Association of serum MMP9 with adverse features of plaque progression in patients with chronic coronary syndrome (CCS)

Background

Previous studies have demonstrated that MMP-9 may be a predictor of atherosclerotic plaque instability and future adverse cardiovascular events, but longitudinal data on the association between MMP9 and coronary disease progression are lacking.

Purpose

This study is aimed at investigating whether MMP9 is associated with atherosclerotic plaque progression.

Methods

MMP9 serum levels were measured in stable patients with chronic coronary syndrome (CCS) undergoing coronary computed tomography angiography at baseline and after a period of 6.5±1.1 years of follow up to assess progression of Total, Fibrous, Fibro-fatty, Necrotic Core, and Dense Calcium plaque volume (PV). The relationship of serum MMP9 with plaque progression was assessed using linear regression analysis, adjusting for clinical variables including, age, sex, risk factors, medical therapy, LDL-C, TG/HDL-C ratio, hs-CRP, and the presence of obstructive CAD (>50% coronary stenosis in at least one major coronary vessels).

Results

A total of 157 patients (58±8 years of age; 66% males) were included in the analysis, with median MMP9 values of 135±186 mg/dL (mean ± SD). Annual changes of Total, Fibrous-Fatty and Necrotic Core PV were significantly different across MMP9 tertiles (Figure 1). Multivariable linear regression analysis demonstrated a positive association between serum levels of MMP9 and annual change of Total and Necrotic Core PV (Figure 1).

Conclusion

Among patients with CCS, MMP9 serum levels were an independent predictor of progression of coronary plaque burden and, in particular, of adverse plaque features, such as Necrotic Core PV. This association was robust and independent from baseline traditional cardiovascular risk factors and medications, supporting for MMP9 a role as a novel marker of residual coronary risk.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020 - Project “Simulation Modeling of coronary ARTery disease: a tool for clinical decision support–SMARTool”

Automatic quantification of plaque progression dynamics as assessed by serial coronary computed tomography angiography using scan-quality-based vessel specific thresholds

Introduction

Use of serial coronary computed tomography angiography (CCTA) allows for the early assessment of coronary plaque progression which may aid in the prevention of major adverse cardiac events (MACE). However, assessment of serial CCTA is done by using anatomical landmarks for matching baseline and follow-up scans. Recently, a tool has been developed allowing for automatic quantification of plaque progression dynamics in serial CCTA utilizing plaque delineation.

Purpose

The aim of this study was to determine the thresholds that define whether there is plaque progression and/or regression. These thresholds depend on the contrast to noise ratio (CNR) which is an objective marker for scan quality as the latter impacts the plaque delineation.

Methods

Thresholds and CNR ratios were determined on 50 patients referred for a CCTA due to thoracic complaints. Two scan phases were selected from each patient in which maximum and minimum differences in plaque delineation were measured. Also, CNR was calculated separately for all three major epicardial coronary vessels. A total of 100 scans were analyzed in the current analysis accounting for a total of 300 coronary vessels. First, vessel and lumen wall delineation was done semi-automatically for all major epicardial coronary vessels. Secondly, manual drawings of 7 regions of interest (ROI) per scan were used to quantify scan quality which was defined using the CNR and calculated for each vessel separately.

As plaque differences of two scans at the same moment in time should always be zero, the minimum and maximum difference in plaque delineation was used in these scans along with the CNR in order to create calibration graphs on which a linear regression analysis was performed (Figure 1, charts A & B). Inter-observer measurements were calculated using Pearson's correlation coefficient.

Results

A total of 300 coronary vessels were assessed at CCTA. Semi-automatic vessel and lumen wall delineation as well as CNR calculation was successful in all cases. Subsequent linear regression analysis performed on the CNR and maximal and minimal plaque delineation differences and taking into account the standard error of the estimate revealed the following formulas for minimum and maximum cut-off values:

Max = [(0.660 − (002 × CNR)] + 0.349

Min = [(−1.028 + (0.012 × CNR)) − 0.61

The average CNR values was 13.4±3.6. Average maximum and minimum difference in plaque delineation was 0.7±0.3mm and −0.9±0.6mm respectively. The inter-observer correlation for CNR values was excellent yielding a correlation coefficient of 0.872 (p<0.001). The importance of using thresholds and subsequent calculation of vessel specific cutoff values is demonstrated in Figure 2.

Conclusion

Development of vessel-specific quality-based thresholds for the quantification and visualization of plaque progression dynamics as assessed by serial CCTA seems feasible and may aid in the early detection of atherosclerosis progression.

Funding Acknowledgement

Type of funding sources: None.

Radiomics-based analysis by machine learning techniques improves characterization of functionally significant coronary lesions

Background

Computed Tomography Coronary Angiography (CTCA) is an effective non-invasive imaging modality for anatomo-functional assessment of coronary artery disease (CAD). Radiomics features have been used for diagnosis or outcome prediction, however, their potential value for characterizing flow limiting coronary lesions has not been explored.

Purpose

To assess whether application of novel radiomics and machine learning (ML) techniques on CTCA derived datasets improves characterization of functionally significant coronary lesions.

Methods

Consecutive patients with stable chest pain and intermediate pre-test likelihood for CAD, who underwent CTCA and PET-or SPECT-Myocardial Perfusion Imaging (MPI) respectively, were prospectively evaluated and included in the analysis. PET-MPI was considered abnormal when >1 contiguous segments showed both stress Myocardial Blood Flow ≤2.3mL/g/min and Myocardial Flow Reserve (MFR) ≤2.5 for 15O-water or <1.79 mL/g/min and ≤2.0 for 13N-ammonia respectively. Defect reversibility (DR) was defined as a summed difference score (SDS) between stress and rest images ≥2. CTCA and functional images were fused to assign each myocardial segment to the pertinent coronary territory. Stenosis severity, plaque characteristics and radiomic plaque features were assessed in the total length of the 3 main coronary vessels. In total, 1765 features were extracted from each vessel and a feature reduction and model creation pipeline was constructed [Figure 1]. Two separate datasets: a) coronary stenosis (≥50%) + plaque characteristics and b) coronary stenosis (≥50%) + plaque characteristics + radiomics were formulated and compared in terms of AUCs accordingly.

