Feasibility and Exploration of a Standardized Protocol for Cardiac CT Assessment of Rheumatic Mitral Disease.

Rheumatic mitral valve disease often requires surgical interventions, such as percutaneous mitral commissurotomy, surgical mitral valve repair, or replacement, especially in severe cases. This necessitates a precise preoperative assessment of the extent of mitral valve disease. Currently, transthoracic echocardiography, the gold standard for preoperative assessment, has limitations, such as restricted acoustic windows and dependence on the operator, which can affect the evaluation of subvalvular structures and calcification of the mitral valve. Previous studies have shown that cardiac computed tomography (CT), with its high resolution, strong multiplanar reconstruction capabilities, and sensitivity to calcifications, can effectively overcome these limitations. Therefore, this study aims to summarize and evaluate the effectiveness of cardiac CT in examining mitral valve leaflets, annulus, and subvalvular structures. It also reviews the feasibility and guiding significance of using cardiac CT to assess characteristic rheumatic mitral valve lesions.

Geometric Changes in Mitral Valve Apparatus during Long-term Cardiac Resynchronization Therapy as Assessed with Cardiac CT.

Purpose To assess long-term geometric changes of the mitral valve apparatus using cardiac CT in individuals who underwent cardiac resynchronization therapy (CRT). Materials and Methods Participants from a randomized controlled trial with cardiac CT examinations before CRT implantation and at 6 months follow-up (Clinicaltrials.gov identifier NCT01323686) were invited to undergo an additional long-term follow-up cardiac CT examination. The geometry of the mitral valve apparatus, including mitral valve annulus area, A2 leaflet angle, tenting height, and interpapillary muscle distances, were assessed. Geometric changes at the long-term follow-up examination were reported as mean differences (95% CI), and the Pearson correlation test was used to assess correlation between statistically significant geometric changes and left ventricular (LV) volumes and function. Results Thirty participants (mean age, 68 years ± 9 [SD]; 25 male participants) underwent cardiac CT imaging after a median long-term follow-up of 9.0 years (IQR, 8.4-9.4). There were reductions in end-systolic A2 leaflet angle (-4° [95% CI: -7, -2]), end-systolic tenting height (-1 mm [95% CI: -2, -1]), and end-systolic and end-diastolic interpapillary muscle distances (-4 mm [95% CI: -6, -2]) compared with pre-CRT implantation values. The mitral valve annulus area remained unchanged. LV end-diastolic and end-systolic volumes decreased (-68 mL [95% CI: -99, -37] and -67 mL [95% CI: -96, -39], respectively), and LV ejection fraction increased (13% [95% CI: 7, 19]) at the long-term follow-up examination. Changes in interpapillary muscle distances showed moderate to strong correlations with LV volumes (r = 0.42-0.72; P < .05), while A2 leaflet angle and tenting height were not correlated to LV volumes or function. Conclusion Among the various geometric changes in the mitral valve apparatus after long-term CRT, the reduction in interpapillary muscle distances correlated with LV volumes while the reduced A2 leaflet angle and tenting height did not correlate with LV volumes. Keywords: Mitral Valve Apparatus, Cardiac Resynchronization Therapy, Cardiac CT Supplemental material is available for this article. © RSNA, 2024.

Coding and coverage for cardiac CT in the era of algorithm-based healthcare procedures and services.

In order for patients to gain the benefit of innovation in cardiac CT, it is necessary for coding, coverage, and payment to adapt to the novelty of algorithm-based healthcare procedures and services (ABHS). Appendix S to the CPT Code Set, the "AI Taxonomy", enables creation of discrete and differentiable codes for reimbursement of ABHS which has been clinically validated and FDA-labeled. Payment policy in OPPS and PFS is evolving to take account of the unique opportunities and issues arising from the clinical adoption of ABHS.

A Pictorial Essay of Coronary Artery Anomalies on Coronary CT Angiography: A Single-Centre Observational Study.

