘mini stroke’)/thromboembolism history
• V - Vascular disease history (prior MI, peripheral artery disease, or aortic plaque)
• A - Age over 65 years
• Sc - Female gender

Each factor gives a score of 1 except those demarcated with ‘2’. Those who score zero, do not need anticoagulation, unless they are undertaking ablation where it is given for some time before and after ablation.  Female gender does not give a point on its own; another factor must be present too.

Aspirin does not manage stroke risk with AF.

There is not enough evidence to suggest that maintenance of sinus rhythm mitigates stroke risk and therefore, anticoagulation continues for life (unless the CHA2DS2VASc score is zero).

It is really very important to discuss matters with your cardiologist. An overview is useful to understand but treatment should be personalised.

This is because there are many considerations which influence management. For example:

• Symptoms with AF, or indeed the lack of. AF with no symptoms may need no treatment of heart rate or rhythm, or indeed simply heart rate control with medication. In this latter scenario, AF continues.
• Length of time that AF has been present. The longer that AF has been present, the more challenging it is to achieve or maintain sinus rhythm.
• Other medical conditions
• Body mass index (BMI) as raised BMI increases the likelihood of paroxysmal AF progressing to persistent and also increases the likelihood of more than one ablation procedure
• The need for anticoagulation based on the CHA2DS2VASc score. This is a separate consideration therefore to heart rate and rhythm control.

Available options for your circumstances should be discussed together with pros and cons. Some matters to consider are:

• Medications can be taken regularly or ‘pill in pocket’
  • There are generally well tolerated. If not, an alternative could be sought. All medications come with a side effect profile but these are generally well tolerated.
  • For some, these are extremely effective and for others, not so much.
  • They may need to be taken for life.
• Catheter ablation
  • Definitive treatment to maintain normal sinus rhythm
  • Carries a risk profile, as do all procedures, but this is small in experienced hands. We do all we can to avoid and mitigate risks. We also know what to do in the rare circumstance where a complication does occur.
  • The procedure itself is well established.
  • This can be performed as a day case.
  • A second or more procedures may be required. This is not because the first ablation failed but rather that AF causes remodelling of the heart at the cellular level that we cannot see or because ‘touch ups’ are required as scar tissue matures.
  • Technology is always progressing, allowing improvement in outcomes.
  • Medications work with variable effectiveness and ablation can therefore give much relief.
  • Where there are symptoms with AF, there is an argument for treating with ablation sooner to give the best chance of success.
  • Medications for AF can stop after the procedure (with the exception of anticoagulation in certain scenarios), mitigating any intolerance experienced and the need to remember to take them.

There are many factors to take into consideration when deciding the best management strategy. It is recommended that this is discussed with your consultant so that a personalised approach and treatment plan is devised for you. This is the gold standard.

Here at OneWelbeck, we have a team of specialists, state of the art facilities and diagnostics, and highly competitive financial packages for self-funding patients as well as those with private health care.