Individual coronary plaque changes on serial CT angiography: Within-patient heterogeneity, natural history, and statin effects in HIV

Application of Quantitative Assessment of Coronary Atherosclerosis by Coronary Computed Tomographic Angiography

Coronary computed tomography angiography (CCTA) has emerged as a pivotal tool for diagnosing and risk-stratifying patients with suspected coronary artery disease (CAD). Recent advancements in image analysis and artificial intelligence (AI) techniques have enabled the comprehensive quantitative analysis of coronary atherosclerosis. Fully quantitative assessments of coronary stenosis and lumen attenuation have improved the accuracy of assessing stenosis severity and predicting hemodynamically significant lesions. In addition to stenosis evaluation, quantitative plaque analysis plays a crucial role in predicting and monitoring CAD progression. Studies have demonstrated that the quantitative assessment of plaque subtypes based on CT attenuation provides a nuanced understanding of plaque characteristics and their association with cardiovascular events. Quantitative analysis of serial CCTA scans offers a unique perspective on the impact of medical therapies on plaque modification. However, challenges such as time-intensive analyses and variability in software platforms still need to be addressed for broader clinical implementation. The paradigm of CCTA has shifted towards comprehensive quantitative plaque analysis facilitated by technological advancements. As these methods continue to evolve, their integration into routine clinical practice has the potential to enhance risk assessment and guide individualized patient management. This article reviews the evolving landscape of quantitative plaque analysis in CCTA and explores its applications and limitations.

Automatic Quantification of Local Plaque Thickness Differences as Assessed by Serial Coronary Computed Tomography Angiography Using Scan-Quality-Based Vessel-Specific Thresholds

INTRODUCTION

The use of serial coronary computed tomography angiography (CCTA) allows for the early assessment of coronary plaque progression, a crucial factor in averting major adverse cardiac events (MACEs). Traditionally, serial CCTA is assessed using anatomical landmarks to match baseline and follow-up scans. Recently, a tool has been developed that allows for the automatic quantification of local plaque thickness differences in serial CCTA utilizing plaque contour delineation. The aim of this study was to determine thresholds of plaque thickness differences that define whether there is plaque progression and/or regression. These thresholds depend on the contrast-to-noise ratio (CNR).

METHODS

Plaque thickness differences between two scans acquired at the same moment in time should always be zero. The negative and positive differences in plaque contour delineation in these scans were used along with the CNR in order to create calibration graphs on which a linear regression analysis was performed. This analysis was conducted on a cohort of 50 patients referred for a CCTA due to chest complaints. A total of 300 coronary vessels were analyzed. First, plaque contours were semi-automatically determined for all major epicardial coronary vessels. Second, manual drawings of seven regions of interest (ROIs) per scan were used to quantify the scan quality based on the CNR for each vessel.

RESULTS

A linear regression analysis was performed on the CNR and negative and positive plaque contour delineation differences. Accounting for the standard error of the estimate, the linear regression analysis revealed that above 1.009 - 0.002 × CNR there is an increase in plaque thickness (progression), and below - 1.638 + 0.012 × CNR there is a decrease in plaque thickness (regression).

CONCLUSION

This study demonstrates the feasibility of developing vessel-specific, quality-based thresholds for visualizing local plaque thickness differences evaluated by serial CCTA. These thresholds have the potential to facilitate the early detection of atherosclerosis progression.

Atherosclerosis With Immune Checkpoint Inhibitor Therapy: Evidence, Diagnosis, and Management: JACC: CardioOncology State-of-the-Art Review

As the clinical applications of immune checkpoint inhibitors (ICIs) expand, our knowledge of the potential adverse effects of these drugs continues to broaden. Emerging evidence supports the association between ICI therapy with accelerated atherosclerosis and atherosclerotic cardiovascular (CV) events. We discuss the biological plausibility and the clinical evidence supporting an effect of inhibition of these immune checkpoints on atherosclerotic CV disease. Further, we provide a perspective on potential diagnostic and pharmacological strategies to reduce atherosclerotic risk in ICI-treated patients. Our understanding of the pathophysiology of ICI-related atherosclerosis is in its early stages. Further research is needed to identify the mechanisms linking ICI therapy to atherosclerosis, leverage the insight that ICI therapy provides into CV biology, and develop robust approaches to manage the expanding cohort of patients who may be at risk for atherosclerotic CV disease.

Cardiovascular computed tomography and HIV: The evolving role of imaging biomarkers in enhanced risk prediction

The treatment of human immunodeficiency virus (HIV) with antiretroviral (ARV) medications has revolutionised the care for these patients. The dramatic increase in life expectancy has brought new challenges in treating diseases of aging in this cohort. Cardiovascular disease (CVD) is now a leading cause of morbidity and mortality with risk matched HIV-positive patients having double the risk of MI compared to HIV-negative patients. This enhanced risk is secondary to the interplay the virus (and accessory proteins), ARV medications and traditional risk factors. The culmination of these factors can lead to a hybrid metabolic syndrome characterised by heightened ectopic fat. Cardiovascular computed tomography (CT) is ideal for quantifying epicardial adipose tissue volumes, hepatosteatosis and cardiovascular disease burden. The CVD risk attributed to disease burden and plaque morphology is well established in general populations but is less clear in HIV populations. The purpose of this review article is to appraise the latest data on CVD development in HIV-positive patients and how the use of cardiovascular CT may be used to enhance risk prediction in this population. This may have important implications on individualised treatment decisions and risk reduction strategies which will improve the care of these patients.

