Diagnostic value of coronary CT angiography in comparison with invasive coronary angiography and intravascular ultrasound in patients with intermediate coronary artery stenosis: results from the prospective multicentre FIGURE-OUT (Functional Imaging criteria for GUiding REview of invasive coronary angiOgraphy, intravascular Ultrasound, and coronary computed Tomographic angiography) study

Stent sizing by coronary CT angiography compared with optical coherence tomography

BACKGROUND

Coronary CT angiography (CCTA) is well-established for diagnosis and stratification of coronary artery disease (CAD). Its usefulness in guiding percutaneous coronary interventions (PCI) and stent sizing is unknown.

METHODS

This is a sub-analysis of the Precise Percutaneous Coronary Intervention Plan (P3) study (NCT03782688). We analyzed 65 vessels with matched CCTA and pre-PCI optical coherence tomography (OCT) assessment. The CCTA-guided stent size was defined by the mean distal reference lumen diameter rounded up to the nearest stent diameter. The OCT lumen-guided stent size was the mean distal reference lumen diameter rounded to the closest stent diameter. The agreement on stent diameters was determined with Kappa statistics, Passing-Bablok regression analysis, and the Bland-Altman method.

RESULTS

The distal reference lumen diameter by CCTA and OCT were 2.75 ​± ​0.53 ​mm and 2.72 ​± ​0.55 ​mm (mean difference 0.06, limits of agreement -0.7 to 0.82). There were no proportional or systematic differences (coefficient A 1.06, 95% CI 0.84 to 1.3 and coefficient B -0.22, 95% CI -0.83 to 0.36) between methods. The agreement between the CCTA and OCT stent size was substantial (Cohen's weighted Kappa 0.74, 95% CI 0.64 to 0.85). Compared to OCT stent diameter, CCTA stent size was concordant in 52.3% of the cases; CCTA overestimated stent size in 20.0% and underestimated in 27.7%.

CONCLUSION

CCTA accurately assessed the reference vessel diameter used for stent sizing. CCTA-based stent sizing showed a substantial agreement with OCT. CCTA allows for PCI planning and may aid in selecting stent diameter.

Atherosclerosis evaluation and cardiovascular risk estimation using coronary computed tomography angiography

Clinical risk scores based on traditional risk factors of atherosclerosis correlate imprecisely to an individual's complex pathophysiological predisposition to atherosclerosis and provide limited accuracy for predicting major adverse cardiovascular events (MACE). Over the past two decades, computed tomography scanners and techniques for coronary computed tomography angiography (CCTA) analysis have substantially improved, enabling more precise atherosclerotic plaque quantification and characterization. The accuracy of CCTA for quantifying stenosis and atherosclerosis has been validated in numerous multicentre studies and has shown consistent incremental prognostic value for MACE over the clinical risk spectrum in different populations. Serial CCTA studies have advanced our understanding of vascular biology and atherosclerotic disease progression. The direct disease visualization of CCTA has the potential to be used synergistically with indirect markers of risk to significantly improve prevention of MACE, pending large-scale randomized evaluation.

Non-Contrast and Contrast-Enhanced Cardiac Computed Tomography Imaging in the Diagnostic and Prognostic Evaluation of Coronary Artery Disease

In recent decades, cardiac computed tomography (CT) has emerged as a powerful non-invasive tool for risk stratification, as well as the detection and characterization of coronary artery disease (CAD), which remains the main cause of morbidity and mortality in the world. Advances in technology have favored the increasing use of cardiac CT by allowing better performance with lower radiation doses. Coronary artery calcium, as assessed by non-contrast CT, is considered to be the best marker of subclinical atherosclerosis, and its use is recommended for the refinement of risk assessment in low-to-intermediate risk individuals. In addition, coronary CT angiography (CCTA) has become a gate-keeper to invasive coronary angiography (ICA) and revascularization in patients with acute chest pain by allowing the assessment not only of the extent of lumen stenosis, but also of its hemodynamic significance if combined with the measurement of fractional flow reserve or perfusion imaging. Moreover, CCTA provides a unique incremental value over functional testing and ICA by imaging the vessel wall, thus allowing the assessment of plaque burden, composition, and instability features, in addition to perivascular adipose tissue attenuation, which is a marker of vascular inflammation. There exists the potential to identify the non-obstructive lesions at high risk of progression to plaque rupture by combining all of these measures.

Endothelial shear stress computed from coronary computed tomography angiography: A direct comparison to intravascular ultrasound

INTRODUCTION

Intravascular ultrasound (IVUS) studies have shown that biomechanical variables, particularly endothelial shear stress (ESS), add synergistic prognostic insight when combined with anatomic high-risk plaque features. Non-invasive risk assessment of coronary plaques with coronary computed tomography angiography (CCTA) would be helpful to enable broad population risk-screening.

AIM

To compare the accuracy of ESS computation of local ESS metrics by CCTA vs IVUS imaging.

METHODS

We analyzed 59 patients from a registry of patients who underwent both IVUS and CCTA for suspected CAD. CCTA images were acquired using either a 64- or 256-slice scanner. Lumen, vessel, and plaque areas were segmented from both IVUS and CCTA (59 arteries, 686 3-mm segments). Images were co-registered and used to generate a 3-D arterial reconstruction, and local ESS distribution was assessed by computational fluid dynamics (CFD) and reported in consecutive 3-mm segments.

