Inflammation & Imaging - ATHERO.ORG · Inflammation & Imaging Ahmed Tawakol, MD ... Tawakol et al ATVB 2015 normoxia hypoxia ... Figueroa Circ CV Imaging 2011 CT PET/CT PET/CT L

Inflammation & Imaging

Ahmed Tawakol, MDCo-Director Cardiac MR PET CT Program

Massachusetts General HospitalHarvard Medical School

Disclosures

• Research Grants:– Genentech, Takeda, Actelion

• Consulting– Actelion, Amgen, Astra Zeneca, Takeda

Maddox et al. JAMA 2014

Non-Obstructive Plaques:

an Important Locus of Plaque Rupture

1-yr MI Risk

Falk et al. Circulation 1995

68%

18%

14%

<50%

50-70%

>70%

% Stenosis

% Cases N

Culprit Plaques:

Caused Insignificant Stenosis

Within 6 Mo Prior to Rupture

Non-Obstructive CAD Assoc w

Nearly 5-fold Increased 1-yr MI Risk

1) Stenosis evaluation • inadequate for plaque evaluation and risk

stratification.

2) Evaluation of wall composition and biology • may provide important insights.

3) Achieved via • combination of molecular and structural imaging.

Imaging Atherosclerosis

Oncology: Demonstrated Clinical Utility of Combined

Biological and Structural Imaging

• Combined molecular and structural imaging (PET-CT) more accurate than structural imaging alone (CT or MR) for tumor staging and localization – Lardinois NEJM 2003, – Antoch, JAMA. 2003

• Transformed Oncology practice and clinical trials

• Prompted wide proliferation of PET/CT

Inflammation: A Central Player

From: Libby P. Nature 2002

Tarkin, Joshi, Rudd Nature CV 2014

Inflammation: Many Targets

FDG-PET Accumulation:

Measure of Tissue’s Glycolytic Rate

Rudd et al JACC 2010

FDG Uptake By Macrophages:

Important in Tumor Imaging

Kubota et al JNM 1994

Macrophage Glycolysis

Increased after M1 Activation

M1

M2-or No Rx

Rodriguez-Prados et al J Immunol 2010

Inflammation and Metabolism in an

Atherosclerotic Environment

Tawakol et al ATVB 2015

normoxia hypoxia

Gly

coly

tic F

lux




normoxia hypoxia

Gly

coly

tic F

lux

Pro

-Infla

mm

ator

y A

ctiv

ity




Glycolytic FluxP

ro-In

flam

mat

ory

Act

ivat

ion

(TN

F al

pha

pg/m

l)

Gly

coly

tic F

lux

Pro

-Infla

mm

ator

y A

ctiv

ity

normoxia hypoxia

FDG Uptake

Linked to Pro-Inflammatory Activation

Satomi et al JNM 2013

PET-CT

Axia

lC

oro

na

l

1.41.2

1.31.0

MeasuredROI

Values

2.5

2.2

2.0

1.2

Whole Vessel

Most Diseased Segment

(MDS)

Mean

Value

Max

Value

2.2

2.0

1.5

1.0

1.4

1.3

2.5

2.2

2.0

1.2

2.5

2.2

2.0

Whole Vessel

TBR

1.77

MDS

TBR

2.23

Axial measurements every 5 mm

1.5

cm

Imaging Endpoints

Arterial FDG Uptake Relates to

Plaque Inflammation

Figueroa Circ CV Imaging 2011

CT PET/CT PET/CT

L

Histopathology

coronal coronal axial axial

R=0.70,p<0.001

FDG uptake (TBR)

Macrophage DensityTawakol JACC 2006

R=0.8,p<0.005

MA Font et at,

Frontiers in Bioscience 2009

Multi-group Confirmation

r = 0.45, P = 0.22

r = 0.77, P = 0.01

: r = 0.67, P = 0.03

: r = 0.67, P = 0.03 M

. Græ

be et al.E

ur J Vasc Endovasc S

urg 2009

R=0.64P<0.001

Taqueti et al Circ Imaging 2014

Arterial FDG Uptake: Relationship to Cardiac

Risk Factors

Kim et al Circulation Imaging 2010

Arterial Inflammation Predicts

Subsequent Plaque Progression

Abdelbaky et al Circ Imaging 2013

Baseline Inflammation (by PET) Precedes Subsequent Local Plaque Calcification (by CT)

