Atrial Fibrillation Ablation

Indications and Results

Oussama M. Wazni, M.D., FACC

AUB MC

NAAMA’s 24th International Medical Convention

Medicine in the Next Decade: Challenges and Opportunities

Beirut, Lebanon

June 26 – July 2, 2010

I have no actual or potential conflict of interest in relation to this program or presentation. I will inform the audience of any off-label uses discussed.

Name of Presenter:__Oussama Wazni______________________________

Atrial Fibrillation

Affects approximately 2 million people in the United States,

Less than 1% in persons younger than 60 years of age to more than 8% in those older than 80 years

Major Cause of Stroke

Increased mortality riskRelative risk of death increased by 1.5 in men

and 1.9 in women

Rate vs. Rhythm

Medical Approach

Neither approach was superior in terms of mortality at long-term follow-up

32.2 % of the AFFIRM study patients experienced serious events

Only 39% of patients taking AAD including amiodarone and 10% of patients taking AV blocking agent were in NSR at the end of the RACE study

In an analysis of the AFFIRM trial, sinus

rhythm was associated with a 47% reduction

in the risk of death whereas use of

antiarrhythmic drug therapy was associated

with a 49% increase in mortality

Limitations of Antiarrhythmic Therapy

<50% efficacy

Pro-arrhythmia

Toxicity

cost

Treatment

In asymptomatic patients then rate control

and anticoagulation strategy

In symptomatic patients then rhythm control

– Antiarrhythmic meds first

– At this time recurrence of AF after only one AAD

is considered an indication for ablation

AMIODARONE

indirect meta-analysis

dronedarone can prolong survival. But there

was a trend: an increased all-cause

mortality risk with amiodarone, at an OR of

1.61 (95% CI 0.97-2.68), fell short of

significance (p=0.066)

8 studies

Piccini JP, Hasselblad V, Peterson ED, et al. Comparative efficacy of

dronedarone

and amiodarone for the maintenance of sinus rhythm in patients with atrial

fibrillation. J Am Coll Cardiol 2009; 54:1089-1095

Alternative

A therapy that restores and maintains sinus rhythm while avoiding the deleterious effects of AADs would improve survival.

Pulmonary vein isolation may be such a therapy.

In a recent observational study involving a relatively large number of patients, Pappone et al. reported that AF ablation was associated with significantly lower mortality and adverse events compared with drug therapy

AF ablation in heart failure improves EF

The Present

Long Term

PAF cure 80-85%

Persistent/ Chronic 60-75%

Previously ineffective AAD may become

very effective

AF begets AF

ERPs and conduction times of the right atrium (RA), left atrium (LA), and the PVs were determined at baseline.

AF was induced and maintained for a period of 15 min.

Stimulation protocol was repeated.

At baseline, the PVs had significantly longer ERPs than the atria. After exposure to AF, the ERPs of both the atria and the PVs decreased significantly.

AF was more frequently induced after the presence of AF, particularly by pacing in the PVs

J Am Coll Cardiol. 2008 Jun 3;51(22):2161-2.

Sinus Begets Sinus

Artificial maintenance of AF leads to a

marked shortening of AERP, a reversion of

its physiological rate adaptation, and an

increase in rate, inducibility and stability of

AF.

All these changes were completely

reversible within 1 week of sinus rhythm.

Circulation. 1995 Oct 1;92(7):1954-68

70 Patients

PV-LA Junction Disconnection

(ICE+CM guided)

N=33

Randomized

Antiarrhythmic drug therapy

for rhythm control

N=37

RAAFT

Wazni et al JAMA

PVI AAD p

Patients 33 37 ns

Age (years) 538 548 ns

Left atrial size (cm) 4.10.8 4.20.7 ns

Duration of AF (years) 52.0 52.5 ns

Paroxysmal AF 32 35 ns

Persistent AF 1 2 Ns

SHD/HTN 25% (8/33) 28% (10/37) ns

Ejection fraction % 535 546 ns

Use of Beta-blockers 57% 62% ns

RAAFTPatient population

Wazni et al JAMA

PVI AAD p

Symptomatic AF

Recurrence

13%(4/32) 63% (22/35) <0.05

Re-hospitalization 9% (3/32) 54% (19/35) <0.01

Embolic events none none ns

Bleeding 6.3% (2/32) 2.9% (1/35) ns

Bradycardia none 8.6% (3/35) < 0.05

Severe PV stenosis none none ns

Mild PV stenosis 3% (1/32) none < 0.05

Moderate PV stenosis 3% (1/32) none < 0.05

RAAFT

Followup Results

Wazni et al JAMA

PABA CHF

Freedom from

symptomatic atrial

arrhythmia

0

ThermoCool AF

Protocol defined failure was lower with catheter ablation vs.