RESULTS

Anatomical plaque characteristics (vessel, lumen, plaque area and minimal luminal area [MLA] per artery) were correlated when measured with IVUS and CCTA: 12.7 ​± ​4.3 vs 10.7 ​± ​4.5 ​mm2, r ​= ​0.63; 6.8 ​± ​2.7 vs 5.6 ​± ​2.7 ​mm2, r ​= ​0.43; 5.9 ​± ​2.9 vs 5.1 ​± ​3.2 ​mm2, r ​= ​0.52; 4.5 ​± ​1.3 vs 4.1 ​± ​1.5 ​mm2, r ​= ​0.67 respectively. ESS metrics of local minimal, maximal, and average ESS were also moderately correlated when measured with IVUS and CCTA (2.0 ​± ​1.4 vs 2.5 ​± ​2.6 ​Pa, r ​= ​0.28; 3.3 ​± ​1.6 vs 4.2 ​± ​3.6 ​Pa, r ​= ​0.42; 2.6 ​± ​1.5 vs 3.3 ​± ​3.0 ​Pa, r ​= ​0.35, respectively). CCTA-based computation accurately identified the spatial localization of local ESS heterogeneity compared to IVUS, with Bland-Altman analyses indicating that the absolute ESS differences between the two CCTA methods were pathobiologically minor.

CONCLUSION

Local ESS evaluation by CCTA is possible and similar to IVUS; and is useful for identifying local flow patterns that are relevant to plaque development, progression, and destabilization.

Outcomes of Functional Testing Versus Invasive Cardiac Catheterization for the Evaluation of Intermediate Severity Coronary Stenosis Detected on Cardiac Computed Tomography Angiography

INTRODUCTION

The aim of this study was to evaluate the effectiveness of functional testing in comparison to invasive coronary angiography (ICA) among acute chest pain patients whose first diagnostic modality was a coronary computed tomography angiogram (CCTA) and were found to have intermediate coronary stenosis, defined as 50%-70% luminal stenosis.

METHODS

We conducted a retrospective review of 4763 acute chest pain patients ≥18 years old who received a CCTA as the initial diagnostic modality. Of these, 118 patients met enrollment criteria and proceeded to either stress test (80/118) or directly to ICA (38/118). The primary outcome was 30-day major adverse cardiac event, consisting of acute myocardial infarction, urgent revascularization, or death.

RESULTS

There was no difference in 30-day major adverse cardiac event among patients who underwent initial stress testing versus directly referred to ICA (0% vs. 2.6%, P = 0.322) following CCTA. The rate of revascularization without acute myocardial infarction was significantly higher among those who underwent ICA versus stress test [36.8% vs. 3.8%, P < 0.0001; adjusted odds ratio: 9.6, 95% confidence interval, 1.8-49.6]. Patients who underwent ICA had a higher rate of catheterization without revascularization within 30 days of the index admission in comparison to those who underwent initial stress testing (55.3% vs. 12.5%, P < 0.0001; adjusted odds ratio: 26.7, 95% confidence interval, 6.6-109.5).

CONCLUSION

Among patients with intermediate coronary stenosis on CCTA, a functional stress test compared with ICA may prevent unnecessary revascularization and improve cardiac catheterization yield without negatively affecting the 30-day patient safety profile.

Recent Trends in Artificial Intelligence-Assisted Coronary Atherosclerotic Plaque Characterization

Coronary artery disease is a major cause of morbidity and mortality worldwide. Its underlying histopathology is the atherosclerotic plaque, which comprises lipid, fibrous and—when chronic—calcium components. Intravascular ultrasound (IVUS) and intravascular optical coherence tomography (IVOCT) performed during invasive coronary angiography are reference standards for characterizing the atherosclerotic plaque. Fine image spatial resolution attainable with contemporary coronary computed tomographic angiography (CCTA) has enabled noninvasive plaque assessment, including identifying features associated with vulnerable plaques known to presage acute coronary events. Manual interpretation of IVUS, IVOCT and CCTA images demands scarce physician expertise and high time cost. This has motivated recent research into and development of artificial intelligence (AI)-assisted methods for image processing, feature extraction, plaque identification and characterization. We performed parallel searches of the medical and technical literature from 1995 to 2021 focusing respectively on human plaque characterization using various imaging modalities and the use of AI-assisted computer aided diagnosis (CAD) to detect and classify atherosclerotic plaques, including their composition and the presence of high-risk features denoting vulnerable plaques. A total of 122 publications were selected for evaluation and the analysis was summarized in terms of data sources, methods—machine versus deep learning—and performance metrics. Trends in AI-assisted plaque characterization are detailed and prospective research challenges discussed. Future directions for the development of accurate and efficient CAD systems to characterize plaque noninvasively using CCTA are proposed.

Challenges in Utilizing CT Coronary Angiography and CT Calcium Scoring to Determine Aeromedical Fitness for Aicrew: A Tale of 3 CTs

The management of coronary artery disease (CAD) in aviators remains as one of the dominant preoccupation in determining vocational fitness. With the emerging awareness and accessibility of non-invasive modalities for assessing CAD, there is an increasing likelihood that aircrew may have undergone some form of functional or anatomic assessment of the coronary circulation, prior to their presentation to the aviation medical examination office. In particular, computer tomographic coronary angiography (CTCA) and CT coronary artery calcium scoring (CACS) had gained significant traction in recent years, as novel scanning algorithms had enabled faster, safer and more affordable imaging. However, the utilization of CTCA and CACS are not without challenges. Against this backdrop, this paper presents three clinical vignettes of aviators who presented to our cardiac department for specialist evaluation and the eventual aeromedical dispositions. The paper also discusses the evolving opportunities and issues in the application of CTCA and CACS findings to aeromedical risk assessment in aviators.

Simultaneous assessment of coronary stenosis relevance with automated computed tomography angiography and intravascular ultrasound analyses and fractional flow reserve

OBJECTIVES

To assess the diagnostic performance of computed tomography angiography (CTA) and intravascular ultrasound (IVUS) derived minimum lumen areas (MLA) from the same lesions that correspond to an FFR ≤0.80.

