The Synergistic Use of Coronary Artery Calcium Imaging and Noninvasive Myocardial Perfusion Imaging for Detecting Subclinical Atherosclerosis and Myocardial Ischemia

Type 2 diabetes mellitus and cardiometabolic outcomes in metabolic dysfunction-associated steatotic liver disease population

The metabolic syndrome, characterized by type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and obesity, collectively increases the risk of cardiovascular diseases. Nonalcoholic fatty liver disease (NAFLD) is a prominent manifestation, affecting over a third of the global population with a concerning annual increase in prevalence. Nearly 70 % of overweight individuals have NAFLD, and NAFLD-related deaths are predicted to rise, especially among young adults. The association of T2DM and NAFLD has led to the proposal of "metabolic dysfunction-associated steatotic liver disease" (MASLD) terminology, encompassing individuals with T2DM, overweight/obesity, hypertension, hypertriglyceridemia, or low HDL-cholesterol. Patients with MASLD will likely have double the risk of developing T2DM, and the combination of insulin resistance, overweight/obesity, and MASLD significantly elevates the risk of T2DM. Cardiovascular diseases remain the leading cause of mortality in the MASLD and T2DM population, with MASLD directly associated with coronary artery disease, compounded by coexisting insulin resistance and T2DM. Urgency lies in early detection of subclinical cardiovascular diseases among patients with T2DM and MASLD. Novel strategies targeting multiple pathways offer hope for effectively improving cardiometabolic health. Understanding and addressing the intertwined factors contributing to these disorders can pave the way towards better management and prevention of cardiometabolic complications.

Transient ischaemic dilation ratio thresholds in patients with zero coronary calcium score undergoing exercise or dipyridamole stress SPECT myocardial perfusion imaging using a cadmium-zinc-telluride camera

Aims

Transient ischaemic dilation (TID) is a marker of underlying extensive coronary artery disease (CAD) during myocardial perfusion imaging (MPI). The cut-off for a normal TID ratio (TIDr) value is often derived from a cohort of individuals with no apparent CAD. Varying criteria have been used to define the absence of CAD. We aim to derive TIDr cut-offs using patients with normal MPI and coronary artery calcium (CAC) score of zero, and compare the TIDr obtained from different software packages.

Methods and results

We studied 232 patients with zero CAC and normal MPI undergoing exercise or dipyridamole stress using either a 1- or 2-day protocol. All patients were scanned in the supine position with a cadmium-zinc-telluride camera. TIDr was automatically generated using quantitative perfusion SPECT (QPS) software initially, and subsequently using Myometrix for comparison. The TIDr cut-offs calculated using the mean + 2 standard deviation were 1.29 and 1.24 for the 1- and 2-day protocol groups, respectively. In patients undergoing a 2-day protocol, dipyridamole stress resulted in significantly higher mean TIDr when compared to exercise stress (1.07 ± 0.13 vs. 1.01 ± 0.12, P = 0.035). Myometrix-derived TIDr were also significantly lower compared to QPS-derived values for most protocols except for 2-day exercise stress.

Conclusion

This study is the first to derive TIDr threshold values using a normal population defined by zero CAC and normal MPI. TIDr was found to vary depending on stress modality, protocol as well as the software used.

Does Coronary Plaque Morphology Matter Beyond Plaque Burden?

PURPOSE OF REVIEW

Imaging of adverse coronary plaque features by coronary computed tomography angiography (CCTA) has advanced greatly and at a fast pace. We aim to describe the evolution, present and future in plaque analysis, and its value in comparison to plaque burden.

RECENT FINDINGS

Recently, it has been demonstrated that in addition to plaque burden, quantitative and qualitative assessment of coronary plaque by CCTA can improve the prediction of future major adverse cardiovascular events in diverse coronary artery disease scenarios. The detection of high-risk non-obstructive coronary plaque can lead to higher use of preventive medical therapies such as statins and aspirin, help identify culprit plaque, and differentiate between myocardial infarction types. Even more, over traditional plaque burden, plaque analysis including pericoronary inflammation can potentially be useful tools for tracking disease progression and response to medical therapy. The identification of the higher risk phenotypes with plaque burden, plaque characteristics, or ideally both can allow the allocation of targeted therapies and potentially monitor response. Further observational data are now required to investigate these key issues in diverse populations, followed by rigorous randomized controlled trials.

Cardiovascular Imaging for Ischemic Heart Disease in Women: Time for a Paradigm Shift

Heart disease is the leading cause of death among men and women. Women have a unique phenotype of ischemic heart disease with less calcified lesions, more nonobstructive plaques, and a higher prevalence of microvascular disease compared with men, which may explain in part why current risk models to detect obstructive coronary artery disease (CAD) may not work as well in women. This paper summarizes the sex differences in the functional and anatomical assessment of CAD in women presenting with stable chest pain and provides an approach for using multimodality imaging for the evaluation of suspected ischemic heart disease in women in accordance to the recently published American Heart Association/American College of Cardiology guidelines for the evaluation and diagnosis of chest pain. A paradigm shift in the approach to imaging ischemic heart disease women is needed including updated risk models, a more profound understanding of CAD in women where nonobstructive disease is more prevalent, and algorithms focused on the evaluation of ischemia with nonobstructive CAD and myocardial infarction with nonobstructive CAD.

