Implications of serial coronary computed tomography angiography in the evaluation of coronary plaque progression

Non-contrast CT-based radiomic signature of pericoronary adipose tissue for screening non-calcified plaque

Objective. To develop two combined clinical-radiomics models of pericoronary adipose tissue (PCAT) for the presence and characterization of non-calcified plaques on non-contrast CT scan. Approach. Altogether, 431 patients undergoing Coronary Computed Tomography Angiography from March 2019 to June 2021 who had complete data were enrolled, including 173 patients with non-calcified plaques of the right coronary artery(RCA) and 258 with no abnormality. PCAT was segmented around the proximal RCA on non-contrast CT scan (calcium score acquisition). Two best models were established by screening features and classifiers respectively using FeAture Explorer software. Model 1 distinguished normal coronary arteries from those with non-calcified plaques, and model 2 distinguished vulnerable plaques in non-calcified plaques. Performance was assessed by the area under the receiver operating characteristic curve (AUC-ROC). Main results. 4 and 9 features were selected for the establishment of the radiomics model respectively through Model 1 and 2. In the test group, the AUC values, sensitivity, specificity and accuracy were 0.833%, 78.3%, 80.8%, 76.6% and 0.7467%, 75.0%, 77.8%, 73.5%, respectively. The combined model including radiomics features and independent clinical factors yielded an AUC, sensitivity, specificity and accuracy of 0.896%, 81.4%, 86.5%, 77.9% for model 1 and 0.752%, 75.0%, 77.8%, 73.5% for model 2. Significance. The combined clinical-radiomics models based on non-contrast CT images of PCAT had good diagnostic efficacy for non-calcified and vulnerable plaques.

Utilizing (serial) coronary computed tomography angiography (CCTA) to predict plaque progression and major adverse cardiac events (MACE): results, merits and challenges

OBJECTIVES

To present an overview of studies using serial coronary computed tomography angiography (CCTA) as a tool for finding both quantitative (changes) and qualitative plaque characteristics as well as epicardial adipose tissue (EAT) volume changes as predictors of plaque progression and/or major adverse cardiac events (MACE) and outline the challenges and advantages of using a serial non-invasive imaging approach for assessing cardiovascular prognosis.

METHODS

A literature search was performed in PubMed, Embase, Web of Science, Cochrane Library and Emcare. All observational cohort studies were assessed for quality using the Newcastle-Ottawa Scale (NOS). The NOS score was then converted into Agency for Healthcare Research and Quality (AHRQ) standards: good, fair and poor.

RESULTS

A total of 36 articles were analyzed for this review, 3 of which were meta-analyses and one was a technical paper. Quantitative baseline plaque features seem to be more predictive of MACE and/or plaque progression as compared to qualitative plaque features.

CONCLUSIONS

A critical review of the literature focusing on studies utilizing serial CCTA revealed that mainly quantitative baseline plaque features and quantitative plaque changes are predictive of MACE and/or plaque progression contrary to qualitative plaque features. Significant questions regarding the clinical implications of these specific quantitative and qualitative plaque features as well as the challenges of using serial CCTA have yet to be resolved in studies using this imaging technique.

KEY POINTS

• Use of (serial) CCTA can identify plaque characteristics and plaque changes as well as changes in EAT volume that are predictive of plaque progression and/or major adverse events (MACE) at follow-up. • Studies utilizing serial CCTA revealed that mainly quantitative baseline plaque features and quantitative plaque changes are predictive of MACE and/or plaque progression contrary to qualitative plaque features. • Ultimately, serial CCTA is a promising technique for the evaluation of cardiovascular prognosis, yet technical details remain to be refined.

Short-Time Changes in Coronary Artery Plaques Assessed by Follow-Up Coronary CT Angiography-Characteristics and Impact on Patient Management

Background: Coronary artery disease (CAD) shows a chronic but heterogeneous clinical course. Coronary CT angiography (CTA) allows for the visualization of the entire coronary tree and the detection of early stages of CAD. The aim of this study was to assess short-time changes in non-calcified and mixed plaques and their clinical impact using coronary CTA in a real-world setting.