Background Congenital anomalies of the coronary artery anatomy (CAAs) encompass a spectrum of disorders, often asymptomatic but potentially carrying severe clinical implications such as arrhythmia, chest pain, myocardial infarction, or sudden death. The estimated prevalence of CAAs in the general population ranges from 0.3% to 1.3%, with underdiagnosis in asymptomatic individuals. Multidetector computed tomography angiography (CTA) has emerged as a vital non-invasive tool for diagnosing and characterising CAAs, offering improved visualisation and aiding in appropriate management decisions. This study aims to analyse the spectrum of CAAs in a tertiary care setting, focusing on imaging features, prevalence, and potential clinical significance, utilising data from patients who underwent multidetector CTA. Methodology A single-centre, retrospective analysis of consecutive coronary angiograms over a five-year period identified patients with CAAs, with imaging conducted using a 128-slice, single-source CT scanner. Detailed imaging evaluation was performed by experienced radiologists, with anomalies classified according to established criteria. Results Among 756 coronary CTA examinations analysed, 37 instances of anomalous coronary vessels were identified. The study revealed a diverse range of anomalies, including myocardial bridging, anomalous origin of coronary arteries, and extracardiac abnormalities. Conclusions This study contributes valuable insights into the prevalence and imaging features of CAAs, enhancing our understanding of these anomalies and guiding improved patient outcomes in cardiovascular care. Future research should focus on elucidating pathophysiological mechanisms and establishing multicenter registries to address the challenges associated with studying these infrequent but clinically significant anomalies.

Recurrent monomorphic ventricular tachycardia in a patient with myocarditis-Importance of understanding and targeting midmyocardial anatomic substrate.

INTRODUCTION: Patients with viral myocarditis can present with challenging life-threatening arrhythmias. Catheter ablation can be a life-saving procedure in some patients with recurrent drug-refractory ventricular arrhythmias. METHODS AND RESULTS: A patient with three prior ablations targeting two different monomorphic ventricular tachycardias (MMVTs) presented with recurrent ventricular tachycardia (VT). Consequently, he underwent epicardial mapping with adjuvant AI-enabled CT images with the creation of a three-dimensional model, which demonstrated a midmyocardial scar. Fractionated potentials were noted during mapping in this region, and entrainment suggested an inner loop. Interestingly, pacing showed two different QRS morphologies identical to his previously ablated VTs with a long stim-QRS at this region. Epicardial ablation carried on during the VT successfully terminated it, but the VT remained inducible and required endocardial ablation to make it noninducible. CONCLUSION: This case emphasizes the importance of recognizing possible three-dimensional VT circuits in some patients and the need to understand and target mid-myocardial substrate from both the endocardium and epicardium to achieve the elimination of the VT circuits.

4-Dimensional Right Ventricular Outflow Tract Segmentation to Evaluate Candidacy for Transcatheter Pulmonary Valve Replacement.

Candidacy for transcatheter pulmonary valve replacement utilizing newer valve platforms is aided by industry-driven fit analyses. We report augmentation of this decision-making process by visualization of 4-dimensional cine imaging of patient-specific right ventricular outflow tract anatomy and a virtual valve model within a virtual reality platform.

Novel Domain Knowledge-Encoding Algorithm Enables Label-Efficient Deep Learning for Cardiac CT Segmentation to Guide Atrial Fibrillation Treatment in a Pilot Dataset.

Background: Segmenting computed tomography (CT) is crucial in various clinical applications, such as tailoring personalized cardiac ablation for managing cardiac arrhythmias. Automating segmentation through machine learning (ML) is hindered by the necessity for large, labeled training data, which can be challenging to obtain. This article proposes a novel approach for automated, robust labeling using domain knowledge to achieve high-performance segmentation by ML from a small training set. The approach, the domain knowledge-encoding (DOKEN) algorithm, reduces the reliance on large training datasets by encoding cardiac geometry while automatically labeling the training set. The method was validated in a hold-out dataset of CT results from an atrial fibrillation (AF) ablation study. Methods: The DOKEN algorithm parses left atrial (LA) structures, extracts "anatomical knowledge" by leveraging digital LA models (available publicly), and then applies this knowledge to achieve high ML segmentation performance with a small number of training samples. The DOKEN-labeled training set was used to train a nnU-Net deep neural network (DNN) model for segmenting cardiac CT in N = 20 patients. Subsequently, the method was tested in a hold-out set with N = 100 patients (five times larger than training set) who underwent AF ablation. Results: The DOKEN algorithm integrated with the nn-Unet model achieved high segmentation performance with few training samples, with a training to test ratio of 1:5. The Dice score of the DOKEN-enhanced model was 96.7% (IQR: 95.3% to 97.7%), with a median error in surface distance of boundaries of 1.51 mm (IQR: 0.72 to 3.12) and a mean centroid-boundary distance of 1.16 mm (95% CI: -4.57 to 6.89), similar to expert results (r = 0.99; p < 0.001). In digital hearts, the novel DOKEN approach segmented the LA structures with a mean difference for the centroid-boundary distances of -0.27 mm (95% CI: -3.87 to 3.33; r = 0.99; p < 0.0001). Conclusions: The proposed novel domain knowledge-encoding algorithm was able to perform the segmentation of six substructures of the LA, reducing the need for large training data sets. The combination of domain knowledge encoding and a machine learning approach could reduce the dependence of ML on large training datasets and could potentially be applied to AF ablation procedures and extended in the future to other imaging, 3D printing, and data science applications.

