NEW ADVANCES IN

THERMOGRAPHY

Christodoulos StefanadisProf. Of Cardiology

Athens medical School, Athens, Greece

Thermal Heterogeneity - Thermal Heterogeneity - AtherosclerosisAtherosclerosis

Prognosis of: • culprit lesion post

PCI• Non-culprit lesion

Epiphany Thermography System

• A mono-rail system. • One thermistor at the distal end

of 3-4 F catheter• Accuracy 0.05oC• Almost wedging at the

atherosclerotic plaque

• Safe, fast procedure • Wedging• Full contact in significant lesions

Epiphany Thermography System

35.5

35.7

35.9

36.1

36.3

36.5

Tem

pera

ture

(o C

)

Atherosclerotic Plaque TemperatureAtherosclerotic Plaque Temperature

Plaque Plaque

DistalProximal Proximal

38.5

38.3

38.1

37.9

37.7

37.5

Thermal Heterogeneity and Thermal Heterogeneity and Prognosis Post PCIPrognosis Post PCI

• Number: 86 pts

• Effort Angina: 30 pts

• Unstable Angina: 30 pts

• AMI: 26 pts

Study PopulationStudy Population

Demographic CharacteristicsDemographic Characteristics

Age (years) 61+ 9N 86Aspirin intake 24/86Statin intake 20/86Hypertension 39/86LV Dysfunction 26/86Diabetes 24/86Total cholesterol (mg/dl) 229 + 37Smoking 48/86Previous MI 22/86

ΔΤ - Clinical EventsΔΤ - Clinical Events

ΔΤ - Clinical Follow-upFV

EventNo Event

2.0

1.5

1.0

0.5

0

-0.5

P < 0.01

ΔΤ (o C

)

Stefanadis C et al, JACC 2001 April

AMIUAEA

2.0

1.5

1.0

0.5

0

-0.5

P < 0.10

P < 0.01

P < 0.001

ΔΤ (o C

)

ΔΤ - Clinical Follow-up

Stefanadis C et al, JACC 2001 April

Clinical Follow-up

Stefanadis C et al, JACC 2001 April

ΔΤ - Clinical EventsΔΤ - Clinical Events

Sensitivity: 86%Specificity: 79%

Cut-off point: 0.5 oC

StatinsNo statins

ΔΤ

(ο C)

2.5

2.0

1.5

1.0

.5

0.0

-.5

Statins and Temperature

Stefanadis C, et al. Eur Heart J (in press)

Study PopulationStudy Population 72Treated pts 35Non-Treated pts 37Effort Angina 21Acute Coronary Syndromes

51

UA

32

AMI

19

StatinsNo statins

Tem

pera

ture

diff

eren

ces

(oC

)2.5

2.0

1.5

1.0

.5

0.0

-.5

SYNDROME

SA

UA

AMI

Statins and Temperature

Stefanadis C, et al. Eur Heart J (in press)

Temperature measurements - coronary flow

Temperature measurements • At proximal vessel wall• At lesion• Flow interruption• At lesion• Balloon deflation

ΔTp

ΔTl

GW

D-GW

Th

Bl

Study Study ProtocolProtocol

0.03.05.08

.1.13.15.17

.2.23.25

Lesion DT Lesion DT+Balloon DT in hyperemiaBaseline Occlusion After deflation

ΔTl (

o C)

Plaque Temperature and Coronary FlowPlaque Temperature and Coronary Flow

Plaque

Vulnerable Patient

Myocardiu

mBlood

VulnerabilityVulnerabilityArter

y

Identification of Vulnerable Identification of Vulnerable PatientPatient

Coronary SinusCoronary Sinus

• In coronary sinus blood is drained mainly from the left coronary artery

• An emerging technique is the measurement of the trans-coronary gradient of various variables such as cytokines, matrix metalloproteinases, etc..

