IVUS Analysis. Myeong-Ki. Hong, MD, PhD. Cardiac Center, Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea

Transcription

1 IVUS Analysis Myeong-Ki Hong, MD, PhD Cardiac Center, Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea

2 Intimal disease (plaque) is dense and will appear white Media is made of homogeneous smooth muscle cells and does not reflect ultrasound (appears dark) Adventitia has sheets of collagen that reflect a lot of ultrasound (appears white)

3

4 Classification of Plaque by IVUS Soft Plaque Fibrous Plaque Fibro-calcific Plaque

5 Normal

6 Soft plaque Not as bright as the adventitia (hypoechoic) Soft refers to the low echogenicity, generally due to high lipid content in a mostly cellular lesion

7 Fibrous plaque As bright or brighter than the adventitia (hyperechoic) Majority of lesions are fibrotic

8 Bright echos (brighter than the adventitia) Obstructs the penetration of ultrasound (acoustic shadowing) Only the leading edge is detected and thickness cannot be determined Calcium

9 Superficial calcium

10 Deep calcium

11 Other Interesting Images

12 Intracoronary Thrombus

13 Incomplete stent apposition

14 Fibrous cap with lipid core

15 Hematoma

16 IVUS Comparison Post-procedure At 6 month follow-up

17 Quantitative IVUS Analysis Non-stented segment Guidewires EEM Area Lumen IVUS catheter Plaque+media Area *PM Area = (EEM-Lumen) Area

18 Proximal Reference Lesion Site Lumen EEM Distal Reference P+M Ca ++ MLD Maximal lumen diam Max P+M Thickness Min P+M Thickness

19 Classification of Remodeling Positive remodeling Intermediate remodeling Negative remodeling Proximal reference Lesion site Distal reference Nishioka. JACC 1996

20 Definitions of Remodeling Lesion/Average Reference EEM CSA - Positive remodeling: > No Remodeling: Negative remodeling: <0.95

21 Proximal Reference Lesion Site Lumen EEM Distal Reference P+M EEM CSA = 20.4 Lumen CSA = 9.7 P+M CSA = 10.7 Max lumen diam = 3.7 MLD = 3.1 Eccentricity = 1.0/0.3 Plaque burden = 0.52 EEM CSA = 21.6 Lumen CSA = 4.5 P+M CSA = 17.1 Max lumen diam = 32.8 MLD = 2.3 Eccentricity = 3.0/0.1 Plaque burden = 0.79 EEM CSA = 13.3 Lumen CSA = 8.9 P+M CSA = 4.4 Max lumen diam = 3.6 MLD = 3.0 Eccentricity = 0.6/0.2 Plaque burden = 0.33 Arc of Ca = 60 Average Reference EEM CSA = 16.9 Remodeling Index = 1.3 => Positive Remodeling

22 Quantitative IVUS Analysis Stented segment Stent Area (mm 2 ) Lumen Area (mm 2 ) Neointimal Area (mm 2 )

23 Stented Artery Guidewire Stent Lumen EEM IVUS catheter Intimal hyperplasia Plaque+media

24 IVUS vs. Angiography

25 LIMITATIONS OF CORONARY ANGIOGRAPHY Focal disease 50% lesion Diffuse disease 50% lesion

26 Angiograpically Silent Disease In 884 native coronary arteries, the plaque burden in the angiographically normal reference segment was 51 ± 13% Mintz GS, et al. Atherosclerosis in angiographically normal coronary artery reference segments. J Am Coll Cardiol 1995;25:

27 LIMITATIONS OF CORONARY Coronary ANGIOGRAPHY Cross-section Angiogram silhouette

28 Irregular Plaque / Irregular Lumen A Cross Section RAO View LAO View B C

29 Limitation of coronary Angiography Poor inter-observer Correlation 100 CASS Study QC Lab 0 Clinical site 100 Fisher et al, CCD 1982

30 IVUS arc of target lesion calcification % of lesions 27 % 26 % 21 % calcified by angiography 15 % 11 % 11% 25% 50% 60% 85% 0 o 90 o o 270 o 360 o Arc of lesion calcium Mintz et al. Circulation 1995;91:

31 % of lesions IVUS eccentricity index 57 % 60 Eccentric by angiography % 53% 60% 8 % 61% 7 % 68% Eccentricity index = max/min P + M thickness Mintz et al. Circulation 1996;93: