Catheter Ablation of Atrial Catheter Ablation of Atrial Fibrillation in the Elderly Fibrillation in the Elderly

Burr Hall, MDBurr Hall, MD**

Wojciech Zareba, MD, PhDWojciech Zareba, MD, PhD**

Scott McNitt, MSScott McNitt, MS**

Darren Traub, DODarren Traub, DO****

James Daubert, MDJames Daubert, MD******

*University of Rochester Medical Center: Rochester, NY

**St. Luke’s Hospital and Health Network: Bethlehem, PA

***Corresponding author. Duke University Health System: Durham, NC

Epidemiology of atrial fibrillation (AF)Epidemiology of atrial fibrillation (AF) AF is the most common arrhythmia in clinical AF is the most common arrhythmia in clinical

practicepractice Approximately 2.2 million people in US have Approximately 2.2 million people in US have

paroxysmal or persistent AFparoxysmal or persistent AF 4.5 million in the European Union4.5 million in the European Union1,21,2

This may be an underestimate of the current This may be an underestimate of the current AF burdenAF burden

Population demographics predict a substantial Population demographics predict a substantial growth of the AF population over the next 30-growth of the AF population over the next 30-40 yrs40 yrs

1) Arch Intern Med. 1995;155:469-473

2) Fuster et al. J Am Coll Cardiol, 2006;

48:149-246

AF is a disease of the elderlyAF is a disease of the elderly

Go et al. JAMA 285: 2370-2375, 2001

Fuster et al. J Am Coll Cardiol, 2006; 48:149-246

AF affects 0.4 – 1% of general population 8% of those >80 years old

The median age of an AF patient is 75

70% of AF patients are ages 65 to 85

>65 years old

Between 1960 and 1990, the US population aged 65 and older grew by 88%; compared to 34% among those less than 65 years old.

Age and Projected Prevalence of AF

Atria Study Go et al; JAMA; 2001

Projected Number of Persons with AF in the United States Between 2000 and 2050

Miyasaka Y, et al. Circulation 2006;114:119-125.

Hospitalizations for Atrial Hospitalizations for Atrial FibrillationFibrillation

Wattigney et al. Circulation, 108 (6): 711, 2003

•Hospitalizations with AF as 1° diagnosis ↑ 34% from 1996 to 2001

•In past 20 years admissions with AF listed in the diagnoses ↑66%

What is wrong with having AF?What is wrong with having AF? Stroke riskStroke risk

Four to six times the Four to six times the general populationgeneral population

Associated with a Associated with a doubling of all cause doubling of all cause mortalitymortality

CHF exacerbationCHF exacerbation Systolic heart failureSystolic heart failure Diastolic heart FailureDiastolic heart Failure

Tachycardia-induced Tachycardia-induced cardiomyopathycardiomyopathy

Economic burden Economic burden $3,600 year/patient$3,600 year/patient 6.7 billion cost burden to 6.7 billion cost burden to

USUS Adapted from Dorian et al. JACC 2000. 36;1303-09

ACC/AHA Guidelines for AF2006

What is wrong with having AF?What is wrong with having AF? SymptomsSymptoms

Often debilitating Often debilitating

0102030405060708090

100

GeneralHealth

Vitality SocialFunction

AFCHFPost MIHealthy

Adapted from Dorian et al. JACC 2000. 36;1303-09

ACC/AHA Guidelines for AF2006

25-40% of patients with paroxysmal atrial fibrillation 25-40% of patients with paroxysmal atrial fibrillation (PAF) will progress to chronic AF over a 10-year period(PAF) will progress to chronic AF over a 10-year period

AF (short duration)

AF (variable duration)

DISEASED ATRIUM + Trigger (?Accentuation of preexisting heterogeneity)

NORMAL ATRIUM + Trigger (pulmonary veins, preexisting heterogeneity)

REMODELINGPERMANENTAtrial Fibrillation

Shivkumar K and Weiss JN. Atrial fibrillation from cells to computers. Cardiovasc Res. 2001.

Wijffels MCEF. Wijffels MCEF. CirculationCirculation 1995 1995

Management of Atrial FibrillationManagement of Atrial Fibrillation

1) Rate control and anti-coagulation1) Rate control and anti-coagulation

2) Rhythm control with anti-arrhythmic 2) Rhythm control with anti-arrhythmic agents (AADs) and anti-coagulationagents (AADs) and anti-coagulation

3) AVJ ablation and pacemaker placement3) AVJ ablation and pacemaker placement

4) Atrial fibrillation ablation4) Atrial fibrillation ablation

AFFIRM

Did AFFIRM actually study rate control Did AFFIRM actually study rate control versus rhythm control in an elderly versus rhythm control in an elderly population?population?

Was there truly equivalence between the Was there truly equivalence between the two strategies?two strategies?

The down side of rate controlThe down side of rate control

Rate control with AV nodal blocking agents was not Rate control with AV nodal blocking agents was not satisfactory in 20% of patientssatisfactory in 20% of patients

5.2% required AVJ ablation with pacemaker placement5.2% required AVJ ablation with pacemaker placement Invasive strategy making patients 100% pacemaker dependentInvasive strategy making patients 100% pacemaker dependent

14.9% (actuarial) crossover to AAD’s at 5 years14.9% (actuarial) crossover to AAD’s at 5 years

•In AFFIRM, all of the mortality benefit associated with the maintenance of SR appears to have been counterbalanced by the increased mortality risk associated with AAD drug use

•This raises the question “What if there was a safer method to maintain SR in this population?”

