**Multimodality Imaging to Detect Vulnerable Plaque in Coronary Arteries and Its Clinical Application Coronary Arteries and Its Clinical Application**

**Multimodality Imaging to Detect Vulnerable Plaque in** 

DOI: 10.5772/intechopen.70183

Pannipa Suwannasom, Yohei Sotomi, Yosuke Miyazaki, Erhan Tenekecioglu, Yoshinobu Onuma and Patrick W. Serruys Erhan Tenekecioglu, Yoshinobu Onuma and Patrick W. Serruys Additional information is available at the end of the chapter

Pannipa Suwannasom, Yohei Sotomi, Yosuke Miyazaki,

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70183

#### **Abstract**

[90] Gherlone EF, Capparé P, Tecco S, Polizzi E, Pantaleo G, Gastaldi G, Grusovin MG. Implant prosthetic rehabilitation in controlled HIV-positive patients: A prospective longitudinal study with 1-year follow-up. Clinical Implant Dentistry and Related Research.

[91] Gherlone EF, Capparé P, Tecco S, Polizzi E, Pantaleo G, Gastaldi G, Grusovin MG. A prospective longitudinal study on implant prosthetic rehabilitation in controlled HIVpositive patients with 1-year follow-up: The role of CD4+ level, smoking habits, and oral hygiene. Clinical Implant Dentistry and Related Research. 2016;18(5):955-964. DOI:

[92] Gay-Escoda C, Pérez-Álvarez D, Camps-Font O, Figueiredo R. Long-term outcomes of oral rehabilitation with dental implants in HIV-positive patients: A retrospective case

[93] Ekfeldt A, Zellmer M, Carlsson GE. Treatment with implant-supported fixed dental prostheses in patients with congenital and acquired neurologic disabilities: A prospective study. The International Journal of Prosthodontics. 2013;26(6):517-524. DOI: 10.11607/

[94] Stoopler ET, Sollecito TP, Greenberg MS. Seizure disorders: Update of medical and dental

[95] Cune MS, Strooker H, van der Reijden WA, de Putter C, Laine ML, Verhoeven JW. Dental implants in persons with severe epilepsy and multiple disabilities: A long-term retrospective study. The International Journal of Oral & Maxillofacial Implants. May-June 2009;24

[96] Tsapakis EM, Gamie Z, Tran GT, Adshead S, Lampard A, Mantalaris A, Tsiridis E. The adverse skeletal effects of selective serotonin reuptake inhibitors. European Psychiatry.

[97] Yadav VK, Ryu JH, Suda N, Tanaka KF, Gingrich JA, Schütz G, Glorieux FH, Chiang CY, Zajac JD, Insogna KL, Mann JJ, Hen R, Ducy P, Karsenty G. Lrp5 controls bone formation by inhibiting serotonin synthesis in the duodenum. Cell. 2008;135(5):825-837. DOI:

[98] Wu X, Al-Abedalla K, Rastikerdar E, Abi Nader S, Daniel NG, Nicolau B, Tamimi F. Selective serotonin reuptake inhibitors and the risk of osseointegrated implant failure: A cohort study.

Journal of Dental Research. 2014;93(11):1054-1061. DOI: 10.1177/0022034514549378

series. Medicina Oral, Patología Oral y Cirugía Bucal. 2016;21(3):e385-e391

considerations. General Dentistry. 2003;51(4):361-366; quiz 367

2012;27(3):156-169. DOI: 10.1016/j.eurpsy.2010.10.006

2016;18(4):725-734. DOI: 10.1111/cid.12353

10.1111/cid.12370

90 Clinical Trials in Vulnerable Populations

ijp.3511

(3):534-540

10.1016/j.cell.2008.09.059

Postmortem studies have described the association between the thin-cap fibroatheroma (TCFA) and the occurrence of acute coronary syndrome (ACS). Both noninvasive and invasive techniques have been refined and used as a research tool to visualize the plaque at a high risk of disruption. There has been a considerable effort to develop the imaging modalities that offer detailed visualization of coronary pathology and accurately predict the adverse cardiac outcomes. This chapter provides an overview of the current and experimental coronary imaging methods to detect vulnerable plaque and discuss the potential implication of multimodality imaging in clinical practice.

