Combination therapy with atherectomy and intravascular lithotripsy (IVL) has emerged as a promising strategy for the treatment of severely calcified occlusive coronary lesions, which potentially enhances procedural efficacy without increasing complication risk. The Dual-Prep Registry is a multicenter, prospective registry designed to evaluate the safety and efficacy of IVL after atherectomy in severely calcified lesions. Combined use was selectively applied when the risk of complications was anticipated to be high with a larger atherectomy burr size, or when it was deemed non-beneficial due to unfavorable guidewire bias. All adverse events were adjudicated by a clinical events committee. Kaplan–Meier analysis was performed to evaluate the primary endpoint of major adverse cardiovascular events (MACE; composite endpoint of cardiac death, myocardial infarction, and target vessel revascularization [TVR]) at 1 year. A total of 118 cases (120 lesions) were enrolled across 20 facilities. Significant comorbidities included diabetes in 56.8 https://jrct.mhlw.go.jp .

BACKGROUND:A combined strategy of atherectomy followed by intravascular lithotripsy (dual-prep strategy) for severely calcified lesions may optimize stent deployment, but mechanistic evidence from prospective optical coherence tomography (OCT) imaging is limited. This study was designed to comprehensively characterize patterns of calcium modification during a dual-preparation strategy and to explore imaging determinants of calcium fracture and stent expansion using serial and 3-dimensional OCT assessment. METHODS:This was a prespecified, multicenter, single-arm OCT substudy of the DUAL-PREP registry, enrolling patients with severely calcified lesions for whom combined treatment with atherectomy and intravascular lithotripsy was deemed preferable based on imaging findings. OCT was analyzed by an independent core laboratory. Multivariable models examined predictors of fracture and stenting performance, including calcium thickness, length, angle, calcified nodules, and morphology (circumferential, eccentric spiral, and eccentric straight types). RESULTS:OCT images were available for 114 of 118 patients (116 lesions; age, 75.9±9.1 years; 69.3% male). All lesions had an OCT calcium score of 4. Calcium fractures were uncommon after atherectomy (2/106 lesions [1.9%]) but markedly increased following intravascular lithotripsy (89/106 lesions [84.0%]; 2.05±1.59 fractures per lesion), with a further increase after stent implantation (101/109 lesions [92.7%]; 2.89±1.67 fractures per lesion). Final stent expansion index was 0.81±0.15 (eccentricity, 0.72±0.09; asymmetry, 0.39±0.15). Eccentric straight-type calcification was associated with a lower likelihood of fracture at final OCT (odds ratio, 0.07 [95% CI, 0.00-0.77]; P=0.029), whereas eccentric spiral and circumferential types showed higher fracture occurrence. CONCLUSIONS:This OCT analysis demonstrated a stepwise increase in calcium fracture during a dual-preparation strategy, with minimal fracture after atherectomy, a marked increase following intravascular lithotripsy, and a further increase after stent implantation. Calcium morphology may provide additional insight into fracture occurrence, supporting the potential value of 3-dimensional assessment in severely calcified lesions. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: jRCT1032230384.

AIMS:Although the advantages of intra-coronary imaging guidance in percutaneous coronary intervention (PCI) have been reported, the advantage of optical coherence tomography (OCT) guided PCI has not been elucidated in patients with ST-elevation myocardial infarction (STEMI). This study assessed the association between OCT findings after stent implantation and 1-year outcomes in an all-comer STEMI population. METHODS AND RESULTS:The ATLAS-OCT trial was a prospective, multicentre, single-arm study enrolling STEMI patients within 24 h of symptom onset. OCT-guided PCI was preferred when feasible. This analysis included patients with analysable post-PCI OCT images. The primary endpoint was target vessel failure (TVF; all-cause death, target vessel myocardial infarction [TVMI], or target vessel revascularization [TVR]). OCT images were analysed independently, and outcomes assessed at 12 months. Of 632 patients, 439 (69.5%) underwent OCT-guided stenting with final analysable imaging. Mean minimal stent area (MSA) and stent expansion (SE) were 6.21 ± 2.27 mm² and 76.8 ± 15.6%, respectively. Optimization criteria (MSA > 4.5 mm² and/or SE > 70%) were met in 87.7%. Suboptimal expansion was associated with higher TVF (20.4% vs. 8.1%; HR 2.57, 95% CI: 1.29-5.11), driven by TVMI and TVR. Each 1 mm² MSA decrease and 10% SE reduction increased TVF odds by 23% and 33%, respectively. Minor OCT findings were not significantly associated with outcomes. CONCLUSION:In STEMI, suboptimal MSA and SE determined by OCT were associated with higher adverse event risk. These findings support OCT-guided PCI optimization to improve outcomes and warrant further evaluation in randomized trials. STUDY REGISTRATION:University Hospital Medical Information Network Clinical Trials Registry of Japan (UMIN-CTR number: 000048590).