J Am Coll Cardiol. 2003;42:20-29.

AFFIRM : Antiarrhythmic Drug Sub-studyAFFIRM : Antiarrhythmic Drug Sub-study

(P<0.01)

(n=106)

(n=125)

(n=116)

Pharmacologic Approaches to Pharmacologic Approaches to Maintain Sinus RhythmMaintain Sinus Rhythm

Low success rateLow success rate 1-year AF recurrence of approximately 1-year AF recurrence of approximately

50%50%• Regardless of anti-arrhythmic agentRegardless of anti-arrhythmic agent• Amiodarone best agent Amiodarone best agent ~~ 65% SR at 16 months 65% SR at 16 months

Side effects commonSide effects common• AmiodaroneAmiodarone

Attrition rate of therapy due to many side effectsAttrition rate of therapy due to many side effects• 18% at 16 months in CTAF trial18% at 16 months in CTAF trial• 11% at one year AFFIRM trial11% at one year AFFIRM trial

Risk of pro-arrhythmiaRisk of pro-arrhythmiaAm J Cardiol 1991;68:335-41NEJM 2000;342:913-20 Am J Geriatr Cardiol, 2002; 11: 370–375Heart Rhythm, 2007; 4: 1577–1599.

The Elderly patient and AAD’sThe Elderly patient and AAD’s

Age related senescence alters the pharmacokinetics of AADs metabolism less predictable increased predilection for side effects Increased risk of pro-arrhythmias

Dayer MB, Hardman SMC. Special problems with antiarrhythmic drugs in the elderly: Safety, tolerability, and efficacy. Am JGeriatr Cardiol, 2002; 11: 370–375.

Curtis AB, Rich MW. Atrial fibrillation in the elderly: Mechanisms and management. Heart Rhythm, 2007; 4: 1577–1599.

Fang MC, Chen J, Rich MW. Atrial fibrillation in the elderly. AmJ Med, 2007; 120: 481–487.

Copyright ©2000 American Heart Association

Wood, M. A. et al. Circulation 2000;101:1138-1144

Meta-analysis of 1100 patients after AV junctional ablation and pacemaker placement for medically refractory atrial fibrillation, atrial flutter or atrial tachycardia: left ventricular function, healthcare use, and New York Heart

Association (NYHA) functional classification

Catheter Ablation of the AV Catheter Ablation of the AV JunctionJunction

AdvantagesAdvantages Improved rate controlImproved rate control Improved QOLImproved QOL Improved LVEFImproved LVEF No AADsNo AADs Less hospitalizationsLess hospitalizations

DisadvantagesDisadvantages Pacemaker Pacemaker

dependencedependence Procedure Procedure

complicationscomplications Continued embolic riskContinued embolic risk Progression of AF to Progression of AF to

more permanentmore permanent

What about AF ablation?What about AF ablation?

Haissaguerre M et al. N Engl J Med 1998;339:659-666

Diagram of the Sites of 69 Foci Triggering Atrial Fibrillation in 45 Patients

94% in PV’s

Copyright ©2001 BMJ Publishing Group Ltd.

Ho, S Y et al. Heart 2001;86:265-270

Important Insights into Pulmonary Vein Architecture

Copyright ©2001 BMJ Publishing Group Ltd.

Ho, S Y et al. Heart 2001;86:265-270

Muscular Sleeves with Gaps of Fatty Tissue and Fibrosis

Mechanisms of AFMechanisms of AFTriggers: Rapid discharges from focal sources

PV

Extra PV sites

Rotors: perpetuate AF

(in PV-LA junction)

Atrial structural remodeling; less organized conduction resulting in fibrillation

Vagal inputs

•Significant reduction in AF recurrence at 1-year with PVI

• QOL also significantly improved with PVI compared to AAD’s

PVI vs AAD as 1st line therapy for PAF

Age > 70 exclusion criteria

There is a disconnect between There is a disconnect between the AF ablation population and the AF ablation population and

the real AF population!!!the real AF population!!!

. J Cardiovasc Electrophysiol, 2007; 18: 23–38

AF ablation in the Elderly Review of AF ablation in the Elderly Review of the Literaturethe Literature

There are no prospective randomized controlled trials comparing the safety and efficacy of catheter ablation for paroxysmal or persistent AF in the elderly to best medical therapy or alternative strategies such as AV node ablation plus pacemaker placement

J Cardiovasc Electrophysiology 2005; 16: 457-61

Pappone HRS 2009

Can we use the same AF ablation Can we use the same AF ablation strategies in younger and older strategies in younger and older

patients?patients?

Older dogs in sinus rhythm (white circles) had lower Vmax and longer AP duration compared to adult dogs (black circles)

Older dogs in SR had significantly greater heterogeneity of repolarization than adult dogs (SD APD90 = standard deviation of action potential duration to 90% repolarization) as well as a larger interregional dispersion of AP duration. These spatial differences in AP duration and refractoriness likely facilitate re-entry; initiation and perpetuation of AF.

ConclusionConclusion Catheter ablation of AF can be safely performed in an

elderly population. There may be a slightly increased risk of peri-procedural

complications

Catheter ablation appears to be efficacious in an elderly population

All data based on retrospective analyses More elderly remain on AADs post-ablation

• This may be an acceptable endpoint for an elderly patient with symptomatic AF

The next step is to perform large scale, randomized trials like AFFIRM to more definitively establish the role of catheter ablation in treating elderly patients with atrial fibrillation