Coronary CT and the coronary calcium score, the future of ED risk stratification?

Computed Tomography (CT) Calcium Scoring in Primary Prevention of Acute Coronary Syndrome and Future Cardiac Events in Patients With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex and chronic autoimmune disease that impacts multiple organ systems and presents with varying symptomatology that makes targeting treatment extremely difficult. The cardiovascular system and more specifically the coronary arteries are heavily affected by SLE causing increased atherosclerosis and subsequently increased acute coronary syndrome (ACS) and increased future cardiac events. ACS is a common occurrence in patients with SLE due to the premature development of atherosclerosis due to the dysregulation of pro-inflammatory cytokines. Calcium scoring has been effectively utilized to identify plaque burden in patients with coronary artery calcification (CAC). Calcium scoring is a score obtained from a computed tomography (CT) image using non-contrast imaging, which provides quantitative information regarding CAC and aids in assessing cardiovascular risk. A calcium score of zero Hounsfeild units can be obtained using CT calcium scoring which indicates no calcium is identified in the coronary arteries and is a strong negative risk predictor for coronary artery disease. Early screening of SLE patients with CT calcium scoring could aid in early detection and treatment subsequently leading to delay of premature coronary atherosclerosis and future cardiac events in this patient population. Multiple studies have used calcium scoring as a method to measure arterial calcification in SLE patients. The Society of Cardiovascular Imaging has now endorsed the idea of obtaining a baseline calcium artery score with a repeat progression scan in 3-5 years. Calcium scoring has also been identified as an effective initial tool for stratification and identification of possible ACS. The various advantages of early calcium scoring signify the further research needed to fully understand and implement the advantages calcium scoring has to offer patients with SLE.

Age and the power of zero CAC in cardiac risk assessment: overview of the literature and a cautionary case

The coronary artery calcium (CAC) score is a marker of advanced coronary atherosclerosis. Numerous prospective cohorts have validated CAC as an independent marker that improves prognostication in atherosclerotic cardiovascular disease (ASCVD) beyond traditional risk factors. Accordingly, CAC is now incorporated into international cardiovascular guidelines as a tool to inform medical decision-making. Particular interest concerns the significance of zero CAC score (CAC=0). While many studies report CAC=0 to virtually exclude obstructive coronary artery disease (CAD), non-negligible rates of obstructive CAD despite CAC=0 are reported in certain populations. Overall, the current literature supports the power of zero CAC as a strong downward risk classifier in older patients, whose CAD burden predominantly involves calcified plaque. However, with their higher burden of non-calcified plaque, CAC=0 does not reliably exclude obstructive CAD in patients under 40 years. Illustrating this point, we present a cautionary case of a 31-year-old patient found to have severe two-vessel CAD despite CAC=0. We highlight the value of coronary computed tomography angiography (CCTA) as the gold-standard non-invasive imaging modality when the diagnosis of obstructive CAD is in question.

Postsystolic shortening on echocardiography as a gateway to cardiac computed tomography in patients with suspected stable angina pectoris

Postsystolic shortening (PSS) by speckle-tracking echocardiography (STE) is a marker of myocardial ischemia and may improve diagnostic strategy. We sought to evaluate if PSS is associated with the coronary artery calcium score (CACS) and stenosis by computed tomography angiography (CTA) in patients with suspected stable angina pectoris (SAP). We retrospectively studied 437 SAP patients (age 58 ± 11 years, 41% male) who underwent STE, evaluation of CACS and assessment of significant stenosis (≥ 50%) by CTA. The postsystolic index (PSI) was defined as follows: 100x([peak negative strain cardiac cycle - peak negative strain systole])/peak negative strain cardiac cycle. A wall had PSS if any segment within the wall had a PSI ≥ 20%. We defined categories for walls with PSS: 0, 1, 2 and ≥ 3, and CACS: 0, 1-100, 101-400 and > 400. Each additional wall with PSS was associated with a 43% relative increase in CACS (95%CI +9% to +87%, P = 0.010), while each 1% absolute increase in the PSI was associated with a 9% relative increase in CACS (95%CI +1% to +18%, P = 0.031). Walls with PSS (OR 1.81 per 1 wall increase, 95%CI 1.27-2.59, P = 0.001) and the PSI (OR 1.12 per 1% increase, 95%CI 1.04-1.21, P = 0.004) were associated with the occurrence of CACS > 400. Additionally, walls with PSS (OR 1.53 per 1 wall increase, 95%CI 1.21-1.93, P < 0.001) was a predictor of significant stenosis by CTA. PSS is associated with CACS and significant stenosis by CTA in patients with SAP and may aid in the selection of patients referred for cardiac computed tomography.

