OCT-derived Thin-cap Fibroatheroma Research Articles

Fractal geometry of culprit coronary plaque images within optical coherence tomography in patients with acute coronary syndrome vs stable angina pectoris.

The main cause of acute coronary syndrome (ACS) is plaque rupture and thrombus formation. However, it has not been fairly successful to identify vulnerable plaque to rupture using conventional parameters of intravascular imaging modalities. Fractal analysis is one of the mathematical models to examine geometrical features of picture image using a specific parameter called as fractal dimension (FD) which suggests geometric complexity of the image. This study examined FD of the optical coherence tomography (OCT)-derived images of the culprit plaque in patients with ACS vs stable angina pectoris (SAP) to evaluate the feasibility of FD for identifying vulnerable coronary plaques prone to provoke ACS distinguished from stable plaques only provoking SAP. We examined 65 cases (34 ACS patients, 31 SAP patients) in which the culprit lesion was imaged by OCT before percutaneous coronary intervention in patients with ACS and SAP. The culprit plaque lesion in the ACS group had a significantly larger mean lipid arc (203.8 ± 39.4° vs 152.3 ± 34.5°, p < 0.001) and a larger lipid plaque length (12.6 ± 5.1mm vs 7.7 ± 2.7mm, p < 0.001) and a thinner fibrous cap thickness (75.3 ± 22.3μm vs 134.8 ± 53.2μm, p < 0.001) than those in the SAP group. The prevalence of OCT-derived macrophage infiltration (Mph) in the entire culprit coronary vessel as well as that of the OCT-derived thin-cap fibroatheroma (TCFA) at the culprit lesion were significantly greater in the ACS group than those in the SAP group, respectively (Mph: 61.8% vs 35.5%, p = 0.048; TCFA: 44.1% vs 6.4%, p < 0.001). The FD of culprit plaque in the ACS group was significantly greater than in the SAP group (2.401 ± 0.073 vs 2.341 ± 0.051, p < 0.001). In multivariate regression analysis, the presence of Mph was a significant determinant of FD (regression coefficient estimate 0.049, CI 0.018-0.079, p = 0.002). The FD of OCT-derived image of culprit coronary plaque in the ACS group was significantly greater than that in the SAP group, indicating that the culprit plaque in ACS were structurally more complex. Therefore, fractal analysis of coronary OCT images might be clinically useful for identifying coronary plaques prone to provoke ACS.

Detection of optical coherence tomography-defined thin-cap fibroatheroma in the coronary artery using deep learning.

The aim of this study was to develop a deep learning model for classifying frames with versus without optical coherence tomography (OCT)-derived thin-cap fibroatheroma (TCFA). A total of 602 coronary lesions from 602 angina patients were randomised into training and test sets in a 4:1 ratio. A DenseNet model was developed to classify OCT frames with or without OCT-derived TCFA. Gradient-weighted class activation mapping was used to visualise the area of attention. In the training sample (35,678 frames of 480 lesions), the model with fivefold cross-validation had an overall accuracy of 91.6±1.7%, sensitivity of 88.7±3.4%, and specificity of 91.8±2.0% (averaged AUC=0.96±0.01) in predicting the presence of TCFA. In the test samples (9,722 frames of 122 lesions), the overall accuracy at the frame level was 92.8% within the lesion (AUC=0.96) and 91.3% in the entire OCT pullback. The correlation between the %TCFA burden per vessel predicted by the model compared with that identified by experts was significant (r=0.87, p<0.001). The region of attention was localised at the site of the thin cap in 93.4% of TCFA-containing frames. Total computational time per pullback was 2.1±0.3 seconds. A deep learning algorithm can accurately detect an OCT-TCFA with high reproducibility. The time-saving computerised process may assist clinicians to recognise high-risk lesions easily and to make decisions in the catheterisation laboratory.

