|Year : 2016 | Volume
| Issue : 2 | Page : 45-47
Optical coherence tomography evaluating the culprit coronary lesion
Jin-Chuan Yan, Cuiping Wang, Yang Zhao, Wei Yuan
Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
|Date of Web Publication||26-Dec-2018|
Prof. Jin-Chuan Yan
Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang
Source of Support: None, Conflict of Interest: None
We present a case in which a 64-year-old man was suffering from accelerated angina for 1 week. Conventional coronary angiography and intravascular ultrasound were unable to detect the culprit coronary lesion. However, optical coherence tomography (OCT) obtained superior images to detect a rupture with thin-cap fibroatheroma plaque in the proximal right coronary artery. The symptom of angina disappeared after one coronary stent covering the ruptured plaque. This case indicates that OCT is a new intravascular imaging modality that allows clear visualization of vulnerable plaques.
Keywords: Intravascular ultrasound, optical coherence tomography, vulnerable plaques
|How to cite this article:|
Yan JC, Wang C, Zhao Y, Yuan W. Optical coherence tomography evaluating the culprit coronary lesion. Cardiol Plus 2016;1:45-7
| Case Report|| |
A 72-year-old male with accelerated angina at rest visited our center on April 16, 2013. Eight months before this visit, he underwent percutaneous coronary intervention (PCI) with three drug-eluting stents in the left anterior descending (LAD) artery. His physical examination and chest X-ray results were normal. An electrocardiogram (ECG) showed a q/Q wave in the II, III, and avF leads and an inverted T wave in V5–6 [Figure 1]. The patient did present with an elevated cardiac troponin I level of 0.20 ng/ml (the normal value is <0.04 ng/ml). Transthoracic echocardiography showed 50% left ventricular ejection fraction and weak, inferior wall motion. Drug therapy, which included antiplatelet agents, a platelet glycoprotein IIb/IIIa receptor antagonist, and low molecular weight heparin, had no effect. He underwent coronary angiography on April 17, 2013. The angiogram showed normal LAD stents [Figure 2]a. The circumflex artery showed total occlusion similar to the previous procedure performed 8 months prior [Figure 2]b. A large right coronary artery with a slight stenotic lesion in the proximal artery was found [Figure 2]c and [Figure 2]d. The patient underwent both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) of the LAD and right coronary. IVUS images were acquired using a 20–50 MHz imaging Eagle Eye Gold catheter (Volcano, Rancho Cordova, CA, USA) and revealed that the right coronary stenotic lesion had a false lumen. The plaque burden was 72.6%, and the minimum lumen area was 5.8 mm2 [Figure 3]a. OCT images were acquired using a nonocclusive technique with the C7XR system (Dragonfly catheter and C7XR, LightLab Imaging). The artery was cleared of blood by continuously flushing with iodixanol 320 (Visipaque, GE Health Care, Cork, Ireland) at a flow rate of 3.0 ml/s. Using OCT, a rupture with a thin-cap fibroatheroma plaque was found in the lesion. A lesion with a 0.70 μm-thick discontinuous fibrous cap, lipid-rich plaque, and intimal tear was acquired [Figure 3]b, [Figure 3]c, [Figure 3]d, [Figure 3]e, [Figure 3]f. The lumen area from the IVUS was sufficient for the right coronary artery, but an unstable and ruptured coronary plaque may cause acute total occlusion in this situation. Therefore, a 3.5 mm × 18 mm Partner stent was placed to cover the ruptured plaque [Figure 4]a. OCT images showed the stent malapposition. The length between the stent and intima was 0.44 mm [Figure 4]b. Postdilation was performed using a 4.0 mm × 12 mm noncompliant balloon [Figure 4]c. The coronary angiography yielded a satisfactory result [Figure 4]d. The patient continued medication with aspirin, clopidogrel, and simvastatin until he no longer presented with symptoms of angina. He was discharged from the hospital 3 days after the procedure and remained asymptomatic for at least 9 months after stenting.