Chemotherapy-induced coronary arteries calcium score deterioration as detected with unenhanced CT portion of FDG PET/CT

This study aims to detect the potential impact of chemotherapy on the coronary calcium scoring (CCS) in lymphoma patients undergoing FDG-PET/CT at baseline and for therapy response using the CT portion of the exam to calculate the CCS. One hundred twelve lymphoma patients were included in the study based on having both baseline and at least 2 post-chemotherapy scans. The unenhanced CT portions of the scans were reviewed to measure the CCS which was then extracted using the Toshiba Vital Program. Agatston scores were assessed as category 1 with zero CCS unit and categories 2 to 5 having more than >1, 11, 101, and 400 CCS units respectively. For statistical analysis, paired T-Tests were used to compare results. The overall changes in total coronary artery calcium (CAC) from baseline to last treatment showed a statistically significant increase in CAC with an average increase of at least 35% in the CAC score. We also compared the overall changes in CAC with patients having category 1 and 2 Agatston at baseline and found no statistical increase in CAC post-chemotherapy. Additionally, we compared the overall changes in CAC with patients having category 3 and 4 Agatston at baseline and found statistically significant increase in CAC post-chemotherapy. In lymphoma patients, chemotherapy may cause worsening of CCS and this can serve as an early indicator of chemotherapy-induced cardiac toxicity. When present, such CCS deterioration can be detected by the unenhanced CT portion of routine oncologic FDG PET/CT scans.

Prognostic Value of Coronary Artery Calcium Score for Determination of Presence and Severity of Coronary Artery Disease

Background

There are controversies regarding the usefulness of coronary artery calcium score (CACS) for predicting coronary artery stenosis. The aim of this study was to determine the prognostic value of CACS for determining the presence and severity of coronary artery disease (CAD) in patients with sign and symptoms of the disease.

Material/Methods

In this cross-sectional study, 748 consecutive patients with suspected CAD, referred for coronary computed tomography angiography (CCTA), were enrolled. The mean CACS was compared between patients with different severities of coronary artery stenosis. The association between CACS and different CAD risk factors was determined as well. Different cutoff points of CACS for discriminating between different levels of coronary artery stenosis was determined using receiver operating characteristic (ROC) curves.

Results

The mean CACS was significantly different between different levels of coronary artery stenosis (P<0.001) and there was a significant positive association between the severity of CAD and CACS (P<0.001,r=0.781). ROC curve analysis indicated that the optimal cutoff point for discriminating between CAD (presence of stenosis) and the non-stenosis condition was 5.35 with 88.6% sensitivity and 86.2% specificity. Area under the curve for different levels of coronary artery stenosis did not have sufficient sensitivity and specificity for discriminating between different levels of CAD severity (<70%).

Conclusions

The study demonstrated that there is a significant association between CACS and the presence as well as the severity of CAD. CACS could have an appropriate prognostic value for the determination of coronary artery stenosis but not for discriminating between different severities of stenoses.

Calcium Scoring and Cardiac Computed Tomography

Although recent advances in noninvasive imaging technologies have potentially improved diagnostic efficiency and clinical outcomes of patients with acute chest pain, controversy remains regarding much of the accumulated evidence. This article reviews the role of coronary computed tomography (CT) angiography in the assessment of coronary risk, and its usefulness in the emergency department in facilitating appropriate disposition decisions. Also discussed is coronary artery calcification incidentally found on CT scans when done for indications such as evaluation of pulmonary embolism or lung cancer. The evidence base and clinical applications for both techniques are described, together with cost-effectiveness and radiation exposure considerations.

Diagnostic efficacy of vessel specific coronary calcium score in detection of coronary artery stenosis

BACKGROUND

Coronary artery calcification which is determined quantitatively by coronary calcium scoring has been known as a sign of coronary stenosis and thus future cardiac events; hence it has been noticed on spotlight of researchers in recent years. Developing different method for early and optimal detection of coronary artery disease (CAD) is really essential as CAD are the first cause of death in population.

