Stroke

ProphylaxisOral anticoagulation

Lauren Butler

Dr Pervez Muzaffar

symptoms

• AF – most common arrhythmia• Asymptomatic/exercise intolerance• chest pain/palpitation/fainting• CCF/TIA• weight loss/diarrhoea• Light-headedness

Diagnosis

• History• Examination (inc manual pulse check)• ECG (essential for diagnosis)• Case specific bloods• Echocardiogram• Cxr

Classification

• Timing and termination based classification• 1st detected - only one diagnosed episode• Paroxysmal - recurrent self terminates < 7 days• Persistent - recurrent lasts for > 7 days• Permanent - on-going long term• Other categories:• Lone AF – age under 60 no h/o CVD/HT/Pulmonary disease• Non-valvular AF – absence of Rheumatic MVD/prosthetic valve or

MV repair• Secondary AF – MI/cardiac

surgery/pericarditis/myocarditis/hyperthyroidism/PE/Pneumonia

We need to improve

• Our prevalence of AF is below national average – 1.12% BwD– 1.74% England

• In BwD we only anticoagulate 42% of High risk AF cases, England 56%, we should aim for 85%!

Stroke in AF

• 14% of all strokes are due to AF• AF increases risk of stroke five-fold• 16 000 strokes per year occur in AF patients,

12 500 of these are directly attributable to the AF• AF strokes tend to be bigger and more disabling• Warfarin reduces stroke risk by around 2/3

Atrial fibrillation (AF) Points Pay stage

AF1. The practice can produce a register of patients with atrial fibrillation 5

AF5. The percentage of patients with atrial fibrillation in whomstroke risk has been assessed using the CHADS2 riskstratification scoring system in the preceding 15 months(excluding those whose previous CHADS2 score is greater than 1) 10 40–90 %

AF6. In those patients with atrial fibrillation in whom there is arecord of a CHADS2 score of 1(latest in the preceding 15months), the percentage of patients who are currently treatedwith anti-coagulation drug therapy or anti-platelet therapy 6 50-90%

AF7. In those patients with atrial fibrillation whose latest recordof a CHADS2 score is greater than 1, the percentage of patientswho are currently treated with anti-coagulation therapy 6 40-70%

• Grasp tool- how does it work?

• Works on all GP software• Set of MIQUEST queries on AF patients• Calculates stroke risk using CHADS2

• With option to use latest CHA2DS2-VASc scoring tool• Highlights those who would benefit from a medication review• Does not assess C/I to warfarin• Results in spread sheet/dashboard format • www.improvement.nhs.uk

Capturing information

Classic Grasp-AF tool view

CHADS2 Score

• Congestive Heart failure 1• Hypertension 1• Age ≥ 75 1• Diabetes 1• Previous Stroke or TIA 2

• Consider anticoagulation if ≥ 2• Use CHA2DS2VASc

assessment tool if < 2

Yet under prescribed

NICE estimate that approximately 40% of patients in whom warfarin is indicated are not receiving it.

RCPE - 91.6% of people with AF should be considered for this treatment

Aspirin vs. Warfarin

• Warfarin represents a 64% reduced stroke risk• BAFTA - Warfarin did not increase haemorrhage risk in

comparison with aspirin (Warfarin 1.4% Aspirin 1.6%)• Falls - Older patients taking warfarin must fall about 295

times in one year for warfarin not to be optimal therapy and the propensity to fall is not a contraindication to the use of antithrombotic agents (especially warfarin) in elderly persons with AF.