Methods: Between 11/2014 and 07/2019, 6,701 patients had a coronary CTA with a third-generation dual-source CT, of whom 77 patients (57 males, 63.8 ± 10.8 years) with a chronic CAD received clinically indicated follow-up CTA. Non-calcified and mixed plaques were analyzed in 1,211 coronary segments. Patients were divided into groups: stable, progressive, or regressive plaques.

Results: Within the follow-up period of 22.3 ± 10.4 months, 44 patients (58%) showed stable plaques, 27 (36%) showed progression, 5 (7%) showed regression. One patient was excluded due to an undetermined CAD course showing both, progressive and regressive plaques. Age did not differ significantly between groups. Patients with plaque regression were predominantly female (80 vs. 20%), whereas patients showing progression were mainly male (85 vs. 15%; p < 0.01 for both). Regression was only observed in patients with mild CAD or one-vessel disease. The follow-up CTA led to changes in patient management in the majority of subjects (n = 50; 66%).

Conclusions: Changes in coronary artery plaques can be observed within a short period resulting in an adjustment of the clinical management in the majority of CAD patients. Follow-up coronary CTA renders the non-invasive assessment of plaque development possible and allows for an individualized diagnostics and therapy optimization.

Utilizing coronary artery calcium to guide statin use

Cardiovascular disease (CVD) is the leading cause of death worldwide, and accounts for over 30% of annual global fatality. Coronary artery calcium (CAC) screening, a highly distinct marker of coronary atherosclerosis, serves as an important arbitrator of atherosclerotic cardiovascular disease (ASCVD). Particularly in asymptomatic individuals, CAC testing offers a model for initiating or prolonging preventative statin therapies and subsequently up- or down-risking of patients. Though recent 2018 ACC/AHA Guidelines on Blood Cholesterol recommend CAC as an arbitrator of statin use, it remains uncertain whether these recommendations have been universally followed. Thus, we present a thorough discussion about CAC as an important determinator of ASCVD risk. In this regard we highlight the key points behind coronary artery calcium scoring, as a critical platform for stratifying risk and guiding future preventative treatments. This review paper supplies a background for the 2018 Cholesterol Guidelines: the rationalization behind CAC as a crucial arbitrator of cardiovascular risk. This paper will first (1) outline the role of CAC in reclassifying ASCVD risk. Next, it will (2) discuss studies that illustrate CAC's markedly novel reduction in the number needed to treat (NNT) to ameliorate one major cardiac event. Being years removed from 2018 Guidelines provides this paper the lens to (3) elucidate upcoming value-based advantages, cost effectiveness, and patient adherence brought by CAC. Last, this paper will also (4) extend the utility of CAC beyond that of the general population, and (5) discuss pertinent limitations brought by CAC score. By summarizing the framework behind recent cholesterol guidelines for ASCVD risk assessment, this review will address the debate of use of CAC for both the clinical setting and preventative therapy applications.

Cardiovascular risk assessment: The foundation of preventive cardiology

The foundation of preventive cardiology begins with knowing the patient's baseline cardiovascular disease (CVD) risk from which the patient-clinician risk discussion informs on the best ways to lower risk through lifestyle management, as well as a decision about the initiation and intensity of pharmacologic therapy. Global CVD risk assessment involves estimation of cardiovascular risk using a basic panel of risk factors. The Framingham Heart Study championed the first such risk scores, followed by others around the world. Most recently, the Pooled Cohort Equations (PCE) have been recommended in the United States as a starting point in CVD risk assessment. Persons at low (<5%) 10-year risk are generally recommended for lifestyle management only and those at highest (>20%) 10-year risk are recommended for both lifestyle and pharmacologic therapy to reduce risk. Assessing the presence of one or more "risk enhancing" factors is intended to inform the treatment decision in those at borderline (5-<7.5%) or intermediate (7.5-20%) risk, with the use of coronary calcium scores to further refine the treatment decision. Moreover, not all those with ASCVD are treated equal, and recent guidelines provide criteria for identifying those at very high risk. While current techniques best predict long-term risk of CVD events, biomarkers strategies are being developed to predict near-term events, and other imaging techniques such as coronary CT angiography and vascular MRI hold promise to identify vulnerable plaque. Validation and incorporating into clinical practice such state of the art techniques will be vital to moving CVD risk assessment to the next level.