Presentation on theme: "Atrial Fibrillation Rate or Rhythm Control"— Presentation transcript:
1Atrial Fibrillation Rate or Rhythm Control Saeed Oraii MDTehran Arrhythmia ClinicApril 2007Shiraz
2“Delirium Cordis”First described by Sir William Harvey in 17th century:observed chaotic motion of atria in open chest animalHeart rhythm irregularity first described in 1903 by HeringECG findings described in 1909 by Sir Thomas Lewis:“irregular or fibrillatory waves and irregular ventricular response” or “absent atrial activity with grossly irregular ventricular response”The irregularity and inequality of heart rhythm associated with atrial fibrillation was first described by Dr. Hering in 1903.Atrial fibrillation is by far the most common sustained arrhythmia diagnosed and treated by physicians. It may be either paroxysmal or chronic. Paroxysms may be brief or lengthy, frequent or infrequent; they may be benign or result in marked symptoms.1
3Atrial fibrillation accounts for 1/3 of all patient discharges with arrhythmia as principal diagnosis6% PSVT6% PVCs18% Unspecified4% Atrial Flutter9% SSS34% Atrial Fibrillation8% Conduction Disease10% VT3% SCD2% VFBaily D. J Am Coll Cardiol. 1992;19(3):41A.
4Incidence and Prevalence Prevalence increases with age4.8 % in the age groupIncreases to8.8% in the age groupDuring the next 7-8 years, the number of people over the age of 80 is expected to quadruple
5Atrial Fibrillation Demographics by Age U.S. population x 1000Population with AF x 100030,00020,00010,000Population with atrial fibrillation500400300200100U.S. population<55- 910- 1415- 1920- 2425- 2930- 3435- 3940- 4445- 4950- 5455- 5960- 6465- 6970- 7475- 7980- 8485- 8990- 94>95Age, yrAdapted from Feinberg WM. Arch Intern Med. 1995;155:
6Projected AF Prevalence: OLMSTED COUNTY DATA12% observed increase in AF incidencebetween 1980 and 2000Miyasaka et al, Circulation 2005; 114:119
7Projections of AF Prevalence in the United States Adults With AF (millions)It is expected that as the number of elderly people in the United States increases, diagnoses of AF will increase proportionally. A recent study applied age-specific estimates of the prevalence of AF to US census data to estimate the number of adults who will be diagnosed with AF in the future.Go and colleagues estimated that the number of patients with AF will approach 3 million within the next 15 years. The authors estimated that in the year 2050, 5.6 million adults in the United States will be diagnosed with AF.Adapted from Go. JAMA. 2001;285:2370.
8Complications and Prognosis 5-fold increase in risk of stroke and thromboembolismStrokes associated with AF are more severeDeath: OR 1.5 –1.9AF worsens diagnosis in CHD and HFImpairment in cognitive functionReduced exercise tolerance
9The 10,000 Foot View … The prevalence of AF is rapidly increasing Aging populationTrue increase in incidenceLifetime risk of AF at age 40 is 25%AF is a progressive disorderCardiac remodeling due to genetic factors, acquired disease, atrial fibrillation itselfUp to 25% of initially self-terminating AF will become chronic in 5 years, > 50% at 10 yearsAssociated with substantial risk of adverse outcomes beyond immediate symptomsStrokeCongestive heart failureDeathAssociated with substantial increase in health care costs and resource utilization
10Therapeutic Approaches to Atrial Fibrillation AnticoagulationRate Control (ventricular response)PharmacologicCatheter modification/ablation of AV nodeRhythm ControlAntiarrhythmic suppressionCurative proceduresCatheter ablationSurgery (maze)
11Thromboembolic prophylaxis Thromboembolic events do not just occur in permanent AFConsider treatment for all patients with AFClustering of events at the time of onset62% RR reduction with adjusted dose Warfarin22% RR reduction with Aspirin0.9% absolute risk increase of major haemorrhage with Warfarin
12Risk Assessment Tools Do not apply to valvular heart disease Risk of thromboembolism depends on other risk factors in patients with AFVarious risk assessment tools availableThere are differences between CHAD2 and the tool favoured in the NICE guidelines