Due to the substantial discrepancy in vessel diameter between the proximal and distal segments, appropriate stent size selection is important in percutaneous coronary intervention (PCI) of the left main bifurcation (LMB). Inadequate stent expansion in both the main trunk and daughter branches after kissing balloon inflation (KBI) may contribute to adverse clinical outcomes. We investigated the relationship between stent size selection and vessel dilation in the distal main vessel (DMV) and side branch (SB). We analyzed 80 cases of single stenting with KBI under optical coherence tomography (OCT) guidance for LMB at the Yamaguchi University Hospital and in the 3D-OCT bifurcation registry. Cases were divided into large and small size stent groups based on whether the stent size exceeded or fell below the average of the distal and proximal reference diameters (AvRD). The percentages of ostial stenosis (

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018 and updated in 2022 (Ozaki et al. in Cardiovasc Interv Ther 33:178–203, 2018), (Ozaki et al. in Cardiovasc Interv Ther 37:1–34, 2022). Following the publication of the 2023 European Society of Cardiology (ESC) Guidelines for the management of acute coronary syndromes, the CVIT Task Force released another revised version in 2024 (Ozaki et al. in Cardiovasc Interv Ther 39:335–375, 2024). In light of new clinical evidence and technological advances that have emerged since then, the Task Force now proposes an updated expert consensus document for the management of ACS focusing on procedural aspects of primary PCI in 2026 version.

BACKGROUND AND AIMS:Spotty calcification in the coronary arteries is considered to represent plaque vulnerability, whereas more advanced calcification is thought to be a feature of advanced stable plaque. However, data supporting this notion is limited. Inflammation plays a key role in atherogenesis, including the formation of early-stage calcification. We aimed to correlate spotty calcification assessed by optical coherence tomography (OCT) with vascular inflammation assessed by percutaneous coronary adipose tissue (PCAT) attenuation on coronary computed tomography angiography (CCTA) and OCT-derived plaque vulnerability. METHODS:Patients with stable angina pectoris who had both CCTA and OCT prior to coronary intervention were included. Patients were classified into two groups according to the type of calcification assessed by OCT at the target lesion: spotty calcification (maximal calcification arc <90° and length <4 mm) and advanced calcification (maximal calcification arc ≥90° or length ≥4 mm) group. Non-calcified plaques, and plaques with mixed spotty and advanced calcification were excluded. RESULTS:Among 355 patients, 77 had spotty calcifications and 72 had advanced calcification. The spotty calcification group showed a significantly higher level of PCAT attenuation of target vessel (-69.6 [-75.2 to -66.1] vs. -74.6 [-83.1 to -69.7 HU], p < 0.001) and a significantly higher prevalence of lipid-rich plaque (94.8 % vs. 72.2 %, p < 0.001) and macrophage (77.9 % vs. 59.7 %, p = 0.016), compared with the advanced calcification group. CONCLUSIONS:Plaques with spotty calcification are associated with a higher level of perivascular inflammation and a higher prevalence of features of plaque vulnerability than those with advanced calcification.