|Figure 1: The electrocardiogram showed q/Q wave in I, II, avF leads and inverted T wave in V5–6|
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|Figure 2: (a) Left anterior descending artery stents is normal. (b) Circumflex total occlusion. (c) Right coronary artery with a slight stenosis lesion in the proximal. (d) Enlarged stenosis lesion in the proximal of the right coronary artery|
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|Figure 3: (a) Intravascular ultrasound showing the stenosis lesion in the proximal of right coronary artery. (b) Optical coherence tomography showing the thin fibrous cap with lipid rich plaque. (c and d) Optical coherence tomography showing the ruptured plaque. (e and f) Optical coherence tomography showing the teared intima|
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|Figure 4: (a) The stent opening process in the rupture plaque lesion. (b) optical coherence tomography showing the stent malapposition. (c) Postdilated with a balloon. (d) The result of last procedure|
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| Discussion|| |
IVUS is the most widely used intracoronary imaging technique in routine practice. It uses ultrasound at a frequency of 20–40 MHz providing an axial resolution of 100–200 μm and lateral resolution of approximately 250 μm. Compared with simple contrast angiography, IVUS can assess stent apposition and expansion after implantation and determine the morphology of atherosclerotic plaques (lipid-rich, calcified, and fibrous). IVUS is three times more powerful than angiography in detecting calcifications and has a sensitivity and specificity of 89% and 97%, respectively. These features of IVUS enable the identification of microscopic changes in the size of atheromas and assessment of their limits and surface. IVUS can be used to determine the histological composition of atherosclerotic plaques (calcium, lipids, fibrosis, and necrotic cores) and can also measure the artery wall and its layers, enabling precise selection of stent diameter and length. It is useful for visualizing deep structures, but its ability to study microstructures is limited as it only has a sensitivity of 37% for detection of plaque ruptures. In contrast to IVUS, OCT uses reflections of infrared light, smaller diameter catheters and provides better spatial resolution and faster data acquisition. The high resolution of OCT (>15 μm) enables accurate assessment of stent strut positioning, endothelialization, and determination of the histological components of coronary plaques (microcalcium deposits and macrophage accumulation).,,,, However, the low axial penetration of OCT (1.5–2 mm) fails to provide optimal visualization of the arterial wall, especially in large vessels in which the outer layers of the artery cannot be identified. OCT also requires the injection of contrast agents during imaging. A major limitation of OCT is its inability to produce images in the absence of coronary flow, i.e., complete occlusion caused by thrombosis or dissection. Furthermore, the requirement of contrast agents in OCT increases the risk of nephropathy in some patients. IVUS and OCT are useful in the study of different coronary diseases and can be used in a complementary manner to obtain definitive diagnoses and help cardiologists select an appropriate invasive strategy.
The patient in the present case study had symptoms of accelerated angina at rest for 1 week. Clinical detection methods such as ECG and cardiac markers indicated that the patient had acute coronary syndrome. Angiography and IVUS failed to find positive culprit lesions or ruptured plaques. However, OCG was able to detect atherosclerotic plaque ruptures, visualize the thin fibrotic cap of the plaque and locate the site of plaque rupture and intimal tear. Therefore, we show that OCT and IVUS are both useful intravascular imaging methods, each with their advantages and limitations.
OCT is a catheter-based invasive imaging system. Using light rather than ultrasound, OCT enhances imaging resolution that may permit the evaluation of clinical and research parameters for the interventional cardiologist. Clinical parameters include diagnostic assessments of coronary atherosclerosis, luminal measurements during PCI, inflammation, lipid necrotic cores, and the presence of thrombi. Research parameters include fibrous cap thickness and strut-level analysis. The versatility of the physical properties of light allows OCT as an imaging modality to improve our understanding of the vascular biology of atherothrombosis and assists our performance of PCI procedures.
Although IVUS imaging is the most commonly used method in coronary intervention, higher resolution can be obtained with OCT. OCT enables a more detailed assessment of certain coronary lesions. Currently, no randomized studies are available to confirm the superiority of OCT over IVUS for different cases. However, the use of methods in a complementary manner can be helpful for the correct assessment of coronary disease, and aid cardiologists in selecting an optimal therapeutic strategy.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
This project was supported by the National Key Clinical Specialty (2011) and the development health engineering of Jiangsu Province (LJ201116, BRA2014162) and Social development of Zhenjiang (SS2012002).
Conflicts of interest
There are no conflicts of interest.
| References|| |
Bourantas CV, Garg S, Naka KK, Thury A, Hoye A, Michalis LK, et al.
Focus on the research utility of intravascular ultrasound – Comparison with other invasive modalities. Cardiovasc Ultrasound 2011;9:2.
Carrizo S, Salinas P, Jimenez-Valero S, Moreno R. Utility of optical coherence tomography to assess a hazy intracoronary image after percutaneous coronary intervention. Korean Circ J 2013;43:44-7.
Regar E, Ligthart J, Bruining N, van Soest G. The diagnostic value of intracoronary optical coherence tomography. Herz 2011;36:417-29.
Bouma BE, Tearney GJ, Yabushita H, Shishkov M, Kauffman CR, DeJoseph Gauthier D, et al.
Evaluation of intracoronary stenting by intravascular optical coherence tomography. Heart 2003;89:317-20.
Otake H, Shite J, Ako J, Shinke T, Tanino Y, Ogasawara D, et al.
Local determinants of thrombus formation following sirolimus-eluting stent implantation assessed by optical coherence tomography. JACC Cardiovasc Interv 2009;2:459-66.
Kubo T, Imanishi T, Takarada S, Kuroi A, Ueno S, Yamano T, et al.
Assessment of culprit lesion morphology in acute myocardial infarction: Ability of optical coherence tomography compared with intravascular ultrasound and coronary angioscopy. J Am Coll Cardiol 2007;50:933-9.
Tanimoto T, Imanishi T, Tanaka A, Yamano T, Kitabata H, Takarada S, et al.
Various types of plaque disruption in culprit coronary artery visualized by optical coherence tomography in a patient with unstable angina. Circ J 2009;73:187-9.
Stamper D, Weissman NJ, Brezinski M. Plaque characterization with optical coherence tomography. J Am Coll Cardiol 2006;47:C69-79.
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