CPVI Plus Electrophysiological Substrate Ablation of the Left

Atrium during Sinus Rhythm (STABLE-SR)

for the Treatment of Persistent AF

Minglong Chen, MD

Division of Cardiology

Nanjing Medical University Hospital, Mainland China

Background

Circumferential PV Isolation (CPVI)

Effective in curing PAF

(The success rate in single procedure was 75.6%, 6M Follow up )

Ouyang, et al . Circulation 2004; 110: 2090-2096.

Efficacy of PVI for persistent AF

Author Year Pts(N) Age(Yr)LA size

(mm)

Follow-up

(months)

Primary

Success(%)

Kanagaratnam 2001 71 57±12 42±8 29±9 21

Lim 2006 51 59±10 45±6 17±9 22

Yamada 2007 14 56±9 39±4 —— 21

Anthony G, et al. Heart Rhythm 2010;7:835-846.

Single Procedure

Limited success rate in persistent AF

Per-AF requiring aggressive ablation strategies

Linear ablation

CTI

LA Roof

Posterior Mitral/MI

Coronary Sinus

CFE ablation

Aggressive ablation strategy

Efficacy of aggressive ablation for per-AF

Anthony G, et al. Heart Rhythm 2010;7:835-846.

“CPVI + Lines + CFE”

Author Year Pts(N) Age(Yr)LA size

(mm)

Follow-up

(months)

Primary

Success(%)

Estner 2008 35 57±9 49±6 19±12 51

Li 2008 92 59±6 42±5 12±11 58

Elayi 2008 49 59±12 46±6 16±1 61

Oral 2009 50 62±8 46±6 10±3 36

RASTA Study

Randomized Controlled Trial 1 year Follow-up

Evaluate the single procedure efficacy of Per-AF

Per-AF (n=156)

Group2 (n=50)

Group3 (n=51)

Group1 (n=55)

PVI PVI+Lines PVI+CFE

PVI PVI+Lines PVI+CFE

*P=0.04

*P=0.004

RASTA Study

Primary Study End Point: Freedom from AF/AT off AADs

29%???

Oral H, et al. J Am Coll Cardiol 2009; 53: 782-9

Does linear ablation and defragmentation really improve the success rate of persistent AF?

----Follow-up results and EP findings in the redo procedures from

169 consecutive patients

Roof-line-1

Roof-line-2

Posterior mitral line-1

Posterior mitral line-2

Posterior mitral line-3

Posterior mitral line-4

The Study Results

169 consecutive Per-AF patients

2007.5~2010.7

Mean age: 56y

Mean LAD: 42mm

Mean AF duration: 24m

15±8 months Follow up

169 pts

SR: 84 pts (50%)

AT: 51 pts (30%)

AF: 34 pts (20%)

AT ablation: 46pts

Macro-AT: 36 Focal-AT: 45

81 ATs

Proarrhythmic effects of linear lesions

Mechanism of AT after AF ablation

Macro-reentrant

Mechanism of AT after AF ablation

Macro-reentrant

Proarrhythmic effects of linear lesions

Mechanism of AT after AF ablation

Ju W, Chen ML, et al. PACE 2011;34(8):919-26.

Focal

Proarrhythmic effects of linear lesions

CFE ablation

Proarrhythmic effects of empiric CFE ablation

Localized reentry as a novel type of the proarrhythmic effects of linear lesion in the left atrium

----Ju et al. PACE. 2011;34:919-926

The ideal ablation strategy of persistent AF

still remains a matter of debate…Veenhuyzen GD, et al. PACE 2009 Mar;32(3):393-8.

Comparison of Left Atrial Electrophysiologic Abnormalities

during Sinus Rhythm in Patients with Paroxysmal, Persiste

nt and Long-Standing Atrial Fibrillation

Par-AF: 30 ptsPer-AF: 22 ptsLS-AF: 28 ptsControl: 20 pts with LAP

Mapping Methods

• A-Focus high density mapping during sinus rhythm

• Mapping was done after CPVI, Per-AF and LS-AF need cardioversion

• NavX: interior and exterior projection, interpolaration were set at 5 mm

• LA voltage, activation time and complex electrograms were analyzed

Comparison of the LA activation time among different populations

The correlation of LA activation time with overall mean bipolar voltage, left atrium diameter ， low voltage index and percentage of complex electrograms

Definition of Complex Electrocardiogram

Distinct deflections ≥ 3

Electrocardiogram duration≥ 50 ms

> 50ms

A: Comparison of the percentage of complex electrograms in LA. B: Comparison of the mean bipolar voltage of complex electrograms. C: Comparison of the duration of complex electrograms.