Relationship of systemic pentraxin-3 values with coronary plaque components on optical coherence tomography and post-percutaneous coronary intervention outcomes in patients with stable angina pectoris

Elevated pentraxin-3 (PTX3) values are associated with vulnerable plaque existence and poor outcomes in acute coronary syndrome patients. The clinical significance of PTX3 values in stable angina pectoris (SAP) patients is, however, undetermined. We investigated the relationship of systemic PTX3 values and coronary plaque components and post-percutaneous coronary intervention (PCI) outcomes in SAP patients. We included 93 consecutive de-novo lesions in 93 SAP patients with a normal pre-PCI high-sensitivity cardiac troponin-T (<0.014ng/mL), undergoing pre- and post-PCI optical coherence tomography (OCT). Systemic PTX3 values were obtained immediately pre- and post-PCI, at 24-h and 9-month post-PCI. Peak post-PCI PTX3 values correlated with thinnest fibrous cap thickness (r=-0.23, p=0.03) and lipid length (r=0.24, p=0.03), and were higher in patients with lesions having OCT-derived thin-cap fibroatheroma (6.67 (3.19-7.33) vs. 3.13 (2.34-4.11) ng/mL, p=0.04) and post-stenting irregular tissue protrusion (4.76 (3.31-6.80) vs. 2.98 (2.23-4.06) ng/mL, p=0.003) than in those without. At 9-month follow-up, cardiac event-free survival was poorer in patients with a peak post-PCI PTX3 value≥4.08ng/mL (upper tertile) (log-rank test χ2=9.0; p= 0.003). Multivariate Cox regression analysis showed a peak post-PCI PTX3 value≥4.08ng/mL as an independent predictor of MACE (hazard ratio, 3.915; 95% CI, 1.129-13.583; p=0.03). Peak post-PCI PTX3 values correlated with pre-PCI plaque characteristics and post-PCI outcomes, providing a good prognostic factor of outcomes in SAP patients undergoing elective PCI.

Association of endothelial function with thin-cap fibroatheroma as assessed by optical coherence tomography in patients with acute coronary syndromes.

BackgroundThinning of the fibrous cap of atherosclerotic plaque is a major component of plaque vulnerability. The high resolution of optical coherence tomography (OCT) provides an accurate measurement of fibrous-cap thickness. Endothelial dysfunction is associated with inflammation and enhanced local expression of matrix metalloproteinases. We investigated the association between endothelial dysfunction and OCT-derived thin-cap fibroatheroma (TCFA) in patients with acute coronary syndromes (ACS).MethodsSeventy-four patients with ACS, who underwent both OCT examinations of the culprit lesion before percutaneous coronary intervention and peripheral endothelial function assessment as assessed by logarithmic value of reactive hyperemia index (Ln_RHI), were enrolled. Age-, sex-, hypertension-, and diabetes-matched non-coronary artery disease (non-CAD) patients were also enrolled (n=15).ResultsLn_RHI levels were significantly lower in ACS patients compared with non-CAD patients (0.56±0.26 vs 0.74±0.22, P=0.01). Furthermore, the Ln_RHIs of ACS patients with TCFA (n=44) were significantly lower than those of ACS patients without TCFA (n=30) (0.50±0.24 vs 0.65±0.26, P=0.01). There was a weak but significant positive correlation between Ln_RHI and fibrous-cap thickness (Spearman’s ρ=0.25, P=0.03). Multivariate logistic regression analysis identified lower Ln_RHI as an independent factor associated with TCFA in ACS patients (OR per 0.1 increase in Ln_RHI: 0.78 [95% CI: 0.62–0.98], P=0.03).ConclusionAdvanced endothelial dysfunction significantly correlates with a thin fibrous cap of coronary plaques in patients with ACS.

Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with non-ST segment elevation acute coronary syndrome.

This study aimed to use optical coherence tomography (OCT) to study the relationship between plaque morphology prior to percutaneous coronary intervention (PCI) and post-PCI cardiac troponin (cTn) elevations in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Furthermore, the relationship between these findings and the adverse cardiac events during follow-up was assessed. Association between post-PCI cTn elevations and OCT findings in NSTE-ACS patients is unclear. We evaluated 167 patients with stable or falling cTn values after admission who underwent PCI. Periprocedural myocardial injury (PMI) was defined as an cTn increase of more than 70× upper limit of normal (ULN) in troponin-negative patients before PCI, or more than new 70× ULN elevation from the previous nadir level in pre-PCI troponin-positive patients. Clinical and OCT findings were compared between patients with (n = 48, 29%) and without (n = 119, 71%) PMI. PMI was associated with age, prior PCI, low estimated glomerular filtration rate (eGFR), OCT-derived thin-cap fibroatheroma (TCFA), plaque rupture, and lipid length. In multivariable analysis, TCFA (odds ratio [OR], 2.88; P = 0.011), eGFR (OR, 0.97, P = 0.003), and lipid length (OR, 1.12, P = 0.020) were independent predictors of PMI. At a median follow-up of 38 months, event-free survival was significantly worse in patients with PMI (log-rank test χ2 = 6.47, P = 0.011). OCT analysis showed that PMI occurs more frequently in lesions with TCFA in NSTE-ACS patients, and may identify patients having a higher risk of adverse cardiac events during follow-up. © 2017 Wiley Periodicals, Inc.