METHODS AND RESULTS

A total of 24 patients (33 arteries) were collected retrospectively according to the following inclusion criteria: presence of a CTA diagnostic followed by an IVUS and FFR percutaneous coronary procedures. CTA and IVUS lumen contours were automatically performed using previously validated methods.The correlation between CTA and IVUS for the MLA was r = 0.45. In terms of MLA, the mean difference between CTA and IVUS was 0.81 mm2. Of note, a much smaller CTA-derived MLA (2.10 mm2) was found to be related to significant FFR lesions compared to that of the MLA derived from IVUS (3.19 mm2). The area under the curve, accuracy, sensitivity and specificity for this CTA-derived MLA were 0.80, 0.76, 0.50 and 0.87, respectively, while these values for IVUS-derived MLA were 0.87, 0.85, 0.80 and 0.87.

CONCLUSIONS

Computed tomography angiography and intravascular ultrasound-derived minimum lumen areas have moderate diagnostic efficiency, albeit slightly better for IVUS, in identifying hemodynamically severe coronary stenoses. The utility of MLA, automatically derived from either CTA or IVUS as an alternative to FFR to guide the decision to revascularize, should be tested clinically.

Coronary arterial geometry: A comprehensive comparison of two imaging modalities

The characterization of vascular geometry is a fundamental step towards the correct interpretation of coronary artery disease. In this work, we report a comprehensive comparison of the geometry featured by coronary vessels as obtained from coronary computed tomography angiography (CCTA) and the combination of intravascular ultrasound (IVUS) with bi-plane angiography (AX) modalities. We analyzed 34 vessels from 28 patients with coronary disease, which were deferred to CCTA and IVUS procedures. We discuss agreement and discrepancies between several geometric indexes extracted from vascular geometries. Such an analysis allows us to understand to which extent the coronary vascular geometry can be reliable in the interpretation of geometric risk factors, and as a surrogate to characterize coronary artery disease.

Extraction of Coronary Atherosclerotic Plaques From Computed Tomography Imaging: A Review of Recent Methods

Background: Atherosclerotic plaques are the major cause of coronary artery disease (CAD). Currently, computed tomography (CT) is the most commonly applied imaging technique in the diagnosis of CAD. However, the accurate extraction of coronary plaque geometry from CT images is still challenging.

Summary of Review: In this review, we focused on the methods in recent studies on the CT-based coronary plaque extraction. According to the dimension of plaque extraction method, the studies were categorized into two-dimensional (2D) and three-dimensional (3D) ones. In each category, the studies were analyzed in terms of data, methods, and evaluation. We summarized the merits and limitations of current methods, as well as the future directions for efficient and accurate extraction of coronary plaques using CT imaging.

Conclusion: The methodological innovations are important for more accurate CT-based assessment of coronary plaques in clinical applications. The large-scale studies, de-blooming algorithms, more standardized datasets, and more detailed classification of non-calcified plaques could improve the accuracy of coronary plaque extraction from CT images. More multidimensional geometric parameters can be derived from the 3D geometry of coronary plaques. Additionally, machine learning and automatic 3D reconstruction could improve the efficiency of coronary plaque extraction in future studies.

Influence of different physiological hemodynamics on fractional flow reserve values in the left coronary artery and right coronary artery

BACKGROUND

Although the left coronary artery (LCA) has a flow profile in that most blood flow occurs during diastole rather than systole, the right coronary artery (RCA) has a flow pattern that is less diastolic dominant. This study assessed whether coronary pressure waveforms distal to stenoses with the same fractional flow reserve (FFR) was the same between the LCA and RCA.

METHODS

A total of 347 vessels from 318 patients who underwent FFR measurements were included. Conventional FFR was calculated as the ratio of the mean coronary distal pressure (Pd) to the mean aortic pressure (Pa) at maximal hyperemia. The pressure drop ratios in systole (PDR_systole) and diastole (PDR_diastole) were calculated as the sum of (Pa minus Pd) divided by the sum of Pa at the intracoronary diastolic and systolic pressure phases, respectively.

RESULTS

Analysis of covariance of the regression line of correlation between conventional FFR and PDR_systole revealed that the slope was significantly greater in the RCA than in the left anterior descending artery (LAD) and left circumflex artery (LCX) (-0.765, -0.578, and -0.589, p < 0.001). On the other hand, the regression line of correlation between conventional FFR and PDR_diastole found that the slope was significantly greater in the LAD and LCX than in the RCA (-1.349, -1.318, and -1.223, p < 0.001).

CONCLUSIONS

The pressure waveform distal to the stenosis differs between the LCA and RCA. In the LCA, the decrease in diastolic pressure mainly contributed to the drop in FFR, whereas in the RCA, it was the decrease in systolic pressure.

Mechanisms of gradual pressure drop in angiographically normal left anterior descending and right coronary artery: Insights from wave intensity analysis

BACKGROUND

This study evaluated the mechanism of decline in coronary pressure from the proximal to the distal part of the coronary arteries in the left anterior descending (LAD) versus the right coronary artery (RCA) from the insight of coronary hemodynamics using wave intensity analysis (WIA).

METHODS

Twelve patients with angiographically normal LAD and RCA were prospectively enrolled. Distal coronary pressure, mean aortic pressure, and average peak velocity were measured at 4 different positions: 9, 6, 3, and 0 cm distal from each coronary ostium.

