Atrial fibrillation (AF) is the most common cardiac rhythm disturbance and increases in prevalence with advancing age. Each year, Tallaght University Hospital in Dublin assesses and admits over 400 patients with stroke and transient ischemic attack. AF is implicated as a causative factor in 33% of these cases. An AF-related stroke is more likely to be fatal, disabling and recurrent than a non-AF related stroke. The risk of AF-related stroke is greatly reduced, however, by early detection and treatment with anticoagulation[1]
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Non-vitamin K antagonist oral anticoagulants (NOACs) have emerged as the preferred oral anticoagulant over vitamin K antagonists (VKAs) for stroke prevention in AF in major published guidelines, and are now the agents of choice for patients newly started on anticoagulation[1]
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The need for a multidisciplinary AF clinic was recognised early at the hospital, given the severe consequences of stroke, potential for adverse events with unsupervised anticoagulation and the importance of early safe anticoagulation at the point of AF diagnosis.
A group of geriatricians/stroke physicians, pharmacists, cardiologists, nurses and haematologists collaborated to set up such a clinic in August 2015. This clinic is a multidisciplinary service with shared decision-making, a format that subsequently formed one of the key recommendations in achieving optimal management of patients with AF as set out by the European Society of Cardiology (ESC) and European Hearth Rhythm Association (EHRA) in recent guidelines[1],[2]
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NOACs, although deemed easier to monitor than warfarin, still represent a high-risk medication with individually nuanced dosing schedules, many drug interactions and important counselling points. NOACs may require some specialist guidance at initiation and always require patient education and follow-up. The EHRA has highlighted the importance of educating and emphasising strict adherence to patients taking NOACs. Pharmacists, as medicine specialists, have an important role to play in the management of these patients. The pharmacist counsels every patient attending our clinic on the indication for anticoagulation, importance of strict adherence and management of missed doses. Each patient is provided with written information and a NOAC alert card.
The clinic template is based on the EHRA’s recommendations for the practical initiation and follow-up scheme for patients taking NOACs[2]
. There are two pathways for patients attending the clinic. The first is for patients who are new to the clinic. These patients are seen initially by a consultant/registrar, who confirms the diagnosis of AF and explains the nature and importance of the condition. Appropriate therapy is selected based on a risk/benefit analysis in consultation with the pharmacist. Product characteristics, patient-related clinical factors and patient preference are taken into account when selecting an agent.
The second pathway involves patients returning to the clinic for a follow-up appointment. These patients are seen first by the pharmacist. Laboratory results are reviewed, as well as clinical parameters including heart rate and blood pressure. Kidney function is accurately calculated by the pharmacist at each clinic. This is of utmost importance as all NOACs have precautions and dose adjustments based on creatinine clearance. The pharmacist reviews the patient’s full list of medications at each clinic, checking for interacting medications and advising on dose adjustments and measures to minimise modifiable risk factors for bleeding. Patients are assessed for adherence, thromboembolic events, bleeding events and side effects. Refresher counselling is provided at each follow-up appointment, with the importance of adherence reiterated. Pharmacist recommendations are then reviewed by the registrar.
Patients are followed up one month after starting a NOAC. Subsequent follow-up intervals are tailored to the patients’ needs, with more frequent monitoring of frail patients and those with renal impairment, bleeding risk factors or adherence issues. Patients who have stable kidney function and report no issues at clinic are discharged back to the care of their GP.
Patients most in need of specialist input are those with medical conditions or comorbidities that may complicate the prescribing of NOACs. Patients with chronic kidney disease pose a challenge for prescribers, as all four NOACs are, to a greater or lesser extent, partly eliminated by the kidneys. Careful consideration must be given when choosing an anticoagulant for this cohort of patients, with due regard to dosing cut-offs for the individual NOACs. Furthermore, the EHRA recommend more frequent monitoring of patients whose creatinine clearance is ≤60mL/min[2]
. More than half of our clinic’s patients (55%) fell into this high-risk group. These patients are followed up at more frequent intervals than those without renal impairment.
Our area of Dublin is expected to experience a 500% increase in the population of those aged over 75 years in the next 15 years. This increase is likely to increase the prevalence of AF and AF-related stroke, and consequently increase pressure on our beds. To ensure maximum efficacy in stroke prevention and to avoid unnecessary admissions in our area, it is envisioned that the clinic will shortly extend its services to include direct access for GPs, including GP referral liaison and online guidance and phone advice to guide initial treatment. Another area for consideration is early identification of inpatients, attenders to the emergency department and acute medical unit patients with AF, and the implementation of ‘point of detection’ stroke-prevention therapy. This strategy would include a clinical pharmacist specialist to advise on appropriate drug dosing, to identify potentially hazardous drug interactions, and to provide patient, family and GP education support.
Christine McAuliffe, pharmacy department
Edwina Morrissey, pharmacy department
David Moore, cardiology department
Ronan Collins, department of stroke
Tara Coughlan, department of stroke
Cathie Burke, atrial fibrillation research nurse
Marguerite Vaughan, pharmacy department
All at Tallaght University Hospital, Dublin
References
[1] Kirchhof P, Benussi S, Kotecha D et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J 2016;37(38):2893–2962. doi: 10.1093/eurheartj/ehw210
[2] Steffel J, Verhamme P, Potpara TS et al. The 2018 European Heart Rhythm Association practical guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation. Eur Heart J 2018;39(16):1330–1393. doi: 10.1093/eurheartj/ehy136