Impact of optical coherence tomography- and coronary angioscopy-assessed neointimal tissue characteristics on occurrence of periprocedural myonecrosis in patients with in-stent restenosis.

Several characteristics of neointimal tissues, including neoatherosclerotic progression, have been reported in lesions with in-stent restenosis (ISR). However, the effects of these characteristics on outcomes after percutaneous coronary intervention (PCI) for ISR lesions remain unclear. We assessed the relationships between neointimal tissue characteristics and the occurrence of periprocedural myonecrosis (PMN) after PCI in ISR lesions. We investigated 72 ISR lesions in 72 patients with stable angina pectoris (SAP) who underwent pre- and post-revascularization optical coherence tomography (OCT) and coronary angioscopy (CAS). All lesions were classified as with PMN, defined by an elevated peak high-sensitivity cardiac troponin-T level during the 24-h post-PCI period, and without PMN. PMN was observed in 23 (31.9 %) lesions. PMN lesions had higher frequencies of OCT-derived thin-cap fibroatheroma (26.1 vs. 6.1 %, P = 0.03), CAS-derived intensive yellow neointima (30.4 vs. 10.2 %, P = 0.04), neointima with complex surface (60.9 vs. 28.6 %, P = 0.01), and CAS-derived atheromatous appearance (CAS-AAP), defined as yellow plaque including complex thrombi underneath disrupted neointimal coverage after ballooning (47.8 vs. 16.3 %, P = 0.008) at the most stenotic sites inside stents, compared to lesions without PMN. Multivariate logistic regression analysis identified CAS-AAP (odds ratio: 3.568, 95 % confidence interval: 1.109-11.475, P = 0.033) as an independent predictor of PMN. For ISR lesions in SAP patients, an OCT- and CAS-based assessment of neointimal tissue characteristics might help to predict the occurrence of PMN.

Assessment of coronary atherosclerosis using optical coherence tomography.

Optical coherence tomography (OCT) is a catheter-based imaging system that uses near-infrared light to produce cross-sectional images of the coronary arteries. With its extraordinarily high resolution (10-20 μm), OCT allows clinicians to observe various morphological features of coronary atherosclerosis in vivo. For example, intimal thickening presents as homogeneous, signal-rich regions on OCT, while fibroatheroma with a lipid-rich necrotic core is characterized by the presence of signal-poor regions with a diffuse border. Furthermore, plaque rupture is detected in 50〜70% of culprit lesions of acute coronary syndrome (ACS), and plaque erosion develops over areas of intimal thickening and/or thick-cap fibroatheroma. Meanwhile, calcified nodules are common in older patients with hypertension and chronic renal disease. Platelet-rich thrombi are visualized as low backscattering structures and often detected in patients with unstable angina, whereas red blood cell-rich thrombi exhibit a high backscattering structure with signal-free shadowing and are frequently noted in patients with acute myocardial infarction. Moreover, OCT-derived thin cap fibroatheroma has been shown to be a predictor of subsequent plaque progression and acute coronary events, while vasa vasorum and the macrophage density are associated with a thin fibrous cap and large necrotic core as well as increased serum levels of inflammatory biomarkers. One current challenge of OCT examinations is to detect morphologic characteristics capable of discriminating vulnerable from stable plaques. The ability to detect vulnerable plaques in vivo would allow physicians to identify patients at high risk for adverse coronary events, thus significantly helping to prevent ACS.