**Keywords:** vulnerable plaque, imaging, IVUS, OCT, CCTA, CMR

#### **1. Introduction**

Cardiovascular diseases are the leading cause of death worldwide. It is predicted that by 2030, the number of deaths from coronary artery disease and stroke will increase from 17.3 million in 2008 to 23.3 million [1]. Current diagnostic strategies emphasize on preventing future coronary events by early identification of the vulnerable patient and modification of the risk by medication. The postmortem data have shown that the coronary events were associated with sudden luminal thrombosis due to plaque rupture. The thin-cap fibroatheroma is the most common constituent of a vulnerable plaque. Consequently, intensive studies in intracoronary imaging have been conducted to demonstrate the relationship between the imaging findings and the cardiovascular events. However, the results from such trials remain

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

controversial. In this chapter, we summarize the currently available coronary imaging techniques and the ongoing development of imaging technologies that detect vulnerable plaque. The clinical application of multimodalities imaging in detecting vulnerable plaque in clinic also discussed.

[9]. Low CT attenuation plaques, defined by <30 HU, were frequently observed in patients with ACS [11] and ruptured fibrous cap [12]. Napkin-ring sign is defined as central lowattenuation plaque with a peripheral rim of higher CT attenuation. It has been suggested that napkin-ring sign is the result of differences in CT attenuation between the large necrotic core (a central low CT attenuation) and fibrous plaque tissue (ring-like higher attenuation) [13]. Presence of NRS is strongly associated with future ACS events, independent of other high-risk coronary CTA features (presence of obstructive plaque, positive remodeling, lowattenuation plaque) [14], and also associated with the presence of TCFA defined by optical coherence tomography (OCT) [15]. Postmortem data reported that positive remodeling is associated with a high macrophage count and large lipid core [16]. CCTA-derived remodeling index has a consistent with histopathological data, lesion with positive remodeling (remodeling index ≥1.1) on CCTA, are associated with a higher percent of the necrotic core and a higher prevalence of the TCFA assessed by virtual histology intravascular ultrasound (VH-IVUS) than those lesions without positive remodeling [17]. In a retrospective study of 1059 patients who underwent CCTA, patients with positive remodeling with low-attenuation plaques were associated with high risk of subsequent ACS as compared to those without such features. (HR: 22.8, 95% CI: 6.9 to 75.2, *p* < 0.001) [9]. Spotty calcification on CCTA is defined as a small, dense (>130 HU) plaque component surrounded by noncalcified plaque tissue and size <3 mm. Small spotty calcification (< 1 mm) was related to vulnerable plaque features defined by VH-IVUS [18]. From all of the above features, CCTA would be considered

Multimodality Imaging to Detect Vulnerable Plaque in Coronary Arteries and Its Clinical…

http://dx.doi.org/10.5772/intechopen.70183

93

Compared with CCTA, cardiac magnetic resonance (CMR) identifies coronary stenosis >50% comparable to CCTA [19] where it could provide a superior in defining soft tissue such as positive remodeling and increased coronary wall thickness [20]. High-intensity coronary signal on T1-weighted MRI is associated with vulnerable morphology [21, 22] and future cardiac events. It has been demonstrated that high-intensity signal is related to the formation of methemoglobin during subclinical plaque rupture or hemorrhage [23]. T2-weighted short inversion recovery sequences have shown their ability to detect coronary wall edema relating to culprit ACS lesions [24]. However, coronary assessment by CMR is hampered by an inherent susceptibility to motion artifact from prolonged acquisition time [25] that limits its applica-

Despite the fact that CCTA and MRI demonstrate morphological characterization of plaque, they could not quantify the degree of plaque inflammation. The positron emission tomography (PET) has been combined with computed tomography to identify the anatomical and degree of inflammation. Although 18F–fluorodeoxyglucose (FDG) is acknowledged as conventional tracer in this field, it is hampered by significant myocardium uptake [26] and arterial wall with inflammation. To avoid the myocardial metabolism artifact, 18F–sodium fluoride (NaF) has been introduced to circumvent the myocardial uptake issue. 18F–NaF could localize individual

as a tool to detect vulnerable plaque in the future.

*3.1.3. Combined positron emission tomography (PET)-CCTA*

*3.1.2. Cardiac magnetic resonance (CMR) imaging*

tion in clinical practice.