RESULTS

The distal-to-proximal coronary pressure ratio during maximum hyperemia gradually decreased in proportion to the distance from the ostium (0.92±0.03 and 0.98±0.03 at 9 cm distal to the LAD and RCA ostium). WIA showed the dominant forward-traveling compression wave gradually decreased and the backward-traveling suction wave gradually decreased in proportion to the decrease in coronary pressure through the length of the non-diseased LAD but not the RCA.

CONCLUSIONS

The pushing wave and suction wave intensities on WIA were diminished in proportion to the distance from the ostium of the LAD despite the wave intensity not changing across the length of the RCA, which may lead to gradual intracoronary pressure drop in the angiographically normal LAD.

Validation of Wall Shear Stress Assessment in Non-invasive Coronary CTA versus Invasive Imaging: A Patient-Specific Computational Study

Endothelial shear stress (ESS) identifies coronary plaques at high risk for progression and/or rupture leading to a future acute coronary syndrome. In this study an optimized methodology was developed to derive ESS, pressure drop and oscillatory shear index using computational fluid dynamics (CFD) in 3D models of coronary arteries derived from non-invasive coronary computed tomography angiography (CTA). These CTA-based ESS calculations were compared to the ESS calculations using the gold standard with fusion of invasive imaging and CTA. In 14 patients paired patient-specific CFD models based on invasive and non-invasive imaging of the left anterior descending (LAD) coronary arteries were created. Ten patients were used to optimize the methodology, and four patients to test this methodology. Time-averaged ESS (TAESS) was calculated for both coronary models applying patient-specific physiological data available at the time of imaging. For data analysis, each 3D reconstructed coronary artery was divided into 2 mm segments and each segment was subdivided into 8 arcs (45°).TAESS and other hemodynamic parameters were averaged per segment as well as per arc. Furthermore, the paired segment- and arc-averaged TAESS were categorized into patient-specific tertiles (low, medium and high). In the ten LADs, used for optimization of the methodology, we found high correlations between invasively-derived and non-invasively-derived TAESS averaged over segments (n = 263, r = 0.86) as well as arcs (n = 2104, r = 0.85, p < 0.001). The correlation was also strong in the four testing-patients with r = 0.95 (n = 117 segments, p = 0.001) and r = 0.93 (n = 936 arcs, p = 0.001).There was an overall high concordance of 78% of the three TAESS categories comparing both methodologies using the segment- and 76% for the arc-averages in the first ten patients. This concordance was lower in the four testing patients (64 and 64% in segment- and arc-averaged TAESS). Although the correlation and concordance were high for both patient groups, the absolute TAESS values averaged per segment and arc were overestimated using non-invasive vs. invasive imaging [testing patients: TAESS segment: 30.1(17.1-83.8) vs. 15.8(8.8-63.4) and TAESS arc: 29.4(16.2-74.7) vs 15.0(8.9-57.4) p < 0.001]. We showed that our methodology can accurately assess the TAESS distribution non-invasively from CTA and demonstrated a good correlation with TAESS calculated using IVUS/OCT 3D reconstructed models.

The three-dimensional speckle tracking echocardiography in distinguishing between ischaemic and non-ischaemic aetiology of heart failure

Aims

The aim of this pilot study was to compare selected three‐dimensional speckle tracking echocardiography (3D STE) parameters in patients with ischaemic and non‐ischaemic aetiology of heart failure (HF) and to identify indices that can differentiate the two pathologies.

Methods and results

Forty patients with left ventricular ejection fraction (LVEF) ≤ 40% were included to the study: 20 patients (age 63 ± 9.0 years, LVEF 29.0 ± 11.3%) with ischaemic cardiomyopathy and 20 patients (age 64.0 ± 11.0 years, LVEF 27.3 ± 7.5%) with non‐ischaemic cardiomyopathy. All patients underwent two‐dimensional (2D) and three‐dimensional (3D) transthoracic echocardiography. Standard echocardiographic parameters, global longitudinal strain, and rotational parameters of left ventricle (LV) were assessed using 3D speckle tracking (3D STE). There were no differences in standard and STE parameters between the two groups. Among rotational parameters, the LV apical rotation (4.9 ± 3.5° vs. 2.3 ± 2.4°, P = 0.0022) was significantly higher in patients with ischaemic HF. Among all echocardiographic parameters, a cut‐off value of 3.28° (area under the curve 0.78; 95% confidence interval, 0.62 to 0.93) was able to distinguish the ischaemic and non‐ischaemic aetiology of HF with a sensitivity of 80% and specificity of 75%.

Conclusions

This is the first study that compares 3D STE parameters between patients with ischaemic and non‐ischaemic cardiomyopathy. It was proved that the apical rotation was significantly higher in patients with ischaemic cardiomyopathy. Our findings suggest that 3D STE might be useful in non‐invasive differentiation between ischaemic and non‐ischaemic aetiology of HF.

Pilot study of the multicentre DISCHARGE Trial: image quality and protocol adherence results of computed tomography and invasive coronary angiography

OBJECTIVE

To implement detailed EU cardiac computed tomography angiography (CCTA) quality criteria in the multicentre DISCHARGE trial (FP72007-2013, EC-GA 603266), we reviewed image quality and adherence to CCTA protocol and to the recommendations of invasive coronary angiography (ICA) in a pilot study.

MATERIALS AND METHODS

From every clinical centre, imaging datasets of three patients per arm were assessed for adherence to the inclusion/exclusion criteria of the pilot study, predefined standards for the CCTA protocol and ICA recommendations, image quality and non-diagnostic (NDX) rate. These parameters were compared via multinomial regression and ANOVA. If a site did not reach the minimum quality level, additional datasets had to be sent before entering into the final accepted database (FADB).

