1. LEADLESS CARDIAC PACEMAKERS:
UNIVERSITY HOSPITAL of Pisa
Division of Cardiovascular Diseases II
LEADLESS CARDIAC PACEMAKERS:
WHAT IS TO BE EXPECTED?
Pisa-Washington 14/12/2016
Dr. Francesca Menichetti
Dr. Maria Grazia Bongiorni
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

2. ONCE UPON A TIME… ADVANCES in PM SYSTEM
1930
2012
In 1930 was created the first devices designed for the recovery of the heart during arrhythmias.
ADVANCES in PM SYSTEM
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

3. Lead: a simple system? COMPONENTS Electrodes Conductors Insulation
Fixation
Connectors
ISSUES
Mechanical failure
Infection, extractions
Mobility resctrinctions
MRI incompability
pacemaker leads are the weakest part of pacing systems, often necessitating their risky removal and replacement

4. Estimated annual complication rate ≈ 5%
Device & Lead Issues
Infection ≈ 1 %
2-7% infection rate for replacement/upgrades1
≤ 0.5% infection rate for new implants1
Malfunction ≈ 2.5 %
% annual ICD lead failure based on age2,3
Occlusion ≈ 0.5 %
9-12% of device replacement or upgrade4
Redundant leads4 ≈ 1 %
4. Field M.E., Jones S.O., Epstien L.M. How to select patients for lead extraction. Heart Rhythm 2007; 4:
Estimated annual complication rate ≈ 5%
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

5. BENEFIT OF LEADLESS APPROACH
Reduced invasiveness
- Percutaneus procedure
- Reduced hardware
- “Invisible to the patient”
Improved Efficiency
- No pocket
- No system connection
- Reduced procedure time
Improved Outcomes
- Fewer complications
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

6. LEADLESS INTRACARDIAC APPROACH
Nanostim (CE)
(St Jude Medical)
Micra (Medtronic)
PM Devices
ICD Devices
LV Leads
December 2012
December 2013
S-ICD (C.H.Boston Sc.)
(CE & FDA)
September 2009
WiCS (EBR)
May 2011

7. Primary efficacy end point 98.3%
MICRA Trial: RESULTS
Low and stable thresholds
at the 6-month visit
Pacing Threshold
Primary efficacy end point 98.3%
Battery longevity estimation 12.5 y
R Wave
Impedance
Assumed performance of 89%
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)
D. Reynolds et al. NEJM Feb. 2016

8. MICRA Trial: comparison with standard PM
Control cohort of 2667 pts with transvenous PM from 6 previously published studies
51% Fewer major complications
54% Fewer Hospitalizations
87% Fewer System Revisions
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)
D. Reynolds et al. NEJM Feb. 2016

9. Histology of lead helix
Optimal electrode tissue interface allows for low and stable chronic thresholds.
Micra Device
Electrode
Fibrotic response
histology of a traditional active fixation electrode compared with the Micra. The blue is fibrotic tissue, with is more represented with the screw fixation system
Histology of lead helix
Histology of Micra
Bonner MD, Eggen M, Hilpisch K, et al. Performance of the Medtronic Micra Transcatheter Pacemaker in a GLP Study. Heart Rhythm. May 2014:11(5):S19.
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

10. Micra with Delivery System
23 F introducer
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

11. 1 2 3 4
After placing a sheath in the femoral vein in the groin (a venogram may be performed but it is optional), the pacemaker is delivered to theRA and then to the apex of the right ventricle using a steerable catheter
The pacemaker is undocked from the delivery catheter while a tethered connection is maintained. In case the position is suboptimal, it can be re-engaged and repositioned.

12. Tag test. The system is pull back for the visual confirmation of at least two tines engaged in several projections. With at least 2 tines fixed, a 15x strenght is necessary to keep device in site

13. Introducer removal
Figure 8 knot

14. Chest X Ray: Final result
Second Department of Cardiology- University Hospital of Pisa (Italy) 14

15. Unanswered questions
Will LCP match the reliability of current PM at long term FU?
Will there be any long-term thrombogenic complications?
What will be the real rates of dislodgement of LCP over time?
Which will be the strategy in the event of battery depletion? Removal or implant an additional device?
Abandoning the device and implanting a second unit is probably a viable option for many patients at elective replacement, given the small size of the unit, 10-year battery life, and mean age of 70 years for initial implantation. However, how this will affect cardiac function, and how many additional devices may be implanted, remains to be determined.
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