Evaluation of calcified lesions by intravascular imaging has revealed that atherectomy devices have only limited impact. However, subsequent use of coronary intravascular lithotripsy (IVL) may increase treatment effectiveness without increasing risk of complications. This study was designed to evaluate the safety and effectiveness of IVL use after atherectomy in severely calcified coronary lesions as pre-treatment for drug-eluting stents (DES). The Dual-Prep registry is a multicenter, prospective registry of consecutive image-guided percutaneous coronary interventions (PCI). The primary effectiveness and safety endpoints were procedural success (residual stenosis < 50% by quantitative coronary angiography) without an in-hospital major adverse cardiac event (MACE) and 30-day freedom from MACE, respectively. Baseline vessel calcification score and final DES expansion were evaluated by optical coherence tomography (OCT). A total of 118 patients with 120 lesions were enrolled at 20 sites. The calcification score of lesions after atherectomy by core-lab assessment was 4.0 in all cases. Rotational atherectomy was applied prior to IVL in 83.9% cases with mean burr size of 1.57 ± 0.20 mm; IVL was subsequently successfully delivered in all cases (mean balloon diameter 3.02 ± 0.45 mm), followed by DES deployment (mean diameter 3.19 ± 0.51 mm, length of 36.3 ± 16.0 mm). The primary efficacy and safety endpoints were met in 98.3% and 98.3% of cases, respectively. A DES expansion index < 0.8 was seen in 42.2%, and an eccentricity index < 0.7 was not observed in any patient. In severely calcified lesions, image-guided atherectomy followed by IVL lesion preparation demonstrated high procedural success rates and satisfactory non-eccentric stent expansion. This approach may be considered for lesions where an ‘IVL-first’ strategy may not be feasible. jRCT1032230384 (Oct 7, 2023). Graphical abstract Dual-Prep registry : atherectomy + IVL before DES implantation strategy for calcified lesion (Calc score ≥ 3 after atherectomy)

BACKGROUND:Owing to the advent of new generation drug-eluting stents, percutaneous coronary intervention (PCI) outcomes are improving. However, the polymers, which have been the most common type of coatings used in drug-eluting stents, have some issues. The study aim was to evaluate the clinical outcomes of patients undergoing PCI with polymer-free sirolimus- and probucol-eluting stents (NP023). METHODS:This clinical trial was a prospective multicenter single-blind noninferiority randomized study performed at 22 hospitals in Japan. We randomly assigned patients in a 2:1 ratio to undergo PCI with either NP023 or durable polymer-based everolimus-eluting stents (control stents) with a 5-year follow-up. The primary outcome was freedom from target lesion failure (TLF) at 9 months, defined as patient-oriented composite of cardiac death, ischemia-driven target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization. The secondary outcome included adverse outcomes at 5 years following the index procedure. RESULTS:Overall, 432 patients (463 lesions) were treated at 22 sites in Japan [mean age, 68 years; males, 345 (80 %); chronic coronary artery diseases, 322 (74.5 %)]. Of the participants, 91 % completed the 5-year follow-up. The Kaplan-Meier estimates of the percentages of patients who were free from TLF were 95.8 % and 97.3 % with NP023 and control stents, respectively (hazard ratio, 0.98; 95 % confidential interval, 0.80-1.21; p < 0.01 for noninferiority). At the 5-year follow-up, the secondary endpoint for safety was not different between the two groups. CONCLUSIONS:The results of this study showed similar outcomes for polymer-free sirolimus- and probucol-eluting stents and durable polymer-based everolimus-eluting stents regarding freedom from TLF at 9 months and other outcomes at 5 years among patients undergoing PCI.

Intravascular imaging for acute coronary syndrome is recommended in the guidelines; however, the actual rate of patients with ST-segment elevation myocardial infarction (STEMI) who successfully undergo optical coherence tomography (OCT)-guided primary percutaneous coronary intervention (PCI) is unclear. This study aimed to determine the feasibility of OCT-guided primary PCI and identify the patient population that would benefit most from OCT guidance in STEMI. The ATLAS-OCT trial was a prospective, single-arm, all-comers study conducted at 16 institutions. The primary endpoint was the feasibility of OCT guidance for primary PCI, defined as successful image acquisition (vessel’s circumferential or > 270° visualization along > 70

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018 and updated in 2022. Recently, the European Society of Cardiology (ESC) published the guidelines for the management of acute coronary syndrome in 2023. Major new updates in the 2023 ESC guideline include: (1) intravascular imaging should be considered to guide PCI (Class IIa); (2) timing of complete revascularization; (3) antiplatelet therapy in patient with high-bleeding risk. Reflecting rapid advances in the field, the Task Force on Primary PCI of the CVIT group has now proposed an updated expert consensus document for the management of ACS focusing on procedural aspects of primary PCI in 2024 version.