RESULTS

We analysed 226 cases (150 CCTA/76 ICA). The inclusion/exclusion criteria were not met by 6 of the 226 (2.7%) datasets. The predefined standard was not met by 13 of 76 ICA datasets (17.1%). This percentage decreased between the initial CCTA database and the FADB (multinomial regression, 53 of 70 vs 17 of 75 [76%] vs [23%]). The signal-to-noise ratio and contrast-to-noise ratio of the FADB did not improve significantly (ANOVA, p = 0.20; p = 0.09). The CTA NDX rate was reduced, but not significantly (initial CCTA database 15 of 70 [21.4%]) and FADB 9 of 75 [12%]; p = 0.13).

CONCLUSION

We were able to increase conformity to the inclusion/exclusion criteria and CCTA protocol, improve image quality and decrease the CCTA NDX rate by implementing EU CCTA quality criteria and ICA recommendations.

KEY POINTS

• Failure to meet protocol adherence in cardiac CTA was high in the pilot study (77.6%). • Image quality varies between sites and can be improved by feedback given by the core lab. • Conformance with new EU cardiac CT quality criteria might render cardiac CTA findings more consistent and comparable.

Diagnostic performance of a fast non-invasive fractional flow reserve derived from coronary CT angiography: an initial validation study

AIM

To validate the computed tomography (CT)-derived fractional flow reserve (FFR_CT) that was computed by new, fast, automatic software and to compare the diagnostic accuracy between FFR_CT and stenosis diagnosed at coronary CT angiography (CCTA).

MATERIALS AND METHODS

A total of 110 patients (76 males, 59±9 years) and 125 vessels underwent CCTA. FFR_CT was computed by fast automatic software and compared with invasive FFR. The diagnostic performance between FFR_CT and CCTA-diagnosed stenosis were compared on the per-patient and per-vessel level.

RESULTS

The computational time of FFR_CT is 10±5 minutes (averaged over 125 vessels). The FFR_CT has a good correlation with invasive FFR (r=0.59, p<0.0001) with a small bias of -0.02 (-0.26-0.23). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FFR_CT were 76.5, 89.5, 89.7, and 76.1% on a vessel level. The area under the receiver operating characteristic curve of FFR_CT was higher than CCTA-diagnosed stenosis (0.82 versus 0.72, P=0.034).

CONCLUSION

The computation of FFR_CT is possible and reliable when using the new, fast, automatic software first employed in the present clinical study. The FFR_CT has a good correlation with invasive FFR and provides better diagnostic performance than CCTA-diagnosed stenosis.

Platelet to lymphocyte ratio predicts all-cause mortality in patients with carotid arterial disease

BACKGROUND

Platelet to lymphocyte ratio (PLR) has been demonstrated as a risk and prognostic marker in many of cardiovascular diseases. A relationship between PLR and severity of carotid stenosis has been shown. The aim of our study was to investigate the relationship between PLR and all cause mortality in patients with carotid arterial disease.

METHODS

This retrospective study included 146 patients who had been performed selective carotid angiography. Carotid stenosis were graded by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Platelet to lymphocyte ratio was calculated as the ratio of platelets to lymphocytes. The end point of the study was all-cause mortality.

RESULTS

During median follow-up of 16 months (0-65 months) 15 (10.3%) patients suffered all-cause mortality. 50 patients (34.2%) underwent carotid endarterectomy and 69 patients (47.3%) had non-carotid cardiac surgery. 38 patients (26.02%) had cerebrovascular events (stroke/transient ischemic attack) at admission. NASCET grades were not different between survivors and non-survivors. Non-survivors had significantly lower hemoglobin (Hb) levels (12.7 ± 1.6 g/dL vs. 13.7 ± 1.7 g/dL, p = 0.031) and they were older than survivors (74.2 ± 8.4 years vs. 68.6 ± 8.5 years, p = 0.029). Non-survivors had significantly higher PLR values compared with survivors (190.3 ± 85.6 and 126.8 ± 53.8, p = 0.017). In multivariate analysis, only PLR predicted all-cause mortality in patients with carotid artery stenosis.

CONCLUSION

In our study, higher PLR was associated with increased all-cause mortality.

Plaque Volume and Morphology are Associated with Fractional Flow Reserve Derived from Coronary Computed Tomography Angiography

Aim: Coronary computed tomography angiography (CCTA)-derived fractional flow reserve (FFRCT) accurately diagnoses ischemic lesions of intermediate stenosis severity. However, significant determinants of FFRCT have not been fully evaluated.

Methods: This was a sub-analysis of the Treatment of Alogliptin on Coronary Atherosclerosis Evaluated by Computed Tomography-Based Fractional Flow Reserve trial. Thirty-nine diabetic patients (117 vessels) with intermediate coronary artery stenosis [percent diameter stenosis (%DS) <70%] in whom FFRCT was measured were included in this study. CCTA-defined, vessel-based volumetric and morphological characteristics of plaques were examined to determine their ability to predict FFRCT.

Results: Patient-based, multivariate linear regression analysis showed that hemoglobinA1c, triglycerides, and the estimated glomerular filtration rate were significant independent factors associated with FFRCT. Vessel-based, univariate linear regression analysis showed that the total atheroma volume (r = -0.233, p=0.01) and the percentage atheroma volume (PAV) (r = −0.284, p=0.002) as well as %DS (r = −0.316, p=0.006) were significant determinants of FFRCT. Among the plaque components, significant negative correlations were observed between FFRCT and low- (r = −0.248, p=0.007) or intermediate-attenuation plaque volume (r = −0.186, p= 0.045), whereas calcified plaque volume was not associated with FFRCT. In the left anterior descending coronary artery (LAD), the plaque volume of each component was associated with FFRCT.

Conclusions: Plaque volume, PAV, and %DS were significant determinants of FFRCT. Plaque morphology, particularly in LAD, was associated with FFRCT in diabetic patients with intermediate coronary artery stenosis.

