Imaging & Physiology Summit 2010 in Soul #1. Basics of Image Interpretation: IVUS/VH/OCT Clinical Application of OCT in Stent Evaluation Mitsuyasu Terashima, MD, PhD, FACC
Stent implantation
Stent Apposition
Incomplete apposition BX 3.5*33mm After stenting of the mid-lad with inflation pressure at 10 atm Incomplete apposition
OCT Image of Implanted stent Just after Deployment Complete stent apposition (CSA) Apposition of stent strut to the vessel wall is evaluated by measuring the distance between the strut surface and adjacent vessel surface. Stent Strut thickness Near infrared light used of strut in OCT cannot penetrate the Dorsal metallic stent strut, so stent Shadowing struts are visualized as linear structures with strong surface reflection and typical dorsal shadowing. Incomplete stent apposition (ISA) Stent Strut > thickness of strut
Jornal of Invasive Cardiology 2009;21:602 605
A B C D E Fig. 3: Cross sectional optical coherence tomography images of individual stents implanted in the phantom model A: Bx Velocity stent, B: Cypher stent, C: Express2 stent, D: Driver stent, E: Vision stent
Frequency (%) 30 20 10 A Manufacturer s nominal thickness Frequency (%) 40 30 20 10 B Manufacturer s nominal thickness 0 120 130 140 150 160 170 Strut Thickness m 0 130 140 150 160 170 18 Strut Thickness m 0 Frequency (%) 40 30 20 10 C Manufacturer s nominal thickness Frequency (%) 30 20 10 D Manufacturer s nominal thickness Frequency (%) 30 20 10 E Manufacturer s nominal thickness 0 10 0 110 120 130 140 150 160 Strut Thickness m 0 70 80 90 100 110 Strut Thickness m 0 60 70 80 90 100 110 Strut Thickness m Fig. 4: Histograms of measurements of individual stents A: Bx Velocity stent, B: Cypher stent, C: Express2 stent, D: Driver stent, E: Vision stent Jornal of Invasive Cardiology 2009;21:602 605
Type of stent Bx- Velocity Table 1. Measured and Manufacturers nominal strut thickness Number Measured Thickness (mm) Table 1 Measured and Manufacturers nominal strut thickness 95% CI (mm) Manufacturer s nominal thickness (mm) 42 145 13 141 to 149 140 (0.0055 inch) Cypher 42 152 11 149 to 155 160 (0.0055 inch + polymer) Express 50 129 12 126 to 132 132 (0.0052 inch) Driver 60 88 10 86 to 91 91 (0.0036 inch) Vision 45 84 14 79 to 88 81 (0.0032 inch) Difference (mm) +5 13-8 11-3 12-3 10 Measured stent strut thickness in m, expressed as mean SD as compared to manufacturers nominal strut thickness; CI: confidence interval 3 14 Jornal of Invasive Cardiology 2009;21:602 605
How to measure? 120µm 140µm 160µm
120µm 140µm 160µm
Fates of Incomplete Apposition Baseline Incomplete Apposition Healed/Resolved Incomplete Apposition Preserved Incomplete Apposition
They concluded that; In Should patients we treat with all SESs. of the ISA incompletely can fail to heal and apposed even struts? complete apposition can be associated Although in-stent with no thrombus neointimal is common hyperplasia. Incomplete findings in DES, stent late apposition stent thrombosis without is a neointimal rare event. hyperplasia was significantly associated Futhermore, with there the is presence no significant of clinical OCT-detected data for relationships thrombus between at follow-up. baseline and ISA may and late constitute stent thrombosis. a potent substrate for late stent Then, thrombosis there any acceptable indication for treatment of ISA?
Flap / Dissection IVUS OCT
Chronic Vascular Responses to Coronary Stenting by Optical Coherence Tomography
Neointimal Coverage of Stent struts
IVUS and OCT image of SES at 3-month follow-up OCT provides detailed visualization of the individual stent struts and a thin neointimal layer over DES struts that IVUS can not detect.
