NOACs in AF

Dr Fiona StewartAuckland Heart Group and Auckland DHB

NOACS for AF

True/False

• All patients should have a CHA2DS2VASc risk assessment on diagnosis of AF

• NOACS are more effective than warfarin in reducing stroke

• Aspirin is a safer option for stroke prevention in the elderly than a NOAC or warfarin

• All patients with non valvular AF on warfarin should switch to a NOAC

CHA2DS2VASc ScoringCHA2DS2-VASc Risk Score

CHF or LVEF < 40% 1

Hypertension 1

Age > 75 2

Diabetes 1

Stroke/TIA/ Thromboembolism 2

Vascular Disease 1

Age 65 - 74 1

Female 1From ESC AF Guidelines

http://www.escardio.org/guidelines-surveys/esc-

guidelines/GuidelinesDocuments/guidelines-afib-FT.pdf

CHA2DS2VASc - Stroke RiskCHA2DS2-VASc

score

Patients (n = 7329) Adjusted

stroke

rate (%/year)

0 1 0

1 422 1.3

2 1230 2.2

3 1730 3.2

4 1718 4.0

5 1159 6.7

6 679 9.8

7 294 9.6

8 82 6.7

9 14 15.2

From ESC AF Guidelines: http://www.escardio.org/guidelines-surveys/esc-

guidelines/GuidelinesDocuments/guidelines-afib-FT.pdf

Swedish National RegistryAnnual Rates of Stroke, TIA, Systemic Embolus

and Pulmonary Embolus

www.escardio.org/guidelines

NOACs vs Warfarin

Reduced rates of– Stroke (19%)– Haemorrhagic stroke (51%)– Death (10%)– Intracranial haemorrhage (52%)

Increased rate of– GI bleed (25%)

42,411 on NOACS, 29,272 on warfarinLancet 2014;383:955-62

The NOACs

Dabigatran Rivaroxaban Apixaban

Factor targeted IIa Xa Xa

Dose 150mg bd110mg bd

20mg die15mg die

5mg bd2.5mg bd

Indications for ↓dose

>80yeGFR 30 - 50

eGFR <50 2 of>80y, <60kg, creat >133

Renal clearance 80% 35% 25%

Hours to max concentration

1-3 2-4 3-4

Dyspepsia 5-10% no no

Blister packed no yes yes

Mrs M aged 84

• Persistent AF

• Hypertension

• Diabetes

• A little unsteady on her feet

On aspirin

Won’t take warfarin

Mrs M

CHA2DS2 - VASc Score = 5

Risk of stroke 6.7%/y

Swedish AF cohort study

– Stroke risk 7.2%/y

– Stroke/TIA/PE/Systemic embolism 15.3%/y

Anticoagulation will reduce this risk by 67%

Aspirin vs ApixabanAVERROES Trial

Apixaban Aspirin

Stroke or systemic embolism 1.6%/y 3.7%/y

Disabling or fatal stroke 1% 2.3%

Death 3.5%/y 4.4%/y

Major bleeding 1.4%/y 1.2%/y

Intracranial bleeding 11 13

Risk of Intracerebral Bleedingwith Falls

• Patients need to have more than 300 falls/year before intracerebral haemorrhage risk exceeds anticoagulant benefit

Aspirin is not appropriate treatment for stroke prevention

with AF in the elderly

NOACs in Over 80s

• Dabigatran 110mg bd

– (watch renal function 3/12)

• Rivaroxaban 15mg/d eGFR < 50

• Apixaban 2.5mg bd

– 2 of age >80, weight < 60kg, creat >133

Drugs to avoid with NOACs

• Avoid Imidazoles (Ketaconazole etc)

• Extreme caution with phenytoin, carbamazepine, St John’s wort

• Rivaroxaban with Protease inhibitors

Who to Switch from Warfarin to a NOAC?

• Ms E

– Rheumatic heart disease

– St Jude (mechanical) Mitral Valve replacement

– Doesn’t like regular blood tests

• NOACs are contraindicated with mechanical heart valves

• Rheumatic heart disease is a relative contraindication

• Will a poorly compliant patient on warfarin become compliant on a NOAC?

Mr G

• INRs vary widely

• Can he switch to a NOAC?

• If so, how?

Switching from Warfarin to NOAC

• Excellent solution when INRs are variable or side effects on warfarin.

• Check creatinine and eGFR– eGFR > 30 - consider NOAC

– Dose based on age, renal function and weight

• Start NOAC when INR < 2

• Monitor renal function– 3/12 ly in elderly, reduced eGFR

– Annually otherwise

NOACS for AF

True/False

• All patients should have a CHA2DS2VASc risk assessment on diagnosis of AF

• NOACS are more effective than warfarin in reducing stroke

• Aspirin is a safer option for stroke prevention in the elderly than a NOAC or warfarin

• All patients with non valvular AF on warfarin should switch to a NOAC