Background
Atrial fibrillation (AF) remains the leading arrhythmia encountered in elderly patients, due to their increased survival rate [1].
The prevalence of AF is approximately 10% in patients ≥80 years old, but the impact of population aging on rates of AF-related ischaemic events is uncertain [2].
Treating older patients with AF is challenging due to their comorbidities, polypharmacy and peculiar pharmacokinetics and pharmacodynamics; therefore, it is important to monitor the management of these patients. This is even more critical in the emergency department (ED) where, under the pressure of time, where it is imperative to initiate anticoagulation or to insist on its being maintained. When assessing the elderly patient presenting to the ED, we have to consider the patient with AF in a holistic manner, i.e., the role of AF as a marker of aggravation or as a risk factor for aggravation should be evaluated together with other chronic or acute conditions contributing to the patient’s state.
One of the challenging problems confronting the physician in relation to AF patients in the ED is the decision on whether there is a need for acute or delayed treatment.
Stroke prevention, through oral anticoagulants (OAC), represents the cornerstone of managing AF patients, as indicated by the guidelines [3] and proven by numerous observational studies [4,5]. However, real-world data emphasise that the prescription rate of OAC is inversely related to age [6,7].
Patients with AF who are older than 80 years of age represent a special population with an estimated prevalence of 10% reported in different trials [8-10]. These patients are often excluded from clinical trials and the option of therapeutic management in this distinct group is often based entirely on expert consensus [11], on available information from real-world registries or on individual physician decision. Therapeutic options should be chosen in this frail population taking into consideration safety before efficacy of the administered drug [1].
Elderly patients with AF presenting to the ED and their challenges
Symptomatic AF relapses compel patients to refer themselves to the ED. This is the main cause of hospital readmission for arrhythmic reasons and represents a common issue encountered by physicians in daily practice. Notably, the relapse rate after the first episode of AF is about 10% in the first 12 months and 5% in the following years [12].
In the elderly group, age per se represents a proven risk factor included in the CHA2DS2-VASC score, but common practice shows us that OAC prescription is dreaded among this group. A routine practice among medical doctors is antiplatelet prescription if the patient has a higher HAS-BLED score. Recent data highlight the increased protective effect against stroke of NOACs over aspirin in patients ≥75 years of age [13].
An increased risk of falls in the geriatric population is reported. Assessment of the risk of falls is fundamental considering the burden that falls impose on patients and family members. In this targeted population, falls are more likely to have multiple causes: drugs, activity, environment, behaviour. Falls usually lead to life-threatening haematomas. The risk of falls is increased in the elderly with OAC use. Because of this, elderly patients prone to risk are undertreated. However, the risk of falls never equals the risk of stroke [14].
The majority of patients over 65 years old take at least five or more drugs. This polypharmacy contributes to inappropriate use, diminished adherence, unanticipated drug interactions, and cumulative side effects. Multiple drug prescription in the senescent population is associated with frequent outpatient visits and hospitalisations, increased burden on the healthcare system, and contributes to the decline of functional and mental status [15]. The increased risk of non-adherence leads to treatment cessation and progression of the disease [16]. When prescribing drugs, especially to elderly patients who most of the time are frail, one always has to take into consideration the risk/benefit ratio.
Management of the geriatric population in the ED
ED physicians have to rapidly and properly asses and manage these patients by addressing rate or rhythm control. A multidisciplinary approach is recommended for the benefit of the patient. The acute treatment started in the ED is usually the only one that the patient receives and will probably affect the long-term outcome of the underlying condition and the patient’s subsequent hospital readmission rate. Medication prescribed in the ED is sometimes continued after discharge at the patient’s own initiative without proper indication. Although the therapeutic options were appropriately addressed in the ED, most of them should be replaced at discharge. Early rectification of inappropriate medication intake may improve geriatric care. A suitable drug evaluation should be performed by a multidisciplinary team, or at least by the patient’s own physician [12].
Should the chosen treatment be administered at once or can it be delayed?
