The accuracy of coronary CT angiography in patients with coronary calcium score above 1000 Agatston Units: Comparison with quantitative coronary angiography

Prediction of high coronary artery calcium (CAC) scores from aortic arch calcification: An efficient tool for selection of non-optimal candidates for coronary CTA?

PURPOSE

Overutilization of healthcare resources is causing a high socioeconomic burden. Patients with high coronary artery calcium (CAC) scores > 1000AU are not optimal candidates for coronary CTA and better suited for other diagnostic strategies. Therefore, our objective was to evaluate whether a 4-scale aortic arch calcification severity (AoArCa) score from CT and X-Ray predicts high-CAC scores.

METHODS

Patients referred to coronary/aortic CT-Angiography were enrolled. The severity of aortic arch calcification (AoArCa) was scored as grade: 0 = absent, 1 = minimal (<25 % of circumference), 2 = mild (25-50 %), 3 = moderate (50-75 %) and 4 = severe (75-100 %) on both thoracic CT and X-ray.

RESULTS

In 130 patients, the absence of AoArCa by CT was highly accurate to rule out CAC > 1000AU (sens. 100 %). No or minimal AoArCa had a high NPV of 95.6 % to rule out CAC > 1000 and grade 0,1 + 2 a NPV of 86.96 %. The AUC of AoArCa by CT for predicting high CAC > 1000 was c = 0.84 (p < 0.001; 95 %CI: 0.771--0.91). For moderate-to-severe AoArCa, accuracy was c = 0.792 (p < 0.001). The intermodality agreement between CT and X-Ray based AoArCa Scores was good (r = 0.824, p < 0.001); ICC = 0.902. For X-ray, AUC was c = 0.715 to predict CAC > 1000 (p < 0.001). In regression models, only moderate-or-severe AoArCa, but not the other CVRF predicted CAC > 1000 (p < 0.001), and there was an association of the number of CVRF.

CONCLUSIONS

Patients with moderate-to-severe aortic arch calcification have a high probability of CAC > 1000AU, but not those with no, minimal and mild. The absence of AoArCa rules out CAC > 1000AU. AoArCa severity may serve as valuable tool for selecting the diagnostic strategy.

Relationship between Coronary Artery Calcium Score and Coronary Stenosis

Background

The coronary artery calcium score (CACS) is commonly employed to quantify the degree of calcification in coronary atherosclerosis. Indeed, increased coronary stenosis severity is associated with a progressive increase in CACS.

Objectives

This study sought to explore the association between CACS and coronary stenosis of ≥50% and ≥70%.

Methods

We conducted a retrospective analysis of patient data collected between July 1, 2017, and March 3, 2022, at Jiangmen Central Hospital. A total of 208 patients, presenting with both symptomatic and asymptomatic manifestations and suspected coronary artery disease (CAD), were included. Statistical analyses included ROC curve assessments, subgroup analyses based on age, and comparisons of CACS values against the presence of coronary stenosis ≥50% and ≥70%.

Results

Ultimately, 208 patients were included, with a median age of 65.0 years and a median CACS of 115.7 (interquartile range: 13.7-369.4). A CACS threshold of ≥1300 demonstrated a specificity of 100% for coronary stenosis of ≥50%. Notably, the percentage of patients with obstructive CAD showing CACS = 0 was significantly higher in those under 65 years (15.1%) compared to patients over 65 years (3.8%) (P=0.005). The inflection point, at which the risk probability for coronary stenosis of ≥50% shifted from being a protective factor to a risk factor, was observed when CACS fell within the range of 63.3 to 66.0.

Conclusion

CACS demonstrates good performance for the detection of coronary artery stenosis.

Subtraction Improves the Accuracy of Coronary CT Angiography in Patients with Severe Calcifications in Identifying Moderate and Severe Stenosis: A Multicenter Study

RATIONALE AND OBJECTIVES

To investigate the diagnostic accuracy of subtraction coronary computed tomographic angiography (CCTAsub) in identifying ≥ 50% and ≥ 70% coronary stenosis in patients with different degrees of calcification.

MATERIALS AND METHODS

In this study, 180 patients with coronary calcified plaques who underwent both coronary CT angiography and invasive coronary angiography (ICA) were prospectively enrolled at five centers. Patients were divided into three groups according to the Agatston score: group A (low to moderate, < 400), group B (high, 400-999), and group C (very high, ≥ 1000). Diagnostic accuracies estimated by area under the receiver operating characteristic curve (AUC) were compared between conventional CCTA (CCTAcon) and CCTAsub, with ICA as a reference standard.