BACKGROUND: Combining morphological and physiological evaluations might improve the risk stratification of patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) culprit lesions. AIMS: We aimed to investigate the clinical utility of morphofunctional evaluation after PCI for identifying ACS patients with increased risk of subsequent clinical events. METHODS: We retrospectively studied 298 consecutive ACS patients who had undergone optical coherence tomography (OCT)-guided PCI. We performed OCT-based morphological analysis and quantitative flow ratio (QFR)-based physiological assessment immediately after PCI. The non-culprit segment (NCS) was defined as the most stenotic untreated segment in the culprit vessel. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel-related myocardial infarction, and ischaemia-driven target vessel revascularisation. RESULTS: During a median follow-up period of 990 days, 42 patients experienced TVF. Cox regression analysis revealed that the presence of thin-cap fibroatheroma (TCFA) in the NCS and a low post-PCI QFR, or the presence of TCFA in the NCS and a high Delta QFR in the NCS (QFR(NCS)), were independently associated with TVF. The subgroup with TCFA in the NCS and a low post-PCI QFR had a significantly higher incidence of TVF (75%) than the other subgroups, and those with TCFA in the NCS and a high Delta QFR(NCS) had a significantly higher incidence of TVF (86%) than the other subgroups. The integration of TCFA in NCS, post-PCI QFR, and Delta QFR(NCS) with traditional risk factors significantly enhanced the identification of subsequent TVF cases. CONCLUSIONS: Combining post-PCI OCT and QFR evaluation may enhance risk stratification for ACS patients after successful PCI, particularly in predicting subsequent TVF.

Abstract Background The superior vena cava (SVC) is known as a major source of atrial fibrillation(AF), non-pulmonary vein AF foci (NPVAF). In some cases, an incessant form of AF (iAF) by SVC firing prevents obtaining the sinus node location, and anatomical SVC isolation has a risk of sinus node injury (SNI). Objective This study was aimed to explore the frequency of iAF by SVC firing and the efficacy of the simplified mapping strategy to avoid SNI. Methods Consecutive AF ablation procedures in the 3 centers were retrospectively investigated including the NPVAF prevalence. Simplified SVC/SN mapping (SSS-map: Obtaining the top-end of the SVC potential and >4points with 5-10mm spacing in the upper lateral side of the right atria (RA) for roughly locating the earliest activation site in sinus rhythm) was performed before PV isolation in the last 138 patients. In case of the initial rhythm at the procedure was atrial fibrillation, cardioversion was performed for obtaining the SSS-map. In the cases in which the high-density mapping catheters were available, the high-density activation maps of the RA in sinus rhythm were obtained to investigate the dislocation of the earliest activation site of the SSS map from the SN location. When SVC isolation was required due to iAF, SVC isolation line was designed based on the location of the top-end of the SVC potential during AF and ablative linear lesions were created to keep the distance of 5-10 mm above the second earliest activation site. Results A total of 1160 procedures in 1089 patients (male: 736[63.4%], age: 69.9, paroxysmal AF: 544[49.9%], first session: 997[85.9%]) was investigated. Prevalence of NPVAF was revealed in 160 of the all procedures (13.7%) (the SVC: 64, the posterior wall of the left atria: 24, the coronary sinus: 19, and others: 53). 16 of 160 NPVAFs (10.0%) developed to iAF by SVC firing. The SSS-map was successfully obtained in all of the last 138 patients (Initial rhythm at the procedure: AF 43.7%, Mapping time: 1.3±0.6 min, number of obtained points: 8.4±1.3). In 21 patients in which the high-density RA map was obtained, the SN dislocation distance was 5.1±2.2mm between the SSS map and the high-density RA map. Five of 138 developed to iAF by SVC firing, and SVC isolation based on the SSS-map was successfully achieved without SNI in the cases. Conclusion This study indicated iAF driven by SVC firing after PV isolation occurred in certain number of patients. The SSS-map before PV isolation was practical and showed the potential to be the mapping strategy avoid the SN injury in such cases.