Angina pectoris? Fake news: a case report of infective endocarditis with giant aortic root abscess detected by cardiac magnetic resonance imaging.

Background: Infective endocarditis (IE) is a rare disease associated with high mortality rates. Clinical presentation is highly variable with a time interval between first onset of symptoms and diagnosis > 1 month in 25% of patients. We present a case of aortic valve endocarditis with aortic root abscess (ARA) with chest pain and ischaemic changes on the electrocardiogram (ECG). Case summary: A 59-year-old Caucasian male with a known bicuspid aortic valve presented at our emergency department with a 2-week history of malaise, subfebrile temperatures, and chest pain episodes. The ECG exhibited ischaemic changes, and laboratory workup showed elevated inflammatory markers and troponin levels. Coronary angiography revealed a one-vessel coronary artery disease with a borderline significant stenosis of the left circumflex artery. Cardiac magnetic resonance imaging showed a large aortic valve vegetation with an ARA expanding intramyocardially, which was not seen on bedside echocardiography. The patient was set on intravenous (i.v.) antibiotics and urgently referred for surgery. The patient received surgical aortic root and valve replacements, reconstruction of the anterior mitral leaflet, and a venous bypass. After successful surgical management followed by 6 weeks of i.v. antibiotics, the patient completely recovered. Discussion: Diagnosing IE in atypical cases, such as those with ischaemic ECG changes, remains challenging. Infective endocarditis should be considered as an early differential diagnosis in individuals with prosthetic or native valve disease. Infective endocarditis poses a significant risk for perivalvular and ARA formation with high mortality. Aortic root abscess may present with unspecific symptoms or unusual ECG changes and might be missed in standard transthoracic echocardiography in up to 30% of cases. Multimodal imaging can help in establishing a prompt and accurate diagnosis, aid in timely treatment and mitigating the risk of complications of IE.

Exploring the relationship between epicardial fat and coronary plaque burden and characteristics: insights from cardiac ct imaging.

Epicardial adipose tissue (EAT) may enhance the risk of coronary artery disease (CAD). We investigated the relationship between EAT density (a maker of local inflammation) and coronary plaque characteristics in stable CAD patients. This study included 123 individuals who underwent coronary artery calcium scan and coronary CT angiography to evaluate CAD. Plaque characteristics were analyzed by semi-automated software (QAngio, Leiden, Netherlands). Non-contrast CT scans were used to measure EAT density (HU) and volume (cc) (Philips, Cleveland, OH). Multivariate regression models were used to evaluate the association of EAT density and volume with different plaque types. The mean (SD) age was 59.4±10.1 years, 53% were male, the mean (SD) EAT density was -77.2±4.6 HU and the volume was 118.5±41.2 cc. After adjustment for cardiovascular risk factors, EAT density was associated with fibrous fatty (FF) plaque (p<0.03). A 1 unit increase in HU was associated with a 7% higher FF plaque, and lower EAT density is independently associated to FF plaque. The association between EAT density and fibrous (p=0.08), and total noncalcified (p=0.09) plaque trended toward but did not reach significance. There was no association between EAT volume and any plaque type. These results suggest that inflammatory EAT may promote coronary atherosclerosis. Therefore, non-contrast cardiac CT evaluation of EAT quality can help better assess cardiovascular risk.

Cardiac computed tomography with late contrast enhancement: A review.