ADT: HR 0.30

Freedom from symptomatic and any (63% vs. 17%, p < 0.001)

recurrent atrial arrhythmia improved with catheter ablation

Adverse events were similar (4.9% vs. 8.8%, p = NS)

Trial design: Patients with symptomatic paroxysmal AF who had failed one antiarrhythmic

drug were randomized in 2:1 fashion to catheter ablation or ADT & monitored for 9 months.

Results

Wilber DJ, et al. JAMA 2010;303:333-40

Catheter ablation

(n = 106)

• Catheter ablation associated with better

intermediate-term outcomes vs. ADT in

patients with symptomatic paroxysmal AF,

who have failed one antiarrhythmic drug

• Further long-term data are awaited

16.0

66.0

%

(p < 0.001)

Conclusions

ADT

(n = 61)

Protocol-defined failure

(p < 0.001)

70.0

19.0

100

50

0

100

50

%

Thermocool AF

Thermocool Complications

1 pericardial effusion,1 edema, 1

pneumonia, 1 vascular complication,and 1

heart failure) in the

catheter ablation group (5/103 [4.9%])

5 patients (2 with life-threatening

arrhythmias and 3 with disabling drug

intolerance requiring discontinuation)

in the ADT group (5/57 [8.8%]).

Cessation of Coagulation

3,355 patients: 2,692 discontinued OAT 3 to 6 months after ablation (Off-OAT group) and 663 remained on OAT after this period (On-OAT group).

CHADS2 1 ≥2 Off-OAT 723 (27%) 347 (13%) On-OAT 261 (39%) 247 (37%)

Follow-up

28 ± 13 months Ischemic Stroke Hemorrhage

Off-OAT 2 (0.07%) 1 (0.04%) p = 0.06 On-OAT 3 (0.45%) 13 (2%) p < 0.0001

No other thromboembolic events occurred.

No Off-OAT group patient with a CHADS2 risk score of ≥2 had an ischemic stroke.

the risk–benefit ratio favored the suspension of OAT after successful AF ablation even in patients at moderate-high risk of TE.

Themistoclakis,JACC February 2010, 735-743

PV Isolation & Substrate ModificationNademanee et al (JACC 2004;43:2044-53)

Pappone et al (Circulation 2004;109:327-334)

Nakagawa et al (HR 2005;2(Suppl):S10-S11)Natale et al.2003

Oral H., Circulation 2003;108:2355

Pappone C., Circulation 2001;104:2539. Paschon, et al..

AF Catheter Ablation Strategies

Targets

1. Pulmonary Vein Isolation

Antral, focal, segmental, ostial

2. Substrate Modification

CFAE’s, lines, circles, tachycardias

3. Autonomic Modulation

“Ganglionic Plexi”

PV Antrum Isolation: Catheter Ablation

PV-LA Junction and SVC

Disconnection

RALA

MA

SVC

PV Antrum Isolation

Post RFA: Voltage Map

ICE Imaging - Transseptal

ICE guided PV-LA junction disconnection

Lasso-Catheter

RLPV

RUPV

PA

SVC Isolation

Pulmonary artery

SVC

Right superior PV

Lasso catheter

SVC Isolation

Importance of ICE

January 2005 and December 2008, PVI was performed in 3,052 patients with therapeutic INR (≥1.8) at the time of ablation.

Mean INR was 2.53 ± 0.62.

Only 3 (0.098%) patients had ischemic strokes.

One patient had a hemorrhagic stroke on the third day postablation but recovered completely by 1-week follow-up.

Bleeding complications occurred in 34 (1.11%) patients; most were minor (0.79%).

Major hemorrhagic complications occurred in 10 (0.33%) patients (tamponade in 5,(0.16%)

hematomas requiring intervention in 2, transfusion necessary in 3).

Wazni et al, Heart Rhythm Journal, 2010

Circular Mapping Approach to PVAI

Major Complications

0.6% 0.0% 0.3%

0.7% 0.0%

Future ?