Coronary artery disease and non-alcoholic fatty liver disease: Clinical correlation using computed tomography coronary calcium scans

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) and coronary artery disease (CAD) have been explored using coronary angiography, which showed a link between severe NAFLD and cardiovascular disease risk. This study's aim is to determine if computed tomography (CT) coronary artery calcium (CAC) scores used to determine CAD severity in asymptomatic populations can help predict the presence of NAFLD.

Methods

This was a retrospective cross‐sectional study of positive CT CAC scores and liver imaging with either CT; ultrasound; magnetic resonance imaging of the abdomen; or CT of the chest, which included liver images. Drinking 7 or 14 drinks per week for a female or male, respectively, and chronic viral hepatitis diagnosis were the exclusion criteria. CT CAC scores, hepatic steatosis, age, gender, lipid and liver panels, weight, blood pressure, F‐4/BARD scores, and hemoglobin A1c were correlated to CAD severity and NAFLD by logistic regression.

Results

A total of 134 patients with a mean age of 62.3 years (σ = 9.1), with 65% males, body mass index 28.5 (σ = 6.0), and 8% diabetics, were recruited. CAD severity was not associated with the presence of hepatic steatosis (odds ratio 1.96 [95% confidence interval, confidence interval 0.74–5.23] P = 0.36). Adjusted for variables, a link between hepatic steatosis, CAD severity, body mass index over 30 (odds ratio 6.77 [95% confidence interval 1.40–32.66] P = 0.02), and diabetes (odds ratio 9.60 [95% confidence interval 0.56–165.5] P = 0.01) was observed.

Conclusions

In patients with CAD detected using a positive CT CAC scan, we determined that BMI over 30 and diabetes were correlated with the presence of NAFLD. There was no direct relationship between CAD presence and hepatic steatosis presence.

Coronary artery calcium testing in low-intermediate risk symptomatic patients with suspected coronary artery disease: An effective gatekeeper to further testing?

Computed tomography for quantification of coronary artery calcium (CAC) is a simple non-invasive tool to assess atherosclerotic plaque burden. CAC is highly correlated with coronary atherosclerosis and is a robust predictor of cardiovascular outcomes. Recently, the 2018 ACC/AHA Cholesterol Guidelines endorsed the use of CAC scores in asymptomatic, intermediate risk individuals where the decision to initiate stain therapy is uncertain. However, whether quantification of CAC may play a role in the assessment of symptomatic individuals remains a matter of debate. In this review, we examine the evidence for the use of CAC in low-intermediate risk patients with chest pain. This appraisal places a particular focus on the growing body of literature supporting the negative predictive value of a CAC score of zero to rule out significant coronary artery disease in those without high-risk features. We also evaluate current guidelines, limitations, and future research directions for CAC scoring in this important subgroup of patients.

Visually assessed coronary and cardiac calcium outperforms perfusion data during scintigraphy in the prediction of adverse outcomes

OBJECTIVES

To determine whether calcifications of the coronary arteries (coronary artery calcium 0 to 4 score), or extending the assessment also to cardiac valves and thoracic aorta (overall calcium 0 to 8 score), as seen on computed tomography for attenuation correction during stress-scintigraphy (SPECT-CT), are associated with total mortality and non-fatal myocardial infarction. We aimed to assess whether these calcifications added to the prognostic value of SPECT imaging.

BACKGROUND

The presence/amount of calcium in the coronary arteries, but also in the heart valves and aorta, has been associated with cardiovascular (CV) and all-cause mortality. This information can be obtained during SPECT-CT examinations, where low resolution CT images are co-registered for attenuation correction of myocardial perfusion, but then discarded.

METHODS

Clinical data were collected on 353 consecutive patients submitted to stress SPECT-CT between Sept 2010 and Oct 2012, for suspected coronary artery disease (CAD). Follow-up data on outcomes were collected retrospectively.

RESULTS

Mean age was 72 and 58% were male. Mean follow-up was 6.4 years, during which 48 subjects died (15 from CV causes) and 10 had non-fatal myocardial infarction (MI). Reversible perfusion defects were detected in 55 patients (15.6%), 39 of whom (11%) had >mild defects. The presence of a calcium score > 1 in the attenuation correction images was the strongest univariate predictor of all-cause death or MI (hazard ratio 7.21, p < .001). On multivariate analysis, controlling for age, gender and myocardial perfusion defects an overall calcium score > 2 remained a predictor of all-cause death or non-fatal MI (hazard ratio 4.12, p < .001).

CONCLUSIONS

Visual assessment of coronary or overall coronary, cardiac and aortic calcium in the CT images used for attenuation correction during SPECT-CT is feasible and reproducible. It was strongly associated with all-cause death and MI, even after controlling for clinical variables and myocardial perfusion data. This simple visual calcium assessment does not add additional costs or radiation, and may significantly improve risk-assessment of patients with suspected CAD undergoing SPECT-CT.