Cardiac computed tomography (CCT) has assumed an increasingly significant role in the evaluation of coronary artery disease (CAD) during the past few decades, whereas cardiovascular magnetic resonance (CMR) remains the gold standard for myocardial tissue characterization. The discovery of late myocardial enhancement following intravenous contrast administration dates back to the 1970s with ex-vivo CT animal investigations; nevertheless, the clinical application of this phenomenon for cardiac tissue characterization became prevalent for CMR imaging far earlier than for CCT imaging. Recently the technical advances in CT scanners have made it possible to take advantage of late contrast enhancement (LCE) for tissue characterization in CCT exams. Moreover, the introduction of extracellular volume calculation (ECV) on cardiac CT images combined with the possibility of evaluating cardiac function in the same exam is making CCT imaging a multiparametric technique more and more similar to CMR. The aim of our review is to provide a comprehensive overview on the role of CCT with LCE in the evaluation of a wide range of cardiac conditions.

The early after discharge cardiac CT for low-risk chest pain study: the ED-CT study.

OBJECTIVES: An accelerated diagnostic pathway is created to aid the management of low-risk patients presenting to the emergency room with chest pain. Records are taken of patient outcomes and factors influencing physician decision-making between inpatient invasive angiography versus early outpatient cardiac CT angiography. METHODS: A cohort study at 30 days post discharge is undertaken over 1 year. Differences are observed between a population of patients who underwent early outpatient CT and a population of ambulatory haemodynamically stable patients who underwent inpatient fluoroscopic angiography. RESULTS: Totally, 369 patients underwent CT (F = 46%) and 37 underwent angiography (F = 30%). Median outpatient CT was at 14 days. At 30 days, 0 patients suffered mortality or myocardial infarction. Eleven percent were recommended for invasive angiography. Two percent of CT patients underwent coronary revascularization. Median calcium score was 0. Twenty percent of the CT population were commenced on high-potency statin or had their pre-existing statin dose intensified. Calcium score affected a composition of statin commencement, angiography, and revascularization (OR 59, P < .001). Age, troponin, vascular disease, and previous coronary revascularization appeared to influence choice between coronary computed tomography angiography (CCTA) and invasive angiography. CONCLUSION: An accelerated diagnostic pathway for outpatient cardiac CT for chest pain resulted in no mortality or myocardial infarction, with a low level of downstream testing and coronary revascularization. ADVANCES IN KNOWLEDGE: At a median time to CCTA of 14 days post discharge from the emergency department, there is no effect on patient major adverse cardiac events.

Edoxaban Improved End-QRS Notches and Early Repolarizations.

Cardiac computed tomography (CT) images sometimes show a donut-like oval structure on the antero-superior wall of the left atrium (LA). What is a donut? Left atrium diverticula (LADs) are common, but there are many unknown features of LADs. The direct effects of pulmonary vein thrombi (PVTs) on the heart are poorly understood. Herein, we report a case report in which we describe the different effects of edoxaban on LA thrombi, the LAD, coronary artery collaterals, early repolarizations, and end-QRS notches using cardiac CT and transesophageal echocardiography (TEE). First, we showed that there was a LAD on the anterior wall of the LA where the LA thrombi from the right lower pulmonary vein (RLPV) thrombi were connected. To our knowledge, this is the first report to reveal LAD's annular transformation and the beneficial effect of edoxaban on the end-QRS notch.

Photon-Counting Versus Dual-Source CT for Transcatheter Aortic Valve Implantation Planning.

BACKGROUND: Cardiovascular CT is required for planning transcatheter aortic valve implantation (TAVI). PURPOSE: To compare image quality, suitability for TAVI planning, and radiation dose of photon-counting CT (PCCT) with that of dual-source CT (DSCT). MATERIAL AND METHODS: Retrospective study on consecutive TAVI candidates with aortic valve stenosis who underwent contrast-enhanced aorto-ilio-femoral PCCT and/or DSCT between 01/2022 and 07/2023. Signal-to-noise (SNR) and contrast-to-noise ratio (CNR) were calculated by standardized ROI analysis. Image quality and suitability for TAVI planning were assessed by four independent expert readers (two cardiac radiologists, two cardiologists) on a 5-point-scale. CT dose index (CTDI) and dose-length-product (DLP) were used to calculate effective radiation dose (eRD). RESULTS: 300 patients (136 female, median age: 81 years, IQR: 76-84) underwent 302 CT examinations, with PCCT in 202, DSCT in 100; two patients underwent both. Although SNR and CNR were significantly lower in PCCT vs. DSCT images (33.0 ± 10.5 vs. 47.3 ± 16.4 and 47.3 ± 14.8 vs. 59.3 ± 21.9, P < .001, respectively), visual image quality was higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001), with moderate overall interreader agreement among radiologists and among cardiologists (κ = 0.60, respectively). Image quality was rated as "excellent" in 160/202 (79.2%) of PCCT vs. 5/100 (5%) of DSCT cases. Readers found images suitable to depict the aortic valve hinge points and to map the femoral access path in 99% of PCCT vs. 85% of DSCT (P < 0.01), with suitability ranked significantly higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001). Mean CTDI and DLP, and thus eRD, were significantly lower for PCCT vs. DSCT (22.4 vs. 62.9; 519.4 vs. 895.5, and 8.8 ± 4.5 mSv vs. 15.3 ± 5.8 mSv; all P < .001). CONCLUSION: PCCT improves image quality, effectively avoids non-diagnostic CT imaging for TAVI planning, and is associated with a lower radiation dose compared to state-of-the-art DSCT. Radiologists and cardiologists found PCCT images more suitable for TAVI planning.

Association of aortic valve calcium with dementia and stroke: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: Calcific aortic valve disease is associated with increased thrombin formation, platelet activation, decreased fibrinolysis, and subclinical brain infarcts. We examined the long-term association of aortic valve calcification (AVC) with newly diagnosed dementia and incident stroke in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: AVC was measured using non-contrast cardiac CT at Visit 1. We examined AVC as a continuous (log-transformed) and categorical variable (0, 1-99, 100-299, ≥300). Newly diagnosed dementia was adjudicated using International Classification of Disease codes. Stroke was adjudicated from medical records. We calculated absolute event rates (per 1000 person-years) and multivariable adjusted Cox proportional hazards ratios (HR). RESULTS: Overall, 6812 participants had AVC quantified with a mean age of 62.1 years old, 52.9 % were women, and the median 10-year estimated atherosclerotic cardiovascular disease (ASCVD) risk was 13.5 %. Participants with AVC >0 were older and less likely to be women compared to those with AVC=0. Over a median 16-year follow-up, there were 535 cases of dementia and 376 cases of stroke. The absolute risk of newly diagnosed dementia increased in a stepwise pattern with higher AVC scores, and stroke increased in a logarithmic pattern. In multivariable analyses, AVC was significantly associated with newly diagnosed dementia as a log-transformed continuous variable (HR 1.09; 95 % CI 1.04-1.14) and persons with AVC ≥300 had nearly a two-fold higher risk (HR 1.77; 95 % CI 1.14-2.76) compared to those with AVC=0. AVC was associated with an increased risk of stroke after adjustment for age, sex, and race/ethnicity, but not after adjustment for ASCVD risk factors. CONCLUSIONS: After multivariable adjustment, AVC >0 was significantly associated with an increased risk of newly diagnosed dementia, but not incident stroke. This suggests that AVC may be an important risk factor for the long-term risk of dementia beyond traditional ASCVD risk factors.

Protocol optimization for functional cardiac CT imaging using noise emulation in the raw data domain.

BACKGROUND: Four-dimensional (4D) wide coverage computed tomography (CT) is an effective imaging modality for measuring the mechanical function of the myocardium. However, repeated CT measurement across a number of heartbeats is still a concern. PURPOSE: A projection-domain noise emulation method is presented to generate accurate low-dose (mA modulated) 4D cardiac CT scans from high-dose scans, enabling protocol optimization to deliver sufficient image quality for functional cardiac analysis while using a dose level that is as low as reasonably achievable (ALARA). METHODS: Given a targeted low-dose mA modulation curve, the proposed noise emulation method injects both quantum and electronic noise of proper magnitude and correlation to the high-dose data in projection domain. A spatially varying (i.e., channel-dependent) detector gain term as well as its calibration method were proposed to further improve the noise emulation accuracy. To determine the ALARA dose threshold, a straightforward projection domain image quality (IQ) metric was proposed that is based on the number of projection rays that do not fall under the non-linear region of the detector response. Experiments were performed to validate the noise emulation method with both phantom and clinical data in terms of visual similarity, contrast-to-noise ratio (CNR), and noise-power spectrum (NPS). RESULTS: For both phantom and clinical data, the low-dose emulated images exhibited similar noise magnitude (CNR difference within 2%), artifacts, and texture to that of the real low-dose images. The proposed channel-dependent detector gain term resulted in additional increase in emulation accuracy. Using the proposed IQ metric, recommended kVp and mA settings were calculated for low dose 4D Cardiac CT acquisitions for patients of different sizes. CONCLUSIONS: A detailed method to estimate system-dependent parameters for a raw-data based low dose emulation framework was described. The method produced realistic noise levels, artifacts, and texture with phantom and clinical studies. The proposed low-dose emulation method can be used to prospectively select patient-specific minimal-dose protocols for functional cardiac CT.

Risk Prediction, Diagnosis and Management of a Breast Cancer Patient with Treatment-Related Cardiovascular Toxicity: An Essential Overview.

Breast cancer is amongst the most common invasive cancers in adults. There are established relationships between anti-cancer treatments for breast cancer and cardiovascular side effects. In recent years, novel anti-cancer treatments have been established, as well as the availability of multi-modal cardiac imaging and the sophistication of treatment for cardiac disease. This review provides an in-depth overview regarding the interface of breast cancer and cancer therapy-related cardiovascular toxicity. Specifically, it reviews the pathophysiology of breast cancer, the method of action in therapy-related cardiovascular toxicity from anti-cancer treatment, the use of echocardiography, cardiac CT, MRI, or nuclear medicine as diagnostics, and the current evidence-based treatments available. It is intended to be an all-encompassing review for clinicians caring for patients in this situation.

A Case of Double Inlet Left Ventricle in a 63-Year-Old Female Patient.

This case report describes the medical history and presentation of an elderly patient who was born with single ventricle physiology, an anomaly that is both unique and complex. Patients with single ventricle cardiac anomalies may be susceptible to life-threatening complications. However, advances in medical treatment and understanding have allowed for clinicians to develop surgical and medical interventions to treat patients with univentricular cardiac defects. This case is unique in the sense that the patient has been able to demonstrate remarkable adaptability to this condition and have a sustained life with little intervention. This report serves to explore the pathophysiology of this condition as well as highlight the human body's astounding resilience to configure itself to abnormal conditions. The patient's presentation will be discussed as well as diagnostics and management utilized by the care providers. Despite its rare occurrence, understanding the manifestations of this complex cardiac abnormality can allow future providers to improve the prognosis and outcomes of patients born with a single ventricle.

Lipoprotein subclasses are associated with Hepatic steatosis: insights from the prospective multicenter imaging study for the evaluation of chest pain (PROMISE) clinical trial.

Objectives: To determine the relationship between lipoprotein particle size/number with hepatic steatosis (HS), given its association with traditional lipoproteins and coronary atherosclerosis. Methods: Individuals with available CT data and blood samples enrolled in the PROMISE trial were studied. HS was defined based on CT attenuation. Lipoprotein particle size/number were measured by nuclear magnetic resonance spectroscopy. Principal components analysis (PCA) was used for dimensionality reduction. The association of PCA factors and individual lipoprotein particle size/number with HS were assessed in multivariable regression models. Associations were validated in an independent cohort of 59 individuals with histopathology defined HS. Results: Individuals with HS (n=410/1,509) vs those without (n=1,099/1,509), were younger (59±8 vs 61±8 years) and less often females (47.6 % vs 55.9 %). All PCA factors were associated with HS: factor 1 (OR:1.36, 95 %CI:1.21-1.53), factor 3 (OR:1.75, 95 %CI:1.53-2.02) and factor 4 (OR:1.49; 95 %CI:1.32-1.68) were weighted heavily with small low density lipoprotein (LDL) and triglyceride-rich (TRL) particles, while factor 2 (OR:0.86, 95 %CI:0.77-0.97) and factor 5 (OR:0.74, 95 %CI:0.65-0.84) were heavily loaded with high density lipoprotein (HDL) and larger LDL particles. These observations were confirmed with the analysis of individual lipoprotein particles in PROMISE. In the validation cohort, association between HS and large TRL (OR: 8.16, 95 %CI:1.82-61.98), and mean sizes of TRL- (OR: 2.82, 95 %CI:1.14-9.29) and HDL (OR:0.35, 95 %CI:0.13-0.72) were confirmed. Conclusions: Large TRL, mean sizes of TRL-, and HDL were associated with radiographic and histopathologic HS. The use of lipoprotein particle size/number could improve cardiovascular risk assessment in HS.