CARDIOLOGY GRAND ROUNDS

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1 CARDIOLOGY GRAND ROUNDS Title: Controversies in AF ablation, pros/cons, LT outcomes Speaker: Bruce D. Lindsay Section Head, Clinical Cardiac Electrophysiology, Vice-Chair Cardiology Cleveland Clinic Date: Monday, October 17, 2016 Time: 7:00 8:00 AM Location: ANW Education Building, Watson Room OBJECTIVES At the completion of this activity, the participants should be able to: 1. Distinguish the concepts related to atrial fibrillation that affect our ablation strategies. 2. Identify factors that affect long term success for ablation of atrial fibrillation. 3. Recognize the potential advantages and limitations of novel technologies for ablation of atrial fibrillation. Physician: This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of Allina Health and Minneapolis Heart Institute Foundation. Allina Health is accredited by the ACCME to provide continuing medical education for physicians. Allina Health designates this live activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) TM. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Nurse: This activity has been designed to meet the Minnesota Board of Nursing continuing education requirements for 1.2 hours of credit. However, the nurse is responsible for determining whether this activity meets the requirements for acceptable continuing education. DISCLOSURE STATEMENTS Speaker: Dr. Lindsay has declared the following relationships; Consultant: Abbott Laboratories, Biosense Webster, and Medtronic, Inc. Planning Committee: Dr. JoEllyn Abraham, Dr. Alex Campbell, Dr. Kevin Harris, Rebecca Lindberg, Dr. Michael Miedema, Dr. Scott Sharkey, Eva Zewdie and Jolene Bell Makowesky have declared that they do not have any conflicts of interest associated with the planning of this activity. Dr. David Hurrell declares the following relationship honoraria: Boston Scientific. ACKNOWLEDGMENT OF SUPPORT This presentation is partially funded by an educational grant from Abbott Vascular. PLEASE SAVE A COPY OF THIS FLIER AS YOUR CERTIFICATE OF ATTENDANCE Signature: My signature verifies that I have attended the above stated number of hours of the CME activity. Allina Health - Learning & Development Chicago Ave - MR Minneapolis MN 55407

2 Controversies in Ablation of Atrial Fibrillation Bruce D. Lindsay, M.D. Cleveland Clinic Disclosures Abbott Scientific Advisory Board Biosense Webster Scientific Advisory Board Medtronic Strategic Advisory Board 1

3 Physiology of AF Reentry vs Automaticity Englemann 1894: Multiple automatic foci Rothberger & Winterberg 1914: Single Automatic focus fires and drives AF Garrey 1924: critical mass required; reentry Moe 1962: Multiple wavelet hypothesis 2

4 Lessons Learned from Mapping Transient Reentry in RA During Human AF Cox JL. J Thoracic and Cardiovasc Surg 1991:

5 Transient Reentry in LA in Human AF Cox JL. J Thoracic and Cardiovasc Surg 1991: Summary of Observations From Washington University OR maps Reentry observed in RA Left atrium demonstrated multiple wave fronts and conduction block Stable left atrial reentry not detected No stable rotors No abnormal automaticity 4

6 Longstanding Persistent and Chronic AF in Humans Sahadevan J. Circulation 2004:110: ) 7 of 9 patients showed short, regular cycle length ( ms) with identical beat to beat morphology LA in 5 and RA in 1; both in 1 The rest of the atria activated irregularly ( fibrillatory conduction ) 2 of 9 showed no evidence of regular activation or constant morphology Rapid regular rhythms may serve as drivers Biatrial High Density Mapping of AF Lee S. Circulation 2015;132: patients with persistent and longstanding AF Multiple foci of different cycle lengths in both atria Sustained or intermittent Predominantly lateral left wall All wave fronts emanated from foci No reentry 5

7 Long Standing AF Allessie MA. Circ Arrhythm Electrophysiol 2010;3: Lateral boundaries of waves formed by conduction block parallel to musculature Lines of block not fixed, changed beat to beat Number of fibrillation waves more complex with longstanding compared to induced AF. Quantification of Transmural Dynamis of AF by Simultaneous Endocardial and Epicardial Optical Mapping in Sheep Gutbrod SR. Circ Arrhythm Electrophysiol 2015;8: AF substrate is a 3D structure with range of discordance between endocardial and epicardial propagation Representative phase maps 6

