Intradialytic MRI of the heart and brain Eleanor Cox 3rd - - PowerPoint PPT Presentation

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Intradialytic MRI of the heart and brain Eleanor Cox 3rd - - PowerPoint PPT Presentation

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Intradialytic MRI of the heart and brain Eleanor Cox 3rd International Symposium on Functional Renal Imaging, Nottingham, 15-17 th October 2019 Background Cardiovascular disease is the leading cause of mortality in dialysis patients

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Intradialytic MRI of the heart and brain

Eleanor Cox

3rd International Symposium on Functional Renal Imaging, Nottingham, 15-17th October 2019

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Background

  • Cardiovascular disease is the leading cause of mortality in

dialysis patients

  • Haemodialysis (HD) causes repetitive circulatory stress

affecting the heart, but also other organs

  • The full extent of organ dysfunction brought about by HD

is not fully understood

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Background

  • MRI has been used in studies assessing organ dysfunction

in HD patients:

  • Effects of starting on dialysis
  • Effects of long term dialysis
  • Intradialytic effects
  • Effect of treatment
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We performed the first study of intradialytic MRI to directly assess the cardiovascular effects of dialysis

CAMRID: Cardiac MRI in Dialysis

  • Do changes occur in cardiac structure, function and perfusion

during dialysis?

  • Is haemodiafiltration (HDF) relatively cardio-protective

compared to haemodialysis (HD)?

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CAMRID

  • 12 patients on HD
  • 10 male
  • age 53 ± 12 years
  • dialysis vintage 56 ± 6 months

5 standard HD sessions 1 standard HD session with MRI 5 standard HD sessions 1 standard HD session with MRI 5 HDF sessions 1 HDF session with MRI 5 HDF sessions 1 HDF session with MRI

RANDOMISATION

RETURN TO BASELINE PRESCRIPTION

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CAMRID

  • 3T Philips Achieva scanner
  • Dialysis performed inside MR scanner
  • Standard dialysis machine positioned ~

3m from scanner using 4.5m blood line extensions (66ml increase in extracorporeal circuit volume)

  • Blood pressure and heart rate

measured throughout

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SLIDE 7

Time (minutes) BASELINE

CAMRID

MR measures:

  • Aortic flow
  • Stroke volume
  • Cardiac output
  • IVC flux
  • Heart rate
  • Myocardial tagging
  • Tissue strain
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SLIDE 8

CAMRID Results

Cardiac index

= volume of blood pumped by the heart per minute (corrected for body surface area)

Stroke volume index

= volume of blood pumped from left ventricle per heart beat (corrected for body surface area)

  • No difference between HD and HDF at baseline
  • During dialysis cardiac index, stroke volume index and IVC flux all decreased,

but no difference between HD and HDF

  • Heart rate did not change significantly with either treatment

However, at 240 min, it was significantly different between HD and HDF

Heart rate Indexed IVC flux (corrected for body surface area)

2.0 2.5 3.0 3.5 4.0 30 120 210 30-min POST Cardiac Index (L/min/m2) 30 35 40 45 50 55 30 120 210 30-min POST Stroke volume index (ml/m2) 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4

  • 30

30 120 210 30-min post IVC Flux Index (L/min/m2) 50 55 60 65 70 75 80 85 90 30 120 210 30-min POST Heart rate (beats per min)

  • 40 50 140 230 50-min

post

  • 40 50 140 230 50-min

post

  • 10 80 170 260 80-min

post

  • 30 60 150 240 60-min

post

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CAMRID Results

Longitudinal-axis assessment of the left ventricle

  • Strain describes the contractility of the left ventricle
  • Reduction (i.e. less negative, less strain) in longitudinal

strain on both HD and HDF from 30 min onwards

Long Axis strain (%)

  • 10
  • 9
  • 8
  • 7
  • 6
  • 5
  • 4
  • 3

Less contractile

Stunning:

  • >20% decrease in strain
  • Split the long axis of the myocardium into

6 segments

  • Stunned segments evident in all patients

from 30 min onwards

  • In each patient, it was the same segments

that were stunned during HD and HDF

  • No difference in strain or number of

stunned segments between HD and HDF

  • 40 50 140 230

70-min post

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CAMRID Results

  • 60
  • 50
  • 40
  • 30
  • 20
  • 10

0.0 0.5 1.0 1.5 2.0 2.5 3.0

% change in cardiac index UF volume (L)

