Dr Lena Marie Izzat Consultant Cardiovascular Physician

Transcription

1 Dr Lena Marie Izzat Consultant Cardiovascular Physician

2 Atrial Fibrillation Most common sustained tachyarrhythmia prevalence increases with age doubling with each advancing decade The prevalence of AF is estimated at 1.3% of the general population and increases sharply with age approaching 10% in those aged over 70 Found in 15% of stroke patients and 2-8% of TIAs Prevalence of AF in Carmarthenshire highest in Wales

3 In the next 4 hours it is estimated that 10 patients with AF will have suffered a stroke Of these 8 patients would have been at high risk of stroke 6 patients should have been on warfarin 5 patients will end up in residential care 3 patients will go home 2 patients will die Personal communication by Dr Matt Fay.

4 Causes of AF Often caused by co-existing medical conditions both cardiac and non-cardiac Associated with increasing age, hypertension, heart failure, diabetes mellitus and valve disease Dietary and lifestyle factors have also been associated with AF Common after surgery, especially cardiothoracic operations

5 Classification of AF Terminology Clinical features Pattern Initial event (first detected episode) Paroxysmal Persistent Permanent ( accepted ) Symptomatic Asymptomatic Onset unknown Spontaneous termination <7 days and most often <48 hours Not self-terminating Lasting >7 days or prior cardioversion Not terminated Terminated but relapsed No cardioversion attempt May or may not reoccur Recurrent Recurrent Established

6 Understanding the Electrophysiology

7 Symptomatic and Myocardial Consequences Palpitations, tiredness, chest discomfort and shortness of breath May precipitate or aggravate LVF (Tachycardiomyopathy): Stunning: Prolonged post-ischaemic myocardial dysfunction Reduction of ventricular filling time Increased myocardial 02 demand

8 Ischemic Stroke Risk 1 in 5 strokes occur in patients with atrial fibrillation 5 fold increased stroke risk in atrial fibrillation Warfarin reduces stroke in AF by 64% Only 15-44% of patients who would benefit from prophylactic anticoagulation receive it, Why?

9 Goals of management of AF Management of AF has two broad objectives: 1. Prevention of complications, including thromboembolism (particularly stroke) and heart failure 1. Relief of symptoms ESC Guidelines for the management of atrial fibrillation Accessed September 2010; National Collaborating Centre for Chronic Conditions. Atrial fibrillation: national clinical guideline for management in primary and secondary care. London: Royal College of Physicians, 2006

10 Treatment STROKE PREVENTION CONTROL OF HEART RATE MAINTENANCE OF SINUS RHYTHM PHARMACOLOGICAL Vitamin K antagonists (e.g. warfarin) Aspirin Clopidogrel PHARMACOLOGICAL -blockers Calcium channel blockers (non-dhp) Digoxin PHARMACOLOGICAL Anti-arrhythmic drugs Class IA Class IC Class III NON-PHARMACOLOGICAL Removal/isolation of left atrial appendage NON-PHARMACOLOGICAL Ablation/permanent pacing NON-PHARMACOLOGICAL Ablation Surgery (MAZE procedure) DHP = dihydropyridine Adapted from Prystowsky EN. Am J Cardiol 2000;85:3D 11D

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12 How can we reduce AF burden? Opportunistic/targeted case detection including taking a manual pulse to detect AF Accurate diagnosis of AF using an ECG Further investigations and clinical assessment, including risk stratification for stroke/thromboembolism Development of a management plan rate-control, rhythm-control or referral to cardiology Antithrombotic therapy as appropriate Follow-up and review

13 Patient identification and risk assessment: GRASPing the opportunity easily GRASP-AF was developed by the West Yorkshire Cardiovascular Network, the Leeds Arrhythmia team and PRIMIS+

14 AF care pathway Case detection Assessment The management and presentation of AF involves all healthcare settings O R Primary/secondary/ emergency care Ratecontrol Rhythmcontrol Referral Primary/secondary care Follow-up Secondary/tertiary care Follow-up

15 Suggested actions People with undiagnosed AF can receive treatment sooner if opportunistic case finding is undertaken using manual pulse palpation Opportunistic case detection and targeting of patients at increased risk: Primary care: appropriate long-term condition registers, people aged >65 years, flu vaccination programme Secondary care: A&E, outpatient clinics and wards, especially care of the elderly