• NB current guidance suggests that Aspirin should not be used for stroke prevention in AF. (RCPE UK 2012)

CHA2DS2-VASc Score• Congestive Heart Failure/ LVD 1• Hypertension 1• Age ≥ 75 years 2 • Diabetes mellitus 1• Stroke/TIA/TE 2• Vascular disease (MI, PAD or aortic plaque)

1• Age between 65 and 74 year 1• Sc - Sex category - Female 1

• Score of ≥ 2 anticoagulation therapy• Score of 1 consider risk/benefit and HAS-

BLED score to aid decision for anticoagulation or antiplatelet therapy

HAS-BLED Score

• Annual Hypertension, Uncontrolled Sys >160mmHg 1pt• Abnormal Kidney (Cr > 200) and/or liver function 1pt each• Stroke 1pt • Bleeding, previous history, anaemia or predisposition 1pt• Labile INR, high INR or poor time in Therapeutic range 1pt

• Elderly, age ≥ 65yrs 1pt• Drugs and/or alcohol, antiplatelets, more than

8 drinks per week 1pt each

• A score of 3 or more is not a contraindication to oral anticoagulation but these patients require extra care

• 0 1.9%• 1 2.8%• 2 4.0%• 3 5.9%• 4 8.5%• 5 12.5%• 6 18.2%

CHADS 2 vs HAS – BLED Risk score Risk score

• 0 1.1%• 1 1.0%• 2 1.9%• 3 3.7%• 4 8.7%• 5 12.5%

Using both….. Lancashire & Cumbria Guidelines

Calculate CHADS2 score ………

CHADS2 > 1 anti-coagulate

CHADS2 ≤ 1 calculate CHA2DS2-VASC

CHA2DS2-VASC >1 anti-coagulate

CHA2DS2-VASC ≤1no treatment (or aspirin)

Consider a risk of bleeding assessment such as the

HAS-BLED score before anticoagulation

New oral anticoagulant drugs

• Dabigatran, RivaroXaban, ApiXabanDabigatrin (Pradaxa ) 150mg bd or 110 mg bd

Rivaroxaban (Xarelto ) 20mg od

Apixaban 5mg bd (not yet licensed for stroke prevention in AF)• NOACs are recommended as an treatment option where warfarin is

either contraindicated or where the patient has a documented hypersensitivity to or intolerance of coumarin anticoagulants severe enough to cause treatment withdrawal

• Studies show similar or better efficacy than warfarin with less risk of bleeding

• No monitoring required• Few drug and diet interactions• Very expensive (but savings on monitoring)

New oral anticoagulant drugs (2)

• Still black triangle drugs – Amber rating in BwD• No simple antidote (but short half life) • In RE-LY trial, Dabigatran higher drop out rate than

warfarin• Higher rate of GI bleeding, lower rate of ICH

• Warfarin is still likely to remain drug of choice for those who are well controlled (TTR 65%)

• However NOACs do have advantages, and will benefit a proportion of the population

Warfarin or NOAC ?Where to refer ?

• Warfarin Anticoag clinic

• NOAC Community cardiology (Mammen)

• Remember – NOACs still carry bleeding risk, black triangle drugs with no antidote

Key points

• Aspirin is ineffective in stroke prevention for AF • If warfarin can not be controlled and compliance

is not the issue then a NOAC should be commenced

• Where compliance is the issue, then is it preferable to at least be able to monitor this?

• Watch NOACs in the elderly and those with poor renal function

• Remember – BwD anticoag service has domiciliary service for patients unable to attend clinic

case

66 years old female presented with sob/tiredness feels skipping beat occasionally when playing golf

no cough no chest pain no fainting no other symptoms

PMH: nil

No allergy

Examination/tests

BP 132/70 pulse 104/min irregular no murmur no ankle oedema no carotid bruits

CNS- normal

Chest- sats 98% RR 20/min no wheeze mild basal crepts

apyrexial

ECG AF 112/min

Requested bloods

Diagnosis?

• CHADS2 Score??

• What would you next?

Anticoagulate?

• CHA2DS2-VASc Score ??

• What is next?

NOAC

• After discussion she decides to be referred to anticoagulation clinic

• She comes back in a week time with her consultant surgeon son who says he does not want her to go on warfarin – but like her to go on Dabigatran (NOAC)

• Your response to his request?

• He wishes to pay for private prescription?