Atrial Fibrillation

Don’t Wait! Stroke prevention in newly diagnosed Atrial Fibrillation (AF)

A seven step practical guide
Evidence:  Newly diagnosed Atrial fibrillation is normally confirmed by a 12 lead ECG, rhythm strip, cardiac monitor (e.g. holter) or Interrogation of implanted Device (loop recorder, PPM). Please attach a copy of confirmatory recording when referring to AF Clinic at TUH

Stroke Prevention: Almost all cases of AF pose some risk of stroke and it is important to start anti-coagulation as soon as possible. Before starting anti-coagulation we recommend the following seven step process

1. Assess Stroke risk The recommended stroke risk tool is CHA2DS2-VASc score - available online at https://chadsvasc.org/ 

2. Who should I anti-coagulate? Based on the CHA2DS2-VASc score the following is the current ESC guidance. 

MenWomen
Definitely indicated   2 or greater    3 or greater (incl 1 for female sex)
Probably indicated      12 (incl 1 for female sex)

* Men with a score of 0 and women with score of 1 still have some risk of stroke and need a specialist opinion.

3. What is the risk of bleeding? Recommended bleeding risk tool is the HASBLED score. https://chadsvasc.org/ 

In general, caution is advised when using anti-coagulation where the HASBLED score > 3. However the risk of bleeding may not be equivalent in seriousness to a stroke. Discuss with the patient, weigh up risk and advise. (e.g. a previous GI bleed in a patient with remote history of peptic ulcer disease may not be as serious as a stroke)

4. How do I prepare to start Anti-coagulation? Take a detailed medical history and bleeding history. Address factors that increase risk of bleeding before starting anti-coagulation such as:

- Uncontrolled hypertension - Alcohol excess 
- Anitplatelet or NSAID or SSRI/SNRI use- Consider a PPI if risk of GI bleeding 

- Discuss any proposed elective surgery or planned dental work
- Check bloods (renal & liver profile, FBC, coagulation, thyroid function)
- Determine renal function: Patient age, weight and creatinine level is required (Cockcroft-Gault equation - available online at https://www.mdcalc.com/creatinine-clearance-cockcroft-gault-equation

5. What options do you have regarding anti-coagulants?

Non Vitamin K Antagonists (NOACS) 
Also known as direct oral anti-coagulants 
Vitamin K Antagonists (VKAs)
 
Factor Xa inhibitors:
- Apixaban (Eliquis)
- Rivaroxaban (Xarelto)
- Edoxaban (Lixiana)
e.g Warfarin

Direct Thrombin Inhibitor*
- Dabigatran (Pradaxa)

ESC recommends a NOAC as first line rather than warfarin. NOACS are renally excreted and below is how to dose them in relation to renal profile https://academic.oup.com/view-large/figure/115896945/ehy136f4.tif

6. Before writing the prescription? Provide patient education and check the patients pre-existing medications for potential interaction or contra-indication. Start anti-coagulation if safe to do so. Make the PCRS application online before the patient's discharge / attendance at clinic. 

7. REFER! Let us know after starting a patient on anti-coagulation
Please refer the patient to the AF clinic as required. The referral form is available through this link. The clinic will see a patient within a four to six week period upon receipt of a referral. 

*Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS: The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC)Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC Endorsed by the European Stroke Organisation (ESO). European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery. 2016.