Rel

ativ

e FD

G U

ptak

e

CTCTPET

Baseline2-yr

Follow-up

Changes in Arterial Inflammation Predict Plaque

Progression: Wall thickness by MR

Early Changes in Inflammation (by PET) Predict Long-Term Changes in Wall Thickness, (by MRI)

Fayad et al Lancet 2011; Tawakol et al ESC 2012

Decreased Increased

6M Change in TBR

Cha

nge

in W

all T

hick

ness

ove

r 24

Mo

PET

1

MR

1

6M

24M

BeginRX

PET

2

MR

2

Figueroa et al JACC Imaging 2013

Arterial FDG Signal Predicts

Risk of Subsequent CVD Events

Risk Categories NRI[95% bootstrap CI]

Events correctly

reclassified

Non-events

correctly

reclassified

< 10% risk

10-20% risk

> 20% risk

29.44%

[13.45,48.42]

12.20% 17.24%

Carotid FDG Uptake

Predicts Early Stroke Recurrence

Marnane et al. Annals of Neurology 2012

Human Treatment Studies

• FDG PET/CT arterial imaging– Widely employed to test effects of therapy– Over a dozen MCTs

• 4 drug classes – Both PET/CT data and outcomes data.– How predictive are PET/CT imaging results?

LaRosa et a NEJM 2005

Hi vs Low-Dose Atorva

PET/CT Imaging Trial Clinical Endpoint Trial

Tawakol et al JACC 2013

Non-Pharmacologic LDL Lowering:

ApheresisA

rt In

flam

mat

ion

(TB

R)

LDL

Van Wijk et al JACC 2014

Pre Post

P=0.03 R=0.71P=0.01

Art

Infla

mm

atio

n (T

BR

)

Response To Therapy: Pioglitazone

Mizoguchi et al JACC CV Imaging 2011

Pio Glimepiride

PET/CT Imaging Trial Clinical Endpoint Trials

Nis

sen

et a

l JA

MA

200

7E

rdm

ann

et a

l JA

CC

200

7

Cha

nge

in P

ET

Sig

nal

Effect of the CETP Antagonist Dalcetrapib

Fayad et al Lancet 2011


Schwartz et al , NEJM 2012

N=15,871

Effect of LPPLA2 Inhibition on

Arterial FDG Uptake

O’D

onog

hue

et a

l JAM

A. 2

014

The

STA

BIL

ITY

In

ve

stig

ato

rs.

N E

ng

l J M

ed

20

14

.

Tawakol et al JACC 2014


N=13,026

N=15,828

Arterial Inflammation is Increased in HIV

Subramanian et al JAMA 2012

Aortic Inflammation is Associated with

High Risk Coronary Plaques

Tawakol et al JAIDS 2014

Aortic TBR

< Median Value

> Median Value

High-Risk

Coronary Plaque Morphology

Low Attenuation Low Attenuation and Positive Remodeling

% S

ubje

cts

with

Hig

h-R

isk

Cor

onar

y P

laqu

es

Atherosclerotic mechanisms

may have important

components that exist outside

the vessel wall

Think outside of the vessel wall…

Multi-Tissue Assessment in Systemic Disease:

Bone Marrow, Splenic, Arterial Axis in Mice

Dutta et al Nature 2012

…and subsequent

aortic plaque inflammation

… increase in splenic granulocyte macrophage

progenitors (GMPs)

MI (LAD Ligation)Triggers b3AR-mediated

progenitor cell release frombone marrow


MI

Arterial Inflammation


MI


Does this axis exist in humans?

Hematopoietic Activation: Relates to Pro-

Inflammatory Gene Activation in Leucocytes

Emami et al JACC Imaging 2015

AC

S

AC

S

AC

SS

tabl

e C

AD

Sta

ble

Sta

ble

Bone Marrow Spleen


MI


Does Hematopoietic tissue activity predict CVD Risk?