RESULTS

There were 86 patients in group A, 44 in group B, and 50 in group C. In identifying ≥ 70% coronary stenosis, subtraction improved the diagnostic accuracies on a per-segment basis in group B (AUC: 0.80 vs 0.92, p = 0.001) and group C (AUC: 0.75 vs 0.84, p = 0.001) after subtraction. When identifying ≥ 50% coronary stenosis, the per-segment AUC of CCTAsub in group B and C were significantly higher than that in CCTAcon (group B: 0.81 vs 0.92, p < 0.001; group C: 0.77 vs 0.88, p < 0.001). However, no improvement was observed in group A.

CONCLUSION

Subtraction achieved better diagnostic accuracy in patients with Agatston score ≥ 400, both in identifying ≥ 50% and ≥ 70% coronary stenosis, which was instructive for the application of subtraction in clinical practice.

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC).

AIM

To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients.

METHODS

Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization.

RESULTS

Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065).

CONCLUSIONS

Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.

The Value of Coronary Computed Tomography Angiography in Patients with a High Calcium Score

Background

We aimed to assess the agreement between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) to determine whether patients with a high coronary artery calcium score (CS) would benefit from CCTA.

Methods

This cross-sectional study was conducted on patients suspected of having coronary artery disease. The patients underwent calcium scoring. The total CS and the number of calcified foci were determined. The calcium score index (CSI) was defined, and coronary arteries were evaluated by CCTA. ICA was performed, and reports of ICA were extracted. All the abovementioned variables were compared. For data analysis, the κ coefficient and the ROC curve were used.

Results

The study population consisted of 195 patients: 124 men (63.6%) and 71 women (36.4%). The median (IQR) value of CS was 529 (229-1042), ranging from 17 to 4717. In all 195 patients, the concordance between the final impression of CCTA and ICA was 90.2%, while the number and type of involved territories were similar at 57.9%. The highest agreement was seen in the left main and right coronary arteries, whereas the lowest agreement was detected in the left anterior descending and the left circumflex artery. The patients were categorized into different CS groups, and in those with a high CS (>1000), the agreement between CCTA and ICA concerning final impression and involved territories was similar to the whole group of patients.

Conclusion

CCTA in patients with a high CS, even exceeding 1000, remains beneficial as the noninvasive available method.

Evaluation of long-term outcomes of percutaneous coronary intervention in patients with moderate to severe calcified coronary artery lesions

Background and Aims

Coronary artery calcification reduces elasticity and can cause hemodynamic disturbances, increasing the risk of cardiovascular complications. Furthermore, coronary calcifications make cardiovascular interventions difficult. The present study aimed to study the cardiovascular outcomes of the coronary intervention of calcified lesions in the Iranian population.

Methods

The present cross-sectional study evaluated patients with moderate to severe calcified coronary artery lesions on angiography who were candidates for percutaneous coronary intervention (PCI). Demographic, echocardiographic, and angiographic data of the patients were recorded. In addition, clinical outcomes, including mortality, myocardial infarction, stroke, and stent thrombosis, were also measured 1 year after the procedure.

Results

A total of 125 participants (65% male and 35% female) with a median age of 69 (13.0) years old were enrolled. The most common calcification degree was 270° (43.5%), followed by 360° (35.5%) and 180° (21.0%). Most patients had thrombolysis in myocardial infarction (TIMI) score of 3 (47.6%). A more than 10% residual coronary minimum lumen diameter was seen in 25.8% of patients. Puncture site hemorrhage and contrast-induced nephropathy were observed in 2 (1.6%) and 1 (0.8%) patients, respectively. Following 1 year after PCI, no cases of mortality, cerebrovascular accident, myocardial infarction, and stent thrombosis were reported. Furthermore, we observed one case of heart failure (0.8%) and target lesion revascularization (0.8%). In addition, we revealed a significant relationship between calcification degree and TIMI (p < 0.001) and body mass index (p = 0.049).

Conclusion

Percutaneous management of calcified lesions with noncompliant balloon and one or two guidewires was associated with a good success rate and few complications.