Results

A total of 292 coronary vessels (140 with corresponding PET-MPI data and 152 with SPECT MPI data) were analysed. Plaque burden and stenosis severity were the only independent predictors of impaired myocardial perfusion on PET-MPI, with an AUC = 0.749, (95% CI: 0.658–0.826). Stenosis severity, kurtosis, contrast, interquartile range and entropy were predictors of an abnormal PET-MPI result and their combination resulted in an AUC = 0.854, (95% CI: 0.775–0.914). The difference between the 2 models was statistically significant (p-diff: 0.02, 95% CI: 0.0165–0.194). Stenosis severity was the only predictor of a DR on SPECT-MPI, AUC = 0.624 (95% CI: 0.542–0.702). Small Dependence High Gray Level Emphasis, Cluster Prominence, Region Length, wavelet Median and square Median were predictors of a positive SPECT result, with AUC = 0.816, (95% CI: 0.745–0.875). The difference between the two models was statistically significant (p-diff: 0.006, 95% CI: 0.152–0.329)

Conclusion

Radiomic futures can be combined with anatomical and morphological characteristics of coronary lesions in CTCA imaging and provide valuable complementary information for characterizing functionally significant coronary lesions.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported from European Regional Development Fund, Operational Programme “Competitiveness, Entrepreneurship and Innovation 2014-2022 (EPAnEK)”, titled: The Greek Research Infrastructure for Personalized Medicine (pMED-GR)

A common plasma lipidomics signature of cardiometabolic and coronary risk in statin users

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Commission in the H2020 program: Project SMARTool, “Simulation

Modeling of coronary ARTery disease: a tool for clinical decision support—SMARTool”

Background and aims

The coexistence of elevated plasma triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) may contribute to the residual cardiometabolic risk of coronary artery disease (CAD) independently of total cholesterol and low-density lipoprotein cholesterol (LDL-C) absolute plasma levels [1]. Aim of this study is to assess whether a high TG/HDL-C ratio is characterized by a specific lipidomics signature in statin users and its relationship with the coronary risk score defined by coronary computed tomography angiography (CTA).

Methods

TG/HDL-C ratio was calculated in 132 patients (68.8±7.7 years, 85 males) with suspected or known CAD referred to coronary CTA and receiving statins treatment in the last 6.3 ± 1.4 years before enrolment. Patients were grouped according to TG/HDL-C ratio quartiles: IQ (≤1.694), IIQ (1.695-2.399), IIIQ (2.400-3.281), and IVQ (>3.282). Coronary CTA exams were analysed according to the modified 17-segment American Heart Association classification [2] and interpretable segments were visually assessed for degree of stenosis and plaque composition. A comprehensive coronary risk score (CTA score) [3], previously validated as predictor of adverse outcome, was calculated in each patient. Except for subjects with normal arteries (CTA score = 0), all patients were classified into 3 groups of CTA score severity:  low (score < 5), intermediate (score 5-20) and high (score > 20) risk [4]. Patient-specific plasma targeted lipidomics was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This approach allowed to quantify 69 circulating lipids encompassing six lipid classes (triacylglycerol [TG], phosphatidylcholine [PC], phosphatidylethanolamine [PE], ceramide [Cer], sphingomyelin [SM], cholesterol ester [CE]). Differential analysis was performed using TG/HDL-C and CTA score annotation.

Results

18 altered lipid species in the group with higher TG/HDL-C ratio were also altered in the group with higher CTA risk score. This common set of lipids is composed of CE(16:0), CE(18:0), PC(38:2), 8 SM [SM(34:2), SM(38:2), SM(41:2), SM(41:1), SM(42:4), SM(42:3), SM(42:1), SM(43:3)], TG(52:1) and 6 PE [PE(34:0), PE(34:1), PE(34:2), PE(36:1), PE(36:2), PE(36:3)], and represents the lipidomics signature associating elevated plasma TG/HDL-C ratio with high CTA risk score in statin users.

Conclusion

In patients with stable CAD under statin treatment, a specific pattern of altered lipids, characterized by reduced plasma levels of cholesterol esters and sphingomyelins and increased levels of triacylglicerols and phosphatidylethanolamines, is associated with high TG/HDL-C ratio and high CTA score. This specific lipidomic signature identifies patients with higher residual cardiometabolic and coronary risk, not tackled by current lipid lowering therapy, unveiling possible new molecular targets of treatment.

Utilizing (serial) coronary computed tomography angiography (CCTA) to predict plaque progression and major adverse cardiac events (MACE): results, merits and challenges

OBJECTIVES

To present an overview of studies using serial coronary computed tomography angiography (CCTA) as a tool for finding both quantitative (changes) and qualitative plaque characteristics as well as epicardial adipose tissue (EAT) volume changes as predictors of plaque progression and/or major adverse cardiac events (MACE) and outline the challenges and advantages of using a serial non-invasive imaging approach for assessing cardiovascular prognosis.

METHODS

A literature search was performed in PubMed, Embase, Web of Science, Cochrane Library and Emcare. All observational cohort studies were assessed for quality using the Newcastle-Ottawa Scale (NOS). The NOS score was then converted into Agency for Healthcare Research and Quality (AHRQ) standards: good, fair and poor.

RESULTS

A total of 36 articles were analyzed for this review, 3 of which were meta-analyses and one was a technical paper. Quantitative baseline plaque features seem to be more predictive of MACE and/or plaque progression as compared to qualitative plaque features.

