12 월 1 일 EP conference

Transcription

1 12 월 1 일 EP conference

2 Classification ( ACC/AHA/ESC ) Paroxysmal : start and stop by themselves, lasting less than 24hrs sometimes lasting up to 7days Persistent : lasting more than 7 days or that requre termination, either pharmacologically or electrically Permanent : long-standing continuous episodes where repeated attemps to terminate have either failed or were not tried.

3 Classification * recurrent : two or more paroxysmal or persistent episodes * reversible cause : cardiac surgery, myocardiac infarction, pulmonary embolism, myocarditis or hyperthyroidism

4 Pathophysiology of AF (1)

5 Pathophysiology of AF (2) Wijffels et al : prolonged AF causes changes in electrical properties (electrical remodeling) of the atrium promoting maintenance of AF. electrical change : decrease in the atrial effective refractory period(erp) decrease the size of the smallest circuit that can maintain reentry, increasing the number of simultaneous circuits that can be accommodated by the atria and stabilizing multi-circuit reentry * reverse remodeling

6 Prevalence of AF stratified by age and sex Overall prevalence : 1%

7 Risk ratios for stroke and death comparing AF to sinus rhythm

8 Prevalence of AF in CHF

9 Stroke risk in AF 15-25% of ischemic stroke clinical stroke and silent stroke From 0.5%/year for young pt without structural heart disease to 12%/year for previous stroke Risk factor : age, gender, HT, ischemic or rheumatic heart disease, prosthetic heart valve, CHF, Hx of stroke or TIA, DM, thyrotoxicosis * less well defined : postmenopausal HRT, alcohol, smoking

10 Annual stroke event Without anticoagulation With anticoagulation

11 Annual stroke event rates ( the Atrial Fibrillation Investigators )

12 Stroke risk in nonvalvular AF given aspirin ( the Stroke Prevention in Atrial Fibrillation ) * Risk factors : women > 75 yrs, HT, Hx of stroke or TIA, impaired LV function

13 CHADS 2 stroke risk stratification in nonvalvular AF

14 CHADS 2 score and annual risk of stroke Low risk : 0 Intermediate risk : 1 or 2 High risk : 3

15 Pharmacologic antithrombotic therapy BAATAF, CAFA, SPINAF, SPAF, AFASAK Overall risk of ischemic stroke without antithrombotic therapy : 4.5%/yr Warfarin : 1.4%/yr (RRR = 68%) Major hemorrhage with warfarin(intracranial, transfusion of two or more units, hospitalization) : 1.3%/yr (control : 1%/yr) EAFT(european) : 66 % RRR of warfarin

16 Aspirin vs Warfarin Aspirin : 16-44%(overall 21%)RRR vs placebo Warfarin : 36% RRR of all stroke(ischemic +hemorrhagic), frequent major bleeding vs aspirin ( AFASAK, AFASAK-II, EAFT, SPAF-II,PATAF ) INR : <2.0 no treatment effect (target of 2.5) recommendation rage 5 major bleeding

17 Ximelagatran(1) prevent the conversion of fibrinogen to fibrin by thrombin ( direct thrombin inhibitor ) predictable pharmacokinetics, fully anticoagulated within a few hours of taking the first dose, no need of monitoring SPORTIF II : three different doses of ximelagatran vs warfarin in small number, 3 months f/u safe and effective in the short term SPORTIF III : non-inferiority trial n=3407 fixed dose ximelagatran(36 mg bid )or adjusteddose warfarin( INR 2-3) primary event rate 2.3%/y with warfarin vs 1.6%/y with ximelagatran( absolute RR 0.7% p=0.10 )

18 Ximelagatran(2) disabling or fatal stroke, mortality, major bleeding : similar combined minor and major hemorrhage : lower (29.8% vs 25.8%/y RRR 14% p=0.007) raised ALT more common with ximelagatran SPORTIF V : slighgtly less favorable finding, again rejecting inferiority Good alternative to warfarin ( Spontaneous resolution of elevated ALT, fixed dose without need checking INR ) Caution : efficacy and safety with artificial valves/ Tx of severe hemorrhage/ breakthrough CVA ( ie, higher dose or switch to warfarin )