Evaluation of plaque composition using iMap-intravascular ultrasound predicts thin-cap fibroatheroma determined by optical coherence tomography

Purpose: The iMap-intravascular ultrasound (iMap-IVUS), a novel radiofrequency intracoronary imaging system, can generate objective and quantitative information about coronary plaque compositions. The aim of this study was to determine whether iMap-IVUS can detect Thin-Cap Fibroatheroma (TCFA), which is a primary type of vulnerable plaque, as determined by Optical Coherence Tomography (OCT). Methods: Seventy nine culprit plaques in 70 patients with stable and 9 with unstable angina pectoris were analyzed using iMap-IVUS and OCT. Quantitative volumetric grayscale and iMap-IVUS analysis was performed across the entire lesion segment, and cross-sectional area analysis was performed to evaluate vessel remodeling. Plaque compositions were classified using iMap-IVUS as fibrotic, lipidic, necrotic and calcified, which are expressed as absolute amounts and as a percentage of plaque volume. We defined OCT-derived TCFA as lipid-rich plaque with a <65-μm thick fibrous cap. Patients were divided into 2 groups according to the presence (TCFA group, n=33) or absence (non-TCFA group, n=46) of TCFA. Results: The vessel volume, lumen volume, and plaque volume were significantly greater, and the prevalence of positive remodeling was significantly higher in the TCFA, than in the non-TCFA group. The absolute and percent necrotic volume (62.6±34.6 vs. 30.0±27.8 mm3, p<0.001, and 42±14 vs. 30±13%, p=0.001, respectively) and the absolute lipidic volume (14.0±5.8 vs. 8.6±5.5 mm3, p<0.001) were significantly greater, and the percent fibrotic volume (46±14 vs. 59±14%, p=0.001) were significantly smaller in TCFA compared with non-TCFA group. Fibrous cap thickness measured by OCT correlated negatively with vessel volume (r= -0.44, p<0.001), lumen volume (r= -0.26, p=0.032), plaque volume (r= -0.44, p<0.001), absolute and percent necrotic volume (r= -0.56, p<0.001, and r= -0.50, p<0.001, respectively), absolute lipidic volume (r= -0.49, p<0.001), and positively with percent fibrotic volume (r=0.50, p<0.001). Multivariate logistic regression analysis showed that absolute necrotic volume was the only independent predictor of the TCFA (odds raio, 1.033; 95% CI, 1.013–1.054; p=0.001). The area under the receiver-operator characteristic curve for absolute necrotic volume predicting the TCFA was 0.80. The optimal cut-off value of absolute necrotic volume for predicting the TCFA was 32.9 mm3 (sensitivity 73%, specificity 69%). Conclusions: Coronary plaque with a greater necrotic volume assessed by iMap-IVUS is closely associated with TCFA determined by OCT.

In vivo detection of lipid-rich plaque by using a 40-MHz intravascular ultrasound: a comparison with optical coherence tomography findings

iMAP™ has recently been introduced as a new tissue characterization method using the 40-MHz intravascular ultrasound (IVUS). However, few data have been published on the comparative findings of other imaging modalities in vivo. We examined 108 matched lesions from 70 patients (35 with stable angina and 35 with acute coronary syndrome) that underwent percutaneous coronary intervention (PCI) using pre-PCI OCT and IVUS. Identification of OCT-derived lipid-rich plaques and thin-cap fibroatheroma (TCFA) was performed using iMAP™. OCT-derived lipid-rich plaques and TCFAs were detected in 56 (51.8 %) and 20 (18.6 %) lesions, respectively. The iMAP™ analysis identified significantly greater percentage of necrotic area (%NA) in the lesions with lipid-rich plaques than in those without [46.5 (29.4-56.9) vs. 24.6 (10.3-41.6) %, p < 0.01]. In the receiver operating characteristic (ROC) analysis, the optimal %NA cut-off value for identifying lipid-rich plaques was 33 % (AUC: 0.75; sensitivity: 73.2 %; specificity: 67.3 %). A greater plaque burden and a larger necrotic area were detected using iMAP™ in the OCT-derived TCFAs than in the non-TCFAs [81.5 (77.3-86.8) vs. 72.7 (60.6-81.0) %, p < 0.01; 7.6 (4.3-9.6) mm(2) vs. 2.7 (1.0-6.0) mm(2), p < 0.01]. For the iMAP™-derived TCFAs, combinations of variables such as necrotic area, % plaque burden, and absolute plaque area showed a relatively low positive predictive value and high negative predictive value (plaque burden >75 % and confluent luminal necrotic area >4.0 mm(2); sensitivity: 75.0 %; specificity: 71.6 %; PPV: 37.5 %; NPV: 92.6 %; and diagnostic accuracy: 72.2 %). The results showed that iMAP™ tissue characterization may help to detect lipid-rich plaque and rule out TCFAs in vivo.