CONCLUSIONS

A critical review of the literature focusing on studies utilizing serial CCTA revealed that mainly quantitative baseline plaque features and quantitative plaque changes are predictive of MACE and/or plaque progression contrary to qualitative plaque features. Significant questions regarding the clinical implications of these specific quantitative and qualitative plaque features as well as the challenges of using serial CCTA have yet to be resolved in studies using this imaging technique.

KEY POINTS

• Use of (serial) CCTA can identify plaque characteristics and plaque changes as well as changes in EAT volume that are predictive of plaque progression and/or major adverse events (MACE) at follow-up. • Studies utilizing serial CCTA revealed that mainly quantitative baseline plaque features and quantitative plaque changes are predictive of MACE and/or plaque progression contrary to qualitative plaque features. • Ultimately, serial CCTA is a promising technique for the evaluation of cardiovascular prognosis, yet technical details remain to be refined.

Longitudinal changes in aortic distensibility in patients with Marfan syndrome

Background

Patients with Marfan syndrome (MFS) may develop aortic dissection due to progressive dilatation in the entire aorta. Increased aortic stiffness, i.e.a. decreased distensibility has been shown to often precede these dismal sequelae. Therefore, we investigated longitudinal changes in aortic distensibility throughout the entire aorta by means of Cardiac Magnetic Resonance (CMR) imaging in patients with MFS.

Methods

This retrospective study included all MFS patients with four CMR examinations performed between 1996 and 2012. Aortic distensibility was measured and calculated by a single analyst, in the ascending, proximal- and distal descending, and abdominal aorta. Changes in distensibility were studied using linear mixed-effects regression models. Furthermore, we investigated the association between distensibility and age, sex, blood pressure, medication use, FBN1 mutation type, and previous aortic root surgery.

Results

In total, 35 MFS patients (age at inclusion 28 [IQR 23–32] years, 54% male) were included. Mean aortic distensibility was low in the ascending and proximal descending aorta (resp. 3.25±1.87, 3.91±1.73x10–3 mmHg–1) at the first scan. Distensibility decreased significantly over time at level 2, 3, and 4 (resp. p=0.021, p=0.002, p=0.038) (Figure 1). The rate of distensibility loss per year (x10–3 mmHg–1/year) was respectively 0.04 and 0.06 in the proximal- and distal descending aorta.

Men seemed to have a lower but more stable distensibility, whereas women showed a higher distensibility at younger age, but a faster deterioration rate over time (difference in distensibility loss per year between men and women: 0.08, p=0.038). Distensibility did not correlate significantly with medication use, FBN1 mutation type or previous aortic root surgery.

Conclusion

Patients with MFS have low distensibility at all levels of the aorta at young age, which keeps decreasing over time. Men had lower distensibility at younger age than women. Distensibility was stably low in men, while still deteriorating over time in women.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): AMC FoundationHorstingstuit Foundation

Quantification of myocardial ischemia and subtended myocardial mass at adenosine stress cardiac computed tomography. A feasibility study

Introduction

Combination of computed tomography angiography (CTA) and adenosine stress CT myocardial perfusion (CTP) allows for coronary artery lesion assessment as well as myocardial ischemia. Nowadays, ischemia on CTP is assessed semi-quantitatively by visual analysis. The aim of this study was to fully quantify myocardial ischemia and the subtended myocardial mass on CTP.

Methods

We included 33 patients referred for a combined CTA and adenosine stress CTP with good or excellent imaging quality on CTP. Firstly, the coronary artery tree was automatically extracted from CTA and the relevant coronary artery lesions (≥50%) were manually defined (Fig. 1A). Secondly, epi- and endocardial contours along with CTP deficits were manually defined in short-axis images (Fig. 1D, 1E). Thirdly, a Voronoi-based algorithm was used to quantify the subtended myocardial mass (Fig. 1B). Fourthly, the perfusion defect and subtended myocardial mass were spatially registered to the CTA and measured in grams (Fig. 1F, 1C). Finally, this can be used to quantitatively correlate the perfusion defect to the subtended myocardial mass.

Results

Voronoi-based segmentation was successful in all cases. We assessed a total of 64 relevant coronary artery lesions. Average values for left ventricular mass, total subtended mass and perfusion defect mass were 118, 69 and 7 grams respectively. In 19/33 patients (58%) the total perfusion defect mass could be distributed over the relevant coronary artery lesion(s).

Conclusions

Quantification of myocardial ischemia and subtended myocardial mass using a Voronoi-based segmentation algorithm seem feasible at adenosine stress CTP and allows for quantitative correlation of coronary artery lesions to corresponding areas of myocardial hypoperfusion.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Elevated triglycerides and low HDL cholesterol predict coronary heart disease risk in patients with stable angina

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The EVINCI study was supported by a grant from the European Union FP7-CP-FP506 2007 project (GA 222915). The SMARTool study was supported by a grant from the European Union H2020-PHC-30-2015 (GA 689068). This study was also partially supported by a grant from AMGEN (Protocol N. 20167781, 2017).

Background. High triglycerides (TG) and low high-density lipoprotein cholesterol  (HDL-C) characterize an atherosclerotic cardiovascular disease (CAD) risk condition defined as atherogenic dyslipidemia.

Aim. To assess whether atherogenic dyslipidemia defined by TG/HDL-C ratio predicts CAD related outcomes in patients with stable angina, independently of other risk factors and treatments.

Methods. We studied 355 patients (60 ± 9 y, 211m) with stable angina from the EVINCI Outcome study. Patients were characterized for clinical, bio-humoral and imaging profiles, managed clinically, and followed for 4.5 ± 0.9 years. A computed tomography angiography (CTA) coronary risk score was obtained at baseline in all patients, and at follow-up in 154 of them. The primary composite outcome was all-cause mortality and non-fatal myocardial infarction. CTA scan was repeated at follow-up in 154 patients to assess CAD progression.