19 Nonpharmacologic antithrombotic TX Ligation or exclusion of the LA appendage Ligation of the LAA at the time of MV op with AF to reduce postop thromboembolism (ACC/AHA guidelines for VHD ) Experimental approach : percutaneous LAA transcatheter occlusion with an implanted device designed to exclude the LAA from the rest of the LA ( no RCT data ) Pulmonary vein isolation with or without LA ablation : sucess rate 75-85%,, improved QOL (Pappone study)

20 ACCP stroke risk and therapeutic guidelines

21 ACC/AHA/ESC guideline for antithrobotic therapy in AF

22 Comment on the guidlines Intermittent AF : same risk of stroke as permanent AF Atrial flutter : same risk of stroke as AF Thromboembolic events despite INR2-3 : increase the target INR warfarin + aspirin or clopidogrel

23 Rhythm control vs heart rate control (1)

24 Rhythm control vs heart rate control (2) (elctrocardioversion)

25 Rhythm control vs heart rate control (3)

26 Individualized approach Underrepresentation : CHF, young with paroxysmal AF Subgroup analysis in AFFIRM : rhythm control might be a better approach in <65 yr, CHF Majority of strokes d/t withdrawal of anticoagulants or subtherapeutic INR

27 First paroxysmal AF Object : to try and prevent further episodes without any specific AAD

28 First persistent AF

29 Recurrent paroxysmal AF

30 Recurrent persistent AF

31 Cardioversion - electrical (1) success rate 75-93%(50% for 5 yrs) Related inversely to the duration of AF, chest wall impedance, LA size Electrode position: anteroposterior > anterolater Posterior position infrascapular and slightly to the Rt of the spine and anterior position slightly to the Lt of the sternum centered at the level of the palpated maximal apical impulse Waveform : monophasic< biphasic( more effective, less energy ) Initial energy setting:>200jouls( more energy for obese and long-standing AF) on monophasic, 150 jouls for starting and 250 jouls for lagre patient on biphasic device

32 Cardioversion - electrical (2) Pretreatmennt with 1mg of ibutilide prior to cardioversion or oral amiodarone for 1 month : decrese reversion and increase maintenance of sinus rhythm Intermittent verapamil combination with continuous propafenone for 3 days before and 3 months after cardioversion : recur 6 %( 10% if given for 3 days prior and 3 days after, or 30% if propafenone alone ) Verapamil or ARB/ACEI with AAD when electrical cardioversion has failed because of early recurrence of AF

33 Cardioversion - pharmacologic Recent onset AF(< 7days,preferably <72 hrs) Success rate : 70% Ideal drug : conversion within an hour Conversion rate : 90% after 1hr of iv flecainide or propafenone, or 50-80%if orally Recommendation : only to monitored pts Caution : 1C ( propafenone, flecainide) paradoxical increase in VR d/t AFL with slower flutter rate and 1:1 AV nodal conduction + AV nodal blocking drugs

34 Pharmacological cardioversion of AF

35 Anticoagulation for cardioversion + hypercoagulability and atrial stunning One prospective cohort : thromboembolism from 5.3 to 0.8 % among anticoagulated pts Cutoff for considering cardioversion without anticoagulation : < 48 hrs Recommendation : even when < 48 hrs with stroke risk factors (d/t newly formed thrombus, adherent to the LA wall within 2 weeks) INR(2-3) for 3 weeks before and 4 weeks after CV Short duration for no evidence of thrombus or dense smoke in the LA and LAA on TEE ( ACUTE trial) heparin (until therapeutic INR)+ warfarin(at least 4 weeks) Discontiuation of warfarin : after 4 weeks, no stroke risk factors

36 Rhythm control-parmacologic AAD : greateset impact on recurrences more than 2 weeks after ECV for episodes of recurrent persistent AF Without AAD : >75% one year recur rate Amiodarone : more efficatious than other drugs ( 30-40% recur rate) but noncardiac side effect, interaction with warfarin, BBB, digoxin Vagally mediated AF( arises from bradycardia after meals or during sleep) : flecainide or disopyramide Recently in German, quinidine + verapamil as safe and effective as sotalol ( unpublished trials )