Hematopoietic Tissue Activity Correlate w Arterial

Activity in Individuals without known Athero


Splenic Activity Predicts Subsequent CVD


Splenic Activity Predicts Subsequent CVD


Sub-Cutaneous

Adipose Tissue

FDG Uptake

Marincheva et al, JACC 2011

FDG Uptake

Aortic Valve Calcification

AS Progression (ECHO)

Mice Humans

Hara et al Circulation 2014

FDG-PET/CT: Characterization of Inflammation in DVT

Neutrophil Depleted

DV

T F

DG

Sig

na

l

ControlMice

3210

*

How could we use

inflammation imaging clinically

today?

Clinical Imaging

Blankstein JACC 2014 Saby et al JACC 2013

Increases sensitivity of modified Duke criteria

Predictive of Death/VT

Serrazin et al JACC 2012

Improved detection

SarcoidosisProsthetic Valve

Endocarditis Device Infection

Future uses:

• Moderate to severe carotid stenosis– Risk stratification to guide treatment

• Chronic Coronary Atherosclerosis– Fine-tune risk– Allocation of treatments

• New treatments will be available– Mounting costs and side effects

• Need to improve ability to allocate treatments– Think like oncologists

– Follow response to expensive/toxic treatments– Switch course when drugs are not working

• Venous Thromboembolism– Predict post thrombotic syndrome– Identify young clots susceptible to thrombolysis

Coronaries?

Culprit Coronary Lesions

Have Higher Arterial FDG Uptake

Rogers et al JACC CV Imaging 2010

Culprit LesionACS

Stable SyndromeNew Stent

Stable SyndromeOld Stent

18F NaF Imaging of Micro-calcification

Localizes to culprit lesionsFar less background uptake than FDG

• Unclear mechanism leading to its uptake in culprit• Unclear If its modifiable by therapy• Unclear If provides additional prognostic info above CAC

Joshi et al, Lancet 2014

NAF UPTAKE IS NOT CELL-SPECIFIC

Irkle A and Vesey A, Newby DE, et al, Rudd JHF and Davenport A, Nature Communications 2015 In Press 2015

Technological Advances

Development of New Tracers

TSPO Imaging

Pugliese et al JACC 2010

Elmaleh et al PNAS 2006

Ado Receptor Imaging

Tahara et al Nature Medicine 2014

Manose Receptor

Imaging

Ga DOTATATE

Courtesy of James Rudd

PET/MR

Acknowledgements

MGH CV Imaging Team• Amr Abdelbaky, MD• Hamed Emami, MD• Amparo Figueroa, MD• Brian Ghoshhajra, MD• Amorina Ishai, MD• Philip Joseph, MD• Udo Hoffmann, MD• Hoey Chyi Lim, BA• Megan Macnabb , BA• Thomas Neilan, MD• Parmanand Singh, MD• Sharath Subramaninan, MD• Richard Takx, MD

Key Collaborators

• Lisardo Bosca, MD• Ciprian Catana, MD• Marcelo DiCarli, MD• Michael E Farkouh MD• Zahi A Fayad PhD• Henry Gewirtz, MD• Michael Jaff, DO• Farouc Jaffer, MD, PhD• Peter Ganz, MD• Stephen Grinspoon, MD• Linda Hemphill, MD• Priscilla Hsue, MD• Janet Lo, MD• Matthias Nahrendorf, MD• Jagat Narula, MD• Miguel Pampaloni, MD• Roger Pitman, MD• James HF Rudd MD PhD• Bruce Rosen, MD, PhD• Marielle Scherer-Crosbie, MD• Lisa Shin, PhD• David Sosnovik, MD• Quinh Truong, MD

Documents

Inflammation & Imaging - ATHERO.ORG · Inflammation & Imaging Ahmed Tawakol, MD ... Tawakol et al ATVB 2015 normoxia hypoxia ... Figueroa Circ CV Imaging 2011 CT PET/CT PET/CT L