Coronary vascular age: An alternate means for predicting stress-induced myocardial ischemia in patients with suspected coronary artery disease

A new method for vascular age estimation based on relative risk difference in vascular aging

OBJECTIVE

The current models of estimating vascular age (VA) primarily rely on the regression label expressed with chronological age (CA), which does not account individual differences in vascular aging (IDVA) that are difficult to describe by CA. This may lead to inaccuracies in assessing the risk of cardiovascular disease based on VA. To address this limitation, this work aims to develop a new method for estimating VA by considering IDVA. This method will provide a more accurate assessment of cardiovascular disease risk.

METHODS

Relative risk difference in vascular aging (RRDVA) is proposed to replace IDVA, which is represented as the numerical difference between individual predicted age (PA) and the corresponding mean PA of healthy population. RRDVA and CA are regard as the influence factors to acquire VA. In order to acquire PA of all samples, this work takes CA as the dependent variable, and mines the two most representative indicators from arteriosclerosis data as the independent variables, to establish a regression model for obtaining PA.

RESULTS

The proposed VA based on RRDVA is significantly correlated with 27 indirect indicators for vascular aging evaluation. Moreover, VA is better than CA by comparing the correlation coefficients between VA, CA and 27 indirect indicators, and RRDVA greater than zero presents a higher risk of disease.

CONCLUSION

The proposed VA overcomes the limitation of CA in characterizing IDVA, which may help young groups with high disease risk to promote healthy behaviors.

Insights into Myocardial Perfusion PET Imaging: the Coronary Flow Capacity

Purpose of Review

The present work summarizes the clinical relevance of coronary flow capacity (CFC) with an eye on future perspectives.

Recent findings

CFC concept has been recently introduced providing a comprehensive framework for coronary physiology evaluation.

Summary

It has been widely demonstrated that coronary artery disease (CAD) is a complex disease with a multifactorial etiology resulting from different pathogenic mechanisms. Cardiac positron emission tomography (PET) currently represents the gold standard for CAD assessment, providing absolute myocardial perfusion data including coronary flow reserve (CFR), calculated as the ratio of hyperemic to rest absolute myocardial blood flows. CFC can be obtained from dynamic PET images by plotting the primary stress perfusion data and CFR values for each pixel on a graph of predefined exact ranges. The routine evaluation of this parameter may add diagnostic and prognostic value to clinical and conventional imaging data.

Quantification of Coronary Artery Atherosclerotic Burden and Muscle Mass: Exploratory Comparison of Two Freely Available Software Programs

Coronary artery calcification and sarcopenia may have a relevant prognostic impact in oncological and non-oncological patients. The use of freeware software is promising for quantitative evaluation of these parameters after whole-body positron emission tomography (PET)/computed tomography (CT) and might be useful for one-stop shop risk stratification without additional radiation ionizing burden and further charges to health care costs. In this study, we compared two semiautomatic freeware software tools (Horos Medical Image software and LIFEx) for the assessment of coronary artery calcium (CAC) score and muscle mass in 40 patients undergoing whole-body PET/CT. The muscle areas obtained by the two software programs were comparable, showing high correlation with Lin’s concordance coefficient (0.9997; 95% confidence intervals: 0.9995–0.9999) and very good agreement with Bland–Altman analysis (mean difference = 0.41 cm2, lower limit = −1.06 cm2, upper limit = 1.89) was also found. For CAC score, Lin’s concordance correlation coefficient was 0.9976 (95% confidence intervals: 0.9965–0.9984) and in a Bland–Altman analysis an increasing mean difference from 8 to 78 by the mean values (intercept = −0.050; slope = 0.054; p < 0.001) was observed, with a slight overestimation of Horos CAC score as compared to LIFEx, likely due to a different calculation method of the CAC score, with the ROI being equal for the two software programs. Our results demonstrated that off-line analysis performed with freeware software may allow a comprehensive evaluation of the oncological patient, making available the evaluation of parameters, such as muscle mass and calcium score, that may be relevant for the staging and prognostic stratification of these patients, beside standard data obtained by PET/CT imaging. For this purpose, the Horos and LIFEx software seem to be interchangeable.