16 Determine stroke/thromboembolic risk High risk: Previous ischaemic stroke/tia or thromboembolic event Age >75 with hypertension, diabetes or vascular disease Clinical evidence of valve disease, heart failure, or impaired left ventricular function on echocardiography Moderate risk: Age >65 with no high risk factors Age <75 with hypertension, diabetes or vascular disease Low risk: Age <65 with no moderate or high risk factors

17 Determine stroke/thromboembolic risk High risk Moderate risk Low risk Consider anticoagulation Consider anticoagulation or aspirin Aspirin 75 to 300 mg/day if no contraindications Contraindications to warfarin? NO Warfarin, target INR = 2.5 (range 2.0 to 3.0) YES Reassess risk stratification whenever individual risk factors are reviewed

18 Rate-control vs. rhythm-control: NICE treatment strategy decision tree Confirmed diagnosis of AF Further investigations and clinical assessment including risk stratification for stroke/thromboembolism Paroxysmal AF Persistent AF Permanent AF OR Rhythm-control Remains symptomatic Rate-control Failure of rhythm-control NICE = National Institute for Health and Clinical Excellence National Collaborating Centre for Chronic Conditions. Atrial fibrillation: national clinical guideline for management in primary and secondary care. London: Royal College of Physicians, 2006

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20 Factors influencing the choice of management strategy The choice of management strategy should be tailored to the patient based on a range of factors Antithrombotic therapy Risk factors for thromboembolism Risk factors for bleeding Rate- vs. rhythm-control Type and severity of symptoms Duration and type of AF Patient age Previous therapies/duration of therapy Left atrial diameter/left atrial appendage flow velocity Other medical conditions, particularly cardiovascular disease Concomitant therapies ESC Guidelines for the management of atrial fibrillation Accessed September 2010; National Collaborating Centre for Chronic Conditions. Atrial fibrillation: national clinical guideline for management in primary and secondary care. London: Royal College of Physicians, 2006

21 Recommendations for antithrombotic therapy according to stroke risk (ESC guidelines 2010) - #1 Recommendations for antithrombotic therapy should be based on the presence (or absence) of risk factors for stroke and thromboembolism, rather than on an artificial division into high, moderate or low-risk categories ESC Guidelines for the management of atrial fibrillation Accessed September 2010

22 Recommendations for antithrombotic therapy according to stroke risk (ESC guidelines 2010) - #2 The CHADS 2 stroke risk stratification should be used as a simple initial (and easily remembered) means of assessing stroke risk, particularly suited to primary care doctors and non-specialists In patients with a CHADS 2 score of 0 1, or where a more detailed stroke risk assessment is indicated, it is recommended to use a more comprehensive risk factor-based approach i.e. CHA 2 DS 2 -VASc incorporating other risk factors for thrombo-embolism. ESC Guidelines for the management of atrial fibrillation Accessed September 2010

23 Recommendations for antithrombotic therapy according to stroke risk (ESC guidelines 2010) - #3 An assessment of bleeding risk should be part of the patient assessment before starting anticoagulation....a new simple bleeding risk score HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly (>65), drugs/alcohol concomitantly), has been derived. ESC Guidelines for the management of atrial fibrillation Accessed September 2010

24 NRAF adjusted stroke rate per 100 patient years, without aspirin How do I risk-assess AF patients simply? Stroke risk assessment with CHADS 2 CHADS 2 criteria Congestive heart failure Score Adjusted stroke risk Hypertension 1 Age >75 yrs 1 Diabetes mellitus 1 Stroke / transient ischaemic attack 1 Gage BF et al. JAMA 2001;285: Based on data from Gage BF et al. JAMA 2001;285: CHADS 2 score