Results. The median value of TG/HDL-C ratio was 2.095 (2.079IQR). At baseline, the proportion of males, smoking, diabetes and metabolic syndrome, as well as circulating bio-markers of abnormal glucose metabolism and myocardial damage progressively increased across quartiles of TG/HDL-C ratio. The CTA score was significantly higher in the IV quartile of the TG/HDL-C ratio and both were the only independent predictors of the primary (CTA Score: HR 1.06, 95%CI 1.03-1.09, p = 0.001; TG/HDL-C IV quartile: HR 2.85, 95%CI 1.30-6.26, p < 0.01). In the 154 patients re-evaluated at follow-up, TG/HDL-C ratio associated cardio-metabolic disorder, systemic inflammation and CTA risk score progressed over time despite increased use of lipid-lowering drugs, anti-diabetics and other cardioactive medications and reduction in LDL-C levels.

Conclusions. In patients with stable angina, the TG/HDL-C ratio expresses a cardio-metabolic atherogenic disorder which is progressive over time and is associated with CAD related outcomes independently of LDL-C levels and treatments.

Quantification of myocardial ischemia and subtended myocardial mass at adenosine stress cardiac computed tomography: a feasibility study

Combination of coronary computed tomography angiography (CCTA) and adenosine stress CT myocardial perfusion (CTP) allows for coronary artery lesion assessment as well as myocardial ischemia. However, myocardial ischemia on CTP is nowadays assessed semi-quantitatively by visual analysis. The aim of this study was to fully quantify myocardial ischemia and the subtended myocardial mass on CTP. We included 33 patients referred for a combined CCTA and adenosine stress CTP protocol, with good or excellent imaging quality on CTP. The coronary artery tree was automatically extracted from the CCTA and the relevant coronary artery lesions with a significant stenosis (≥ 50%) were manually defined using dedicated software. Secondly, epicardial and endocardial contours along with CT perfusion deficits were semi-automatically defined in short-axis reformatted images using MASS software. A Voronoi-based segmentation algorithm was used to quantify the subtended myocardial mass, distal from each relevant coronary artery lesion. Perfusion defect and subtended myocardial mass were spatially registered to the CTA. Finally, the subtended myocardial mass per lesion, total subtended myocardial mass and perfusion defect mass (per lesion) were measured. Voronoi-based segmentation was successful in all cases. We assessed a total of 64 relevant coronary artery lesions. Average values for left ventricular mass, total subtended mass and perfusion defect mass were 118, 69 and 7 g respectively. In 19/33 patients (58%) the total perfusion defect mass could be distributed over the relevant coronary artery lesion(s). Quantification of myocardial ischemia and subtended myocardial mass seem feasible at adenosine stress CTP and allows to quantitatively correlate coronary artery lesions to corresponding areas of myocardial hypoperfusion at CCTA and adenosine stress CTP.

Global cardiac sympathetic denervation is associated with diffuse myocardial fibrosis in non-ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

 

Occurrence of ventricular tachycardias (VT) has been related to changes in sympathetic innervation and myocardial tissue in ischemic cardiomyopathy. In non-ischemic cardiomyopathy (NICM) patients with VT, the relation between global cardiac sympathetic innervation and non-ischemic fibrosis is less clear. The current gold standard in electrophysiology to identify non-ischemic fibrosis relies on unipolar endocardial voltage mapping.

Objective

To establish the relationship between global cardiac sympathetic innervation and global fibrosis.

Methods

29 patients (93% male, 58 ± 14 years, mean LVEF 38%±13) from the ‘Leiden Nonischemic Cardiomyopathy Study’ undergoing VT ablation between 2011-2018 were included. Endocardial voltage mapping was performed and the mean endocardial unipolar voltage (UV) was taken as a surrogate for global fibrosis. Global cardiac sympathetic innervation was analyzed by 123-I-MIBG imaging using heart-to-mediastinum ratio (HMR). A cut-off of 1.8 was used to delineate between normal (>1.8) and denervated (<1.8). HMR was correlated with mean UV.

Results

For patients with global cardiac sympathetic denervation a linear relationship was present between HMR and mean UV (R = 0.5278, P = 0.0431. There was no significant linear relationship for patients with normal cardiac sympathetic innervation between HMR and mean UV (R=-0.1696, P = 0.5795).

Conclusion

Global cardiac sympathetic denervation is related to myocardial fibrosis in patients with NICM and VT. The data support an interplay between denervation and fibrosis which may contribute to arrhythmogeneity, as observed in ICM. Abstract Figure.

Prediction of impaired myocardial blood flow (MBF) with the use of machine learning techniques on CTCA based parameters

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported in part from European Regional Development Fund, Operational Programme “Competitiveness, Entrepreneurship and Innovation 2014-2020 (EPAnEK)”, titled: The Greek Research Infrastructure for Personalized Medicine (pMED-GR) , no. GR 5002802 ,and by Greece and the European Union (European Social Fund-ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning 2014-2020» in the context of the project “Assessment of coronary atherosclerosis: a new complete, anatomo-functional, morphological and biomechanical approach”, Project no. 504776

Background

Computed Tomography Coronary Angiography (CTCA) is a non-invasive imaging modality, used effectively for anatomo-functional assessment of coronary artery disease (CAD). Machine learning (ML) processes can effectively allow the extraction of useful information from multidimensional feature spaces for evaluation of coronary lesions.

Purpose

To investigate the ability of ML for predicting impaired myocardial blood flow (MBF) by combining computational fluid dynamics (CFD) derived parameters with quantitative plaque burden, plaque morphology and anatomical characteristics obtained from CTCA.

Methods

53 patients (31 male, mean age 64.7 ± 7.1 years) with intermediate pre-test likelihood of CAD who underwent CTCA and PET-MPI were included. PET was considered positive when > 1 contiguous segment demonstrated MBF ≤ 2.3 mL/g/min for 15O-water or ≤ 1.79 for 13N-ammonia respectively. CFD derived parameters such as a previously validated, virtual functional assessment index (vFAI), segmental endothelial shear stress (ESS), as well as anatomical and plaque characteristics were assessed. Seven classifiers were implemented and internally validated using 5-fold cross validation, repeated 1000 times. Using sequential forward selection (SFS), the highest rank features combination, based on appearances in the highest mean area under curve (AUC) classification scheme, was selected and features performance was evaluated following exhaustive search (ES).

