Different Treatments Used to Control Patients with Af

A 66-year-old female presents to emergency department feeling generally unwell for the past week, associated with dizziness on standing and central chest/epigastric pain radiating to the shoulders. The patient also reported intermittent palpitations and chest pain for the past week. The patient described the pain as ‘heartburn’ across her chest and denied any history of radiation to the left arm or jaw and dyspnoea. The patient experienced the most severe episode this morning soon after waking, and felt light-headed, with palpitations and chest discomfort. Her past medical history included hypertension controlled with 10mg Amlodipine and 50mg Atenolol once daily, as well as 10mg Atorvastatin once daily. She was a non-smoker, had an alcohol intake of 4 units weekly, and was independent with normal mobility.

On physical examination, the patient was in no obvious distress and looked comfortable. She had warm extremities and was well perfused, with a blood pressure of 112/68mmHg and pulse of 68 beats per minute (BPM), cardiovascular, respiratory and abdominal examinations were unremarkable. Her Electrocardiogram (ECG) on admission showed an HR 132, with narrow QRS complexes and no p waves, consistent with a diagnosis of fast atrial fibrillation (AF). Prior to discharge, her repeat ECG showed normal sinus rhythm. The patient was diagnosed with the new onset of AF and was treated with Rivaroxaban 20mg OD, Bisoprolol 10mg OD, and amiodarone 200mg OD and 400mg TDS.

Aim

After finding this case study I was interested to learn more about the different approaches to treating AF how a decision is made regarding rate vs. rhythm control I began to do my own research on how the rate controlling drug works, why rhythm control drug was not appropriate in this patient, and the other treatments available to patients with AF. In this essay, I will give a brief overview of AF, with a focus on the different treatments that are used to control patients with AF and which treatment is more significant for the patient in the long-term.

AF is the most common sustained cardiac arrhythmia; it can cause a range of symptoms from dyspnoea to chest pain and palpitations, which can impair quality of life without treatment. It is prevalent in the population in people over 50 and is usually uncommon in infants unless structural or functional abnormality. It has been calculated that in the year 2000 the NHS had spent a total of £459 million including drug treatment and hospital admissions having an impact on healthcare. If affected patients do not get appropriate therapeutic intervention it can increase the risk of stroke five-fold. This is one of the more common but extremely serious complications of AF, alongside congestive heart failure and myocardial infarction.

The main focus in the management of AF is to reduce the chances of severe symptoms such as tachycardia-induced cardiomyopathy (TIC) and stroke. The control of heart rate and rhythm are initially important to restore sinus rhythm; however, it is also important to consider the risk of thromboembolism therefore unless contraindicated therapeutic dose of an oral anticoagulant should be commenced. An AF patient should be assessed for both stroke and bleeding risk. The stroke risk is calculated by the used of CHA2DS2-VASc stroke risk score as my patient did not have this risk assessment completed within the patient notes I have worked out the result for the patient and her result would have been 3 points, therefore, my patient is in the moderate-high risk and is a candidate for anticoagulation which my patient was prescribed with Rivaroxaban 20mg OD. Similar to the stroke risk assessment the HAS-BLED scoring assessment the patient's result would be 2 points which state that anticoagulant can be considered, however, the patient does have a moderate risk for a major bleed.

An important factor in determining the management plan is the type of AF the patient has been diagnosed with, there are three different types which are dependent on how long the patient has AF. The first type is paroxysmal AF this occurs spontaneously and lasts less than seven days and doesn’t usually require treatment, persistent AF lasts longer than seven days and requires treatment however sometimes can resolve spontaneously. Finally, the last type is permanent AF which lasts for more than a year and can be usually be controlled with medication or surgery.

The management depends upon the type of AF diagnosed, Currently, AF patients are treated either pharmacologically or non-pharmacologically depending on the type, symptoms, co-morbidities and most importantly how it affects the patient. The treatment is with either a rate or a rhythm controlling drug which both work differently depending on what part of the heart they are placing their effect on. A rate-controlling drug focusses its effect on controlling the ventricular rate, most likely with calcium channel blockers, beta blocker or digoxin. The rhythm controlling drugs are introduced in patients who remain in AF such as amiodarone and sotalol and can use electrical cardioversion to restore sinus rhythm.

Over the last few years, management for AF has dramatically grown and different drugs and procedures have been introduced for both ventricular rate control and rhythm conversion. The initial management of a patient in AF is to haemodynamically stabilise the patient, establish ventricular rate control and to prevent adverse embolic complications. Another goal is termination of AF and possibly restoring sinus rhythm. A significant factor for the patient and clinician when choosing a management plan for an AF patient is whether a patient will benefit from a rate and rhythm control approach. Commonly rate control is the initial management which is simpler than a rhythm control approach to AF, involves less toxic medications and less invasive procedures, compared to rhythm control which uses potential drugs that can have a toxic effect on the patient or an invasive procedure e.g. catheter ablation or surgery however, when rhythmic treatment is successful the patient will restore sinus rhythm. A rate-controlling intervention is mainly used in asymptomatic patients with AF, particularly in patients with recurrent AF the preferred drug is rate control as the initial management.

