Feasibility of combined use of intravascular ultrasound radiofrequency data analysis and optical coherence tomography for detecting thin-cap fibroatheroma (original) (raw)
Related papers
Feasibility of Noninvasive Assessment of Thin-Cap Fibroatheroma by Multidetector Computed Tomography
JACC: Cardiovascular Imaging, 2009
The purpose of this study was to investigate whether multidetector computed tomography (MDCT) can noninvasively help assess thin-cap fibroatheroma (TCFA). B A C K G R O U N D Plaque rupture and thrombus formation play key roles in the onset of acute coronary syndrome. TCFA is recognized as a precursor lesion for plaque rupture, and MDCT angiography can potentially help identify plaques prone to rupture. M E T H O D S We enrolled 105 patients with coronary artery disease (acute coronary syndromes, n ϭ 31; stable angina pectoris, n ϭ 74). Culprit lesions were assessed by both MDCT and optical coherence tomography (OCT). Patients were divided into a TCFA and a non-TCFA group according to OCT findings; clinical and MDCT observations were compared for 2 groups. R E S U L T S There were no differences in patients' characteristics between the 2 groups. OCT revealed 25 TCFAs at the culprit site in 105 patients. Acute coronary syndrome was more frequent in the TCFA group than in the non-TCFA group (52% vs. 23%, p ϭ 0.01). High-sensitive C-reactive protein was higher in the TCFA group (0.32 Ϯ 0.32 mg/dl vs. 0.17 Ϯ 0.16 mg/dl, p Ͻ 0.001). Positive remodeling identified by MDCT was observed more frequently in the TCFA group than in the non-TCFA group (76% vs. 31%, p Ͻ 0.001). Computed tomography attenuation value of the culprit plaque in the TCFA group was lower than that in the non-TCFA group (35.1 Ϯ 32.3 HU vs. 62.0 Ϯ 33.6 HU, p Ͻ 0.001). The frequency of ring-like enhancement in the TCFA group was higher than in the non-TCFA group (44% vs. 4%, p Ͻ 0.0001). The sensitivity, specificity, positive predictive value, and negative predictive value of ring-like enhancement for detecting TCFA are 44%, 96%, 79%, and 85%, respectively. By stepwise regression, the ring-like enhancement, high-sensitive C-reactive protein, and diagnosis of acute events were associated with the presence of TCFA at the culprit site.
Circulation Journal, 2009
ecent intracoronary imaging studies using intravascular ultrasound (IVUS) have shown that plaque rupture may be present not only in the culprit lesion but also in non-culprit lesions. 1-3 Multiple plaque ruptures have been reported in 10-79% of patients with acute coronary syndrome (ACS), 1,4,5 suggesting more extensive plaque vulnerability as a result of systemic inflammation. 3 The precursor of plaque rupture is known as thin cap fibroatheroma (TCFA), which is characterized by an avascular, hypocellular necrotic core with an overlying fibrous cap measuring <65 μm. 6-10 Because the resolution of current IVUS systems is 100-150 μm, the frequency and geographical distribution of in vivo TCFA has not been investigated by IVUS. Optical coherence tomography (OCT) is a high-resolution (10-20 μm) imaging method 11-14 that could provide an accurate measurement of the thickness of the fibrous cap 15 and thus enable a diagnosis of TCFA. Accordingly, we hypothesized that OCT might enable accurate detection of frequency and spatial distribution of TCFA in vivo. To test this hypothesis, we first evaluated the frequency and distribution of TCFA by 3-vessel histological and OCT examinations in ex vivo human coronary artery specimens and second, we conducted 3-vessel IVUS and OCT analyses to evaluate the feasibility of this method in vivo. Methods Ex Vivo Study We examined coronary arterial segments from 38 human cadavers (24 males, 14 females, mean age 74±7 years). Of these, 6 had symptomatic cardiovascular disease (16%). Hypercholesterolemia was defined as a total cholesterol level ≥240 mg/dl or medication use; hypertension was systolic blood pressure (BP) ≥140 mmHg, diastolic BP ≥90 mmHg, or use of an antihypertensive drug; diabetes mellitus was use of antidiabetic medications (insulin or oral hypoglycemic agents). The study protocol was approved by the Ethics Committee of Kawasaki Medical School, and written informed consent was given by each family. Segments measuring approximately 5 cm length were obtained from the proximal site of the 3 major coronary
Diagnosis of Thin-Capped Fibroatheromas in Intravascular Optical Coherence Tomography Images
Circulation-cardiovascular Interventions, 2016
Background-Intravascular optical coherence tomography (IVOCT) images are recorded by detecting light backscattered within coronary arteries. We hypothesize that non-thin-capped fibroatheroma (TCFA) etiologies may scatter light to create the false appearance of IVOCT TCFA. Methods and Results-Ten human cadaver hearts were imaged with IVOCT (N=14 coronary arteries). IVOCT and histologic TCFA images were co-registered and compared. Of 21 IVOCT TCFAs (fibrous cap <65 µm, lipid arc >1 quadrant), only 8 were true histologic TCFA. Foam cell infiltration was responsible for 70% of false IVOCT TCFA and caused both thickcapped fibroatheromas (ThCFAs) to appear as TCFA and the appearance of TCFAs when no lipid core was present. Other false IVOCT TCFA etiologies included SMC-rich fibrous tissue (12%) and loose connective tissue (9%). If the lipid arc >1 quadrant ("obtuse") criterion was disregarded, 45 IVOCT TCFAs were identified, and sensitivity of IVOCT TCFA detection increased from 63% to 87%, and specificity remained high at 92%. Conclusions-We demonstrate that IVOCT can exhibit 87% (95% CI 75% to 93%) sensitivity and 92% specificity (95% CI 86% to 96%) to detect all lipid arcs (both obtuse and "acute," <1 quadrant) TCFA and we also propose new mechanisms involving light scattering that explain why other plaque components can masquerade as TCFA and cause low PPV of IVOCT for TCFA detection (47% for obtuse lipid arcs). Disregarding the lipid arc >1 quadrant requirement enhances the ability of IVOCT to detect TCFA.