Clinical Implications of Moderate Coronary Stenosis on Coronary Computed Tomography Angiography in Patients with Stable Angina

PURPOSE

The present study investigated the diagnostic accuracy and clinical implications of moderate stenosis (50-69%, Coronary Artery Disease Reporting and Data System, grade 3) on coronary computed tomography angiography (CCTA), compared with invasive coronary angiography (ICA).

MATERIALS AND METHODS

Two hundred and seventy-six patients who underwent ICA due to moderate stenosis alone on CCTA were selected from our prospective registry cohort.

RESULTS

Diagnostic concordance between CCTA and ICA was found in only 50 (18%) patients. Among the 396 vessels and 508 segments with moderate stenosis, diagnostic concordance was found in 132 vessels (33%) and 127 segments (25%). Segments with calcified plaque had lower diagnostic concordance than those with mixed or non-calcified plaque (22% vs. 28% vs. 27%, respectively, p=0.001). While calcified plaque burden did not have an influence on severe stenosis (≥70%) on ICA, higher burden of non-calcified plaque was correlated with a greater incidence of ICA-based severe stenosis, which was more frequent in patients with ≥3 segments of non-calcified plaque (75%) than those without non-calcified plaque (22%, p<0.001). Typical angina and mixed or non-calcified plaque were correlated with a higher incidence of under-diagnosis, while the use of next-generation computed tomography scanners reduced the incidence of under-diagnosis. Increased body weight, left circumflex artery involvement, and calcified plaque were independent factors that increased the risk of over-diagnosis of CCTA.

CONCLUSION

The diagnosis of moderate stenosis by CCTA may be limited in estimating the exact degree of ICA-based anatomical stenosis. Unlike calcific burden, non-calcific burden was positively correlated with the presence of severe stenosis on ICA.

Elevated plasma levels of Mac-2 binding protein predict poor cardiovascular outcomes in patients with acute coronary syndrome

BACKGROUND

Mac-2 binding protein (M2BP) is an inflammatory glycoprotein associated with carotid atherosclerosis and all-cause mortality in patients with suspected coronary artery diseases. We aimed to explore the potential association of plasma M2BP levels with unstable plaque morphology and cardiovascular outcomes in patients with acute coronary syndrome (ACS).

PATIENTS AND METHODS

We compared plasma M2BP levels among three groups: 216 patients with ACS, 82 patients with stable angina pectoris, and 50 controls. Angiographic analyses of complex lesions were carried out in patients with ACS and they were followed up prospectively for 12 months for the occurrence of major adverse cardiovascular outcomes (MACEs).

RESULTS

Patients with ACS showed significantly higher plasma levels of M2BP than patients with stable angina pectoris (P<0.001) and controls (P<0.001). M2BP levels correlated positively with the presence (P<0.001) and extent (P=0.005) of complex lesions. During follow-up, 45 (20.8%) cases of MACEs occurred. Survival analysis indicated that high M2BP levels were associated with a poor prognosis (log-rank P=0.008). After Cox multivariate adjustment, plasma M2BP levels remained an independent predictor of MACEs either as a continuous variable (hazard ratio: 1.178, 95% confidence interval: 1.093-1.270, P<0.001) or as a categorical variable (hazard ratio: 2.783, 95% confidence interval: 1.433-5.404, P=0.002).

CONCLUSION

Plasma M2BP levels might be predictive of unstable plaque and were associated independently with poor cardiovascular outcomes in patients with ACS.

A multifunctional CT technology: Reality or illusion for patient risk assessment?

A high-speed, multi-slice coronary computed tomography (CT) imaging has emerged as a promising or clinically available multifunctional technique for the assessment of myocardial ischemia, viability, ischemia-induced cardiac dysfunction, and coronary atherosclerotic alterations in patients with suspected or known coronary artery disease. Despite several technical issues remain to be resolved, cardiac CT imaging will have a reality as a multifunctional modality for guiding physicians in better decision-making for favorable clinical outcomes in patients with suspected coronary artery disease, provided that this imaging technology can contribute to characterization and localization of high-risk coronary atherosclerosis in combination with the quantitative evaluation of functional myocardial ischemia.

Diagnostic Accuracy of Coronary CT Angiography for the Evaluation of Bioresorbable Vascular Scaffolds

OBJECTIVES

The purpose of this study was to assess the diagnostic accuracy of coronary computed tomography angiography (CTA) for bioresorbable vascular scaffold (BVS) evaluation.

BACKGROUND

Coronary CTA has emerged as a noninvasive method to evaluate patients with suspected or established coronary artery disease. The diagnostic accuracy of coronary CTA to evaluate angiographic outcomes after BVS implantation has not been well established.

METHODS

In the ABSORB II (A Bioresorbable Everolimus-Eluting Scaffold Versus a Metallic Everolimus-Eluting Stent II) study, patients were randomized either to receive treatment with the BVS or everolimus-eluting metallic stent. At the 3-year follow-up, 238 patients (258 lesions) treated with BVS underwent coronary angiography with intravascular ultrasound (IVUS) evaluation and coronary CTA. The diagnostic accuracy of coronary CTA was assessed by the area under the receiver-operating characteristic curve with coronary angiography and IVUS as references.