16. Retrievability
Pre-Clinical Experience The Micra® device has been successfully retrieved after 28 months in chronic animal models utilizing standard percutaneous tools and methods
In this pre-Clinical Experience Micra has been successfully retrieved after 28 months in chronic animal model using a custom sheath combined with market-released tool. On the lefft you can note the fibrous response on endocardial surface
Bongiorni MG, Segreti L, DI Cori A, et al.
Heart Rhythm Case Reports 2016; 2:43–46
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

17. Left ventricular resynchronisation LCP Combination of LCP and s-ICD
Multi-chamber leadless pacing systems
Two separate devices may be responsible for sensing cardiac events in different chambers and delivering electrical stimulation to the different chambers. In some instances, each of the devices may be able to detect and/or deliver electrical stimulation to one chamber of the heart.
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

18. Epi vs Endo LV stimulation
3D reconstruction of electrical activation times in the RV and LV
acute animal study wich indicate that the use of an endocardial LV pacing electrode may increase the efficacy of resynchronization therapy as you can see from this 3D reconstruction of electrical activation times in the RV and LV comparing Epicardial from CS and Endocardial LV stimulation
Caroline van Deursen et al. Circ Arrhythm Electrophysiol. 2009;2:

19. Left ventricular resynchronisation LCP
WiCS-LV is co-implanted with a pacemaker, ICD, or CRT device. It provides bi-ventricular pacing by sensing the RV pacing output of the co-implant and generating ultrasound targeted at the electrode that is converted to an electrical output to pace the LV. Contrast injection in this view illustrates the electrode attachment is clearly past the endocardial border.
The longitudinal strain echocardiographic evaluation shows significant reduction of mechanical dyssynchrony during simultaneous right ventricle and LVendo pacing

20. more echo guided implant
March 2012 study stopped
redesign catether
more echo guided implant
the study was stopped because of an hight complication rate so the cathether was redesigned and the implant is now more echo guided. A new multi-centre study was started but too small number of pts
Auricchio A, et al, Europace (2014) 16, 681–688

21. SELECT-LV Study Endocardial LV pacing in previous failed CRT patients
BIV pacing achieved in 97.1% and 88.5% at 1 and 6 m. Promising clinical response and a Safety comparable with standard CRT
BIV pacing achieved in 97.1% at 1 m
Promising clinical response
Safety comparable with con CRT

22. The S-ICD, not leadless but extravascular
80 J max output (Max 5 shocks/episode)
Biphasic, 50% tilt wave
Post-shock pacing ON/OFF
Episode memory
Induction test
Real time S-ECG
Standard
Reverse
Distal Sensing
Electrode A
9 FR
Coil
Pisa Experience
FU mths (range 1-40 mths)
Prox Sensing
Electrode B
The subcutaneous ICD leaves the vessels and the heartreally “untouched”. It is able to deliver up t joule biphasic shocks per episode, but it’s able to pace the heart only after a shock at 50 bpm for 30 seconds. On the right we present our experience. The totality of the shock were success at the first time, and the totality of the T waves oversensig were corrected by reprogramming. We have some inappropriate schocks in theunconditional zone on AFL, but no recurrences after sotalol
100% First shock success rate
100% TWOS, corrected by
Reprogramming
AFL 220 bpm, unconditional zone no recurrences after sotalol

23. Surgical lead extraction
Clinical case
G.A. 29 yrs
TV lead extraction
31/03/11
Surgical lead extraction
04/04/11
HCM
II prevention
Lead endocarditis
Bilateral
Axill-subcl.
occlusion
S-ICD implant
12/04/11
PRE
POST

24. LCP as complement to the S-ICD
Option for delivery of commanded ATP
Future pacing indications or brady-pacing support
Enhancement S-ICD discriminiation by providing intracardiac sensing
Option for delivery of post shock pacing
Communication with a subcutaneous ICD would allow both bradycardia and anti-tachycardia pacing, and would probably improve rhythm discrimination

25. CONCLUSIONS
The devices of the future could be largely devoid of intravascular leads
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

26. “Today you don’t think of a pacemaker implantation as something sensational. Well, ladies and gentlemen, then you are all wrong. It is still a sensation-for the patient”
Arne Larsson
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)

27. LEADLESS CARDIAC PACEMAKERS:
UNIVERSITY HOSPITAL of Pisa
Division of Cardiovascular Diseases II
LEADLESS CARDIAC PACEMAKERS:
WHAT IS TO BE EXPECTED?
Pisa-Washington 14/12/2016
Dr. Francesca Menichetti
Dr. Maria Grazia Bongiorni
Division of Cardiovascular Diseases - University Hospital of Pisa (Italy)