The Journal of Cardiovascular Computed Tomography: 2020 Year in review

The purpose of this review is to highlight the most impactful, educational, and frequently downloaded articles published in the Journal of Cardiovascular Computed Tomography (JCCT) for the year 2020. The JCCT reached new records in 2020 for the number of research submissions, published manuscripts, article downloads and social media impressions. The articles in this review were selected by the Editorial Board of the JCCT and are comprised predominately of original research publications in the following categories: Coronavirus disease 2019 (COVID-19), coronary artery disease, coronary physiology, structural heart disease, and technical advances. The Editorial Board would like to thank each of the authors, peer-reviewers and the readers of JCCT for making 2020 one of the most successful years in its history, despite the challenging circumstances of the global COVID-19 pandemic.

A review of serial coronary computed tomography angiography (CTA) to assess plaque progression and therapeutic effect of anti-atherosclerotic drugs

Change in coronary artery plaque on serial catheter intravascular ultrasound (IVUS) is an established technique to monitor the therapeutic effect of drugs on coronary atherosclerosis. Recent advances in coronary computed tomography angiography (CTA) now allow for non-invasive assessment of change in coronary plaque. Because coronary CTA is noninvasive, it enables clinical trials with lower-risk populations, higher retention rates, and lower costs. This review presents an overview of serial coronary CTA as a noninvasive imaging technique to gauge the therapeutic effect of anti-atherosclerotic therapies. Furthermore, it reviews the increasing use of serial CTA as an imaging endpoint in completed and ongoing clinical trials.

Implementation of Cholesterol-Lowering Therapy to Reduce Cardiovascular Risk in Persons Living with HIV

The widespread availability of highly effective antiretroviral therapies has reduced mortality from opportunistic infections in persons living with HIV (PLHIV), resulting in an increase in atherosclerotic cardiovascular disease (ASCVD) and other chronic illnesses (Samji et al. 2013). Although there has been a decline in morbidity and mortality from ASCVD in the past several decades, contemporary studies continue to report higher rates of cardiovascular events (Rosenson et al. 2020). HIV has been identified as a risk enhancer for ASCVD by multiple professional guideline writing committees (Grundy Scott et al. 2019, Mach et al. 2020); however, the utilization of cholesterol-lowering therapies in PLHIV remains low (Rosenson et al. 2018). Moreover, the use of statin therapy in PLHIV is complicated by drug-drug interactions that may either elevate or lower the blood statin concentrations resulting in increased toxicity or reduced efficacy respectively. Other comorbidities commonly associated with HIV present other challenges for the use of cholesterol-lowering therapies. This review will summarize the data on lipoprotein-associated ASCVD risk in PLHIV and discuss the challenges with effective treatment. Finally, we present a clinical algorithm to optimize cardiovascular risk reduction in this high-risk population.

Quantitative coronary computed tomography angiography for the detection of cardiac allograft vasculopathy

Objectives

To associate coronary wall volume and composition, derived from coronary computed tomography angiography (CTA), with cardiac allograft vasculopathy (CAV) detected on invasive coronary angiography (ICA) in heart-transplanted (HTX) patients.

Methods

We included consecutive adults who received ICA and coronary CTA for evaluation of CAV ≥ 10 months after HTX. In all coronary segments, we assessed lumen and wall volumes and segmental length, calculated volume-length ratio (VLR) (volumes indexed by segmental length; mm³/mm), wall burden (WB) (wall/wall + lumen volumes; %), and assessed proportions of calcified, fibrotic, fibro-fatty, and low-attenuation tissue (%) in coronary wall. We rendered independent CTA measures associated with CAV by ICA, tested their discriminatory capacity, and assessed concordance between CTA and ICA.

Results

Among 50 patients (84% men; 53.6 ± 11.9 years), we analyzed 632 coronary segments. Mean interval between HTX and CTA was 6.7 ± 4.7 years and between ICA and CTA 1 (0–1) day. Segmental VLR, WB, and proportion of fibrotic tissue were independently associated with CAV (OR = 1.06–1.27; p ≤ 0.002), reaching a high discriminatory capacity (combination of all three: AUC = 0.84; 95%CI, 0.75–0.90). Concordance between CTA and ICA was higher in advanced CAV (88%) compared with that in none (37%) and mild (19%) CAV. Discordance was primarily driven by a large number of segments with coronary wall changes on CTA but without luminal stenoses on ICA (177/591; 25%).

Conclusion

CTA-derived coronary wall VLR, WB, and the proportion of fibrotic tissue are independent markers of CAV. Combination of these three parameters may aid the detection of early CAV not detected by ICA, the current standard of care.

Key Points

• Coronary CTA detects CAV in HTX patients.

• Coronary wall volume-length ratio, wall burden, and proportion of fibrotic tissue are independently associated with CAV.

• In contrast to ICA, coronary CTA may identify the early stages of CAV.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06653-3) contains supplementary material, which is available to authorized users.