The initial assessment particularly involves risk stratification. This is established by an appropriate balance of the stroke risk, evaluated by the CHA2DS2-VASc score, and bleeding risk, estimated through the HAS-BLED score. However, the decision concerning treatment should always take into consideration the stroke versus bleeding risk. Under no circumstances should a hasty decision be made. It should therefore be reserved for the moment of optimal evaluation.
Although the ESC position paper on bleeding risk and AF management asserts that “bleeding risk is almost inevitably lower than stroke in patients with AF”, it could be further reduced by re-evaluating antithrombotic therapeutic strategies in high-risk patients [3,11].
In order to maintain the balance between risk stratification and optimal therapeutic management, the initial assessment must be thorough, reliable and accurate. Fear of haemorrhages can lead to the wrong decision: OAC therapy is often avoided, delayed or replaced by antiplatelet therapy [7].
An individual approach is the keystone of treatment
Despite the pressure on the ED and the importance of making an immediate decision, rushing to make a patient assessment should be avoided. The patient should benefit from a shared decision taking into account the benefits and risks of the treatment.
Assessment of comorbidities and drug adherence thereafter should be implemented by practitioners. Patient adherence to medication has always been a challenge. Drug non-adherence can be influenced by factors related to the patient, medication, healthcare provider and socioeconomics [17].
When managing an elderly patient with AF, the physician has to consider not only preventing thromboembolic episodes, but also improving the patient’s clinical status by reducing their symptoms. This contributes to reduction in mortality and hospitalisation and an improved quality of life. Anticoagulant therapy reduces thromboembolic events while rhythm or rate control help to alleviate patients’ clinical discomfort. Catheter ablation has established its role in AF treatment.
Elderly patients with AF should be anticoagulated, unless a contraindication is present. Classic oral anticoagulants such as vitamin K antagonists (VKA) have many known drawbacks (establishing the right dose through international normalised ratio [INR] values performed periodically, food interactions, etc.).
NOACs have opened new options among the elderly. Available NOACs used in daily clinical practice include dabigatran (a direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (direct factor Xa inhibitors).
In low-risk patients (CHA2DS2-VASc= 0), an overuse of OAC was reported, that could be explained by cardioversion (either performed during the index hospitalisation or planned immediately after discharge). Current guidelines recommend at least four weeks of oral anticoagulation after cardioversion, irrespective of the CHA2DS2-VASc score and of the type of cardioversion (pharmacological or electrical). Unfortunately, in daily practice, there are reasons, such as “unsuitable” patients, first detected/paroxysmal AF or a previous haemorrhagic event, often encountered for not prescribing OAC [18].
In the ED, when assessing an elderly AF patient treated with OAC, a thorough medical history is essential to appreciate which OAC is being taken, the dose administered, and the last dose taken. The physician evaluating the elderly patient has to estimate the renal function (usually affected) which influences the OAC half-life, thus increasing the bleeding risk [11].
It is important to obtain information about the time of the last dose of OAC taken in order to know if and when the next dose should be administered, especially because OACs have a prolonged half-life in the elderly. In the case of a non-anticoagulated elderly AF patient, a dose of anticoagulant should be administered at once provided the patient does not have any contraindications (concomitant major haemorrhagic events, patient’s option).
Elderly patients on edoxaban have lower rates of stroke and other thromboembolic events, and more important bleeding events [8].
Taking into account all of the above-mentioned particularities, a suitable management when treating very old patients with AF in the ED is the individual approach. This should be an evidence-based decision in accordance with the ESC 2016 guidelines concerning the treatment of old patients with AF, strategies for the management of geriatric patients and individualised clinical pharmacology of administered drugs [3].
Numerous debates have challenged whether or not to administer oral anticoagulants to elderly AF patients as the first therapeutic choice. The use of OAC is suboptimal in elderly subjects despite their higher CHA2DS2-VASc score.