14Therapeutic Approaches to Atrial Fibrillation AnticoagulationRate ControlPharmacologicCatheter modification/ablation of AV nodeRhythm ControlAntiarrhythmic suppressionCurative proceduresCatheter ablationSurgery (maze)
15AF: Pharmacologic Rate Control DigitalisBeta BlockersCalcium Channel Blockers (verapamil, diltiazem)Amiodarone (in special settings)
16Atrial Fibrillation: Rate Control Essential in all patientsPersistent tachycardia rates can induce cardiomyopathy and heart failureOccasional follow-up holter monitor to ascertain rate controlTarget: bpm restbpm with exercise
17Adequate Rate Control AFFIRM RACE HOT CAFÉ Average HR of ≤80 beats/min at rest and either a maximum of ≤110 bpm during a 6-minute walk or an average of <100 bpm on 24-hour Holter monitoring, with the rate not exceeding 110% of maximum predicted age-adjusted exercise rate.RACEResting heart rate on a 12-lead ECG of ≤100 beats/minHOT CAFÉA heart rate of 70–90 beats/min on a resting 12-lead ECG and ≤140 beats/min during moderate exercise
18Digoxin: some words of caution Oldest and most commonly prescribed drug for control of ventricular ratePredominant acute effect is mediated by the autonomic nervous systemAn important slowing effect of the AV node is mediated by enhanced vagal toneNot effective during periods of increased sympathetic toneNot effective in paroxysmal atrial fibrillation
19AVN Ablation and PPM Paroxysmal AF – DDDR pacing with mode switch Permanent AF – VVIR pacemakerBiventricular devices may be better in preserving LV function
20AVN Ablation and PPM Pros: Controls and regularizes ventricular rate Effective at improving symptoms, QOL and ? LV functionCons:PermanentDetrimental effects of RV pacing, especially if reduced LV function alreadyStill have thromboembolic riskContinue to have loss of atrial contractile function
21Ablate and pace Suitable for AF with symptomatic rapid ventricular rate unresponsive to drug Rx, or when drug Rx not toleratedCurative AF ablation not suitable or not possiblePatients with a bradycardia indication for pacingMore suited to elderly (less requirement for generator changes and lead revision)
22Therapeutic Approaches to Atrial Fibrillation AnticoagulationRate Control (ventricular response)PharmacologicCatheter modification/ablation of AV nodeRhythm ControlAntiarrhythmic suppressionCurative proceduresCatheter ablationSurgery (maze)
24Antiarrhythmic Therapy for Atrial Fibrillation AdvantagesHigh efficacy for some patients, at least initially (< 50% of all patients)Low initial costNoninvasiveDisadvantagesHigh recurrence rateHigh long-term costNon-curativeAdverse effectsPotential proarrhythmia
26Rhythm vs Rate control Trials PIAFLancet 2000AFFIRMNEJM 2002RACESTAFJACC 2003Hot CAFÉChest 2004
27Rate vs. Rhythm controlNone of the RCTs found rate control inferior in terms of mortality or quality of life.One study showed rate control reduced the mortality in patients without Heart Failure, in over 65s and in patients with CHD.Reduced rates of hospitalization and adverse events with rate controlNo difference in the rate of thromboembolic or hemorrhagic eventsRate control is more cost effective.
28AFFIRM: Atrial Fibrillation Follow-up Investigation of Rhythm Management DesignMulticenter, randomized, open, parallel groupPatients4060 patients who had atrial fibrillation that was likely to be recurrent, with other risk factors for stroke or death. Patients with contraindications for anticoagulant therapy were excludedFollow up and primary endpointPrimary endpoint: all-cause mortality. Mean 3.5 years follow up.TreatmentRate control: >1 rate-controlling drugs, plus anticoagulant, orRhythm control: >1 antiarrhythmics, plus cardioversion as necessary; anticoagulant encouraged but could be discontinuedNonpharmacological therapies and changes in pharmacological therapy, including crossover between groups, were permitted.The AFFIRM Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825–33.
