An open-source universal strain

software platform for monitoring the

effects of microgravity on left

ventricular systolic function

1Patrick Gladding, 1Andrew Cave, 2Shafkat Anwar, 3Kazuaki Negishi, 4Zoran Popovic, 4Jill

Odabashian, 5Jagir R. Hussan, 5Peter Hunter, 6Mohammed Kassemi, 7Benjamin Levine, 8,9James D.

Thomas 1North Shore hospital, Waitemata District Health Board, Auckland New Zealand, 2St. Luis Children’s

Hospital, St. Luis, Missouri, USA, 3Menzies Research Institute, University of Tasmania, Hobart,

Australia,4Cleveland Clinic Foundation, Cleveland, Ohio, USA, 5Auckland Bioengineering Institute,

University of Auckland, New Zealand, 6NASA Glen Research Centre, Cleveland, Ohio, USA, 7University of Texas Southwestern Medical Center, Dallas, Texas, 8Blumh Cardiovascular Institute,

Northwestern University Feinberg School of Medicine, Illinois, USA, 9National Space Biomedical

Research Foundation, Houston, Texas, USA

Cardiac ultrasound project

• Aim: Develop an open-source

universal strain based cardiac

model (Cloud-enabled)

NASA Grant NCC 9-58

Effects of Microgravity on the Heart

Figure 8: Predicted change in heart shape at end-

diastole on Earth (green) and in microgravity (red).

Global Longitudinal Strain

• Advantages of LV Strain c/w Ejection Fraction: • Not as dependent on endocardial definition

• LV geometric assumptions

• More sensitive therefore detects early cardiomyopathy

Speckle tracking

Healthy

Cardiomyopathy

Space Station echocardiogram

6

Stages

1. Construct Cardiac atlas

2. Apply model to ISS echocardiograms

3. Strain comparison between vendors

4. Strain comparison model and vendors

5. Apply in clinical practice

6. Integrate other sources of data

7

Vivid E9 HDI 5000

Training (step 1) followed by In-flight

echocardiography (step 2)

Comparison of multiplatform,

multisoftware compatibility

Establish

echo atlas

Storage of data (step 3),

followed by analytics

EchoPac VVI

Formfitting mesh with fiber orientation (purple),

velocity vectors (blue), and strain (red)

Apply existing

fiber orientation

model from

Cardiac Atlas Project

Personalized cardiac model

Analytical steps:

reconstruct DICOMs

to apply 3D mesh

ISS project

• Echos on ISS reviewed in real-time with remote guidance at Cleveland Clinic

• Analysed at UoA Bioengineering dept

Training on synthetic datasets

• Training speckle

tracking algorithms on

synthetic

echocardiograms

• Acknowledgement:

Dr. Jan Dhooge’s lab,

Netherlands

• Model fitting and

hyperthreading

9

10

ABI Strain model vs Gold Standard (VVI)

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y = 0.5081x - 8.9346 R² = 0.5192

-26.0

-24.0

-22.0

-20.0

-18.0

-16.0

-14.0

-12.0

-10.0

-26.0 -24.0 -22.0 -20.0 -18.0 -16.0 -14.0 -12.0 -10.0

AB

I mo

de

l GLS

Velocity Vector Imaging GLS

Pearson correlation r = 0.72, p<0.05

13 astronauts, 67 separate echocardiograms

Software comparisons

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• n=10 patient with mixed cardiac disease

– Same machine, same images

• EchoPAC vs VVI r = 0.92, p <0.0001 (mean

difference -1+/- 4)

• EchoPAC vs EchoInsight r = 0.84, p = 0.001 (mean

difference -3 +/- 9).

– Different machine, same patients

• HDI5000 was also comparable r = 0.69, p = 0.002

(mean difference -3 +/- 7)

Reduced Strain in microgravity

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12.0

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24.0

0 50 100 150 200

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gitu

din

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trai

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Days in Space

Longitudinal strain reduces 2.8% in microgravity (p<0.05)

Reduction in LV function vs Days in flight

y = -0.0042x + 17.833 R² = 0.0153

12.0

13.0

14.0

15.0

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0 20 40 60 80 100 120 140 160 180

Po

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Days in Flight

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• Loss of 1% strain for every 100 days in space (r = 0.16, p=0.5)

• Mars ~300d for one-way trip - 6% loss

• Insufficient numbers to make firm conclusion

15

Echo metadata analytics

Application: Case study

• 41 year old semiprofessional rugby player

• FHx hereditary cardiomyopathy

• Low-normal EF 50%, abnormal strain (– 10.5%)

• Placed on ACEi

• Genetic testing

18

Father with cardiac Tx 33yrs of age

Universal – Vsan ultrasound .avi

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Prof. Peter Hunter, Former astronauts Leroy Chao, Ellen Baker, David Hilmers, Robert Satcher; PI Dr. Jin Thomas

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Software developed in New Zealand

Integration: Advanced ECG

• Sensitive, high sampling frequency, accurate.

HERO – Homozygous twins project

• Mark Kelly • Scott Kelly

• Prolonged

space flight

• Twin control

• Effects on

multiple health

outcomes –

CV, Genomics

etc

– iPOP

Stanford

• Time dilation

Application: TeleEcho, ECG and Genomics in the 3rd

World

Fiji: Oct 20-23rd 2013

Benefits to New Zealand

• Builds on existing expertise in high tech

sector

• Overseas funding and employment, with

retention

• Attracts other technologies:

– Advanced ECG algorithms, nanosensor array

• Fellowship opportunities

• Is cool….

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Acknowledgements

Dr. Jagir Hussan Prof. Peter Hunter

Prof. Jim Thomas Prof. Benjamin Levine

Conclusion

• We have developed a universal open-source software for highly accurate assessment of left ventricular function using strain

• Reproducibility below clinical gold standard but open source code will hopefully evolve

• Next step integrate MRI

– ICV 2.0: Atrial fibrillation (LA structure, mechanics)

• Ideal for Cloud-based environment

– Plugin for StudyCast™ (CoreSound Imaging)

• Potential for integrating other sources of clinical data e.g. ECG, genomics 26