Dynamic Mitral Annuloplasty Device Design Concepts, Experimental Insights and First-in-Man

MiCardia:
Dynamic Mitral Annuloplasty
Device Design Concepts,
Experimental Insights and
First-in-Man
Maurice Buchbinder, MD
Foundation for Cardiovascular Medicine
La Jolla, CA


Why Degradable Stents?
Disclosure

M.Buchbinder – Scientific Advisory,
Board Member


Ischemic MR
• Ischemic Mitral Regurgitation (IMR) is seen
in up to 20% of patients following acute
myocardial infraction. (Hickey; Circulation 1988;78:151-
159, Lamas; Circulation 1997; 96:827-833)

• Treatment of IMR includes medical therapy
and in severe cases surgical repair with an
undersized annuloplasty ring to reduce the
size of the mitral annulus and improve
leaflet coaptation.

Ischemic MR
• Following isolated annuloplasty surgery
recurrent (>2+) MR is seen in 10-30% of
patients (McGee; J. Thorac Cardiovasc Surg 2004;128:916-24)

• Recurrent MR appears to be commonly seen
within the first year following surgery and
remains relatively stable thereafter (McGee; J. Thorac
Cardiovasc Surg 2004;128:916-24)

• Unlike in dilated cardiomyopathy IMR is
associated with asymmetric deformation of the
annulus (Kwan; Circulation. 2003;107:1135.)

Current technology does not cope with
dynamic ischemic disease
• MITRAL
•Residual post-op Edwards Physio
occurrence of 6-
10%
•6m recurrence of
15%-25% Medtronic Duran
•3 Yr, recurrence of
30% to 50%
• TRICUSPID
•“Upon Discharge”
recurrence of 25% SJM Tailor
to 30%
•Directly contributes
to the onset of HF ATS Simulus
when untreated

MiCardia Semi-Rigid Dynamic
Annuloplasty “C” Ring (Degenerative)

Baseline Shape (Implanted)

Transparent = Baseline
Red = Post Activation Shape


MiCardia Rigid Dynamic Annuloplasty
“D” Ring (Ischemic)

Baseline

MiCardia Dynamic Ring
Transparent = Baseline
Red = Activated Shape


The MiCardia Dynamic Ring
• “C” and “D” shapes available sizes 28mm through 36mm
• Without activation functions as a “standard” ring
• Pre-attached electrodes used for activation make the ring
Dynamic


Intra-Operative Re-shaping
• Each RF wire is connected
to the propriatary MiCardia
RF generator.
P1 P3
• Following implantation and
pending degree of residual
P2
MR ,Wires are activated as
to re-shape the ring in vivo

• Echocardiography confirms
effectiveness of activation
during and post re-shaping


Dynamic Ring - Features
• Implants identical to
existing technology

• Semi-rigid metal core
maintains its shape.


Intra-Operative Reshaping
Early “In-Vivo” experience
• A-P distance
shortening by
0.5-3.0mm
• Inter-Commissural
distance contracted
by 1.0-3.5mm
• No heat damage to
the surrounding Postero-Medial commissure
activation
tissue
Courtesy Dr. Alex Marmureanu

Degenerative Ring Activation

Pre-Activation Intra-Op Activation

Ultimate Valve
Repair Modality


Percutaneous Reshaping
• The implanted ring is
accessed via transeptal
approach.
• Thru a Deflectable guide
catheter system for optimal
positioning
• An Expandable basket with
built in RF electrodes is used
to activate the ring upon
contact in multiple zones.
• On line echocardiography
confirms effectiveness of
activation during and after re-
shaping

Percutaneous Animal Experience

• A-P distance
shortened by
0.3-2.9mm
• Inter-Commissural
Distance
contracted by
1.2- 3.6mm


TransQ Device Platform

• Single lead, atrial exit
• No flow interference
• Subcutaneous “pocket“
deployment of lead
• Simple outpatient activation
30 Minute Outpatient
Adjustment • Activate days, weeks or
By Interventional months after the initial
Cardiologist procedure to correct
recurrence


Transcutaneous Activation
• Lead Exits Left
Atrium
• Completely
encapsulated 40 days
• Connects to
MiCardia RF
Generator
• Allows for Delayed
Activation



• Full activation takes
place within 60
seconds.



• No infection
• No dehiscence
• Full activation 60+
days
• 100% in-growth
• 40 and 60 day testing


26 Human Implants completed
(June 09)


First-in-Man Experience
February 2008
• 4+MR with P2 leaflet prolapse

• Leaflet resection with implantation of a
28mm D+ ring.

• Reduced to trace MR


P2 prolapse


4+MR with eccentric anterior jet


Post repair no MR acute and at discharge


Ring shape at discharge


Future Developments
2004-2008 2009-2010 2009-2011

Mitral

Mitral

Shape Magnetic
Memory

Tricuspid
Percutaneous External
Tricuspid

Intra-Operative Trans‐Q


Magnetic Ring
• Magnetic drive: no motor
• AP + or AP - models
• Infinitely adjustable
• Can be titrated
• Reversible
• Multiple activations
• Percutaneous activation via
R. Heart Access (16Fr)
• External via TEE access


Conclusion
• From this early clinical experience the MiCardia Dynamic
Annuloplasty Ring appears to be a promising device for
treatment of Mitral regurgitation.

• The In-Vivo adjustable feature may be an extremely
valuable tool for optimization of surgical results

• Further percutaneous adjustments in ring geometry in
the healing phase could be a compelling advantage for
its use .


Dynamic Mitral Annuloplasty Device Design Concepts, Experimental Insights and First-in-Man

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