25 Stroke risk assessment with CHA 2 DS 2 -VASc CHA 2 DS 2 -VASc criteria Congestive heart failure/ left ventricular dysfunction Score Hypertension 1 Age 75 yrs 2 Diabetes mellitus 1 Stroke/transient ischaemic attack/te Vascular disease (prior myocardial infarction, peripheral artery disease or aortic plaque) Age yrs 1 Sex category (i.e. female gender) CHA 2 DS 2 -VASc total score Rate of stroke/other TE (%/year)* * Theoretical rates without therapy: assuming that warfarin provides a 64% relative reduction in TE risk (2.7% ARR), based on Hart et al. TE = thromboembolism 1 Lip GYH et al. Stroke 2010;41: Hart RG et al. Ann Intern Med 2007;146:

26 hat to use for whom? uidance from European Society for Cardiology n 2010 saw the demotion of aspirin Risk category One major risk factor or 2 clinically relevant non-major risk factors One clinically relevant non-major risk factor CHA 2 DS 2 -VASc score 2 1 Recommended antithrombotic therapy Oral anticoagulant (OAC) Either OAC or aspirin mg daily. Preferred: OAC rather than aspirin No risk factors 0 Either aspirin mg daily or no antithrombotic therapy. Preferred: no antithrombotic therapy rather than aspirin European Heart Journal 2010;1:1 61.

27 Why are OACs preferred to aspirin? Warfarin better Placebo better AFASAK SPAF BAATAF CAFA SPINAF EAFT All trials RRR 64% *, ARR 2.7% (95% CI: 49 74%) RRR (%) Random effects model; Error bars = 95% CI; * p>0.2 for homogeneity; Relative risk reduction (RRR) for all strokes (ischaemic and haemorrhagic) 100 Compared to a 19% RRR, 0.7% ARR for aspirin Hart RG et al. Ann Intern Med 2007;146:

28 How are AF patients at risk of stroke currently being managed? Preadmission medications in patients with known atrial fibrillation who were admitted with acute ischemic stroke (high-risk cohort, n=597) Sub- therapeutic warfarin, 29% No antithrombotic 29% Therapeutic warfarin, 10% Dual antiplatelet therapy, 2% Single antiplatelet agent, 29% Gladstone DJ et al. Stroke 2009;40:

29 Cumulative survival Why time in therapeutic range (TTR) matters Warfarin group % 61 70% 51 60% 41 50% 31 40% <30% Non warfarin Survival to stroke (days) Morgan CL et al. Thrombosis Research 2009;124:37 41.

30 CHA 2 DS 2 -VASc overall event rates %/year Major (including intracranial) bleeding Intracranial Major CHA 2 DS 2 -VASc No of patients

31 Clinical characteristics comprising the HAS-BLED bleeding risk score HAS-BLED risk criteria Points awarded Hypertension 1 Abnormal renal and liver function (1 point each) 1 or 2 Stroke 1 Bleeding 1 Labile INRs 1 Elderly (e.g. age >65 years) 1 Drugs or alcohol (1 point each) 1 or 2 INR International Normalized Ratio Maximum 9 points ESC Guidelines for the management of atrial fibrillation Accessed September 2010; adapted from Pisters R et al. Chest 2010; March 18 (Epub ahead of print)

32 Oral anticoagulation for stroke prevention in AF CHADS 2 score 2 No Yes Yes Age 75 years No Yes 2 other risk factors* OAC Congestive heart failure Hypertension Age 75 years Diabetes Stroke/TIA/thrombo-embolism (doubled) No 1 other risk factor* Yes OAC (or aspirin) *Other clinically relevant nonmajor risk factors: age 65-74, female sex, vascular disease No Nothing (or aspirin) OAC = oral anticoagulant; TIA = transient ischaemic attack ESC Guidelines for the management of atrial fibrillation Accessed September 2010

33 ESC Guidelines: rate-control vs. rhythm-control Individualized strategy, based on careful consideration of benefits and risks for each patient Restoration of sinus rhythm is an important determinant of outcome, but potential benefits of rhythm-control are often offset by limited efficacy and adverse events of existing anti-arrhythmic agents All patients with one major stroke risk factor require anticoagulation, even if in normal sinus rhythm Rate-control is a reasonable strategy in elderly patients with minimal AF symptoms Factors favouring a rhythm-control strategy include: Younger age Troublesome symptoms despite rate control ESC Guidelines for the management of atrial fibrillation Accessed September 2010