Classification of Neointimal Coverage ~ Morphology ~
Intimal Stent Strut Coverage Type 1 & 2
Intimal Stent Strut Coverage Type 3
Intimal Stent Strut Coverage Type 4
Definition of Neointimal Coverage of Struts Uncovered Struts Covered Struts Type 1 Stent Strut Stent Strut Type 3 NIT Type 2 Dorsal Shadowing Type 4 NIT Ito t, et al, 2006 ACC
Intimal Coverage of unapposed Stent Strut
Classification of Neointimal Coverage of Strut by Kobe University (1) Well apposed with neointima (2) Well apposed without neointima (3) Malapposed with neointima (4) Malapposed without neointima (5) Side branch orifice with neointima (6) Side branch orifice without neointima Malapposition: Incomplete Stent Apposition (ISA) Fig. Images of stent in chronic phase OCT
Is the scientific consensus of OCT findings obtained?
How about this? No1
How about this? No2
Comparison of Neointimal Growth between Paclitaxel-Eluting Stent, Sirolimus-Eluting Stent, and Bare-Metal Stent
Frequencies of Covered Strut / Stents P < 0.01 ( % ) 100 P < 0.01 90 80 70 60 50 98.8 2.1% 96.2 3.8% 86.7 11.7% BMS 3M n = 10 PES 3M n = 13 SES 3M n = 13
CASE: BMS, SES and PES ~ 4-month f/u ~ Distal
CASE: BMS, SES and PES BMS ~ 4-month f/u ~ Cypher Taxus
26 head-to-head (n>35,000 ) TAXUS Stent Thrombosis (%) 1 18 3.0-2.5-3 2.0-1.5-1.0-0.5- Even with inclusion of the outliers 23 14 19 5 10 2 6 11 12 22 21 13 Slope=1.25 n=35,539 20 24 0-25 I I I I I I I 0 0.5 1.0 1.5 2.0 2.5 3.0 CYPHER Stent Thrombosis (%) 16 26 8 15 9 4 Slope=0.79 TAXUS ST = 1.02 Cypher ST 95% CI (0.79, 1.25) R 2 = 0.76 7 Slope=1.02 17 Slope=1.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 I-DIABETES I-SMART I-DESIRE TAXI DEScover S.T.E.N.T. SIRTAX MILAN C & T Reward CORPAL REALITY TC-WYRE REAL LONG DES II SORT OUT II BASKET Cervinka Di Lorenzo Han YL Petronio PROSIT Zhang T-SEARCH/RESEARCH DIABETES I, II RESEARCH Long TAXUS Meta / Cypher Meta n=250 n=360 n=200 n=202 n=6,509 n=10,159 n=1,012 n=529 n=2,769 n=652 n=1,353 n=1,558 n=1,676 n=500 n=2,098 n=545 n=70 n=180 n=416 n=100 n=308 n=449 n=1,084 n=160 n=122 n=2,278 Trials excluded in analysis: SOLACI (ST not reported) ARRIVE I / II, e-cypher, TAXUS V and SISR ( differences in protocol definitions).
Characteristics of Neointima ~ intensity, pattern ~
Usual Neoitima of BMS
Common findings in 1 st generation DES SES SES
Heterogeneous neointima of 1 st generation DES Layered Mosaic PES SES SES
59 y.o. male Pre Post Cypher 2.5*23 Stenting 4M fu
Case 2: OCT at 4 months fu
Specimen Retrieved by DCA This case will be presented tommorow!
Anomalous pattern of Neointima Peri-stent staining Peri-strut ulcer like apperance / Peri-strut halo
Neointima following stent implantation have various patterns of morphology or characteristics (intensity, etc). Question? Which patterns are safe (protective for stent thrombosis)? Which patterns are dangerous? Which patterns are within the acceptable range?
Summary OCT provides various information and new aspects of implanted stents. Unfortunately, consensus of definition of OCT findings has not been obtained. Therefore, interpretation of the study using OCT requires attention. Lager population study should be required to clarify the relationships between OCT findings and clinical outcomes after achieving consensus standard of OCT findings.