Application of Optical Coherence Tomography in Percutaneous Coronary Intervention

Optical coherence tomography (OCT) is a high resolution imaging technique that offers microscopic visualization of the coronary artery. The fast scanning speed and simple imaging procedure of new-generation frequency-domain OCT make this technology easy to use in the clinical setting. The OCT examination is useful for guidance and risk stratification of percutaneous coronary intervention (PCI). OCT-derived thin-cap fibroatheroma, which is characterized by large lipid-core and thin fibrous cap <65 μm, is a predictor of peri-PCI complications, such as angiographic no-reflow, microvascular obstruction, and post-PCI cardiac troponin I elevation. Stent malapposition, tissue protrusion, and stent edge dissection are assessed in more detail by OCT than with conventional intravascular imaging modalities. Neointimal coverage at strut level assessed by OCT could be a surrogate endpoint for quickly scrutinizing safety after drug-eluting stent implantation. The OCT findings of in-stent neoatherosclerosis, such as lipid-rich neointima, microvascular proliferation, and neointimal plaque rupture, are associated with very late stent failure, including thrombosis and restenosis. With its excellent ability to assess coronary atherosclerosis and to guide PCI, OCT provides new insights into interventional cardiology.

Plaque Characteristics of Thin-Cap Fibroatheroma Evaluated by OCT and IVUS

The purpose of this study was to assess plaque characteristics of optical coherence tomography (OCT)-derived thin-cap fibroatheroma (TCFA) by integrated backscatter intravascular ultrasound (IB-IVUS). Radiofrequency signal-derived IVUS tissue characterization technology has become clinically available and provided objective and quantitative plaque characteristics of the coronary vessel wall. Integrated backscatter IVUS is one of the tissue characterization methods that can possibly provide quantitative plaque characteristics of the OCT-derived TCFA. Eighty-one coronary lesions with plaque burden >40% were selected and analyzed with both IB-IVUS and OCT. The OCT-derived TCFA was defined as a presence of thin fibrous cap (<65 μm) overlying a signal-poor lesion with diffuse border representing a lipid-rich plaque. By conventional gray-scale IVUS, external elastic membrane (EEM) cross-sectional area (CSA), lumen CSA, plaque plus media (P+M) CSA, plaque burden and remodeling index were measured. By IB-IVUS, plaque characteristics were further classified as fibrosis, dense fibrosis, calcification, or lipid pool. Optical coherence tomography identified 40 TCFAs (49%) and 41 non-TCFAs. The EEM CSA, P+M CSA, plaque burden, and remodeling index were significantly larger in OCT-derived TCFA than non-TCFA. By IB-IVUS, percentage lipid pool area (= lipid pool area/P+M CSA × 100) was significantly higher (62.4 ± 12.8% vs. 38.4 ± 13.1%, p<0.0001) and percentage fibrosis area (= fibrosis area/P+M CSA × 100) was significantly lower (34.6 ± 11.4% vs. 50.5 ± 8.7%, p<0.0001) in OCT-derived TCFA than non-TCFA. By receiver-operator characteristic curve analysis, percentage lipid pool area ≥55%, percentage fibrosis area ≤41%, and remodeling index ≥1.0 were predictors of OCT-derived TCFA. The OCT-derived TCFA had larger plaque burden and positive remodeling with predominant lipid component and less fibrous plaque assessed by IB-IVUS.