CONDENSED ABSTRACT

Calcium in the coronary arteries, heart valves and aorta has been associated with worse prognosis. We sought to determine whether assessment of such calcifications on computed tomography images (co-registered for myocardial perfusion attenuation correction and then discarded) are independently associated with long-term outcome on top of available data. We enrolled 353 consecutive patients, referred for suspected coronary artery disease. An overall calcium score > 1 in the attenuation correction images was the strongest univariate (hazard ratio 7.21, p < .001) and multivariate predictor of all-cause death or non-fatal MI (hazard ratio 4.12, p < .001), even after controlling for clinical variables and myocardial perfusion data.

Feasibility and accuracy of SPECT myocardial perfusion imaging in end-stage lung disease

BACKGROUND

Coronary artery disease (CAD) is associated with increased mortality in patients with chronic lung disease. However, non-invasive diagnostic of CAD is difficult, especially in patients with more advanced disease. Therefore, we aimed to assess the feasibility and accuracy of SPECT-myocardial perfusion imaging (MPI) stress testing with regadenoson in patients with end-stage lung disease (ELD) undergoing assessment of stable CAD.

METHODS

Between January 2012 and May 2018, 102 patients with ELD, who were referred to our institution for lung transplant evaluation, were assessed retrospectively. All patients underwent both stress SPECT-MPI as well as coronary angiography.

RESULTS

The mean age in our population was 57±6 years. All patients had severe pulmonary function impairment. During stress SPECT-MPI 14 patients (14%) reported regadenoson-related symptoms, but only 2 patients (2%) required medical treatment. Coronary angiography revealed obstructive CAD in 20 patients (20%). Among those, 5 patients had abnormal SPECT-MPI and PCI was performed in 3 patients accordingly. In 14 patients with obstructive CAD, revascularization was deferred based on normal SPECT-MPI findings.

CONCLUSIONS

SPECT-MPI using regadenoson is well tolerated in patients with ELD and can help to make decisions about coronary revascularization before lung transplant.

Optimizing the Assessment of Patient Clinical Risk at the Time of Cardiac Stress Testing

Due to a marked temporal decline in inducible myocardial ischemia over recent decades, most diagnostic patients now referred for cardiac stress testing have nonischemic studies. Among nonischemic patients, however, long-term risk is heterogeneous and highly influenced by a variety of clinical parameters. Herein, we review 8 factors that can govern long-term clinical risk: coronary risk factor burden; patient symptoms; exercise capacity and exercise test responses; the need for pharmacologic stress testing; autonomic function; musculoskeletal status; subclinical atherosclerosis; and psychosocial risk. To capture the clinical benefit provided by both assessing myocardial ischemia and these additional parameters, the authors propose that a cardiac stress tests report have an additional component beyond statements as to the likelihood of obstructive coronary artery disease and/or magnitude of ischemia. This added component could be a comment section designed to make referring physicians aware of aspects of long-term risk that may influence clinical management and potentially lead to changes in the intensity of risk factor management, frequency of follow-up, need for further testing, or other management decisions. In this manner, the increasingly frequent normal stress test result might more commonly influence treatment recommendations and even patient behavior, thus leading to improvement in patient outcomes even in the setting of normal stress test results.

Fragmented QRS on surface electrocardiogram as a predictor of perfusion defect in patients with suspected coronary artery disease undergoing myocardial perfusion imaging

Background

Fragmented QRS (FQRS) on surface electrocardiogram (ECG) is associated with the presence of myocardial scar tissue and may have prognostic value after certain ischemic events. We aimed to examine the anatomical correlation of FQRS with the presence of perfusion abnormalities in patients with suspected coronary artery disease (CAD).

Methods

Patients without a known history of CAD, who were referred for myocardial perfusion imaging (MPI) between January 2016 and May 2016, were enrolled. The presence of FQRS on surface ECG was evaluated. The presence of FQRS, number of leads with FQRS, and the location of FQRS as well as patient characteristics were compared in patients with normal versus abnormal MPI. Multivariate model was constructed to identify independent factors associated with perfusion defect.

Results

One hundred four women and 94 men were enrolled. Fragmentation of anterior, lateral, and inferior leads was detected in 13 (6.5%), 17 (8.5%), and 36 (18.1%) subjects, respectively. MPI was normal in 134 (67.6%) patients. FQRS was significantly more common in patients with abnormal MPI (p < 0.001). Age (odds ratio [OR]: 1.05 [1.02–1.08]; p = 0.001), number of the leads presenting FQRS (OR: 1.46 [1.12–1.92] p = 0.006), and diabetes (OR: 2.33 [1.16–4.69]; p = 0.018) were independent predictors of the presence of perfusion defect on MPI.

Conclusion

In the absence of known CAD, FQRS is associated with the presence of perfusion abnormalities. Incorporating FQRS in diagnostic armamentarium may aid us in selecting patients who may benefit from MPI.