New Contrast Media for K-Edge Imaging With Photon-Counting Detector CT

ABSTRACT

The recent technological developments in photon-counting detector computed tomography (PCD-CT) and the introduction of the first commercially available clinical PCD-CT unit open up new exciting opportunities for contrast media research. With PCD-CT, the efficacy of available iodine-based contrast media improves, allowing for a reduction of iodine dosage or, on the other hand, an improvement of image quality in low contrast indications. Virtual monoenergetic image reconstructions are routinely available and enable the virtual monoenergetic image energy to be adapted to the diagnostic task.A key property of PCD-CT is the ability of spectral separation in combination with improved material decomposition. Thus, the discrimination of contrast media from intrinsic or pathological tissues and the discrimination of 2 or more contrasting elements that characterize different tissues are attractive fields for contrast media research. For these approaches, K-edge imaging in combination with high atomic number elements such as the lanthanides, tungsten, tantalum, or bismuth plays a central role.The purpose of this article is to present an overview of innovative contrast media concepts that use high atomic number elements. The emphasis is on improving contrast enhancement for cardiovascular plaque imaging, stent visualization, and exploring new approaches using 2 contrasting elements. Along with the published research, new experimental findings with a contrast medium that incorporates tungsten are included.Both the literature review and the new experimental data demonstrate the great potential and feasibility for new contrast media to significantly increase diagnostic performance and to enable new clinical fields and indications in combination with PCD-CT.

Coronary artery calcification-does it predict the CAD-RADS category?

Purpose

Coronary calcium scores (CCSs) in cardiac-gated computed tomography (CCT) are diagnostic for coronary artery disease (CAD). This study aims to investigate if CCSs can foretell CAD-reporting and data system (CAD-RADS) without performing computed tomography angiography (CTA).

Methods

Profiles of 544 patients were studied who had gone through CCT and CTA; the number of calcified regions of interest (ROIs), the Agatston, area, volume, and mass CCSs were calculated. Among the CAD-RADS categories (1 to 5), the mean values were compared for each CCS separately. A cut-offfor each CCS was declared using ROC curve analysis, more than which could predict significant CAD (CAD-RADS 3 to 5). Also, logistic regression models indicated the most probable CAD-RADS category based on the CCSs. P < 0.05 was considered significant.

Results

Among 53% male and 47% female participants with a mean (SD) age of 62.57 (0.84) years, numbers of calcified ROIs were significantly different between each pair of CAD-RADS categories. While other CCSs did not show a significant difference between CAD-RADS 1 and 2 or 2 and 3. All CCSs were significantly different between the non-significant and significant CAD groups; cut-offs for the number of calcified ROIs, the Agatston, area, volume, and mass scores were 9, 128, 44mm², 111mm³, and 22 mg, respectively. Formulae A and B predicted the most probable CAD-RADS category (accuracy: 79%) and the probability of significant/non-significant CAD (accuracy: 81%), respectively.

Conclusion

CCSs could predict CAD-RADS with an accuracy of 80%. Further studies are needed to introduce more predictive calcium indices.

The Journal of cardiovascular computed tomography: A year in review 2021

This review aims to summarize original articles published in the Journal of Cardiovascular Computed Tomography (JCCT) for the year 2021, focusing on those that had the most scientific and educational impact. The JCCT continues to expand; the number of submissions, published manuscripts, cited articles, article downloads, social media presence, and impact factor continues to increase. The articles selected by the Editorial Board of the JCCT in this review focus on coronary artery disease, coronary physiology, structural heart disease, and technical advances in cardiovascular CT. In addition, we highlight key consensus documents and guidelines published in the Journal in 2021. The Journal recognizes the tremendous work done by each author and reviewer this year - thank you.

Diagnostic accuracy of coronary computed tomography angiography for the evaluation of obstructive coronary artery disease in patients referred for transcatheter aortic valve implantation: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic accuracy of coronary computed tomography angiography (CCTA) for the evaluation of obstructive coronary artery disease (CAD) in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS

EMBASE, PubMed/MEDLINE, and CENTRAL were searched for studies reporting accuracy of CCTA for the evaluation of obstructive CAD compared with invasive coronary angiography (ICA) as the reference standard. QUADAS-2 tool was used to assess the risk of bias. A bivariate random effects model was used to analyze, pool, and plot the diagnostic performance measurements across studies. Pooled sensitivity, specificity, positive ( + LR) and negative (-LR) likelihood ratio, diagnostic odds ratio (DOR), and hierarchical summary ROC curve (HSROC) were evaluated. Prospero registration number: CRD42021252527.

