Engager™ Transapical System Pre-Implantation Imaging, Patient and Size Selection August 2013 Innovating for life. UC201301195c EE.

Engager™ Transapical SystemPre-Implantation Imaging, Patient and Size Selection

August 2013

Innovating for life.

UC201301195c EE

AcademiaMedical Education

INTERNATIONAL. CAUTION: For distribution only in markets where Engager™ is approved. Medtronic, Inc. 2013. All Rights Reserved.

Objectives

• Discuss patient selection including indications and contraindications for use

• Outline guidelines for echocardiography and MSCT for patient and bioprosthesis size selection



Indications for Use

• Symptomatic severe aortic stenosis• High or extreme risk for operative

mortality– Logistic EuroSCORE I ≥20% or comorbidity judged

by the heart team to pose an absolute or relative contraindication for conventional aortic valve replacement

• The system is intended for use in patients with life expectancy of at least one year following TAVI

• Transapical procedure



Contraindications

• Known hypersensitivity to (that cannot be controlled with premeds):– Aspirin – Heparin– Ticlopidine– Clopidogrel– Contrast Media– Nitinol

• Intracardiac mass, thrombus or vegetation• Aortic aneurysm• Sepsis or acute endocarditis



Contraindications Continued

• Bleeding diathesis or coagulopathy• Cardiogenic shock or suspected cardiogenic

shock• The safety and performance of valve in valve

procedures has not been evaluated• The safety and performance of the Engager™

bioprosthesis placed within another bioprosthesis or placed within a unicuspid or bicuspid aortic valve has not been studied*

* Reference source Engager™ Instructions for Use



MSCT Criteria for Bioprosthesis Selection

Echocardiography for Patient EvaluationAortic annulus diameter > 19 mm and < 26 mm



Engager™ Bioprosthesis Dimensions

Device Size

Inflow

Outer Diameter

A

(mm)

Throat

Outer

Diameter

B

(mm)

Control Arm Outer

Diameter

C

(mm)

Outflow

Outer Diameter

D

(mm)

Length of Device

E

(mm)

23 mm 27.0 19.0 27.0 23.0 25.5

26 mm 30.0 21.0 30.0 26.0 27.5

A

BBE

D

C C



Different echo definitions of annulus in use

Annulus – inner edge-to-edge diameter at leaflet insertion

24 mm

Derek nDerek Chin, et

al.Arnold Ng, et al.

Annulus – diameter at the leaflet hinge, including all the calcium

Sizes and Sizing



Echo (A and B) vs MSCT (C, D, E)

A B

C D E



Even in a round anatomy, the diameter (blue) is underestimated by 2D echo (red) as the measurement does not pass through the center

In an elliptic anatomy the 2D echo diameter (red) is typically close to the minor diameter of the ellipse (blue). The major diameter (white) is not taken into account, this underestimates the effective annulus diameter

Standard 2D Echo Limitations



Hamdan, Schwammenthal J Am Coll Cardiol 2012

Assessment of the Aortic Annulus



Ellipticity 1 : 1.14 Ellipticity 1 : 1.38

Min diameter: 21 mmMax diameter: 24Perimeter-derived annulus diameter: 22.5Perimeter: 71 mm

Min diameter: 21 mmMax diameter: 29Perimeter-derived annulus diameter: 25Perimeter: 79 mm

Aortic Annulus Is Non-CircularThe degree of non-circular varies substantially



Ellipticity 1 : 1.14 Ellipticity 1 : 1.38

Min diameter: 21 mmMax diameter: 24Perimeter-derived annulus diameter: 22.5Perimeter: 71 mm

Min diameter: 21 mmMax diameter: 29Perimeter-derived annulus diameter: 25Perimeter: 79 mm

Aortic Annulus Is Non-CircularThe degree of non-circular varies substantially



Perimeter AreaMin. diameter

Max. diameter


Assessment of the Aortic Annulus



Variation of annular dimensions throughout the cardiac cycle

Perimeter shows least variation




Relative Percent Change of Aortic Annular Dimensions

Normal subjects Aortic stenosis


In Normal subjects strain averages 2.2 % , in Aortic Stenosis 0.6 %



Systole Diastole

Deformation Dynamics of the Aortic Annulus Systole Diastole

Aortic annulus

Mitral annulus

“Valvular interdependence” of the aorto-mitral orifice:Aorto-Mitral Coupling

Aortic and mitral annulus are embedded within one common aorto- mitral orifice, so that reciprocal changes of size and shape of each element result from the pressure- sensitive motion of its common aorto-mitral septum.




SystoleDiastole

A larger area can be inscribed by the same perimeter (finger length) by assuming a rounder (less elliptic) shape

The circle is the shape with the largest area for a given length of perimeter



Lessons for Sizing in TAVI?

Requirements for an ideal annular parameter for sizing:•Integrates dimensions across the whole 2-dimensional annular plane•Is most stable during the cardiac cycle•Independent of annular shape



Only Annular Perimeter Fulfills Requirements• Circumferentially integrates annular dimension

(effective, or mean circumferential diameter can be easily obtained by dividing perimeter into π)

• Shows minimal variation during the cardiac cycle• Is not affected by shape (in contrast to area) and

stretches only minimally at physiologic pressures



Measurements for Assessment of Anatomic Fit by MSCT

• Aortic annulus perimeter-derived diameter • Sino-tubular junction (STJ) • Sinus of Valsalva (SoV)

Aortic Annulus Sinus of Valsalva

• Measured from double-oblique axial slice showing nadirs of

all 3 leaflets (basal plane)• Perimeter-derived annulus

diameter = perimeter / π• Perimeter & area trace

(reference)

• Measured from double oblique axial slice

• SoV diameter = 2 x (average of 3 radius measurements)

• Measured from double-oblique axial slice

• STJ diameter = (max + min) / 2

Sino-Tubular Junction



Aortic Annulus Measurement ExamplePerimeter 75 mm

Perimeter-derived annulus diameter24 mm22mm

26mm75mm



Screening by EchoSizing (anatomical fit) by MSCT

Echocardiographic: Annulus Diameter

19 to 26 mm

MSCT:Perimeter: 66-74 mm Perimeter-derived annulus diameter: > 21 and < 23.6 mmSTJ > 23 mmSoV > 27 mm

MSCT:Perimeter: 72-84 mmPerimeter-derived annulus diameter: > 23 and < 26.7 mmSTJ > 26 mmSoV > 30 mm

Engager™ 26 mmEngager™ 23 mm

Failure to align the bioprosthesis with the native valve through incorrect bioprosthesis selection could result in a cardiovascular injury including obstruction, perforation or dissection of vessels that may require

intervention



Summary

• Appropriate patient selection will lead to safe and effective Engager™ system implantations

• Echocardiography assists with patient screening

• MSCT is the best modality for accurate bioprosthesis size selection

Engager is a registered trademark of Medtronic, Inc.

For more information and a complete list of adverse events, warning and contraindications reference Engager IFU.

Engager™ Transapical System Pre-Implantation Imaging, Patient and Size Selection August 2013 Innovating for life. UC201301195c EE.

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