Percutaneous coronary intervention (PCI) for coronary bifurcation disease remains one of the most challenging situations in interventional cardiology in terms of procedural success rates and long-term cardiac events. Optical coherence tomography (OCT), with a higher signal-to-noise ratio and the ability to distinguish plaque components, can display the true condition of bifurcation lesions without overlapping or shortening and achieve detailed visualization of vascular structures, which is superior to those of other imaging modalities. Three-dimensional (3D) reconstruction of OCT images (3D-OCT) helps to gain a more informed understanding of the geometry and morphology of bifurcation lesions and provide additive information on plaque distribution. Following stent implantation, 3D-OCT can also guide the re-crossing of guide wires through stent struts jailing the side branch (SB) ostium and more clearly display the jailing strut configuration, as well as the ideal position of the guidewire recrossing point and stent struct link connection, to confirm the optimal guidewire position and understand interactions between stents and vessel walls, which may improve clinical results after PCI. The present review provides an up-to-date overview of the clinical use of 3D-OCT for accurate assessment of bifurcation anatomy, guiding the optimal guidewire rewiring into SB during bifurcation stenting, and evaluation of post-PCI results, offering novel information about atherosclerotic disease or stenting process.

Physiological coronary branching at the bifurcation has a constant fractal ratio (FR) of the diameter of the mother vessel to the sum of daughter vessels on quantitative coronary angiography (QCA). We sought to investigate the FR of diseased coronary bifurcations using QCA and intravascular ultrasound (IVUS) and its impact on late lumen loss after percutaneous coronary intervention (PCI). In multicentre prospective studies of the J-REVERSE and 3D OCT Bifurcation Registry, 402 and 109 bifurcations treated with stenting that completed QCAs and IVUS examinations, respectively were analysed. FR was investigated at the reference sites pre-PCI and the minimum lumen diameter (MLD) post-PCI. In the QCA analysis, constant FR was observed in the pre-PCI reference (0.62 ± 0.08) and in the post-PCI MLD site (0.74 ± 0.10), which was greater (p < 0.05). In the IVUS analysis, the constant FR in the post-PCI MLD site (0.67 ± 0.06) was similar to that in the pre-PCI reference (0.66 ± 0.06) and close to the physiological FR value (0.678). The fourth quintile of pre-PCI reference FR in the IVUS analysis showed numerically least late lumen loss in proximal main vessel (MV) (0.16 ± 0.22 mm) and distal MV (0.13 ± 0.32 mm) and significantly less in the side branch compared to higher FR quintile (− 0.14 ± 0.27 mm vs. 0.10 ± 0.19 mm, p = 0.004), while no relationship was found in the QCA analysis. FR in the diseased coronary bifurcation was more accurately assessed on IVUS than on QCA, and the accomplishment of physiological FR might lead to less late lumen loss after bifurcation PCI.

Aims Optical coherence tomography (OCT) can identify high-risk plaques indicative of worsening prognosis in patients with acute coronary syndrome (ACS). However, manual OCT analysis has several limitations. In this study, we aim to construct a deep-learning model capable of automatically predicting ACS prognosis from patient OCT images following percutaneous coronary intervention (PCI).Methods and results Post-PCI OCT images from 418 patients with ACS were input into a deep-learning model comprising a convolutional neural network (CNN) and transformer. The primary endpoint was target vessel failure (TVF). Model performances were evaluated using Harrell's C-index and compared against conventional models based on human observation of quantitative (minimum lumen area, minimum stent area, average reference lumen area, stent expansion ratio, and lesion length) and qualitative (irregular protrusion, stent thrombus, malapposition, major stent edge dissection, and thin-cap fibroatheroma) factors. GradCAM activation maps were created after extracting attention layers by using the transformer architecture. A total of 60 patients experienced TVF during follow-up (median 961 days). The C-index for predicting TVF was 0.796 in the deep-learning model, which was significantly higher than that of the conventional model comprising only quantitative factors (C-index: 0.640) and comparable to that of the conventional model, including both quantitative and qualitative factors (C-index: 0.789). GradCAM heat maps revealed high activation corresponding to well-known high-risk OCT features.Conclusion The CNN and transformer-based deep-learning model enabled fully automatic prognostic prediction in patients with ACS, with a predictive ability comparable to a conventional survival model using manual human analysis.Clinical Trial Registration The study was registered in the University Hospital Medical Information Network Clinical Trial Registry (UMIN000049237). Graphical Abstract Deep-learning-driven optical coherence tomography (OCT) analysis for cardiovascular outcome prediction in patients with acute coronary syndrome (ACS). A deep-learning model utilizing a convolutional neural network (CNN) and a transformer enables automatic prediction of cardiovascular outcomes from post-percutaneous coronary intervention (PCI) OCT images in patients with ACS. Harrell's C-index is significantly higher than that of the conventional model including only quantitative factors, and comparable to that of the conventional model including both quantitative and qualitative factors.

