Hypothesis

r = -0.63

p = 0.0001

Flexible guide wire

Collapsed basket

Shaft

A penny!

0.014” Diameter

Basket CatheterBasket Catheter

Wires with built-in Thermocouples

0.0014” Flexible Guide wire

PRESSURE WIRE

HUMAN STUDY

CLINICAL:

RISK FACTORS:

59Y Female with

Cardiomyopathy and Angina

Smoker

Family history of CAD

LAD

Thermal Mapping in RCA Using Pressure Wire

39.65

39.66

39.67

39.68

39.69

39.7

39.71

39.72

39.73

1 26 51 76 101

126

151

176

201

226

251

276

301

326

351

376

401

426

451

476

501

526

# of Measurements

Tem

per

atu

re (

C)

DISTAL END

STENOSES90%

OSTIUM

stenosis

Distal end

CLINICAL:

39 y male with

MI

RISK FACTORS:

Hypertension

DM

Family history

Thermal Mapping of LCX using Pressure Wire

38.765

38.775

38.785

38.795

38.805

38.815

38.825

38.835

38.845

1 126 251 376 501 626 751 876 1001 1126# of Measurements

Te

mp

(C

)

STENOSIS

CLINICAL:

RISK FACTORS:

44y male

Angina

Kidney insuff

Smoker

DM

Hypertension

Obesity

normal

normal

1 cm

Temperature Mapping in LAD(William Flusche)

38.32

38.33

38.34

38.35

38.36

38.37

38.38

38.39

38.4

1

119

237

355

473

591

709

827

945

1063

1181

1299

1417

1535

No of Measurements

Tem

p (

C)

LAD:100% PROXIMAL OCCLUSION

LCA:70% MID STENOSIS

RCA:SMALL ,NON DOMINANT CLINICAL:

RISK FACTORS:

68 MALE

Angina

MI

HYPERTENSION

OBESITY

DM

0.5 cm

RANGE OF TEMPERATURE

00.020.040.060.080.1

0.120.140.16

1 2 3 4 5 6 7 8 9 10

oC

of Atherosclerotic Plaques and its Correlation with

•Morteza Naghavi MD,•Reji John MD, Said Siadaty MD,

•Sameh Naguib MD, Roxana Grasu MD, •KC Kurian MD, Mohammad Madjid MD,•James T. Willerson MD, Ward Casscells

MD,

The University of Texas-Houston Texas Heart Institute

pH HeterogeneitypH Heterogeneity

Temperature HeterogeneityTemperature Heterogeneity

pH

9.00

8.88

8.75

8.63

8.50

8.38

8.25

8.13

8.00

7.88

7.75

7.63

7.50

7.38

7.25

7.13

7.00

6.88

6.75

6.63

No

of p

oint

s w

ith th

e sa

me

ph

140

120

100

80

60

40

20

0

pH Distribution in 48 Human Carotid Plaques

This histogram demonstrates distribution of pH measured in 858 points in 48 carotid plaques of 48 patients. A marked variation

ranging from 6.5 to 8.9 is seen.

Watanabe Rabbit Aorta

pH

9.5

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

pH Heterogeneity in 9 Watanabe Rabbit Aortas

2220231717191026252428N =

11 human umbilical artery

pH

9.59.39.18.98.78.58.38.17.97.77.5

7.37.16.96.76.56.36.15.95.75.5

pH Heterogeneity in 11 Human Umbilical Arteries

calcif ied&thrombosedLipid Rich

pH

9.0

8.5

8.0

7.5

7.0

6.5

pH in Lipid Rich Yellow Areas vs. Calcified areas

Areas with large lipid core exhibit higher temperature and lower pH

p < 0.01

Correlation of pH and Temperature in Human Carotid Plaques Varied by the Areas

We see a marked inverse correlation between temperature and pH of plaques that varies by macroscopic characteristics of plaques.

p < 0.01

Fluorescence Single-Emission Imaging Microscopy of a Predominantly Lipid Rich Plaque Shows

Significant Microscopic pH Heterogeneity Mostly Acidic

Catheter Tipped with a Side Looking Silvered Conical 0.5 mm Mirror

cm0.5mm

Conclusions

1.1. Temperature at the lumen of living carotid plaques Temperature at the lumen of living carotid plaques correlates with density of inflammatory cells, and correlates with density of inflammatory cells, and inversely with cap thickness.inversely with cap thickness.

2.2. Differences of more than 0.3 C were seen in all Differences of more than 0.3 C were seen in all specimens but only a minority had differences of 2specimens but only a minority had differences of 2o o C or C or more.more.

3.3. Large differences in temperatures were more often Large differences in temperatures were more often found in patients who were younger, symptomatic, found in patients who were younger, symptomatic, female, and not taking aspirin.female, and not taking aspirin.

Conclusionscontinued

4.4. These temperature differences can be detected These temperature differences can be detected by infrared cameras. by infrared cameras.

5.5. Compared to normal arteries, inflamed and Compared to normal arteries, inflamed and lipid-rich plaques are acidic, while calcified and lipid-rich plaques are acidic, while calcified and thrombosed plaques are alkaline.thrombosed plaques are alkaline.

6.6. Plaque pH correlates moderately and inversely Plaque pH correlates moderately and inversely with plaque temperature.with plaque temperature.

Conclusionscontinued

7.7. Stefanadis and colleagues have reported that hot Stefanadis and colleagues have reported that hot plaques confer higher risk; it will be important to plaques confer higher risk; it will be important to determine whether plaque prognosis is best determined determine whether plaque prognosis is best determined by T, by T, ∆∆T, pH, T, pH, ∆∆pH or a combination.pH or a combination.

8.8. Heating to 41Heating to 41ooC decreases expression of pro-C decreases expression of pro-inflammatory genes.inflammatory genes.

9.9. Heating to 42-43Heating to 42-43ooC causes apoptosis, mainly of C causes apoptosis, mainly of macrophages.macrophages.

Conclusionscontinued

10.10. Near-IR Spectroscopy can estimate plaque Near-IR Spectroscopy can estimate plaque protein/lipid ratios and may also provide protein/lipid ratios and may also provide inferences as to concentrations of plaque Hinferences as to concentrations of plaque H++, , NO, glucose, ONO, glucose, O2 2 and oxidants.and oxidants.

11.11. IR and near IR may predict plaque behaviour IR and near IR may predict plaque behaviour alone or in combination with ultrasound, alone or in combination with ultrasound, angioscopy, magnetic resonance or angioscopy, magnetic resonance or immunoscintigraphyimmunoscintigraphy