In Vivo Characterization of Coronary Atherosclerotic Plaque by Use of Optical Coherence Tomography
Circulation, 2005
Background-The current understanding of the pathophysiology of coronary artery disease is based largely on postmortem studies. Optical coherence tomography (OCT) is a high-resolution (Ϸ10 m), catheter-based imaging modality capable of investigating detailed coronary plaque morphology in vivo. Methods and Results-Patients undergoing cardiac catheterization were enrolled and categorized according to their clinical presentation: recent acute myocardial infarction (AMI), acute coronary syndromes (ACS) constituting non-ST-segment elevation AMI and unstable angina, or stable angina pectoris (SAP). OCT imaging was performed with a 3.2F catheter. Two observers independently analyzed the images using the previously validated criteria for plaque characterization. Of 69 patients enrolled, 57 patients (20 with AMI, 20 with ACS, and 17 with SAP) had analyzable images. In the AMI, ACS, and SAP groups, lipid-rich plaque (defined by lipid occupying Ն2 quadrants of the cross-sectional area) was observed in 90%, 75%, and 59%, respectively (Pϭ0.09). The median value of the minimum thickness of the fibrous cap was 47.0, 53.8, and 102.6 m, respectively (Pϭ0.034). The frequency of thin-cap fibroatheroma (defined by lipid-rich plaque with cap thickness Յ65 m) was 72% in the AMI group, 50% in the ACS group, and 20% in the SAP group (Pϭ0.012). No procedure-related complications occurred. Conclusions-OCT is a safe and effective modality for characterizing coronary atherosclerotic plaques in vivo. Thin-cap fibroatheroma was more frequently observed in patients with AMI or ACS than SAP. This is the first study to compare detailed in vivo plaque morphology in patients with different clinical presentations. (Circulation. 2005;111:1551-1555.)
Inflammatory markers and plaque morphology: An optical coherence tomography study
International Journal of Cardiology, 2012
Background: OCT with its unique image resolution is the ideal method to detect culprit lesion characteristics in different clinical presentations. The identification of inflammatory markers related to plaque characteristics may be of clinical importance. Methods: Thirty-two patients with acute coronary syndromes (ACS) and fourteen patients with stable angina pectoris (SAP) were enrolled in this study. Culprit lesion morphology was assessed by optical coherence tomography (OCT) in patients with ACS and SAP. The possible relations between serum levels of high sensitivity-C reactive protein (hs-CRP) and interleukin-18 (IL-18) with plaque characteristics were investigated in those patients. Results: Plaque rupture and thin-cap fibroatheroma (TCFA) were detected more frequently in ACS patients compared with SAP patients, (78.6% vs. 14.3%, p b 0.001, 92.9% vs. 14.3%, p b 0.001, respectively). Higher levels of serum hs-CRP and IL-18 were found in patients with plaque rupture vs. those with no plaque rupture (median value: 19.2 mg/L vs. 1.6 mg/L, p b 0.001 and 219.5 pg/ml vs. 127.5 pg/ml, p = 0.001 respectively), and TCFA vs. those without TCFA (median value: 15.2 mg/L vs. 1.6 mg/L, p = 0.004 and 209.0 pg/ml vs.153.2 pg/ml, p = 0.03 respectively). Serum hs-CRP was the only independent predictor of plaque rupture (p = 0.02, odds ratio 1.1, 95% confidence interval 1.0 to 1.2). A cut-off value of hs-CRP N 4.5 mg/L could detect ruptured plaque with a sensitivity of 91.7% and a specificity of 77.8%. Conclusions: OCT detected plaque rupture and TCFA more frequent in ACS patients compared with SAP. Elevated hs-CRP and IL-18 were positively related to plaque instability and rupture.
Plaque and thrombus evaluation by optical coherence tomography
The International Journal of Cardiovascular Imaging, 2011
Intravascular Optical Coherence Tomography has been explored as an imaging tool for vessel wall and thrombus characterization. OCT enables a high resolution arterial wall imaging, and light properties allow tissue characterization. It has been proved one of the most valuable imaging modalities for the evaluation of vulnerable plaque and thrombus. OCT has a unique capacity in volumetric quantification of calcium, and unlike ultrasound, light can easily penetrate calcified plaques. Finally, this review paper will address aspects of the validation method of plaque characterization and potential pitfalls and put in perspective new approaches that may help the evolution of the field.
The international journal of cardiovascular imaging, 2008
In the current issue of the journal, Knollmann et al. describe results from a quantitative post-mortem coronary plaque analysis with CT angiography (CTA) in comparison to histology . Plaque burden was quantified on a per-segment and a per-patient basis and demonstrated an overall fair correlation to histology, but significant overestimation with CT. Further analysis of calcified and non-calcified plaque components demonstrated best correlation for calcified plaque with overestimation of plaque burden. In contrast, there was relatively poor correlation for non-calcified plaque components and in particular the lipid core area, which was underestimated with CT in comparison to histology. Importantly, the correlation was better for patient-based analysis (average of all segments) versus segment-based analysis. For segment-based analysis of individual plaques the correlation between histology and CT was limited for small plaques.
Heart International, 2010
According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA) as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT), in order to detect not only thin cap fibroatheroma (TCFA), but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable) submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible) with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA). OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016), higher levels of hs-CRP (P=0.019) and triglycerides (P=0.040). The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003). Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with higher hs-CRP.