30AFFIRM Drugs used in rate and rhythm control groups a Rate control Used drug forUsed drugUsed drug forUsed druginitial therapyat any timeinitial therapyat any timeNo.(%)No.(%)No.(%)No.(%)Rate control:data available1957202712662033Digoxin949(48.5)1432(70.6)417(32.9)1106(54.4)Beta-blocker915(46.8)1380(68.1)276(21.8)1008(49.6)Diltiazem583(29.8)935(46.1)198(15.6)610(30.0)Verapamil187(9.6)340(16.8)56(4.4)204(10.0)Rhythm control:data available1265202719602033Amiodarone2(0.2)b207(10.2)735(37.2)1277(62.8)Sotalol1(0.1)b84(4.1)612(31.2)841(41.4)aA few patients in the rate and a significant number in the rhythm control groups received other antiarrhythmicsbThese patients immediately crossed over to the rhythm control group, a protocol violationAFFIRM Investigators.N Engl J Med2002;347:1825–33.
31AFFIRM Goals of AFFIRM Anticoagulate: Resting HR <8024 hr Holter average <100 bpm. No HR above 110% of age predicted maximumHR <110 on a six min walkAnticoagulate:-If over 48hrs of AF, must anticoag before cardioversion.-Warfarin (6-12wks), heparin, LMWH-Aspirin-If Lone AF aspirin or nothing
32AFFIRM - RESULTS -No significant difference between rate control and rhythm control groups in:all-cause mortality (25.9 vs. 26.7%, P=0.08)composite secondary endpoint (death, disabling stroke or anoxic encephalopathy, major bleeding, and cardiac arrest)total number of central nervous system events (stroke or hemorrhage)Nonsignificant trends were towards reduction of all- cause mortality and CNS events with rate control, compared with rhythm controlSignificantly reduced hospitalization in rate control group compared with rhythm controlFewer patients initially assigned to rate control crossed over to rhythm control than crossed from rhythm to rate control (15 vs. 38% at 5 years; P<0.001)NOTE ON LAST POINT: paper shows crossover at 1, 3 and 5 years; have included only the latter here
35AFFIRM - SUMMARY-In patients who had atrial fibrillation and were at high risk for stroke or death, comparison of rate and rhythm control showed:No significant difference in all-cause mortality, composite secondary endpoint (death, disabling stroke, disabling anoxic encephalopathy, major bleeding, cardiac arrest) or ischemic strokeA nonsignificant trend to reduction of all-cause mortality and stroke with rate controlReduced hospitalization with rate controlCrossover to the other control method was lower in the rate control group
36RACE Trial Rate Control vs. Electrical Cardioversion 522 patients with persistent atrial fibrillation or atrial flutter (24 hours-1 year)2 cardioversions within 1 yearRate control to HR < 100 bpm and no symptomsRhythm control: Sotalol followed by Flecainide or Propafenone followed by AmiodaronePrimary endpoint: cardiovascular death, admission or CHF, Thromboembolic events, severe bleeding, pacemaker implantation or severe anti-arrhythmic side effects
38Rate vs. Pharmacologic Rhythm control Favor of rate controlFavor of rhythm controlPersistent AFHistory of AF more than 1 yearLess symptomatic> than 65 years of ageHistory of HTNPrevious AAD failureLA > 60 mmNo history of CHFPatient preferenceParoxysmal AFFirst episode of AFMore Symptomatic< than 65 years of ageNo history HTNNo Previous AAD failureLA < 60 mmHistory CHFPatient preference
39Who is under-represented in AFFIRM? Young patientsParoxysmal atrial fibrillationCHFReduced systolic functionIsolated diastolic dysfunctionDisabling symptoms of AFWhat therapies are under-represented ?Other (newer?) drugsNon-pharmacologic therapies
40What AFFIRM Does Not Tell Us? Optimal management for patients with moderate or severe disabling symptoms related to atrial fibrillationOutcome if better tools to maintain sinus rhythm were availableLong-term implications of rate vs. rhythm control (mean duration of follow-up only 3.5 years)
41Nonpharmacological Approaches to Atrial Fibrillation Pacemaker therapy2. Ablation3. Surgery