Diagnostic value of clinical risk scores for predicting normal stress myocardial perfusion imaging in subjects without coronary artery calcium

BACKGROUND

We evaluated if risk scores commonly used to predict the absence of significant stenosis at coronary computed tomography (CT) angiography are useful to predict a normal stress myocardial perfusion imaging (MPI) study.

METHODS

Our cohort included a total of 1422 consecutive patients with zero coronary artery calcium score (ZCS) who underwent 82Rb PET/CT for evaluation of suspected coronary artery disease (CAD). Predictive models were constructed as reported by Genders et al. and Alshahrani et al., and the probability of abnormal summed stress score (SSS) and of reduced myocardial perfusion reserve (MPR) based on these risk scores was assessed.

RESULTS

In the overall population, the prevalence of abnormal SSS was 0.10 and the prevalence of reduced MPR was 0.17 (both P < .001).The observed frequencies of abnormal SSS and reduced MPR vs the probabilities predicted by the Genders and Alshahrani models were above the diagonal identity line, highlighting an underestimation of the observed occurrence by these models. The areas under the receiver operating characteristic curve of the Genders and Alshahrani models indicated lack of discriminative ability for predicting abnormal SSS (0.547 and 0.527) and reduced MPR (0.509 and 0.538). The Hosmer-Lemeshow test revealed that both models underestimated the observed occurrence of abnormal SSS and reduced MPR.

CONCLUSIONS

Available models were unable to identify among patients with ZCS those with a low probability of a normal stress MPI study. Thus, an optimal approach to rule out from MPI patients without detectable coronary calcium still needs to be improved.

Planning the Follow-Up of Patients with Stable Chronic Coronary Artery Disease

Cardiovascular disease remains the leading cause of death among Europeans, Americans, and around the world. In addition, the prevalence of coronary artery disease (CAD) is increasing, with the highest number of hospital visits, hospital readmissions for patients with decompensated heart failure, and a high economic cost. It is, therefore, a priority to try to plan the follow-up of patients with stable chronic CAD (scCAD) in relation to the published data, experience, and new technology that we have today. Planning the follow-up of patients with scCAD goes beyond the information provided by clinical management guidelines. It requires understanding the importance of a cross-sectional and longitudinal analysis in the clinical history of scCAD, because it has an impact on the cost of healthcare in relation to mortality, economic factors, and the burden of medical consultations. Using the data provided in this work facilitates and standardizes the clinical follow-up of patients with scCAD, and following the marked line makes the work for the clinical physician much easier, by including most clinical possibilities and actions to consider. The follow-up intervals vary according to the clinical situation of each patient and can be highly variable. In addition, the ability to properly study patients with imaging techniques, to stratify at different levels of risk, helps plan the intervals during follow-up. Given the complexity of coronary artery disease and the diversity of clinical cases, more studies are required in the future focused on improving the planning of follow-up for patients with scCAD. The perspective and future direction are related to the valuable utility of integrated imaging techniques in clinical follow-up.

An Update on Coronary Artery Calcium Interpretation at Chest and Cardiac CT

Coronary artery calcium (CAC) is a marker of overall coronary atherosclerotic burden in an individual. As such, it is an important tool in cardiovascular risk stratification and preventive treatment of asymptomatic patients with unclear cardiovascular disease risk. Several guidelines have recommended the use of CAC testing in shared decision making between the clinician and patient. With recent updates in clinical management guidelines and broad recommendations for CAC, there is a need for concise updated information on CAC interpretation on traditional electrocardiographically gated scans and nongated thoracic scans. Important points to report when interpreting CAC scans include: the absolute Agatston score and the age, sex, and race-specific CAC percentile; general recommendations on time-to-rescan for individuals with a CAC score of 0; the number of vessels with CAC; the presence of CAC in the left main coronary artery; and specific highlighting of individuals with very high CAC scores of greater than 1000. When risk factor information is available, the 10-year coronary heart disease risk can also be easily assessed using the free online Multi-Ethnic Study of Atherosclerosis risk score calculator. Recent improvements in standardizing the reporting of CAC findings across gated and nongated studies, such as the CAC Data and Reporting System, show promise for improving the widespread clinical value of CAC in clinical practice. © RSNA, 2021.

