Are patients with persistent Atrial Fibrillation and a CHADS2

score of ≥ 2 on warfarin?

Lucinda StephensonBinscombe Medical Centre

July 2011

Introduction• Prevalence of AF 1.2%• 18% strokes- AF• AF associated with worse morbidity and

mortality• ~ 40% of patients not on warfarin

– Prevent 6000 strokes a year– Save 4000 lives a year

CHADS2CHAD item Score

Congestive heart failure 1

Hypertension 1

≥ 75 years old 1

Diabetes 1

Prior stroke or TIA 2

Risk calculation for CHADS2

Total Score Risk of Stroke Antithrombotic therapy

indicated

0 Low Aspirin

1 Moderate Warfarin or aspirin

≥2 High Warfarin

Risk of stroke stratified by CHADS2 score

CHADS2 score Annual stroke risk (95% CI)

0 1.9%

1 2.8%

2 4%

3 5.9%

4 8.5%

5 12.5%

Bleeding risk with warfarin• >75 years• Taking anti-platelets or NSAIDS• Multiple drug treatments• Uncontrolled hypertension• History of bleeding• History of poorly controlled anticoagulation therapy

• (Falls- 295 times in 1 year)

Contraindications to warfarin

• Pregnancy• Hypersensitivity to warfarin• Within 2 days of surgery• Bacterial endocarditis• Severe renal or hepatic disease• Peptic ulcer• Severe hypertension

Standard

• All patients with persistent AF who have a CHADS2 score ≥ 2 and no contraindications to warfarin should be treated with warfarin

Data Collection

• Retrospective audit• GRASP– Provides a sat of MIQUEST queries to

identify patients with AF– Calculates CHADS2 score

Results

• 240/10315 patients with atrial fibrillation/flutter 2.33%– 11.51% > 65 and AF/flutter

• Risk profile for thromboembolismCHADS2

scoreNumber Percentage

0 39 16.25

1 56 23.33

>1 145 60.42

Warfarin use in high risk patients (CHADS2>1)

Number Percentage

Patients on warfarin 77 53.1Patients not on warfarin 68 46.9

CHADS2 score

None Anti-platelet

Warfarin Both

0 20 11 6 21 16 27 11 2

>1 20 48 71 6

Patients on warfarin and anti-platelet agents in CHADS2 groups

CHADS2 2

• 36 patients not on warfarin• 10 patients warfarin C/I

Consider warfarin• 9 patients• 12487 (SJP)- is on warfarin• 20781 (MDB)• 20972 (MDB)• 21079 (MCW)• 22688 (POD)• 23962 (MCW)• 24188 (MCW) • 29940 (POD) has been referred to cardiology• 33715 (CEG)

Warfarin contraindicated• 9 patients• 11088 (POD) bladder cancer• 20425 (KAJ) GI bleed• 23551 (SJP) oesophageal cancer-palliative• 26180 (MCW) 91 dementia• 42883 (ASC) previous DU• 42912 (POD) dementia, previous subdural• 43139 (POD) dementia• 43248 (CEG) dementia• 44175 (POD) dementia

Cardioversion

• 4 patients• 10241 (POD) atrial flutter• 13404 (MCW) atrial flutter• 15018 (CEG) • 20027 (CEG)

Cardiology Review- not suitable

• 4 patients• 12114 (MCW)• 12889 (ASC)• 16613 (MCW)• 20339 (ASC)

Paroxysmal Atrial Fibrillation• 8 patients• 11666 (SJP)- 1 episode• 15373 (MCW)- AF resolved• 20676 (MDB)• 20428 (ASC)• 20924 (POD)• 22061 (ASC) paroxysmal atrial tachycardia• 39129 (ASC) seen by cardiology not for warfarin @ present• 44560 (MDB) being ix by cardiology for presyncope

Other

• 2 patients• 10618 (SJP) on chemotherapy on

therapeutic clexane• 11268 (MDB) ECG SR with 1 ectopic

CHADS2 3• 8/33 not on warfarin• 44892- should be on aspirin

– RIP (41799)– Palliative care- carcinoid (PAF-ablation) (12120)– Warfarin stopped- 2 ablations now SR. On aspirin (33896)– 103 started on aspirin by RSCH 2001, warfarin not indicated

(34600)– Extreme fragility and dementia. On aspirin (41617)– Dementia, on aspirin (44427)– Warfarin C/I- Upper GI bleed (45018)

CHADS2 4• 4/21 not on warfarin– Warfarin stopped 2003 due to falls, still having falls

and not safe walking alone (10207)– Paroxysmal AF. Aspirin stopped due to GORD.

(20801)– End stage dementia. On clopidogrel (36920)– Warfarin stopped 2006 due to falls. On aspirin and

dipyridamole (39301)

CHADS2 score 5

• 2/9 not on warfarin– New patient in NH, dementia. On Aspirin

and dipyridamole (44664)– Ablation and ICD now on aspirin (41941)

Further Action/ Re-audit• Registered GP to review patients’ notes and if in

agreement, send letter to invite patients to discuss warfarin/ refer to cardiology

• Code patients appropriately that are not suitable for warfarin

• Re-audit on a 6 monthly basis• New patients with AF- calculate CHADS2 score and

assess suitability for warfarin

Conclusion

• Binscombe are performing well• More a case of coding patients

appropriately

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fibrillation underestimated? Stroke 2005; 36: 360-366• NICE CG036 Atrial fibrillation: the management of atrial fibrillation costing report: implementing NICE

guidance in England 2006. http://www.nice.org.uk/Guidance/CG36/CostReport/pdf/English• Brian F, Gage et al. Validation of clinical classification schemes for predicting stroke. JAMA 2001;

285:2864-2870• NHS improvement. Commissioning for stroke prevention in primary care- the role of atrial fibrillation

06/09• Mant et al The Lancet 370: 11.08.07• BNF March 2009 Pharmaceutical Press• SIGN guideline No 36 http://www.signs.ac.uk/guidelines/fulltext/36/index.html March 1999• Man-Son-Hing et al Arch Intern Med 1999; 159 (7):677-85