Study Findings

• With AF progression there was a lower mean bipolar voltage, higher low voltage index and more prevalent and larger LVZ area in LA

• With AF progression there was also conduction abnormalities characterized by prolonged LA activation time and more proportion of complex electrogram

• The cutoff value to define low voltage zone (0.1~0.4mV) and the transitional zone (0.4~1.3mV) was defined

New ablation strategy

Novel ablation strategy for Per-AF

CPVI

Cavotricuspid isthmus ablation

LA high density electroanatomic mapping

Substrate modification

Check linear lesions to achieve bidirectional block

To double check PV being isolated

Cardioversion

AF = atrial fibrillation; CPVI = circumferential pulmonary vein isolation; CTI = cavotricuspid isthmus; DC = direct current; SR = sinus rhythm; LA = left atrium; HDM = high density mapping; LVZ = low voltage zone; TZ = transitional zone

AF = atrial fibrillation; CPVI = circumferential pulmonary vein isolation; CTI = cavotricuspid isthmus; DC = direct current; SR = sinus rhythm; LA = left atrium; HDM = high density mapping; LVZ = low voltage zone; TZ = transitional zone

Pilot Study of Circumferential Pulmonary Vein Isolation Plus Electrophysiological Substrate Ablation in the Left Atrium During Sinus Rhythm (STABLE-SR) in the

Treatment of Chronic Atrial FibrillationClinicalTrials.gov Identifier: NCT 01716143

Representation of substrate-based ablation during SR in the LA besides CPVI

Example of relatively “healthy” LA and does not need additional ablation

No LVZ was found in the LA body

No LVZ was found in the LA body

No CFE was found in TZ

No CFE was found in TZ

Example of diffused LVZ and SR-CFEs within TZ

Color bar setting: 0.1~0.4 mV

Color bar setting: 0.1~0.4 mV

Color bar setting: 0.4~1.3 mV

Color bar setting: 0.4~1.3 mV

Lesion deployed based on HDM mapping results

Continuous ablation of the site with CFE till the voltage was < 0.1 mV

The circular catheter was dislodged from the PVsThe circular catheter was dislodged from the PVs

Example of HDM after CPVI

Notice the distribution of LVZ and TZ with CFEs

Lesion deployment according to HDM results

Homogenization of LVZ, modification of the TZ sites with CFEs and joining these areas to the right lesion ring and the anterior mitral annulus actually create a narrow band of conduction block in the left anterior septal wall.

Pacing from the LAA to check the conduction block

ResultsBaseline Patient Characteristics (N=68)

Number of patients 68

Age, yrs 52.5 ± 10.5

Male, n 61 (89.7)

AF duration, months 19.5 ± 21.6

Hypertension, n 38 (55.9)

Structural heart disease, n 6 (8.8)

LA diameter, mm 40.9 ± 4.1

LVEF, % 63.0 ± 5.3

CHADS2 score 1.0 ± 0.8

Results

Percentage of patients with LA substrates at different regions

75 enrolled pts

CPVI + CTI ablation

Failed ( 9.3% )SR ( 90.7% )

cv

68 7

Aggressive ablation

STABLE - SR

Distribution of LVZ and TZ of 57 Regions and the Corresponding Ablation Strategies

Region Number Linear ablation LVZ homogenization

Roof 16 16 0

Anterior 19 7 12

Posterior 17 2 15

Lateral 1 1 0

Septum 4 1 3

Left atrial appendage 0 0 0

• Freedom of ATa off AADs after a single-ablation procedure: 53 of

68 (77.9%)

• Types of recurrent arrhythmia• PAF in 12 of 68 (17.6%)

• persistent AF in 2 of 68 (2.9%)

• AT in 1 of 68 (1.5%)

• Arrhythmia recurred within the first year after ablation in 6 of 68

(8.8%) patients. Nine (13.2%) patients had recurrences after 12

months after ablation.

ResultsFollow-up (21.5 ± 7.8 months)

68 pts

Ata Free (53) Ata occurrence (15)

PAF (12) PeAF (2) AT (1)

• Total procedure: 212 ± 34 minutes

• Total fluoroscopy time: 31 ± 7 minutes

• Adverse Events 2 (2.9%) femoral hematomas

Results

Comparative Study of STABLE-SR vs. STEPWISE in the Treatment of Chronic Atrial Fibrillation

ClinicalTrials.gov Identifier: NCT 01761188

Randomized

Comparative

Multicenter

Single blind

Prospective

Launched in June 6, 2013

Conclusion

Aggressive ablation strategy is “a knife with two blades”

linear ablation and CFE ablation should be highly selective,

but not empirical and extensive

CPVI plus substrate based ablation (LVZ ablation and co

mplex electrgram modification) might be a more electroph

ysiological individualized ablation strategy for chronic AF

patients

“Nanjing Approach”