Results

92 coronary segments were analyzed and 34 features derived from CTCA were extracted. Classifiers performance are depicted in Figure A. k-NN was the best classifier with AUCmean = 0.791 (SENSmean= 0.622, SPECmean = 0.840, p < 0.05). Clusters of features and number of appearances are presented in Figure B. The combination of vFAI, stenosis severity and lumen area demonstrated the highest AUC (1473 times). ES results are depicted in Figure C. The combination of vFAI and lumen area was the best predictor among all the combinations (AUCmean = 0.830, SENSmean =0.61, SPECmean =0.83, p < 0.05) followed by vFAI and stenosis severity (AUCmean = 0.81, SENSmean =0.72, SPECmean = 0.87, p < 0.05) and vFAI alone (AUCmean = 0.806, SENSmean =0.61, SPECmean =0.87, p < 0.05).

Conclusion

ML analysis is feasible for predicting with reasonable specificity abnormal MBF by PET, using a combination of CFD derived parameters and anatomical features. vFAI as a single characteristic was a specific predictor of impaired MBF, whilst in combination with stenosis severity, maintained almost the same AUC and specificity values and resulted in improved sensitivity. On the other hand, addition of lumen area to vFAI, increases the AUC and provides a relatively good specificity but low  sensitivity.

Abstract Figure 1

445Effects of losartan and beta-blockers on aortic root dilatation in patients with Marfan Syndrome - results of the extended COMPARE trial

Introduction

Despite several randomized trials, beneficial effects of Losartan and β-blockers in adults with Marfan syndrome (MFS) are not entirely clear. The COMPARE trial previously showed a small but significant beneficial effect of Losartan on top of β-blocker use on aortic root dilatation rate. Yet, this effect was not reproduced by other trials, although in general a favourable effect of Losartan could be demonstrated. All trials in adults with MFS showed lower than expected aortic root dilatation rates, suggesting mildly affected study populations. Therefore we extended the follow-up period of the COMPARE trial up to 10 years and aimed to assess the clinical outcomes of the study cohort, as well as the effect of medication regimes on aortic root dilatation rates in the subgroup of patients with a native aortic root at initial randomization.

Methods

Patients previously enrolled in the COMPARE trial were retrospectively analyzed. Cardiovascular events (aortic dissections, ruptures and operations) and all-cause mortality were assessed. Individual aortic root dilatation rates were estimated in patients with a native aortic root at time of randomization on the basis of linear regression analysis of multiple transthoracic echocardiogram (TTE) results. Correlations between aortic root dilatation rates and cumulative Losartan or β-blocker treatment days were assessed with Spearman's rho (ρ).

Results

During a median follow-up of 8.0 years, two dissections and three deaths occurred in the 151 patients with a native aortic root at time of randomization. The 122 patients that were eligible for aortic root dilatation analysis, underwent a median of 6 TTEs. The median aortic root dilatation rate in these patients was 0.28 (interquartile range 0.09 - 0.59) mm/y. These patients were further classified as either patients with a stable aortic root (n=102) or with aortic root growth (n=20), based on the threshold of 0.9 mm per year. Patients with aortic root growth had significantly more aortic root replacements during follow-up (17/20 vs 18/102, P=0.001).

Furthermore, aortic root dilatation rate was negatively correlated with the number of Losartan treatment days (ρ=−0.272, P=0.003), β-blocker treatment days (ρ=−0.217, P=0.017) and with the duration of follow-up (ρ=−0.437, P<0.001).

Conclusions

Our results support previous findings that Losartan and β-blockers appear to be equally effective on aortic root dilatation rate in Marfan Syndrome patients. The low event rate in the long term follow-up of this subgroup of the COMPARE trial represent a relatively mildly affected study population and an aggressive prophylactic surgical regime.

P6167Low leptin plasma levels are associated with progression of coronary atherosclerosis in patients with stable coronary artery disease from the SMARTool Study

Background

Leptin is an adipokine involved in energy homeostasis and has been related with established vascular risk factors. However, studies on the association of leptin plasma levels with coronary artery disease (CAD) have yielded conflicting results.

Purpose

Aim of the present study was to evaluate the association between leptin plasma levels and presence, severity and progression of coronary atherosclerosis in patients with suspected stable CAD.

Methods

In a cohort of 257 patients with symptoms of stable CAD enrolled in the SMARTool study, coronary computed tomography angiography (CTA), plasma leptin levels and clinical and bio-humoral CAD risk profile (including glucose, lipid and inflammation variables) were obtained at enrolment and after 6±1yrs of follow-up. Sixty-four patients were revascularized and the remaining 193 represent the population for the present study. CTA findings were categorised as no-minimal CAD (<30% stenosis), non-obstructive CAD (30%-50% stenosis) and obstructive CAD (≥50% stenosis in at least one major coronary vessel). A CTA risk score (based on plaque extent, severity, composition, and location) was calculated at baseline and at follow-up to assess coronary atherosclerotic burden and its progression (Δ CTA score≥5).

Results

CTA findings showed obstructive CAD in 11% of patients at baseline and in 15% at follow-up (p<0.0001). CTA risk score, was 8.03±7.80 at baseline and increased to 10.33±8.17 at follow-up (p<0.0001) with CAD progression in 20% of patients. Leptin plasma levels were inversely related with CTA findings both at baseline and follow-up (Figure). In a Cox model, baseline plasma leptin was an independent predictor of CAD progression, after adjustment for clinical risk factors, biomarkers, and treatment (HR 0.572, 95% CI 0.393–0.834, P=0.0037).