Among patients with AF over 90 years of age, warfarin was associated with a lower risk of ischaemic stroke and a net clinical benefit [19]. Compared with warfarin, NOACs were associated with a lower risk of intracranial haemorrhages. Thus, OAC may still be considered as thromboprophylaxis for elderly patients, with NOACs, however, being the more favourable choice [3,11].
A large proportion of this population receives a prescription of a reduced dose of NOACs (the reason lies in the fear of bleeding). Thus, a more fragile patient is outlined. Inappropriate dosing of NOACs has become a common practice among practitioners, despite clear guideline recommendations [3]. In order to take preventive measures, to reduce the risk of bleeding, physicians choose to prescribe lower NOAC dosage (especially true for apixaban), resulting in a decreased efficacy [8].
However, some NOACs preserve efficacy at lower dosages (especially convenient in the very elderly). Dabigatran should be reduced in elderly patients, in contrast with rivaroxaban or edoxaban, where no dose adjustment is required. Apixaban dose adjustment depends on the indications and further criteria. Recent data indicate that an inappropriate dose reduction of NOACs is associated with lower thromboembolic event prevention [20].
Despite the best efforts of guideline experts and evidence-based recommendations founded on demonstrated efficacy, many AF patients who meet the criteria for anticoagulant therapy are not treated correctly. Low rates of compliance and treatment adherence were reported in middle- and low-income countries.
There are several reasons why the elderly are not compliant with their prescribed therapy. They often have multiple comorbid conditions and have to use more drugs than their younger counterparts [15].
Identifying the best approach between adherence to the current recommendations of the guidelines to treat patients with AF and pharmacotherapy in the elderly is not as easy as it may seem. A suitable approach could be to apply the principles of personalised medical treatment, towards clinical and pharmacological assessments of all the therapeutic agents used and their interactions (drug and food interactions) [17].
Rate control is the preferred therapeutic approach. Different registries and clinical trials suggest that the general management strategy for elderly patients is a rate control approach, which may be associated with reduced mortality and hospitalisations, compared with a rhythm-control approach [1,21].
The thromboembolic event rates are similar in patients treated with pharmacological rhythm control strategies versus rate control therapies, as proven by important trials [21].
An integrated age-related management of patients presenting to the ED, with a preferred choice of rate control in elderly subjects, is however suggested by some studies [13].
This was confirmed by the investigators of the ATRIA study which showed that the clinical benefit of warfarin increases with older age, reaching a maximum benefit in patients ≥85 years old [5]. The fear of haemorrhages, although trivial and improperly attributed to OAC in this population, may be unfounded. Some trials indicate that antiplatelet agents are not fully benign in octogenarians in whom aspirin caused more adverse events than warfarin [3,5,20]. Underprescription of NOACs is presented in studies that outline that old age is a negative predictor in terms of guideline adherence [17]. In elderly patients with AF, OAC underprescription is associated with an increased risk of cardiovascular mortality, thromboembolism and major bleeding [16,20].
The presence of adverse side effects must be taken into consideration when administering a drug. Due to antithrombotic drug consumption, rhythm and rate control pills prescribed, the underlying disease management and presence of comorbidities, the AF patient presenting in the ED can be a “ticking bomb”. The efficacy of guideline-recommended strategies remains uncertain due to this population being under-represented in clinical trials [1].
NOACs should be the preferred choice rather than aspirin or other antiplatelet agents in elderly patients, but this must be supported by warranted, randomised clinical trials and real-world registries with this targeted population.
Conclusions
In summary, when treating an old patient with AF one should remember “we, as good doctors, treat the patient not the disease”.
A better awareness of the risk/benefit balance, the implementation of risk stratification criteria with a correct evaluation of bleeding risk could improve NOAC prescription and help the evaluating doctor to make a more suitable and timely decision of the appropriate drug to be administered.
Due to increased life expectancy, the senescent population constitutes a significant percentage of our ED patients. Thus, efforts should be made in order to redefine the appropriate anticoagulant therapy.
In the ED, in case of a non-anticoagulated patient, a dose of anticoagulant should be administered at once.
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