RESULTS

Fourteen studies (2533 patients) were included. In the intention-to-diagnose patient-level analysis, sensitivity and specificity for CCTA were 97% (95% CI: 94-98%) and 68% (95% CI: 56-68%), respectively, and + LR and -LR were 3.0 (95% CI: 2.1-4.3) and 0.05 (95% CI: 0.03 - 0.09), with DOR equal to 60 (95% CI: 30-121). The area under the HSROC curve was 0.96 (95% CI: 0.94-0.98). No significant difference in sensitivity was found between single-heartbeat and other CT scanners (96% (95% CI: 90 - 99%) vs. 97% (95% CI: 94-98%) respectively; p = 0.37), whereas the specificity of single-heartbeat scanners was higher (82% (95% CI: 66-92%) vs. 60% (95% CI: 46 - 72%) respectively; p < 0.0001). Routine CCTA in the pre-TAVI workup could save 41% (95% CI: 34 - 47%) of ICAs if a disease prevalence of 40% is assumed.

CONCLUSIONS

CCTA proved an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI; the use of single-heartbeat CT scanners can further improve these findings.

KEY POINTS

• CCTA proved to have an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI. • Routine CCTA in the pre-TAVI workup could save more than 40% of ICAs. • Single-heartbeat CT scanners had higher specificity than others in the assessment of obstructive CAD in patients referred for TAVI.

Prognostic Value of Computed Tomography-Derived Fractional Flow Reserve Comparison With Myocardial Perfusion Imaging

OBJECTIVES

The aim of this study was to compare the incremental prognostic value of coronary computed tomography (CT) angiography (CCTA)-derived machine learning fractional flow reserve CT (ML-FFRct) versus that of ischemia detected on single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) on incident cardiovascular outcomes.

BACKGROUND

SPECT MPI and ML-FFRct are noninvasive tools that can assess the hemodynamic significance of coronary atherosclerotic disease.

METHODS

We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and SPECT MPI. ML-FFRct was computed using a ML prototype. The primary outcome was all-cause mortality and nonfatal myocardial infarction (D/MI), and the secondary outcome was D/MI and unplanned revascularization, percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) occurring more than 90 days postimaging. Multiple nested multivariate cox regression was used to model a scenario wherein an initial anatomical assessment was followed by a functional assessment.

RESULTS

A total of 471 patients (mean age: 64 ± 13 year; 53% males) were included. Comorbidities were prevalent (78% hypertension, 66% diabetes, 81% dyslipidemia). ML-FFRct was <0.8 in at least 1 proximal/midsegment was present in 41.6% of patients, and ischemia on MPI was present in 13.8%. After a median follow-up of 18 months, 7% of patients (n = 33) experienced D/MI. On multivariate Cox proportional analysis, the presence of ischemia on MPI but not ML-FFRct significantly predicted D/MI (HR: 2.3; 95% CI: 1.0-5.0; P = 0.047; or HR: 0.7; 95% CI: 0.3-1.4; P = 0.306 respectively) when added to CCTA obstructive stenosis. Furthermore, the model with SPECT ischemia had higher global chi-square result and significantly improved reclassification. Results were similar using the secondary outcome and on several sensitivity analyses.

CONCLUSIONS

In a high-risk patient cohort, SPECT MPI but not ML-FFRct adds independent and incremental prognostic information to CCTA-based anatomical assessment and clinical risk factors in predicting incident outcomes.

Resource implications following expansion of computed tomography coronary angiography: An Australian experience

INTRODUCTION

To determine the downstream utilisation of Computed Tomography Coronary Angiography (CTCA) in a single Australian tertiary centre.

METHODS

A single-centre retrospective study analysed 1460 patients undergoing CTCA between 1st January 2015 to 31st December 2018 at a tertiary hospital in Victoria, Australia, with a catchment area of 500,000 people. The coronary stenosis grading, plaque characteristics and coronary calcium score were identified. The downstream impact was assessed by measuring the number of stress echocardiograms, myocardial perfusion scans (MPS), invasive coronary angiograms and subsequent revascularisations.

RESULTS

The number of CTCA's performed steadily increased from 59 in 2015 to 395, 461 and 545 in 2016, 2017 and 2018 respectively. Seven hundred and fifty-seven (52%) were females, and 703 (48%) males with 724 (50%) normal CTCA studies. The number of downstream stress echocardiogram performed each year was 2, 60, 46 and 16, respectively, accompanied by MPS numbers of 0, 21, 29, and 18. There were 9, 37, 57 and 64 invasive coronary angiograms with 1, 13, 19 and 22 corresponding revascularisations. Despite small increases in absolute numbers of patients presenting with chest pain (from 2678 in 2015 to 3660 in 2018), there was a significant increase in downstream further testing from 11 in 2015 to 98 in 2018.

CONCLUSION

The use of CTCA expansion has resulted in an increase in downstream testing. Therefore, resource planning with regards to CTCA expansion will have to account for increased rates of functional testing, invasive angiography and revascularisation.