atrial fibrillation and anticoagulation dr mark merrick gp hannage brook medical centre wirksworth...

Atrial Fibrillation and Anticoagulation

Dr Mark MerrickGP Hannage Brook Medical CentreWirksworth

Meeting funded by Bayer HealthCare

X-Impact is organised and funded by Bayer HealthCare. This meeting contains promotional content.

L.GB.MKT.07.2015.11874 July 2015

X-Impact is organised and funded by Bayer HealthCare. This meeting includes promotional content

This meeting has been organised and funded by Bayer.

Xarelto (rivaroxaban) prescribing information

is available on request at this meeting

Adverse events should be reported.

Reporting forms and information can be found at www.mhra.gov.uk/yellowcard.

Adverse events should also be reported to Bayer plc.

Tel : 01635 563500 Fax : 01635 563703 Email : [email protected]

http://www.mhra.gov.uk/yellowcard

mailto:[email protected]


Prevalence of AF


Patients with AF have a five-fold higher stroke risk than those without AF

AF doubles the risk of stroke when adjusted for other risk factors

Without preventive treatment, each year approximately 1 in 20 patients (5%) with AF will have a stroke

It is estimated that 15% of all strokes are caused by AF and that 12,500 strokes per year in England are directly attributable to AF

Stroke in AF


20% are fatal 60% are disabling

Compared to non AF strokes:-

70% increased hospital mortality40% decrease in chance of discharge home20% increase length of hospital stay

AF strokes are severe strokes


Reduces relative risk of stroke by approx 65 %

Absolute risk reduction:- Primary stroke 2.7 % Secondary stroke 8.4 %

Numbers needed to treat for 1 year to prevent 1 stroke:- Primary stroke 37 Secondary stroke 12 Overall 25 (approx)

Risk reduction with warfarin


NOACS

Studies show to be at least as effective and probably more effective than

Warfarin at stroke reduction in AF


ROCKET AF – Primary efficacy endpoint

Number of subjects at riskRivaroxaban▼ 6958Warfarin 7004

Warfarin

Rivaroxaban

Days since randomization

0 120 240 480 600 7200

1

2

3

4

5

6

840360

Cu

mu

lati

ve e

ven

t ra

te (

%)

Stroke or systemic embolism


ASPIRIN

There is no role for aspirin in the treatment of AF

It may be used in conjunction with an anticoagulant if there is coexisting

vascular disease eg MI, PAD


CHA2D2S2 VASC

ITEM SCORE

Congestive Heart Failure or Left

Ventricular Dysfunction 1

Hypertension 1

Age >/= 75 2

Diabetes 1

Stroke/TIA 2

Vascular disease (MI, PAD) 1

Age (65-74) 1

Sex category (female) 1


CHA2D2S2 VASC Score Annual Stroke Rate

0 0.8%

1 2%

3 3.7%

4 5.9%

5 9.3%

6 15.3%

7 19.7%

8 21.5%

9 23.6%


HAS-BLED SCORE


Anticoagulation may be with apixaban, dabigatran, rivaroxaban or a vitamin K antagonist

Discuss the options for anticoagulation with each patient and base the choice on their clinical features and preferences

NICE June 2014


Which Anticoagulant?


Warfarin- Pros Warfarin has been prescribed for more than 50 years.

Warfarin remains an established and cost effective option for anticoagulation in patients.

Can be used in valve disease including valve replacement.

INR gives clinicians a guide to patient compliance.

Effective and familiar use of antidote with vitamin K should a severe bleed occur whilst being treated.

Clearance of warfarin is not affected by renal function.

For patients with poor adherence, long half life may be advantageous


Warfarin - Cons

Warfarin - time to peak effect ranges from 3-5 days and a half-life averaging 40 hours.

Warfarin is known to interact with many food and drugs

Patients may have difficulty around complying with or accessing INR monitoring

Narrow therapeutic range

Poor INR control associated with increased morbidity and mortality


NICE Guideline for AF (June 2014)

Review TTR at each visit (exclude 1st 6 weeks and must be over a period of ≥ 6/12):

Reassess if over the past 6 months: x2 INRs > 5 or x1 INR > 8 or x2 INRs < 1.5 TTR < 65%

Try to correct and take into account reasons for poor control: Cognitive function Adherence Illness Interacting drug Rx Lifestyle inc.diet and EtOH

If cannot be improved consider other strategies


NOACS - PROS

As well tolerated as warfarin

No food and minimal drug interactions

Predictable anticoagulant response (no A/C monitoring)

Fixed dosing

As or more effective than warfarin

Rapid onset and offset of action


NOAC - CONS

Short half life – missed does means inadequate anticoagulation

Cost

Renal function determines dose. Not suitable for severe renal impairment.

Does require baseline tests and ongoing monitorring

Not suitable for valvular AF

No known antidote


Bleed risks of NOACs

NOACS all have lower risk of Intracranial Bleeds

Warfarin has slightly lower GI bleed risk than Rivaroxaban and Dabigatran (trials use different criteria so no head to head data)

GI bleeds on NOACS seem less severe


Renal Function and NOACS

All NOACs are a reasonable choice in mild to moderate CKD

Estimated Creatinine Clearance should be calculated to determine dose.Cockroft-Gault equation uses age ,weight and serum creatinine)

CrCl> 50 ml/min: No dosing adjustments required

CrCl30-50 ml/min: use lower dose

CrCl15-30 ml/min: do not use dabigatran


Safe Prescribing of NOACs

Counselling the importance of strict adherence to therapy is the most crucial aspect of NOAC Rx (reinforce at every FU)

Routine monitoring:Hb and liver function (annually)Renal function:

· Annually for CKD stage I–II (CrCl≥60 ml/min)· 6 monthly for CKD stage III (CrCl30–60 ml/min)· 3 monthly for CKD stage IV (CrCl≤30 ml/min)

Regular (3 monthly) follow up:CounsellingSide effectsMedication review (interactions)


Drug Interactions

Verapamil (use lower dose dabigatran) Amiodarone Dronedarone “Azole” antifungals HIV protease inhibitors Rifampicin, St John’s wort and phenytoin

(drugs that affect CYP and P450)


Switching Warfarin to a NOAC: INR < 2.0: start NOAC immediately INR 2.0-2.5: start NOAC the next day

NOAC to warfarin: Initiate warfarin with NOAC concomitantly until INR ≥ 2 Re-test INR 24hrs after NOAC discontinuation

Missed doses: pt should take forgotten dose up till 6h (if bd NOAC) or 12h (if od

NOAC) after scheduled intake

otherwise skip dose and take next dose as scheduled


Hannage Brook AF Audit 11/14

- Practice size 8500

- Number on AF register 207

- Score of 2 or more

but no anticoagulation 63- Score of 1 (no anticoag) 8- Score 2 or more on aspirin 40- Score 1 on aspirin 4


Nottingham City CCG: The Huge opportunity in Af

750 AF patients undiagnosed

•In addition, use of CHA2DS2-Vasc instead of CHADS2and reducing exception reporting for anticoagulation to less than 15%, a further 2000high risk AF patients could be anticoagulated

This will likely result in: 56 fewer strokes per year 19 fewer deaths per year £660,000 reduction in AF stroke related hospital admission costs per

year


Discussion

Choosing which anticoagulantFear of new drugsPatients worried re change (esp if on aspirin)Worried not having INRComplianceMedidose Domiciliary patientsGP-Pharmacy communication

atrial fibrillation and anticoagulation dr mark merrick gp hannage brook medical centre wirksworth...

Documents

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bayer healthcareximpact

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bayer plc

af strokes

primary stroke

stroke reduction

treatment of af