48Randomized Trials of Ablation for PAF STABILE: EHJ : ; prior AAD failure; 1 episode/mo 6 mo duration; included 32% persistent AF; AAD given to ablation group; PVI+MI+CTI; blanking 1 mo; HM + 3 mo daily event montioring; endpoint 30 sec AFWANZI: JAMA 2005: 293: ); No prior AAD; 1 episode/mo 3 mo duration; PVAI; blanking 2 mo; HM + 1,3 mo event monitoring; endpoint 15 sec AF. Pilot study for RAAFT (400 pt trial)JAIS: HRS Scientific Sessions 2006; Prior AAD failure, 2 episodes/mo 6 mo duration; PVI+CTI+lines; blanking 3 mo; HM + symptom diaries; endpoint 3 min AF or palpitationsPAPPONE: JACC 2006 in press, doi 10:1016. Limited prior AAD; 2 episodes /mo 6 mo duration;CPVI+CTI+lines; blanking 6 wks, daily event monitoring; endpoint 30 sec AFMajor complications in 1-4% of ablation groups
49Can Ablation Improve Survival? Pappone et al JACC 2003; 42:
50Catheter ABlation Versus ANtiarhythmic Drug Therapy for Atrial Fibrillation (CABANA) Randomized trial comparing ablation to best drug therapy (rate or rhythm control)Primary endpoint: mortality (powered for 30% mortality reduction assuming 12% 3 yr mortality in drug group)Secondary endpoints:Composite (death, disabling stroke, serious bleeding, cardiac arrest)Freedom from AF recurrence (irrespective of symptoms)Health care costs and resource utilizationQuality of lifePlanned 3000 pts, 120 enrolling centersPilot phase approved starting late 2006, full study pending approval
51Catheter ABlation Versus ANtiarhythmic Drug Therapy for Atrial Fibrillation (CABANA) Enrollment criteria> age 65, or < 65 with > 1 risk factor for strokeEligible for both AF, and at least 2 membrane active drugs or 3 rate control drugsParoxysmal (at least 2 episodes in prior 3 mo), persistent or chronic AFAblation technique to include PVI + additional procedures (lines, CFAE, ganglionated plexi)3 month blanking period in both groups (repeat ablation, or change in AAD permitted). Crossover to ablation in drug group strongly discouragedFollow-up with holter monitor, daily TTM (2 wks every 6 mo), and ILR (proposed 750 pt substudy)
52Curative AF ablation Potential harm Death Stroke Exacerbation of arrhythmia (flutters)Tamponade / PV stenosisFailure and redo ratePotential benefitsSymptomatic benefitNo need for AADs ?Thromboembolic benefit ?Mortality benefit?
53Who Should be Offered Ablation Here and Now? Patients with symptomatic, drug refractory atrial fibrillation, should be judged on an individual basis according to the Ablation Centre’s experienceIdeally, the patient should satisfy the following criteria:A rhythm control strategy is preferred and other therapeutic options are not as appropriateAttempts with at least 1 AAD have failedPreferably <70 (certainly <80!)Preferably normal heart or mild-moderate structural heart disease (LVEF>45%?)Preferably not a very dilated left atriumPrepared to accept risk of stroke (based on patient factors and institution’s results)Prepared to accept failure (based on institution’s results)Prepared to accept need for a re-do procedure (based on institution’s results)
54Points to remember:Will need Warfarin 1 month before and minimum 3 months after procedureMay require ongoing AA drug RxAFib and LA flutter often occur in first few months after procedure. True success should be assessed after 3-6 monthsPermanent AFib may be considered, but ~50% success rate
57Key Messages All patients with AF need thromboembolic risk assessment. Rate control will benefit most of our patients but adequate rate control is necessary.Digoxin is not first line drug for rate controlThe plethora of antiarrhythmic drugs currently available for the treatment of AF is a reflection that none is wholly satisfactory, each having limited efficacy combined with poor safety and tolerability.Catheter ablation considered a Class 2a indication for patients with symptomatic persistent or paroxysmal AF after failure of an initial trial of AAD therapy (AHA/ACC/ESC Guidelines)
58Tehran Arrhythmia Clinic Tehran Arrhythmia Center