Review of cardiovascular imaging in the Journal of Nuclear Cardiology 2019: Positron emission tomography, computed tomography and magnetic resonance

In 2019, the Journal of Nuclear Cardiology published excellent articles pertaining to imaging in patients with cardiovascular disease. In this review we will summarize a selection of these articles to provide a concise review of the main advancements that have recently occurred in the field and provide the reader with an opportunity to review a wide selection of articles. In this first article of this 2-part series we will focus on publications dealing with positron emission tomography, computed tomography and magnetic resonance. We will specifically discuss imaging as it relates to coronary artery disease, atherosclerosis and inflammation, coronary artery calcification, cardiomyopathies, cardiac implantable electronic devices, prosthetic valves, and left ventricular assist devices. The second part of this review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography.

Hybrid anatomo-functional imaging of coronary artery disease: Beneficial irrespective of its core components

Coronary artery disease (CAD) is the most common and important cause of ischemic heart disease, with major implications on global morbidity and mortality. Non-invasive testing is crucial in the diagnostic and prognostic work-up of patients with or at risk of CAD, and also to guide decision making in terms of pharmacologic and revascularization therapy. The traditional paradigm is to view anatomic (i.e., coronary computed tomography) and functional imaging (e.g., myocardial perfusion scintigraphy) tests as opposing alternatives. Such approach is too reductionist and does not capitalize on the strengths of each type of test while risking to overlook the inherent limitations. The combination of anatomic and functional tests in a logic of hybrid imaging holds the promise of overcoming the limitations inherent to anatomic and functional testing, enabling more accurate diagnosis, prognosis, and guidance for revascularization in patients with CAD.

Behind Traditional Semi-quantitative Scores of Myocardial Perfusion Imaging: An Eye on Niche Parameters

The evaluation of stress-induced myocardial perfusion defects by non-invasive myocardial perfusion imaging (MPI) modalities has a leading role in the identification of coronary artery disease, and has excellent diagnostic and prognostic value. Non-invasive MPI can be performed using conventional and novel gamma cameras or by PET/CT. New software has allowed novel parameters that may have a role in the identification of early marks of cardiac impairment to be evaluated. We aim to give an overview of niche parameters obtainable by single photon emission CT (SPECT) and PET/CT MPI that may help practitioners to detect initial signs of cardiac damage and identify new therapy targets. In particular, we summarise the role of left ventricular geometry indices for remodelling, phase analysis parameters to evaluate mechanical dyssynchrony, the concept of relative flow reserve in the evaluation of flow-limiting epicardial stenosis, vascular age and epicardial adipose tissue as early markers of atherosclerotic burden, and emerging parameters for the evaluation of myocardial innervation, such as the total defect score.

Sympathetic nervous system in age-related cardiovascular dysfunction: Pathophysiology and therapeutic perspective

Cardiovascular diseases such as heart failure and metabolic syndrome have high prevalence in the elderly population and are leading causes of death, disability, hospitalization, driving high healthcare costs worldwide. To reduce this social and economic burden there is urgency to find effective therapeutic targets. Several studies have linked the dysfunction of the Sympathetic Nervous System and β-adrenergic receptor signaling with the pathogenesis of age-related cardiovascular diseases. Therapeutic treatments that restore their functions have been shown to be effective in subjects with cardiovascular comorbidities. In fact, lifestyle interventions (such as exercise training and diet) as well as pharmacologic treatments (e.g. β-blockers or moxonidine) and mini-invasive interventions (renal sympathetic denervation) have beneficial effects on age-related cardiovascular diseases. In the current "Medicine in focus" article we will discuss the pathogenic role of the Sympathetic Nervous System in age-related cardiovascular diseases as well as current and new therapeutic approaches.