National Institute and Care Excellence (NICE) (2014) state rate control should be the first line of treatment in newly diagnosed AF, which is the chosen treatment for my patient. A rate control is also used in patients with paroxysmal cause and if the clinicians think that heart failure could be the primary cause. The goal of the ventricular rate control is to attain a rate of less than 100 BPM, by partially blocking signals in the atria and preventing them from being conducted to ventricles by increasing the refractoriness of the AV node resulting in reduced ventricular rate, effectively allowing the heart to pump slower and more efficiently. Medications that are commonly used include beta-blockers or a rate-limiting calcium channel blocker is the first choice and digoxin. NICE recommend monotherapy with a beta-blocker, not sotalol due to its adverse effects, or a rate-limiting calcium-channel blocker as initial therapy as part of a rate controlling intervention. This is independent of a patient’s heart rate, co-morbidities, and personal preference.

Guidelines also state that for patients with non-paroxysmal AF that remain sedentary to consider digoxin monotherapy. If monotherapy does not control the patient’s symptoms and it is thought to be due to poor ventricular control consider combination therapy of two of the following: beta blocker, digoxin and calcium-channel blocker (diltiazem). It is stated by NICE that amiodarone should not be prescribed for long-term rate control.

Rate control medications have some side effects such as fatigue, dyspnoea, pre-syncope and some more serious effects such as inducing a pro-arrhythmia which is more frequent occurrences of pre-existing arrhythmias, also digoxin can be toxic and cause nausea and vomiting initially however if not appropriately treated can cause serious cardiovascular complications. As rate control drugs do not cure AF the patient has to be on a life-long treatment which can cause atrial enlargement due to the increased workload and can increase chances of stroke.

The other type of treatment is rhythm control which is used in symptomatic patients after being trialled with ventricular rate-controlling drugs and being unsuccessful and whose symptoms continue after heart rate has been controlled or for whom a rate control strategy has not been successful.

As AF has been shown to be an independent factor of mortality in AF patient’s research shows that restoring sinus rhythm is more important and delivers a beneficial outcome and decreasing mortality and hospitalisation. There are two main types of rhythm control, cardioversion and drug treatment for restoration of sinus rhythm. The pharmacological drugs commonly used are amiodarone and beta-blockers sotalol, they both work on different ion channels to control the rhythm of the heart. The drug sotalol has an effect by blocking potassium channels to prolong action potentials and refectory periods resulting in slower heart rates. Whereas, amiodarone works by prolonging repolarisation by inhibiting sodium and potassium ion channels resulting in a decrease in heart rate and vascular resistance. The electrical cardioversion is a procedure where electrical currents are delivered to the heart to convert the arrhythmia to sinus rhythm. However, after given the extra cost and potential risks associated with antiarrhythmic drugs patients have been less likely to try this approach. Although amiodarone is usually well tolerated it can cause some common adverse effects such as bradycardia, hyperthyroidism, phototoxicity, slate grey skin, pulmonary toxicity (including pneumonitis and fibrosis), taste disturbance, tremor, and nausea. The other common side effects with sotalol, bradycardia this risk is increased further in patients with severe hypertension, cold extremities, fatigue and visual disturbances.

There has been controversial discussion around rate and rhythm control in treating AF patients, some studies recommend rate control is more beneficial than rhythm control and some suggest rhythm control results have better long-term benefits. There have been many standardised trails to demonstrate the benefit and risks between rate versus rhythm control in AF patients, Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) and Rate Control versus Electrical Cardioversion (RACE) these studies evaluated approaches of rate and rhythm control in AF. Research shows that rate control is a much easier and simpler method for a patient to incorporate into their lives and therefore, a better outcome for the patient as there are more chances for a patient to be compliant with medication, leading to many clinicians ruling out the rhythmic control. Results from the AFFIRM study suggest that beta-blockers had a better success rate of 74% compared to that of 54% in calcium-channel blockers in achieving rate control when they were either used alone or combined with digoxin and therefore, more patients are put on beta-blocker over a calcium channel blocker unless contraindications. Subsequently, the drugs have adverse effects such as exacerbation of asthma and chronic obstructive pulmonary disease (COPD) which can become problematic for younger patients with structural/functional defects or elderly patients who have COPD and causing acute exacerbations and worsening of dyspnoea resulting in emergency hospitalisation. It has also been found to exacerbate depression having a big impact on a patient’s life and unfortunately risks potentially a patient’s mental state, resulting in further healthcare support. This should be taken into consideration when taking a patient history as a physician associate it will be imperative to gain a detailed history from the patient to avoid this issue.