OBJECTIVES

To evaluate predictive value of vessel specific coronary artery calcium (CAC) score in predicting obstructive coronary artery disease.

PATIENTS AND METHODS

In this diagnostic test study we evaluated patients with coronary computed tomography angiography (CCTA) and CAC score which had been referred to two referral radiology center in Tehran, Iran and finally we selected 2525 patients in a single and sequential pattern to create a diagnostic study. The whole-heart CAC scores and vessel specific CAC scores were calculated individually for the 4 major epicardial coronary arteries in 2 distinct group; group A ( patients with previous history of CABG) and group B (patients without history of CABG). For evaluation of obstruction tree cut off points were described: 0 > ; at least 1 segment with any kind of stenosis, ≥ 50; at least 1 segment with stenosis ≥ 50, ≥ 70; at least 1 segment with stenosis ≥ 70.

RESULTS

Mean of coronary calcium scores in terms of each coronary artery vessel increase by increasing coronary stenosis grade in group B; LAD, RCA, LCX respectively have mean CAC score 6.06, 6.21 and 5.04 in normal patients and 221.6, 226.7 and 106.6 in patients with complete stenosis. As expected these findings don't work for group A. Also By increasing calcium score cutoff in all four vessels sensitivity decreased and specificity increased but steal LAD had higher sensitivity than other vessels and LM had higher specificity. Thus using calcium score method is useful for ruling out stenosis in LAD while calcium score of LM can predict existence of stenosis in LM. However none of the vessel specific CAC can reach to 100% sensitivity and specificity of CCTA method.

CONCLUSIONS

CCTA is highly superior than vessel specific CAC score thus to minimize patients radiation does maybe we can eliminate CAC scan as a routinely perform procedure at the beginning of the CCTA.

Rationale and design of a randomized trial comparing initial stress echocardiography versus coronary CT angiography in low-to-intermediate risk emergency department patients with chest pain

BACKGROUND

Comparative effectiveness research (CER) has become a major focus of cardiovascular disease investigation to optimize diagnosis and treatment paradigms and decrease healthcare expenditures. Acute chest pain is a highly prevalent reason for evaluation in the Emergency Department (ED) that results in hospital admission for many patients and excess expense. Improvement in noninvasive diagnostic algorithms can potentially reduce unnecessary admissions.

OBJECTIVE

To compare the performance of treadmill stress echocardiography (SE) and coronary computed tomography angiography (CTA) in ED chest pain patients with low-to-intermediate risk of significant coronary artery disease.

DESIGN

This is a single-center, randomized controlled trial (RCT) comparing SE and CTA head-to-head as the initial noninvasive imaging modality. The primary outcome measured is the incidence of hospitalization. The study is powered to detect a reduction in admissions from 28% to 15% with a sample size of 400. Secondary outcomes include length of stay in the ED/hospital and estimated cost of care. Safety outcomes include subsequent visits to the ED and hospitalizations, as well as major adverse cardiovascular events at 30 days and 1 year. Patients who do not meet study criteria or do not consent for randomization are offered entry into an observational registry.

CONCLUSIONS

This RCT will add to our understanding of the roles of different imaging modalities in triaging patients with suspected angina. It will increase the CER evidence base comparing SE and CTA and provide insight into potential benefits and limitations of appropriate use of treadmill SE in the ED.

Imagining the future of diagnostic imaging

Cardiovascular imaging has become essential to achieving a better understanding of cardiovascular diseases. Due to the advent of new technology and the refinement of existing technologies, imaging's role has extended into the biological, functional, and hemodynamic diagnosis of multiple pathophysiologic processes. Current and future trends in cardiovascular imaging will focus on improving early diagnosis of vascular disease, so as to be able to promote cardiovascular health, and on its development as a useful tool in clinical decision-making. Imaging is also increasingly used to quantify the effect of novel therapies. The rapid development of molecular imaging and fusion imaging techniques improves our understanding of cardiovascular processes from the molecular and cellular points of view and makes it possible to design and test new preventive interventions. The proliferation and integration of imaging techniques in different clinical areas and their role in "translational imaging" plays an important part in the implementation of personalized therapeutic and preventive management strategies for patients with cardiovascular disease.