8 Noninvasive Electrocardiographic Imaging Ramanathan C, et al. Nature Medicine 2004;10: Focal Origin in PAF Cuculich PS. Circulation. 2010;122:

9 Complex Rotors: Emerges and Breaks in into 2 Fronts Cuculich PS. Circulation. 2010;122: AF Complexity Cuculich PS. Circulation. 2010;122:

10 Focal Impulse and Rotor Modulation for Ablation of AF: FIRM Registry Miller JM. J Cardiovasc Electrophysiol 2014;24: Physiology of Long Standing Persistent AF PAF LSPAF Progressive scar burden Progressive complexity of atrial activation 9

11 Definitions of AF Paroxysmal: Recurrent 2 episodes that terminate within 7 days or cardioversion <48 hours Persistent: 7 days or cardioversion > 48 hours; up to a year in duration Long-standing Persistent: AF > 1 year duration MRI Detection of Scar Akoum N. Curr Cardiol Rep 2014;16:518 10

12 Four Stages of LA Fibrosis Marrouche N. JAMA 2014;311: Atrial Fibrosis vs Stage of AF Akoum N. Curr Cardiol Rep 2014;16:518 11

13 Cumulative Incidence of AF Recurrence Marrouche N. JAMA 2014;311: Other Factors Affecting Success Valve disease Hypertension Diastolic dysfunction Cardiomyopathy Dilated HCM Prior surgery LA size Other: Obesity, alcohol, sleep apnea 12

14 Ablation of Persistent or Long- Standing Persistent AF Limitations of Clinical Data for Ablation of Persistent or Long Standing Persistent AF Smaller number of patients Paucity of multi-center randomized clinical trials Data often mixes with persistent and longstanding persistent AF Mixture of Lone AF with AF associated with structural heart disease 13

15 Limitations of Clinical Data for Ablation of LSPAF Suboptimal follow up Variable approaches to ablation Lesion sets Therapeutic endpoints Effective lesion formation Strategies for Ablation of Atrial Fibrillation Elimination of Common Triggers Linear lines to prevent reentry Elimination of complex fractionated atrial electrograms (CFAE) Target areas adjacent to scar Target repetitive wavelets Target stationary rotors 14

16 Long Term Outcomes of Ablation Updated World Wide Survey Capatto R, et al. Cir Arrhythm Electrophysiol 2010;3:32-38 Number Success No AAD Success With AAD Overall Success Paroxysmal % ( ) 9.1% ( ) 84.0% ( ) Persistent % ( ) 10% ( ) 74.8% ( ) Long Lasting % ( ) 7.9% ( ) 71% (67/4-76.3) 15

17 Long-Term Outcome of AF Ablation: Impactand Predictors of Very Late Recurrence Wokhlu A, et al. J Cardiovasc Electrophysiol 2010;21: Mayo Clinic N=774 PAF 55%, Persistent or Longstanding 45% Elimination of AF PAF 2 years Persistent AF 2 years Higher rate of late recurrence with Persistent AF from 1.0 to 2.5 years PAF recurrence rate increased 12% Persistent recurrence rate increased 20% Rate and Timing of Recurrence 16

18 Impact of Type of AF and Repeat Ablation on Long-Term Freedom from AF Bhargava M, et al, Heart Rhythm 2009;6: Natural History and Long Term Outcomes of Ablated Atrial Fibrillation Hussein A A et al. Circ Arrhythm Electrophysiol 2011;4: Long Term Follow Up of 831 Patients 69% PAF and 31% Persistent Median Follow Up 55 months 3-13 months 24% Late Recurrence >12 months 8.9% Mean Follow up 55 months 17

19 Kaplan Meier curves for arrhythmia-free survival after AF ablation. Early Recurrence <1 yr, single ablation All Recurrence (Early & Late) Late Recurrence No early recurrence All Recurrence After Last Ablation Hussein A A et al. Circ Arrhythm Electrophysiol 2011;4: Outcomes For Patients With Early Recurrence Hussein AA. Circulation Arrhythmia & Electrophysiology 2011;4: % underwent repeat ablations All showed recovery of one or more PVs 79% remained free of arrhythmias after the 2 nd ablation 21% had recurrence after the 2 nd ablation 65% of these were controlled by medications 18