Figure 1

Conclusion

Plasma leptin is inversely associated with coronary atherosclerotic burden and disease progression in patients with stable CAD. This association is independent of known factors affecting leptin levels. These results could prompt further investigations on the pathophysiological mechanisms of this association.

Acknowledgement/Funding

EU H2020 research and innovation program under grant agreement No 689068

Accuracy and reproducibility of fast fractional flow reserve computation from invasive coronary angiography

Fractional flow reserve (FFR) guided percutaneous coronary intervention (PCI) is associated with favourable outcome compared with revascularization based on angiographic stenosis severity alone. The feasibility of the new image-based quantitative flow ratio (QFR) assessed from 3D quantitative coronary angiography (QCA) and thrombolysis in myocardial infarction (TIMI) frame count using three different flow models has been reported recently. The aim of the current study was to assess the accuracy, and in particular, the reproducibility of these three QFR techniques when compared with invasive FFR. QFR was derived (1) from adenosine induced hyperaemic coronary angiography images (adenosine-flow QFR [aQFR]), (2) from non-hyperemic images (contrast-flow QFR [cQFR]) and (3) using a fixed empiric hyperaemic flow [fixed-flow QFR (fQFR)]. The three QFR values were calculated in 17 patients who prospectively underwent invasive FFR measurement in 20 vessels. Two independent observers performed the QFR analyses. Mean difference, standard deviation and 95% limits of agreement (LOA) between invasive FFR and aQFR, cQFR and fQFR for observer 1 were: 0.01 ± 0.04 (95% LOA: -0.07; 0.10), 0.01 ± 0.05 (95% LOA: -0.08; 0.10), 0.01 ± 0.04 (95% LOA: -0.06; 0.08) and for observer 2: 0.00 ± 0.03 (95% LOA: -0.06; 0.07), -0.01 ± 0.03 (95% LOA: -0.07; 0.05), 0.00 ± 0.03 (95% LOA: -0.06; 0.05). Values between the 2 observers were (to assess reproducibility) for aQFR: 0.01 ± 0.04 (95% LOA: -0.07; 0.09), for cQFR: 0.02 ± 0.04 (95% LOA: -0.06; 0.09) and for fQFR: 0.01 ± 0.05 (95% LOA: -0.07; 0.10). In a small number of patients we showed good accuracy of three QFR techniques (aQFR, cQFR and fQFR) to predict invasive FFR. Furthermore, good inter-observer agreement of the QFR values was observed between two independent observers.

Coupling between MRI-assessed regional aortic pulse wave velocity and diameters in patients with thoracic aortic aneurysm: a feasibility study

AIMS

Thoracic aortic aneurysm (TAA) is potentially life-threatening and requires close follow-up to prevent aortic dissection. Aortic stiffness and size are considered to be coupled. Regional aortic stiffness in patients with TAA is unknown. We aimed to evaluate coupling between regional pulse wave velocity (PWV), a marker of vascular stiffness, and aortic diameter in TAA patients.

METHODS

In 40 TAA patients (59 ± 13 years, 28 male), regional aortic diameters and regional PWV were assessed by 1.5 T MRI. The incidence of increased diameter and PWV were determined for five aortic segments (S1, ascending aorta; S2, aortic arch; S3, thoracic descending aorta; S4, suprarenal and S5, infrarenal abdominal aorta). In addition, coupling between regional PWV testing and aortic dilatation was evaluated and specificity and sensitivity were assessed.

RESULTS

Aortic diameter was 44 ± 5 mm for the aortic root and 39 ± 5 mm for the ascending aorta. PWV was increased in 36 (19 %) aortic segments. Aortic diameter was increased in 28 (14 %) segments. Specificity of regional PWV testing for the prediction of increased regional diameter was ≥ 84 % in the descending thoracic to abdominal aorta and ≥ 68 % in the ascending aorta and aortic arch.

CONCLUSION

Normal regional PWV is related to absence of increased diameter, with high specificity in the descending thoracic to abdominal aorta and moderate results in the ascending aorta and aortic arch.

Screening for coronary artery disease after mediastinal irradiation in Hodgkin lymphoma survivors: phase II study of indication and acceptance†

BACKGROUND

Cardiovascular diseases are the most common nonmalignant cause of death in Hodgkin lymphoma (HL) survivors, especially after mediastinal irradiation. We investigated the role of computed tomographic coronary angiography (CTA) as a screening tool for coronary artery disease (CAD) in asymptomatic HL survivors, and related CTA findings to exercise testing and subsequent interventions.

PATIENTS AND METHODS

Patients were eligible for this phase II study if at least 10 years disease-free and treated with mediastinal radiotherapy. Screening consisted of electrocardiogram, exercise testing and CTA. Primary end point was significant CAD (stenosis >50%) on CTA. CTA screening was considered to be indicated for testing in a larger population if ≥6 of 50 CTA scanned patients (12%) would need revascularization. Screening was evaluated with a questionnaire before and after screening.

RESULTS

Fifty-two patients were included, and 48 patients underwent CTA. Median age was 47 years, time since HL diagnosis 21 years. There were 45 evaluable scans. Significant CAD on CTA was found in 20% (N = 9), significantly increased compared with the 7% expected abnormalities (P = 0.01, 95% confidence interval 8.3% to 31.7%). In 11% (N = 5), significant stenosis was confirmed at coronary angiography, and revascularization was carried out. Additionally, two patients were treated with optimal medical therapy. Ninety percent of patients were content with screening, regardless whether the CTA showed abnormalities.

CONCLUSIONS

Prevalence of significant CAD among HL survivors is high, while asymptomatic even in the presence of life-threatening CAD. This might justify screening by CTA in asymptomatic HL survivors who had mediastinal radiotherapy, but needs to be evaluated in a larger cohort. The trial protocol was approved by the Ethics Committee of the LUMC and registered with ClinicalTrials.gov, NCT01271127.