RESULTS

The mean difference in coronary CTA-derived minimal luminal diameter was -0.14 mm (limits of agreement -0.88 to 0.60) with quantitative coronary angiography as reference, whereas the mean difference in minimal lumen area was 0.73 mm² (limits of agreement -1.85 to 3.30) with IVUS as reference. The per-scaffold diagnostic accuracy of coronary CTA for detecting stenosis based on coronary angiography diameter stenosis of ≥50% revealed an area under the receiver-operating characteristic curve of 0.88 (95% confidence interval [CI]: 0.82 to 0.92) with a sensitivity of 80% (95% CI: 28% to 99%) and a specificity of 100% (95% CI: 98% to 100%), whereas diagnostic accuracy based on IVUS minimal lumen area ≤2.5 mm² showed an area under the receiver-operating characteristic curve of 0.83 (95% CI: 0.77 to 0.88) with a sensitivity of 71% (95% CI: 44% to 90%) and a specificity of 82% (95% CI: 75% to 87%). The diagnostic accuracy of coronary CTA was similar to coronary angiography in its ability to identify patients with a significant lesion based on the IVUS criteria (p = 0.75).

CONCLUSIONS

Coronary CTA has good diagnostic accuracy to detect in-scaffold luminal obstruction and to assess luminal dimensions after BVS implantation. Coronary angiography and coronary CTA yielded similar diagnostic accuracy to identify the presence and severity of obstructive disease. Coronary CTA might become the method of choice for the evaluation of patients treated with BVS.

Impact of plaque characteristics on the degree of functional stenosis

Coronary CT angiography (CCTA) is mainly regarded as a gatekeeper for invasive coronary angiography, in face of its widely recognized value to noninvasively rule out significant coronary stenosis. Nevertheless, it is also increasingly recognized that this noninvasive modality can depict several atherosclerotic plaque features and quantify total coronary plaque burden. This opens a new field for cardiac CT, since these atherosclerotic features beyond stenosis severity have been correlated with the degree of functional significance, and are the focus of the present manuscript. Although recently acknowledged and documented in CCTA studies, the relation between plaque burden and functional significance has been previously described using several intracoronary imaging modalities, which are also reviewed in the manuscript, to help put in perspective the relation between anatomy and function in coronary artery disease.

A systematic review of imaging anatomy in predicting functional significance of coronary stenoses determined by fractional flow reserve

Fractional flow reserve (FFR) is the current gold standard to assess the physiological significance of coronary stenoses. With the development of coronary imaging techniques, several anatomic parameters have been investigated in vivo and their associations with FFR have been studied. The aim of this review is to summarize the accuracy of anatomic parameters derived by the present coronary imaging techniques including invasive coronary angiography, coronary computed tomography angiography, intravascular ultrasound and optical coherence tomography, in predicting a significant FFR. The impact of patient characteristics, lesion locations, variability of FFR and imaging resolution on the predictive ability are discussed.

Diagnostic Performance of Intravascular Ultrasound-Derived Minimal Lumen Area to Predict Functionally Significant Non-Left Main Coronary Artery Disease: a Meta-Analysis

BACKGROUND AND OBJECTIVES

Intravascular ultrasound (IVUS)-guided percutaneous coronary intervention frequently results in unnecessary stenting due to the low positive predictive value of IVUS-derived minimal lumen area (MLA) for identification of functionally significant coronary stenosis. We appraised the diagnostic accuracy of IVUS-derived MLA compared with the fractional flow reserve (FFR) to assess intermediate coronary stenosis.

SUBJECTS AND METHODS

We searched MEDLINE and Cochrane databases for studies using IVUS and FFR methods to establish the best MLA cut-off values to predict significant non-left main coronary artery stenosis. Summary estimates were obtained using a random-effects model.

RESULTS

The 17 studies used in our analysis enrolled 3920 patients with 4267 lesions. The weighted overall mean MLA cut-off value was 2.58 mm². The pooled MLA sensitivity that predicted functionally significant coronary stenosis was 0.75 (confidence interval [CI]: 0.72 to 0.77) and the specificity was 0.66 (CI: 0.64 to 0.68). The positive likelihood ratio (LR) was 2.33 (CI: 2.06 to 2.63) and LR (-) was 0.33 (CI: 0.26 to 0.42). The pooled diagnostic odds ratio (DOR) was 7.53 (CI: 5.26 to 10.76) and the area under the summary receiver operating characteristic curve for all the trials was 0.782 with a Q point of 0.720. Meta-regression analysis demonstrated that an FFR cut-off point of 0.75 was associated with a four times higher diagnostic accuracy compared to that of 0.80 (relative DOR: 3.92; 95% CI: 1.25 to 12.34).

CONCLUSION

IVUS-derived MLA has limited diagnostic accuracy and needs careful interpretation to correlate with functionally significant non-left main coronary artery stenosis.

Echocardiographic assessment of myocardial ischemia

Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology.

How to Utilize Coronary Computed Tomography Angiography in the Treatment of Coronary Artery Disease

Coronary computed tomography angiography (CCTA) has high negative predictive power for detecting coronary artery disease. However CCTA is limited by moderate positive predictive power in the detection of myocardial ischemia. This is not unexpected because the diameter of a stenosis is a poor indicator of myocardial ischemia and discrepancy between the severity of stenosis and noninvasive tests is not uncommon. The value of stenosis for predicting future development of acute coronary syndrome represented by plaque rupture has been questioned. CCTA identifies the characteristics of high-risk plaque including positive remodeling, low density plaque and spotty or micro-calcification. Also, additional evaluation of myocardial ischemia using computational flow dynamics, and luminal attenuation gradient are expected to increase both diagnostic performance for hemodynamically significant stenosis and the predictive power for future cardiovascular risk. Technical advances in CCTA would enable evaluation of both coronary artery stenosis and myocardial ischemia simultaneously with high predictive performance, and would improve vastly the clinical value of CCTA.