BACKGROUND:Side branch (SB) occlusion during bifurcation stenting is a serious complication. This study aimed to predict SB compromise (SBC) using optical coherence tomography (OCT). METHODS AND RESULTS:Among the 168 patients who enrolled in the 3D-OCT Bifurcation Registry, 111 bifurcation lesions were analyzed to develop an OCT risk score for predicting SBC. SBC was defined as worsening of angiographic SB ostial stenosis (≥90%) immediately after stenting. On the basis of OCT before stenting, geometric parameters (SB diameter [SBd], length from proximal branching point to carina tip [BP-CT length], and distance of the polygon of confluence [dPOC]) and 3-dimensional bifurcation types (parallel or perpendicular) were evaluated. SBC occurred in 36 (32%) lesions. The parallel-type bifurcation was significantly more frequent in lesions with SBC. The receiver operating characteristic curve indicated SBd ≤1.77 mm (area under the curve [AUC]=0.73, sensitivity 64%, specificity 75%), BP-CT length ≤1.8 mm (AUC=0.83, sensitivity 86%, specificity 68%), and dPOC ≤3.96 mm (AUC=0.68, sensitivity 63%, specificity 69%) as the best cut-off values for predicting SBC. To create the OCT risk score, we assigned 1 point to each of these factors. As the score increased, the frequency of SBC increased significantly (Score 0, 0%; Score 1, 8.7%; Score 2, 28%; Score 3, 58%; Score 4, 85%; P<0.0001). CONCLUSIONS:Prediction of SBC using OCT is feasible with high probability.

BACKGROUND:Coronary artery calcification is an integral part of atherosclerosis. It has been suggested that early coronary artery calcification is associated with active inflammation, and advanced calcification forms as inflammation subsides. Inflammation is also an important factor in plaque vulnerability. However, the relationship between coronary artery calcium burden, vascular inflammation, and plaque vulnerability has not been fully investigated. OBJECTIVES:This study aimed to correlate calcified plaque burden (CPB) at the culprit lesion with vascular inflammation and plaque vulnerability. METHODS:Patients with coronary artery disease who had both computed tomography angiography and optical coherence tomography were included. The authors divided the patients into 4 groups: 1 group without calcification at the culprit lesion; and 3 groups based on the CPB tertiles. CPB was calculated as calcified plaque volume divided by vessel volume in the culprit lesion. The authors compared pericoronary adipose tissue (PCAT) attenuation for vascular inflammation and optical coherence tomography-derived vulnerable features among the 4 groups. RESULTS:Among 578 patients, the highest CPB tertile showed significantly lower PCAT attenuation of culprit vessel compared with the other groups. The prevalence of features of plaque vulnerability (including lipid-rich plaque, macrophage, and microvessel) was also lowest in the highest CPB tertile. In the patients with calcification, higher age, statin use, and lower PCAT attenuation were independently associated with CPB. CONCLUSIONS:Greater calcium burden is associated with a lower level of vascular inflammation and plaque vulnerability. A greater calcium burden may represent advanced stable plaque without significant inflammatory activity. (Massachusetts General Hospital and Tsuchiura Kyodo General Hospital Coronary Imaging Collaboration; NCT04523194).