37 AF drug selection to maintain sinus rhythm Low risk of TdP : male with normal QTc

38 Rhythm control - nonpharmacologic (1) surgery simple procedure( removal or plication of the LAA to reduce the risk of thromboembolism), variety ( aimed at preventing recurrence of AF- partly surgical incisions and partly RF or cryoablation) No RCT or endpoint and selection criteria Limited to pts undergoing heart surgery for another indication, primarily MV op, highly symptomatic from AF in experienced center

39 Rhythm control - nonpharmacologic (2) Devices Atrial-based pacing ( Multisite pacing, shock therapy, software options for pacing maneuvers intended to either prevent AF, terminate AF or combination ) Recommendation : primary prevention AF in pts with SSS receiving pacemaker for symptomatic bradycardia and enough bradycardia paced in the atrium > 90% of the time + organized tachyarrhythmia( atrial flutter or atrial tachycardia) with AF + can take AAD ( hybrid therapy)

40 Rhythm control - nonpharmacologic (3) Catheter ablation Initial : RF in the earlier Maze op Radiofrequency or cryoablation(ra,la or both) Important site : Where the thoracic veins, particularly the PVs enter the atria End point : Denervation by ablation vagal ganglia located in the fat pad of the AV groove Ix : highly symptomatic pts, primarily with paroxysmal AF, failed drug therapy d/t inefficacy or intolerance, willing to undertake a lengthy procedure Attractive and hopeful procedure :cure over 65% (Cx : PV stenosis (9% 2 to 3%))

41 Drugs for maintenance of sinus rhythm

42 Rate control Good HR control : resting HR < 100 bpm, increase exercise tolerance, increased ability to exercise, regularization of VR By AFFRIM trial : resting HR < 80 bpm, assessment of HR with activities of daily living by 6-minute walk test ( <110 bpm), Holter monitoring average HR 100 bpm over 24 hrs, maximum houly rate 110% of the maximum predicted rate during exercise based on age and gender

43 Rate control pharmacologic (1) In typical AF and no AV node disease : Ventricular rate bpm Digoxin, nondihydropyridine CCB(verapamil, diltiazem),bb (1) Digoxin : less useful as single agent in younger, physically active except for elderly, heart failure / very useful when added to BB or CCB * act within 15-30mins with a peak effect attained in 1 to 5 hrs

44 Rate control pharmacologic (2) (2) Betablocker : effective therapy, iv esmolol, metoprolol, propranolol * Chronotropic incompetence : hybrid therapy by adding a pacemaker to protect from symptomatic bradycardia (3) Verapamil: less chronotropic incompetence, negative inotropic * iv diltiazem : less negative inotropic than verapamil, overall success rate 98%

45 Drugs used for rate control

46 Rate control - nonpharmacological Ix : who have severe symptoms highly likely to be due to rapid ventricular rate, who cannot be effectively controlled with medications, or who develop intolerable adverse drug effects during pharmacological therapy RFCA : (1 < 2 ) (1) ablation of slow pathway to AV node(20% possibility of developing complete HB) (2) complete AV junction ablation with permanent pacemaker implantation(97.4% success rate,3.5% recur ) VVIR mode - reduced symptoms, peak VR both during rest and exercise compared to pharmacologic approach - stroke risk need to continue anticoagulation - VF or SCD postprocedure : 2.1% ( for at least 6 weeks 80bpm )

47 AF with WPW Risk of SCD d/t conduction at high rates to the ventricle over the accessory pathway Hemodynamic instable : ECV Hemodynamic stable : iv procainamide contraix : iv AV blocking agent d/t accelerate HR, precipitate VF cardiac arrest, related to sudden hypotension After stable : catheter ablation

48 AF with HCMP Suppression of the arrhythmia : disopyramide, amiodarone, sotalol Rate control : BB or CCB Anticoagulation : high tendency to develop thromboembolic events

49 AF with HF (1) AF prevalence : 10-30% Impair LV myocardium and/or lead to overt cardiac decomposition No solid evidence that AF is independent predictor of worse outcome More sensitive to the adverse effects( arrhythmic death ) Ix of Tx: control symptoms( worsening HF related to loss of atrial contraction and/or RVR)

50 AF with HF (2) AF-CHF trial Amiodarone or dofetilide as first line BB with or without digoxin for rate control Ablate and pace approach to improve ventricular function in selected pts resistant to drug therapy

51 Thank you for your attention! Thank you for your attention!