Quantification of coronary artery Stenosis by Area Stenosis from cardiac CT angiography

Non-invasive cardiac computed tomography angiography (CTA) is widely used to assess coronary artery stenosis and give clinical decision-making support to clinicians. The severity of stenosis lesion is commonly graded by a range of percent Diameter Stenosis (DS), which can introduce false positive diagnoses or over-estimation, triggering unnecessary further procedures. In this paper, a system and the associate methods to quantify stenosis by the percent Area Stenosis (AS) from cardiac CTA is presented. In the process, coronary artery tree is segmented and the centerline is extracted by Hessian filtering and the minimal path method. After a serial of 2D cross-sectional artery images along the artery centerline are obtained, lumen areas are segmented by ellipse-fitting with deformable models, and consequently to compute the lesion's AS. Experimental results on 5 CTA data sets show that compared to DS, AS better correlates to the reference standard for stenosis quantification, suggesting the efficacy of the proposed system.

Accuracy of intravascular ultrasound and optical coherence tomography in identifying functionally significant coronary stenosis according to vessel diameter: A meta-analysis of 2,581 patients and 2,807 lesions

INTRODUCTION

Accuracy of intracoronary imaging to discriminate functionally significant coronary stenosis according to vessel diameter remains to be defined.

METHODS

PubMed, Scopus, and Google Scholar were systematically searched for studies assessing diagnostic accuracy (area under the receiver operating characteristic curve [AUC], the primary end point) and sensitivity and specificity (the secondary end points) of minimal luminal area (MLA) or of minimal luminal diameter (MLD) derived from intravascular ultrasound (IVUS) or optical coherence tomography (OCT) to detect functionally significant stenosis as determined with fractional flow reserve (FFR).

RESULTS

Fifteen studies were included, 2 with 110 patients analyzing only left main (LM), 5 with 224 patients and 306 lesions using OCT, and 9 with 1532 patients and 1681 lesions with IVUS. Median MLA for the OCT studies was 1.96 mm(2) (1.85-1.98 mm(2)), 2.9 mm(2) (2.7-3.1 mm(2)) for MLA of all lesions assessed with IVUS, 2.8 mm(2) (2.7-2.9 mm(2)) for lesions with an angiographic diameter >3 mm, 2.4 mm(2) (2.4-2.5 mm(2)) for lesions <3 mm, and 5.4 mm(2) (5.1-5.6 mm(2)) for LM lesions. For OCT-MLA, AUC was 0.80 (0.74-0.86), with a sensitivity of 0.81 (0.74-0.87) and specificity of 0.77 (0.71-0.83), whereas OCT-MLD had an AUC of 0.85 (0.79-0.91), sensitivity of 0.74 (0.69-0.78), and specificity of 0.70 (0.68-0.73). For IVUS-MLA, AUC was 0.78 (0.75-0.81) for all lesions, 0.78 (0.73-0.84) for vessels with a diameter >3 mm, and 0.79 (0.70-0.89) for those with a diameter <3 mm. Left main AUC was 0.97 (0.93-1).

CONCLUSION

Intravascular ultrasound and OCT had modest diagnostic accuracy for identification hemodynamically significant lesions, also with specific cutoff for different diameters. Invasive imaging for assessment of LM severity demonstrated excellent correlation with FFR. What is already known about this subject? Fractional flow reserve represents the criterion standard to evaluate the prognostic value of coronary stenosis, whereas its relationship with IVUS and OCT remains to be assessed. What does this study add? Despite improvement, IVUS and OCT do not predict functional stenosis, even with dedicated cutoff, apart from LM disease. How might this impact on clinical practice? The recent guidelines of myocardial revascularization have stressed the crucial role of FFR before performing percutaneous coronary intervention on LM, whereas intravascular imaging is often exploited to drive revascularization. The present analysis stresses the point that LM percutaneous coronary intervention may be driven only by intravascular imaging, given the high accuracy for significant ischemic lesions, whereas for other vessels, these 2 techniques mirror 2 different aspects.

Pre-participation and follow-up screening of athletes for endurance sport

Physical activity increases life expectancy and sport is a priori not harmful. Exhausted sporting activity (e.g. endurance running, triathlon, cycling or competitive sport) can lead under individual conditions to negative cardiac remodelling (pathological enlargement/function of cardiac cavities/structures) or in worst case to cardiac arrhythmias and sudden cardiac death (SCD). This individually disposition can be genetically determined or behaviourally/environmentally acquired. Overall competitive young male athletes suffer five-fold higher than non-competitive athletes from sudden death and athletes aged over 30 bear a potential for arrhythmias, atrial fibrillation or a 20-fold higher possibility for SCD as female athletes. Patients with diabetes, coronary disease, obesity or hypertension require different special managements. Screening of cardiorespiratory health for sport activities has a lot of faces. Basically there is a need for indicated examinations or possible preventive measures inside or outside of pre-competition screening. The costs of screening compared to expenditure of whole effort for sporting activities are acceptable or even negligible, but of course dependent on national/regional settings. The various causes and possibilities of screening will be discussed in this article as basic suggestion for an open discussion beyond national borders and settings.

Noninvasive and Invasive Assessments of the Functional Significance of Intermediate Coronary Artery Stenosis: Is This a Matter of Right or Wrong?

Coronary computed tomographic angiography (cCTA) has emerged in recent years as a noninvasive modality to evaluate coronary artery disease. Many studies have revealed the excellent diagnostic accuracy of cCTA when compared with invasive coronary angiography (ICA) or intravascular ultrasound (IVUS). It is generally accepted that the functional significance of coronary artery stenosis is important to make treatment decisions; however, cCTA, ICA, and IVUS are limited in the ability to determine the physiologic significance of coronary stenosis. The FIGURE-OUT study compared the noninvasive and invasive assessment of the functional significance of intermediate coronary artery stenosis.