Thermography is a new technique for detecting atherosclerotic plaque vulnerability. A new catheter-based system called the Epiphany Thermography System can precisely measure plaque temperature and has shown higher temperatures in proximal versus distal plaque segments. Studies have found that greater temperature differences between segments correlate with increased risk of future cardiac events, with optimal sensitivity of 86% and specificity of 79%. Preliminary research also indicates statin therapy may lower plaque temperatures and heterogeneity. Further clinical studies are still needed but thermography shows promise as an early detection method for vulnerable plaques.

1. NEW ADVANCES IN
THERMOGRAPHY
Christodoulos Stefanadis
Prof. Of Cardiology
Athens medical School, Athens, Greece

2. Thermal Heterogeneity -Thermal Heterogeneity -
AtherosclerosisAtherosclerosis
Prognosis of:
• culprit lesion post
PCI
• Non-culprit lesion

3. Epiphany Thermography System
• A mono-rail system.
• One thermistor at the distal end
of 3-4 F catheter
• Accuracy 0.05o
C
• Almost wedging at the
atherosclerotic plaque
• Safe, fast procedure
• Wedging
• Full contact in significant
lesions

4. Epiphany Thermography System

5. 35.5
35.7
35.9
36.1
36.3
36.5
Temperature(o
C)
Atherosclerotic Plaque TemperatureAtherosclerotic Plaque Temperature
PlaquePlaque PlaquePlaque
DistalDistalProximalProximal ProximalProximal
38.5
38.3
38.1
37.9
37.7
37.5

6. Thermal Heterogeneity andThermal Heterogeneity and
Prognosis Post PCIPrognosis Post PCI
• Number: 86 pts
• Effort Angina: 30 pts
• Unstable Angina: 30
pts
• AMI: 26 pts
Study PopulationStudy Population

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

8. ΔΤ - Clinical EventsΔΤ - Clinical Events

9. ΔΤ - Clinical Follow-up
FV
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

10. 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

11. Clinical Follow-up
Stefanadis C et al, JACC 2001 April

12. ΔΤ - Clinical EventsΔΤ - Clinical Events
Sensitivity: 86%
Specificity: 79%
Cut-off point: 0.5 o
C

13. 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 72
Treated pts 35
Non-Treated pts 37
Effort Angina 21
Acute Coronary
Syndromes
51
UA
32
AMI
19

14. StatinsNo statins
Temperaturedifferences(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)

15. Temperature measurements
- coronary flow
Temperature measurements
• At proximal vessel wall
• At lesion
• Flow interruption
• At lesion
• Balloon deflation
ΔTp
ΔTl

16. GW
D-GW
Th
Bl
StudyStudy ProtocolProtocol

17. 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

18. Plaque
Vulnerable Patient
Myocardiu
m
Blood
VulnerabilityVulnerability
Arter
y

19. Identification of VulnerableIdentification 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

20. Atherosclerosis andAtherosclerosis 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;

21. 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
C

22. CS
Th
In Vivo Coronary SinusIn Vivo Coronary Sinus
ThermographyThermography

23. 38.3
38.35
38.4
38.45
38.5
38.55
38.6
38.65
38.7
Temperature(o
C)
Coronary Sinus Temperature
Right AtriumRight Atrium
Coronary SinusCoronary Sinus
Right AtriumRight Atrium
ΔT = Difference of temperature between CS and right atrium

24. 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) 62.1±9.8 59.9±9.4 60.0±9.5
0.57
BP (mmHg) 134.5±13.3 137.3±14.3 138.6±14.1
0.38
Chol (mg/dl) 214.1±13.1 218.2±14.1 199.5±14.4
0.47
Diabetes 3(11%) 1(10%) 1(4%)

25. 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

26. 0
.1
.2
.3
.4TemperatureDifference(oC)
0 2 3
Control RCA LCA
Coronary Sinus TemperatureCoronary Sinus Temperature
MeasurementsMeasurements
0.09±0.07o
C
0.15±0.08
0.27±0.10

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

28.
StudyStudy ProtocolProtocol
- Baseline
- Flow interruption
- Balloon deflationTemperature recordings
- Recordings

29. DGW
Coronary Sinus and FlowCoronary Sinus and Flow
Temperature
recordings
- Baseline
- Flow interruption
- Balloon deflation
- Recordings

30. 0
.05
.1
.15
.2
.25
.3
.35
.4
ƒ T
ΔTl(o
C)
Coronary Sinus and FlowCoronary Sinus and Flow
Temperature difference (ΔΤ) between patients with CAD and controls
CADControls

31. 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.

32. 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.