• Measurement of blood temperature in coronary sinus may provide significant iformation regarding the inflammatory process within the myocardium

Atherosclerosis and Atherosclerosis and Widespread InflammationWidespread Inflammation

• In this study the authors showed that inflammation is widespread • Even if lesions are found only in RCA, the inflammatory markers (activated leukocytes) are found also in great cardiac vein

Buffon and Maseri, N Engl J Med 2002;July

Th

Shaft

Coronary Sinus Thermography Catheter

A 7F thermography catheter

Proximal part: A steering arm with a connector for the thermistor lead-wires

Distal part: The distal 7 cm of the shaft of the catheter consist of a soft material.

A thermistor probe is positioned at the tip of the catheter.

Manipulation of the steering arm proximally enables the distal end of the catheter to be curved (0o -180o ).

C

CS Th

In Vivo Coronary Sinus In Vivo Coronary Sinus ThermographyThermography

38.3

38.35

38.4

38.45

38.5

38.55

38.6

38.65

38.7

Tem

pera

ture

(o C)

Coronary Sinus Temperature

Right Atrium

Coronary Sinus

Right Atrium

ΔT = Difference of temperature between CS and right atrium

Baseline Characteristics IBaseline Characteristics I   LCA RCA Controls P-

value 

N 27 10 23

Males 24(89%) 10(100%) 21(91%)

0.55

Age (years) 62.19.8 59.99.4

60.09.5 0.57

BP (mmHg) 134.513.3 137.314.3 138.614.1

0.38

Chol (mg/dl) 214.113.1 218.214.1 199.514.4

0.47

Diabetes 3(11%) 1(10%) 1(4%)

0.67

Smoking 8(35%) 4(40%) 5(22%)

0.55 

Family history 10(37%) 4(40%) 5(22%)

0.42

b-Blockers 20(74%) 8(80%) 13(56%)

0.28

Baseline Characteristics IIBaseline Characteristics II

   LCA RCA Controls P-

value 

N 27 10 23

Aspirin 22(81%) 9(90%) 17(74%)

0.55

Nitrates 18(67%) 7(70%) 11(49%)

0.31

Statin 14(52%) 6(60%) 7(30%)

0.18

ACE inhibitors 8(29%) 3(30%) 3(13%)

0.33

Heart rate (1/min) 732 699 708

0.53

LV mass (g/m2) 9723 9520 9720

0.64

EF (%) 649 629 666

0.69

0

.1

.2

.3

.4Te

mpe

ratu

re D

iffer

ence

(oC

)

0 2 3

Control RCA LCA

Coronary Sinus Temperature Coronary Sinus Temperature MeasurementsMeasurements

0.090.07oC

0.150.08

0.270.10

The ‘Cooling Effect’ of Coronary Blood Flow on Heart in Patients With Coronary Artery Disease

Study Study ProtocolProtocol- Baseline

- Flow interruption- Balloon deflationTemperature recordings

- Recordings

DGW

Coronary Sinus and FlowCoronary Sinus and Flow

Temperature recordings

- Baseline

- Flow interruption- Balloon deflation

- Recordings

0

.05

.1

.15

.2

.25

.3

.35

.4

ƒ T

Δ Tl (

o C)

Coronary Sinus and FlowCoronary Sinus and Flow

Temperature difference (ΔΤ) between patients with CAD and controls

CADControls

0

.05

.1

.15

.2

.25

ƒT ƒT-B

ΔT (o C

)

Baseline Balloon Inflation

Coronary Sinus and FlowCoronary Sinus and Flow

Temperature difference (ΔΤ) in control subjects at baseline and during interruption of coronary flow.

Conclusions•Today’s challenge is to identify and treat the vulnerable plaques.•Thermography is a new promising method for the early detection of vulnerable plaques.• Aggressive lipid therapy, antiplatelet agents and medications have favorable results in thermal heterogeneity.•Clinical studies are required to investigate whether there is clinical benefit from lowering thermal heterogeneity locally at the culprit or non-culprit lesions.