Right ventricular ejection fraction measured by multigated planar equilibrium radionuclide ventriculography is an independent prognostic factor in patients with ischemic heart disease

BACKGROUND

The number of studies on the prognostic value of the right ventricular ejection fraction (RVEF) in patients with ischemic heart disease (IHD) is limited, whereas it is widely accepted that the left ventricular ejection fraction (LVEF) is a strong prognostic factor. We assessed whether RVEF measured by multigated planar equilibrium radionuclide ventriculography (RNV) is an independent prognostic factor in patients with IHD.

METHODS AND RESULTS

We retrospectively identified 347 consecutive patients with IHD (mean age 71 ± 11 years; 18% women) who underwent multigated planar equilibrium RNV between 2004 and 2008 to determine the LVEF, which also provided the RVEF (mean 44.7% ± 11.0%). We categorized patients according to RVEF in ≥40% (n = 240) and <40% (n = 107). Patients were followed for a median of 826 days (range 3-2,400) for the occurrence of events [all-cause mortality (n = 60), cardiac mortality (n = 33), and cardiac hospitalization (n = 78)]. Cox regression analysis with significant univariate predictors [coronary artery revascularization (P = .003), diuretics (P = .03), and statins (P < .001)] showed that an RVEF <40% was associated with a 2.90 (1.68-5.00)-fold higher risk of all-cause death. Accordingly, a decreased RVEF was associated with a 2.15 (1.34-3.43)-fold increase in the risk of cardiac hospitalization and a 5.11(2.32-11.23)-fold risk of cardiac death.

CONCLUSION

RVEF measured by multigated planar equilibrium RNV is an independent prognostic factor in patients with chronic IHD.

An unanticipated copy number variant of chromosome 15 disrupting SMAD3 reveals a three-generation family at serious risk for aortic dissection

Several genes involved in the familial appearance of thoracic aortic aneurysms and dissections (FTAAD) have been characterized recently, one of which is SMAD3. Mutations of SMAD3 cause a new syndromic form of aortic aneurysms and dissections associated with skeletal abnormalities. We discovered a small interstitial deletion of chromosome 15, leading to disruption of SMAD3, in a boy with mild mental retardation, behavioral problems and revealed features of the aneurysms-osteoarthritis syndrome (AOS). Several family members carried the same deletion and showed features including aortic aneurysms and a dissection. This finding demonstrates that haploinsufficiency of SMAD3 leads to development of both thoracic aortic aneurysms and dissections, and the skeletal abnormalities that form part of the aneurysms-osteoarthritis syndrome. Interestingly, the identification of this familial deletion is an example of an unanticipated result of a genomic microarray and led to the discovery of important but unrelated serious aortic disease in the proband and family members.

Prevalence of coronary artery disease and plaque morphology assessed by multi-slice computed tomography coronary angiography and calcium scoring in asymptomatic patients with type 2 diabetes

OBJECTIVE

The purpose of the study was to evaluate the prevalence of CAD as well as plaque morphology in asymptomatic patients with type 2 diabetes using multi-slice computed tomography (MSCT). In addition, the relation between calcium score and MSCT findings was explored.

DESIGN

In 70 patients, coronary calcium scoring and non-invasive coronary angiography were performed. Angiograms showing atherosclerosis were further classified as obstructive (> or =50% luminal narrowing) CAD or not. Plaque type (non-calcified, mixed and calcified) was determined. Finally, the relation between calcium score and MSCT findings was explored.

RESULTS

A calcium score <10 was observed in 31 (44%) patients. A calcium score of 10-100 was observed in 14 (20%) patients while a score of 101-400 or >400 was identified in 12 (17%) and 13 (19%) patients respectively. Non-invasive coronary angiography showed CAD in 56 (80%) patients. 322 coronary segments with plaque were identified, of which 132 (41%) contained non-calcified plaques, 65 (20%) mixed plaques and 125 (39%) calcified plaques. The percentage of patients with obstructive CAD paralleled increasing calcium score. The presence of CAD was noted in 17 (55%) patients with no or minimal calcium (score <10).

CONCLUSIONS

MSCT angiography detected a high prevalence of CAD in asymptomatic patients with type 2 diabetes. A relatively high proportion of plaques were non-calcified (41%). Importantly, a calcium score <10 did not exclude CAD in these patients. MSCT might be a useful technique to identify CAD in asymptomatic patients with type 2 diabetes with incremental value over calcium scoring.

Contrast echocardiography as a useful additional diagnostic tool in evaluating a primary cardiac tumor

The current report describes a case of a primary cardiac lymphoma. For early and appropriate treatment of a cardiac mass it is not only important to determine its localization and extension but also to differentiate between malignant and benign lesions. This report demonstrates that not only transthoracic echocardiography but also the other different forms of echocardiography such as transesophageal echocardiography, as well as contrast and intracardiac echocardiography, are useful tools in the diagnostic workup of cardiac masses.

Underestimation of severity of mitral regurgitation with varying hemodynamics

Transesophageal echocardiography (TEE) is a valuable technique to assess mitral valve anatomy and the mechanism of mitral regurgitation (MR). We present the case of a 35-year-old woman with severe MR due to restrictive motion of the posterior mitral leaflet, who was referred for mitral annuloplasty. Under physiologic circumstances, a severe (grade 3+) MR was present, whereas in the operating room during general anesthesia, the MR had disappeared almost completely. The downgrading of MR due to general anesthesia and the associated mechanisms of this phenomenon are discussed in this case.

Intracardiac pseudotumor caused by mitral annular calcification

The current report describes a rare case of a pseudotumor in the left ventricle. Transthoracic and transesophageal echocardiography demonstrated a round, echodense, mobile mass attached to the posterior mitral leaflet and annulus. At surgical exploration caseous annular calcification of the posterior mitral leaflet was diagnosed. After resection of the mass, successful mitral valvular plasty was performed. Review of the literature indicated that mitral annular calcification is associated with an increased risk of stroke. Optimal treatment may be surgery, especially when valve plasty can be performed, although randomized trials are currently lacking.