34 Management cascade for patients with AF Atrial fibrillation Anticoagulation issues Record 12-lead ECG Assess TE Risk Presentation EHRA scrore Associated disease Initial assessment Oral anticoagulant Aspirin None Rate and rhythm control AF type Symptoms Rate control ±Rhythm control Antiarrhythmic drugs Ablation Treatment of underlying disease Upstream therapy Consider referral ACEI = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; PUFA = polyunsaturated fatty acid; TE = thromboembolism ACEIs/ARBs Statins/PUFAs Others ESC Guidelines for the management of atrial fibrillation Accessed September 2010

35 Paroxysmal AF AF Begets AF Asymptomatic and infrequent : No Treatment / pill in the pocket Standard Beta blockers : First line : Bisoprolol / sotalol Symptomatic at rest : Class 1c (Flecainide /Propafenone) Beware IHD/ structural heart disease and atrial flutter. Second line: Dronedarone in presence of CV risk factor (DM,HT,TIA, EF>40%/ large LA/ age>70y) HF: Amiodarone

36 Persistent AF AF Begets AF Recent onset symptomatic AF requires prompt assessment and hospital management Obvious underlying causes should be excluded and treated. (ischaemia / sepsis etc..) AF present< 48 h : Chemical or Electrical cardioversion with LMWt heparin Warfarin is not usually required prior to cardioversion.

37 Persistent AF>48 hours Synch. D/C cardioversion with Warfarin. Warfarin anticoagulation is essential for 4-6 weeks and continued according to CHADS2 / CHA2DS2vasc score min 4-6 weeks

38 CARDIOVERSION Predictors of success: Short duration Atrial flutter Younger age Predictors of failure: LA enlargement > 5cm Structural heart disease Cardiomegaly

39 Permanent AF/ Rate Control: What Drugs Target resting HR < 110, if symptoms persist aim for RHR< 80 / exercise: 110 Beta blockers : First line Rate limiting calcium antagonists: second line Digoxin: sedentary patients Combination therapy when monotherapy fails In chronic HF, Digoxin may reduce symptoms and hospitalisations +/- Amiodarone

40 Novel and emerging Pharmacological and EP Treatment Direct Thrombin Inhibitors / Factor Xa inhibitors Dabigatran : RE-LY trial / Dabigatran warfarin alternative, already in use in orthopaedic VTE prophylaxis New Class III antiarrhythmic : Dronedarone positive outcome data in PAF with risk factors AF Ablation Omega 3 (Calo L)? Statins (ARMYDA 3)? ACE / ARB (LIFE)?

41 Llanelli AF Clinic Went live January 2009 Invitations sent to Carmarthenshire catchment area GP s Open to all physicians, A&E department, CSNs and surgical pre-assessment clinics.

42 Who is Referred? Newly diagnosed atrial fibrillation where cardiology advice is deemed suitable. Patients with established diagnosis who require specialist input ( PAF or Chronic AF)

43 Required Assessment prior to Clinic Referral Brief clinical and treatment history Physical examination. ECG essential. FBC / U&E / glucose/ TFT Optional referral for open access echocardiography

44 At the Clinic CV Risk Factor Assessment (Q Risk) Physical Examination / ECG CHADS II score Referral to anticoagulant clinic if appropriate Referral for Echo if appropriate Management plan and decision on rhythm control or rate control strategy Tertiary centre referral for non-pharmacological management if appropriate Other CV tests arranged if needed (ETT / CAG)

45 Audit of 222 initial patients Referral Source Cardiology clinic 30 Inpatient 23 Consultant 47 Preassessment 12 GP 105 Cardiac Nurse 4 Anaesthetist post surgery N=

46 Age

47 CHADS 2 Score N/A SR N=222 Anticoagulation clinic referrals all seen on day of clinic

48 Referred for Echo on day of clinic % 27 2 Yes No NA N=222

49 Diagnosis Paroxysmal Persistent Chronic/Permanent Not in AF N=222

50 Decision Rate Control Rhythm control Na (not in AF) 9 N=222

51 Conclusions Team effort involving physicians, CSNs, cardiac technicians and anticoagulant service. Patients assessed promptly and thoroughly Investigations and anticoagulation decided and often initiated as one-stop. Seamless transfer between departments. Referral to tertiary centre for AF ablation in suitable patients when applicable.

52 Thank you