20 Recurrence Rates in Patients with Paroxysmal Vs Persistent AF Hussein AA. Circulation Arrhythmia & Electrophysiology 2011;4: N Recurrence In 1 st YR Late Recurrence P Value Paroxysmal (19%) 45(7.8%) < Persistent (35%) 29 (11.3%) < Risk Factors for Late Recurrence Hussein AA. Circulation Arrhythmia & Electrophysiology 2011;4: Older age Nonparoxsmal AF Left Atrial Size 19

21 Types of Recurrent Arrhythmias Hussein AA. Circulation Arrhythmia & Electrophysiology 2011;4: Early Recurrence Late Recurrence P Value Atrial Fibrillation 83% 78% ns Atrial Flutter 48% 27% Atrial Tachycardia 6% 4% ns Natural History and Long Term Outcomes of Ablated Atrial Fibrillation Hussein A A et al. Circ Arrhythm Electrophysiol 2011;4: Observations from Repeat Ablations Recovery of 1 or more PV in 100% Long Term Efficacy after 1 or more ablations 79% Free of AF without drugs 11% Free of AF with Drugs 5% Refractory AF 20

22 Star AF Trial Verma a. NEJM 2015;372: patients with persistent AF Strategies Targeting Persistent AF 21

23 Ablation of Persistent AF Targeting Low-Voltage Areas with Selective Activation Characteristics Jadidi AS. Circ Arrhythm Electrophysiol 2016 Freedom From Arrhythmias Voltage Guided Ablation vs PVI Jadidi AS. Circ Arrhythm Electrophysiol

24 Mapping Complex Atrial Fractionated Electrograms Nademanee K. Journal of Cardiology (2010) 55, 1 12 PAF 89% Persistent 85% Permanent 71% Nademanee K. JACC 2008;51: Residual Arrhythmogenic Foci Predict Recurrence Long-Standing Persistent AF Kurotobi T. Canadian J Cardiol 2014;30:

25 Median Number of Driver Regions Ablated to Terminate AF Increases with Duration of AF Haissaguerre M. Circulation 2014:130: AF Free outcome was more favorable with termination 2. 85% Free of AF at 1 year Phase Maps of AF Showing Intermittent Reentry Haissaguerre M. Circulation 2014:130: Rotation Inferior LA Rotation Posterior Upper RA 24

26 AFACART Trial: Ablation Based on Non- Invasive Mapping Persistent AF Drivers in both atrial (2/3 LA and 1/3 RA) Increased number of drivers associated with decreased success Termination rates 64% Drivers only 66% Drivers and PVI 73% Drivers/PVI/Linear lesions 72% AF Free after 1 or more 12 months Mapping Stable Rotor Activity Swarup V. J Cardiovasc Electrophysiol;25:

27 Extended Follow UP of Confirm Trial Narayan SM. J AM Coll Cardiol 2014;63: Impact of Rotor Ablation on Nonparoxysmal Atrial Fibrillation Mohanty S. JACC. Accepted April

28 Focal Impulse and Rotor Modulation TOPERA/Abbott REAFFIRM Johannes Brachmann /Germany Focal Impulse and Rotor Modulation for persistent AF Enrollment completed Why Do We Fail? 27

29 AF Propagation Through Ablation Lines in Canines Melby SJ.Heart Rhythm 2008;5: Conduction velocities are slowed through residual gaps Propagation of wave fronts during pacing and AF occurred through majority of gaps as small as 1.1 mm. Correlation Between PV Isolation Gaps and Freedom from AF at 12 months Contact force >10 g did not improve success Stable contact >73% of time improved success Gaps > 10.6 mm correlated with 12 month failure B 100% 15/16 90% 80% 93.8% 70% 60% 50% 40% 8/24 30% 20% 33.3% 10% 0% Gaps No Gaps Subanalysis of Smart AF Trial (submitted) 28

30 Impact of Lesion Sets on Surgical Efficacy Melby SJ. Ann Surg 2006:244: Conclusions Mapping of AF substrate is feasible but complex Repetitive wavelets, stationary rotors, automaticity Need strategy for RA to ablate Persistent AF Paroxysmal AF Persistent AF Persistent AF Long Standing Persistent AF 29

31 Conclusions Success rate is lower but can improve QOL Often require multiple ablations PVI alone has limited efficacy Strategies for substrate modification are evolving Conclusions Advances in technology may permit rapid analysis of complex repetitive wavelets or rotors Information derived from these studies may alter current approaches to ablation of AF 30