Research has shown that that restoration of sinus rhythm can reduce the risk of emergency hospital admission and stroke, improve the ejection fraction, reduce atrial hypertrophy, and improve exercise capacity, further improving patient’s quality of life, which would have a positive impact on a patient. However, studies show that the use of rhythm control drugs leads to an increased number of hospital admissions due to recurrence of AF. When a rhythmic controlled AF patient requires hospitalisation, a rate controlling drugs are often given intravenously to reduce symptoms during attacks, therefore, patients with rhythmic control and cannot be treated alone they require a combination of both rhythm and rate control. This shows there is dependence on rate control once sinus rhythm has been established previously and shows that there will be cost implications with costlier pharmacological drugs and increased hospital admissions causing a burden on healthcare. Compared to rate control cost both AFFIRM and RACE studies showed that rate control is less costly than rhythm control, making this more favourable due to financial budget restraints.

However, in a selected minority of patients, particularly younger and physically active a rhythm control strategy may be preferred. It has been found that restoring sinus rhythm is more important than a rate control management in persistent AF, AFFIRM supports this by finding reduced mortality rates where there was a control on sinus rhythm and also use of oral anticoagulants, showing a strong correlation in amiodarone restoring sinus rhythm. AFFIRM study shows that within the rhythm controlled group there was an increase by 1-5 fold of a non-cardiovascular death, however, largely driven by increased death from cancer and pulmonary disorders. This marries up with the adverse side effects of increased levels of amiodarone and fibrosis, which may suggest that patients died due to toxic amounts of rhythm control drugs. Although many of the studies suggest there are long-term benefits of restoring and maintaining sinus rhythm such as has improving ejection fraction, reducing left atrial size, allowing AF patients to increase exercise capacity, and improving the quality of life for AF patients, the toxic side effects of rhythm controlling drugs may outweigh the initial benefits in the long-term. In the two largest of these, there was even a trend to increased mortality in the rhythm control group, which may have been due to potential toxicity of drugs and also the inappropriate withdrawal of anti-coagulants in the rhythm control group leading to an increase in thromboembolic events.

As a stroke is one of the most serious adverse events in AF, potentially once the heart was back in sinus rhythm, it should have reduced the risk of stroke and avoid the need for anticoagulation. Unfortunately, this is not always the case and even if the patient is no longer symptomatic, studies show that ECG monitoring shows the presence of asymptomatic incidents often remain, which can make it questionable of the success of restoring sinus rhythm.

RACE studies showed after pooling all the evidence that there was no clear mortality benefit of rhythm control over rate control in patients with asymptomatic AF. RACE also found no substantial significance between rate and rhythm control in patients with AF, although the studies did not include a broad spectrum of patients and excluded younger patients and patients that had severe symptoms the results can only be valid to patients that have no other co-morbidities and patients that were not affecting their daily life and were able to endure their AF only. Showing that these results may not be as valid when deciding a treatment plan for AF patients in other populations, making it an irrelevant source to aid the treatment plan to alleviate the patient’s symptoms and to improve the patient’s long-term outcome.

Conclusion

To conclude as rate control therapy is more important currently compared to a rhythm control therapy because of its advantages for a large percentage of patients with AF, as there is less chance of toxic drug use, reduces the risk of harm to the patient. In my opinion, the studies indicate that unless rate control therapy has been unsuccessful that it less vital to aggressively restore sinus rhythm. I feel this is very important as AF primarily affects 65+ who more than likely have other co-morbidities however, the other important group of patients who can be affected especially younger and physically active individuals and those in whom have congenital defects a rhythm control strategy would be a preferred approach taking into consideration age, other conditions and patients preference.

A future trial should concentrate on the long-term effects of treatment in the largest proportion of patients with AF, those with symptomatic permanent AF, with the aim of improving patient’s quality of life. The inadequate data provides a lack of answers however by completing future trials including a wider range of patients with AF gathering better representation so that the result are applicable to the wider population. To find treatments that are aimed at all groups of people with AF all different age ranges, gender, ethnicities and also different types of AF. NHS England have stated that if treatment for AF is optimised that there is a potential to save £241 million which would be beneficial for both the patient and NHS, by educating general practitioners, implementing diagnostic devices and having pharmacist-run anticoagulation services there has been a reduction in ischaemic events these programmes are being optimised and NHS are encouraging all areas in the country to implement these changes.

I feel that as a future physician associate I would take a thorough history of a patient to ensure all co-morbidities are discussed and the patient’s preference for how they would like to be treated. In the future I would like to encourage a patient to choose a rhythm controlling therapy, however, until rhythm control therapies are less toxic and have more effective pharmacological drugs for a wider range of patients, it would be ideal to follow NICE on the initial treatment and should remain as rate control in the majority and rhythm in the minority who would benefit. There is more benefit in restoring sinus rhythm in patients who have been diagnosed with AF at a young age and asymptomatic as there are risks associated with prolonged AF which can cause premature death. As a physician associate I would take into account the patients age and conditions and also to educate the patient on the potential risks of prolonged use of rate-controlling drugs and also the toxic effect of the antiarrhythmic drugs however, also state the better long-term outcome for the patient for being in sinus rhythm as this would also decrease chances of the complications that are associated with AF and should be offered both treatments and to be able to make the decision for themselves and take the patients preferences into consideration.