Aortic valve regurgitation due to cusp aneurysm: a case report

Two-dimensional echocardiography is a valuable tool in visualizing and monitoring aortic valve and root abnormalities. We present a rare case of a patient with massive aortic regurgitation due to cusp aneurysm, which was accurately diagnosed by echocardiography and treated by valve replacement. A complicated course with recurrent aneurysms of the aortic wall after aortic valve replacement was remarkable in this case. Although different possible etiologies could not be determined, endocarditis and/or aortitis may be the most likely explanation of the complicated and finally fatal course of this patient.

Cardiac tumour

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Direct coronary stent implantation does not reduce the incidence of in-stent restenosis or major adverse cardiac events: six month results of a randomized trial

STUDY OBJECTIVE

To compare the long-term angiographic, clinical and economic outcome of direct stenting vs stenting after balloon predilatation.

PATIENT POPULATION AND METHODS

Four hundred patients with coronary stenoses in a single native vessel were randomized to direct stenting vs stenting after predilatation. A major adverse cardiac and cerebral event (MACCE) was defined as death, myocardial infarction, stent thrombosis, target restenosis, repeat target- and non-target vessel-related percutaneous coronary intervention, target lesion revascularization, coronary artery bypass surgery and stroke.

RESULTS

Stents were successfully implanted in 98.3% of patients randomized to direct stenting vs 97.8% randomized to stenting preceded by predilatation. The primary success rate of direct stenting was 88.3%, vs 97.8% for stenting preceded by balloon dilatation (P=0.01). The angiographic follow-up at 6 months included 333 of the 400 patients (83%). The binary in-stent restenosis rate was 23.1% of 163 patients randomized to direct stenting vs 18.8% of 166 patients randomized to balloon predilatation (P=0.32). By 185+/-25 days, MACCE had occurred in 31 of 200 (15.5%) patients randomized to direct stenting, vs 33 of 200 (16.5%) randomized to predilatation (P=0.89). At 6 months, costs associated with the direct stenting strategy (Euros 3222/patient) were similar to those associated with predilatation (Euros 3428/patient, P=0.43). However, procedural costs were significantly lower. It is noteworthy that, on multivariate analysis, a baseline C-reactive protein level >10 mg l(-1)was a predictor of restenosis (odds ratio: 2.10, P=0.025) as well as of MACCE (odds ratio: 1.94, P=0.045).

CONCLUSIONS

Compared to stenting preceded by balloon predilatation, direct stenting was associated with similar 6-month restenosis and MACCE rates. Procedural, but not overall 6-month costs, were reduced by direct stenting. An increased baseline CRP level was an independent predictor of adverse long-term outcome after coronary stent implantation.

Early and late allergic reaction in the nose assessed by whole body plethysmography

Physiological changes during late phase nasal responses after allergen challenge are difficult to establish and different criteria are used for the definition of a positive late phase nasal reaction. The objective of this study was to assess the value of whole body plethysmography in detecting changes in nasal airway resistance after allergen challenge and to suggest criteria for the definition of early and late phase nasal reactions. Nasal challenge with allergen was performed in 15 allergic patients. Nasal resistance was followed until 10 h after allergen challenge and on a control day using whole body plethysmography. The mean percentage changes in the inspiratory nasal resistance during the early phase period (0.25-2 h) and the late phase period (4-10 h) were significantly higher on the allergen challenge day than on the control day (p=0.001 and p=0.01, respectively). The mean percentage change in the inspiratory nasal resistance during the early and late phase period on the control day plus 2 times the standard deviation served as cut-off point for a positive reaction. Using this definition, all patients had early reactions and 7 of the 15 patients (47%) also had late reactions. We conclude that whole body plethysmography is a useful, noninvasive method for the measurement of the physiological changes in the nose following allergen challenge.

Vessel wall changes in the proximal non-treated segment after PTCA. An in vivo intracoronary ultrasound study

Intimal disruption is known to induce prolonged intimal functional disturbance and is thought to be one of the mechanisms contributing to restenosis after PTCA. Although such damage can be induced by minimal trauma, the inevitable far greater disruption caused by passage of the PTCA apparatus through the stenosis does not appear to induce significant angiographically documented intimal proliferation. Pathological studies, however, have suggested that such a process might occur. Intravascular ultrasound allows in vivo study of vessel wall shape and constitution and is a far more sensitive detector of coronary atheroma than angiography. In this study we sought to determine the frequency of such functional disturbances and to assess their significance with respect to restenosis. The study group comprised 18 patients who underwent IVUS examination immediately after PTCA and at 6-months follow-up. They were analysed for luminal dimensions and vessel wall changes at the site of PTCA and at the level of the proximal non-treated segment. Seven patients (38%) had restenosed at follow-up IVUS examination; two patients had angiographically demonstrated luminal narrowing proximal to the PTCA site whereas seven had new intimal thickening in the proximal non-treated segment demonstrated by IVUS. Six patients had no intimal changes in either PTCA treated or untreated segments. Proximal intimal thickening was seen more frequently in those in whom increased intimal thickening at the PTCA site was noted. A trend (P < 0.1) was found towards an increased rate of new proximal vessel disease in those patients who had angiographically restenosed. IVUS demonstrates new intimal thickening in proximal non-treated segments in a considerable number of or patients undergoing PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous plaque rupture visualized by intravascular ultrasound

An intravascular ultrasound examination was performed in order to evaluate an angiographically complicated lesion. Intravascular ultrasound was able to demonstrate spontaneous plaque rupture in a patient with recent acute subendocardial infarction. The inconclusive angiographic appearance was clarified by the intravascular examination and led us to conclude that the myocardial infarction was due to plaque rupture with subsequent thrombotic occlusion, which had spontaneously resolved by the time of the study.