HD HDF Linear (HD) Linear (HDF)

HD: r = -0.83, p < 0.001 HDF: r = -0.85, p = 0.01

  • Similar correlations for stroke volume index
  • No correlation with UF volume and heart rate

2 3 4 5 6 7 0.0 0.5 1.0 1.5 2.0 2.5 3.0

Number of stunned segments UF volume (L)

HD HDF Linear (HD) Linear (HDF)

HD: r = 0.70, p = 0.017 HDF: r = 0.59, p = 0.049

  • Increase in UF volume leads to an increase in the

number of stunned segments

Less contractile Cardiac Index Stunned Segments

Peak stress: Correlation with ultrafiltration (UF) volume

HD: r = -0.81, p = 0.01 HDF: r = -0.84, p = 0.01

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CAMRID Summary

  • During dialysis:
  • Reduced cardiac index, stroke volume index, indexed IVC flux, longitudinal strain
  • Stunned segments evident in all patients
  • Higher UF volume  greater decrease in cardiac index, stroke volume index

 more stunned segments BUT….

  • There were no intradialytic differences between HD and HDF

WHY?

  • Relatively healthy patients for the first intradialytic MRI study
  • Reasonably well preserved ejection fraction
  • Relatively stable intradialytic BP
  • Low UFV
  • Fall in body temperature occurred during both study sessions
  • Dialysate cooling improves intradialytic hemodynamic stability and provides short- and

long-term cardioprotection#

# Odudu A et al. Clin J Am Soc Nephrol 10: 1408–1417(2015); Selby NM et al. Clin J Am Soc Nephrol 1: 1216–1225 (2006)

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HD-REMODEL

  • Haemodialysis interventions to reduce multi-organ

dysfunction (HD-REMODEL)

  • Does cooled haemodialysis have a protective effect on
  • rgan perfusion and circulatory stress compared with

standard haemodialysis?

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HD-REMODEL 3T Philips Ingenia

Standard or Cooled HD SCAN 1 SCAN 2 SCAN 3 SCAN 4

  • 120

30 60 90 120 150 180 210 240 270 300 330

Time (minutes)

Other

tests

Other

tests 5 standard HD sessions 1 standard HD session with MRI 5 standard HD sessions 1 standard HD session with MRI 5 cooled HD sessions 1 cooled HD session with MRI 5 cooled HD sessions 1 cooled HD session with MRI

RANDOMISATION

RETURN TO BASELINE PRESCRIPTION

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HD-REMODEL

HEART

Ejection Fraction Cardiac Index Stroke Volume Index LV wall mass Diastolic Dysfunction Blood flow velocity Vessel area Cardiac Index Stroke Volume Index Longitudinal Strain Circumferential Strain

LV Short Axis cine Ascending Aorta PC-MRI MR Tagging MOLLI

Myocardial T1 Myocardial perfusion

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HD-REMODEL

BRAIN

Perfusion Blood flow velocity Vessel area

ASL Carotid and Basilar arteries PC-MRI DTI

Cortical thickness Grey matter volumes

MPRAGE

Fractional anisotropy

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HD-REMODEL

KIDNEY

Cox EF et al. Front Physiol 8: 696 (2017)

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HD-REMODEL

KIDNEY

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HD-REMODEL

Late-Breaking Clinical Trials

November 7, 2019, 10:00 AM to 12:00 PM

‘A Randomized Cross-Over Trial Using Intradialytic MRI to Compare the Effects of Standard vs. Cooled Haemodialysis on Cerebral Blood Flow and Cardiac Function’

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SLIDE 19

Acknowledgements

CKRI: Nick Selby Maarten Taal Latha Gullapudi Isma Kazmi Bethany Lucas Rebecca Noble Kelly White Nurses and Technicians Previous CKRI: Chris McIntyre Tobias Breidthardt Azharuddin Mohammed Huda Mahmoud

Thank you to our Patients

SPMIC: Sue Francis Charlotte Buchanan Chris Bradley Ben Prestwich Alex Daniel Previous SPMIC: Alex Gardener