Multiple Coronary Lesion Instability in Patients With Acute Myocardial Infarction as Determined by Optical Coherence Tomography

Autopsy studies have suggested that acute myocardial infarction (AMI) represents a pan-coronary process of vulnerable plaque development. We performed multifocal optical coherence tomographic (OCT) examination to compare coronary lesion instability between AMI and stable angina pectoris (SAP). A total of 42 patients with AMI (n = 26) or SAP (n = 16) who had multivessel disease and underwent multivessel coronary intervention were enrolled in the present study. The OCT examination was performed not only in the infarct-related/target lesions, but also in the noninfarct-related/nontarget lesions. OCT-derived thin-cap fibroatheroma (TCFA) was defined as a lesion with a fibrous cap thickness of <65 microm. In the infarct-related/target lesions, plaque rupture (77% vs 7%, p <0.001) and intracoronary thrombus (100% vs 0%, p <0.001) were observed more frequently in AMI than in SAP. The fibrous cap thickness (57 + or - 12 vs 180 + or - 65 microm, p <0.001) was significantly thinner in AMI and the frequency of OCT-derived TCFA (85% vs 13%, p <0.001) was significantly greater in AMI than in SAP. In the noninfarct-related/nontarget lesions, the frequency of plaque rupture was not different between the 2 groups. Intracoronary thrombus was observed in 8% of AMI, but it was not found in SAP. The fibrous cap thickness (111 + or - 65 vs 181 + or - 70 microm, p = 0.002) was significantly thinner in AMI and the frequency of OCT-derived TCFA (38% vs 6%, p = 0.030) was significantly greater in AMI than in SAP. Multiple OCT-derived TCFAs in both the infarct-related/target and the noninfarct-related/nontarget lesions were observed in 38% of patients with AMI but not in patients with SAP (p = 0.007). In conclusion, the present OCT examination demonstrated multiple lesion instability in the presence of AMI.

Feasibility of combined use of intravascular ultrasound radiofrequency data analysis and optical coherence tomography for detecting thin-cap fibroatheroma

To evaluate the feasibility of the combined use of virtual histology (VH)-intravascular ultrasound (IVUS) and optical coherence tomography (OCT) for detecting in vivo thin-cap fibroatheroma (TCFA). In 56 patients with angina, 126 plaques identified by IVUS findings were analysed using both VH-IVUS and OCT. IVUS-derived TCFA was defined as an abundant necrotic core (>10% of the cross-sectional area) in contact with the lumen (NCCL) and %plaque-volume >40%. OCT-derived TCFA was defined as a fibrous cap thickness of <65 microm overlying a low-intensity area with an unclear border. Plaque meeting both TCFA criteria was defined as definite-TCFA. Sixty-one plaques were diagnosed as IVUS-derived TCFA and 36 plaques as OCT-derived TCFA. Twenty-eight plaques were diagnosed as definite-TCFA; the remaining 33 IVUS-derived TCFA had a non-thin-cap and eight OCT-derived TCFA had a non-NCCL (in discord with NCCL visualized by VH-IVUS, mainly due to misreading caused by dense calcium). Based on IVUS findings, definite-TCFA showed a larger plaque and vessel volume, %plaque-volume, higher vessel remodelling index, and greater angle occupied by the NCCL in the lumen circumference than non-thin-cap IVUS-derived TCFA. Conclusion Neither modality alone is sufficient for detecting TCFA. The combined use of OCT and VH-IVUS might be a feasible approach for evaluating TCFA.

Very late drug-eluting stent thrombosis

We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS).Neoatherosclerosis in neointima has been reported in BMS and in DES.Thirty patients with 36 stented lesions [BMS (n = 17) or DES (n = 19)] > 3 years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥ 70% diameter stenosis were excluded.The median duration from implantation was 126.0 months in the BMS group and 60.0 months in the DES group (p < 0.001). Lipid-laden intima (58.8% vs. 42.1%, p = 0.317), thrombus (17.6% vs. 5.3%, p = 0.326), and calcification (35.3% vs. 26.3%, p = 0.559) did not show significant differences between BMS and DES. When divided into 3 time periods, the cumulative incidence of lipid-laden neointima from > 3 years to < 9 years was similar between BMS and DES (42.9% vs. 42.1%, p = 1.000). Furthermore, it continued to gradually increase over time in both groups. OCT-derived thin-cap fibroatheroma (TCFA) was observed in 17.6% of BMS- and 5.3% of DES-treated lesions (p = 0.326). No stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p = 0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p = 0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p = 0.361) did not differ significantly.At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES.