Impact of Hybrid Iterative Reconstruction on Agatston Coronary Artery Calcium Scores in Comparison to Filtered Back Projection in Native Cardiac CT

PURPOSE To investigate whether the effects of hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) measurements using the Agatston score lead to changes in assignment of patients to cardiovascular risk groups compared to filtered back projection (FBP). MATERIALS AND METHODS 68 patients (mean age 61.5 years; 48 male; 20 female) underwent prospectively ECG-gated, non-enhanced, cardiac 256-MSCT for coronary calcium scoring. Scanning parameters were as follows: Tube voltage, 120 kV; Mean tube current time-product 63.67 mAs (50 - 150 mAs); collimation, 2 × 128 × 0.625 mm. Images were reconstructed with FBP and with HIR at all levels (L1 to L7). Two independent readers measured Agatston scores of all reconstructions and assigned patients to cardiovascular risk groups. Scores of HIR and FBP reconstructions were correlated (Spearman). Interobserver agreement and variability was assessed with ĸ-statistics and Bland-Altmann-Plots. RESULTS Agatston scores of HIR reconstructions were closely correlated with FBP reconstructions (L1, R = 0.9996; L2, R = 0.9995; L3, R = 0.9991; L4, R = 0.986; L5, R = 0.9986; L6, R = 0.9987; and L7, R = 0.9986). In comparison to FBP, HIR led to reduced Agatston scores between 97 % (L1) and 87.4 % (L7) of the FBP values. Using HIR iterations L1 - L3, all patients were assigned to identical risk groups as after FPB reconstruction. In 5.4 % of patients the risk group after HIR with the maximum iteration level was different from the group after FBP reconstruction. CONCLUSION There was an excellent correlation of Agatston scores after HIR and FBP with identical risk group assignment at levels 1 - 3 for all patients. Hence it appears that the application of HIR in routine calcium scoring does not entail any disadvantages. Thus, future studies are needed to demonstrate whether HIR is a reliable method for reducing radiation dose in coronary calcium scoring.

The correlation of epicardial adipose tissue on postmortem CT with coronary artery stenosis as determined by autopsy

The goal of this study was to assess whether epicardial and paracardial adipose tissue volumes, as determined by computed tomography (CT), correlate with coronary artery stenosis as determined by autopsy. The postmortem CT data and autopsy findings of 116 adult human decedents were retrospectively compared. Subjects were classified into three groups according to their degree of coronary artery stenosis: ≥50, <50%, and no stenosis. Epicardial and paracardial adipose tissue volumes were calculated based on manual segmentation after threshold based masking. In addition, epicardial adipose tissue thickness was measured using a caliper. All three parameters (thickness of epicardial fat and volumes of both epicardial and paracardial fat) were compared among the three groups and correlated with the degree of coronary artery stenosis. The group with no coronary artery stenosis showed the lowest mean values of epicardial adipose tissue volume, while the coronary artery stenosis ≥50 % group showed the highest volume. All measured variables (thickness of epicardial fat and volumes of both epicardial and paracardial fat) correlated significantly with the grade of coronary artery stenosis, even after controlling for BMI, however, epicardial adipose tissue volume exhibited the strongest correlation. This study reveals that there is an association between the degree of coronary artery stenosis and the amount of epicardial fat tissue: The larger the volume of epicardial fat, the higher the degree of coronary artery stenosis.

Gender-Specific Associations between Circulating T-Cadherin and High Molecular Weight-Adiponectin in Patients with Stable Coronary Artery Disease.

Close relationships exist between presence of adiponectin (APN) within vascular tissue and expression of T-cadherin (T-cad) on vascular cells. APN and T-cad are also present in the circulation but here their relationships are unknown. This study investigates associations between circulating levels of high molecular weight APN (HMW-APN) and T-cad in a population comprising 66 women and 181 men with angiographically proven stable coronary artery disease (CAD). Plasma HMW-APN and T-cad were measured by ELISA and analysed for associations with baseline clinical characteristics and with each other. In multivariable analysis BMI and HDL were independently associated with HMW-APN in both genders, while diabetes and extent of coronary stenosis were independently associated with T-cad in males only. Regression analysis showed no significant association between HMW-APN and T-cad in the overall study population. However, there was a negative association between HMW-APN and T-cad (P=0.037) in a subgroup of young men (age <60 years, had no diabetes and no or 1-vessel CAD) which persisted after multivariable analysis with adjustment for all potentially influential variables (P=0.021). In the corresponding subgroup of women there was a positive association between HMW-APN and T-cad (P=0.013) which disappeared after adjustment for HDL. After exclusion of the young men, a positive association (P=0.008) between HMW-APN and T-cad was found for the remaining participants of the overall population which disappeared after adjustment for HDL and BMI. The existence of opposing correlations between circulating HMW-APN and T-cad in male and female patient populations underscores the necessity to consider gender as a confounding variable when evaluating biomarker potentials of APN and T-cad.

Three-year efficacy and safety of new- versus early-generation drug-eluting stents for unprotected left main coronary artery disease insights from the ISAR-LEFT MAIN and ISAR-LEFT MAIN 2 trials.

BACKGROUND In percutaneous coronary intervention (PCI) patients new-generation drug-eluting stent (DES) has reduced adverse events in comparison to early-generation DES. The aim of the current study was to investigate the long-term clinical efficacy and safety of new-generation DES versus early-generation DES for PCI of unprotected left main coronary artery (uLMCA) disease. METHODS The patient-level data from the ISAR-LEFT MAIN and ISAR-LEFT MAIN 2 randomized trials were pooled. The clinical outcomes of PCI patients assigned to new-generation DES (everolimus- or zotarolimus-eluting stent) versus early-generation DES (paclitaxel- or sirolimus-eluting stent) were studied. The primary endpoint was the composite of death, myocardial infarction (MI), target lesion revascularization and stroke (MACCE, major adverse cardiac and cerebrovascular event). RESULTS In total, 1257 patients were available. At 3 years, the risk of MACCE was comparable between patients assigned to new-generation DES or early-generation DES (28.2 versus 27.5 %, hazard ratio-HR 1.03, 95 % confidence intervals-CI 0.83-1.26; P = 0.86). Definite/probable stent thrombosis was low and comparable between new-generation DES and early-generation DES (0.8 versus 1.6 %, HR 0.52, 95 % CI 0.18-1.57; P = 0.25); in patients treated with new-generation DES no cases occurred beyond 30 days. Diabetes increased the risk of MACCE in patients treated with new-generation DES but not with early-generation DES (P interaction = 0.004). CONCLUSIONS At 3-year follow-up, a PCI with new-generation DES for uLMCA disease shows comparable efficacy to early-generation DES. Rates of stent thrombosis were low in both groups. Diabetes significantly impacts the risk of MACCE at 3 years in patients treated with new-generation DES for uLMCA disease. ClinicalTrials.gov Identifiers: NCT00133237; NCT00598637.

Decreased phosphatidylcholine plasmalogens - A putative novel lipid signature in patients with stable coronary artery disease and acute myocardial infarction.

OBJECTIVE Glycerophospholipids and sphingolipids are structurally heterogeneous due to differences in the O- and N-linked fatty acids and head groups. Sphingolipids also show a heterogeneity in their sphingoid base composition which up to now has been little appreciated. The aim of this study was to investigate the association of certain glycerophospholipid and sphingolipid species with stable coronary artery disease (CAD) and acute myocardial infarction (AMI). METHODS The lipid profile in plasma from patients with stable CAD (n = 18) or AMI (n = 17) was compared to healthy subjects (n = 14). Sixty five glycerophospholipid and sphingolipid species were quantified by LC-MS. The relative distribution of these lipids into lipoprotein fractions was analyzed. RESULTS In the CAD cohort, 45 glycerophospholipid and sphingolipid species were significantly lower compared to healthy controls. In the AMI group, 42 glycerophospholipid and sphingolipid species were reduced. Four PC plasmalogens (PC33:1, PC33:2, PC33:3 and PC35:3) showed the most significant difference. Out of eleven analyzed sphingoid bases, four were lower in the CAD and six in the AMI group. Sphingosine-1-phosphate (S1P) levels were reduced in the AMI group whereas an atypical C16:1 S1P was lower in both groups. Phosphatidylcholine and sphingomyelin species were exclusively present in lipoprotein particles, whereas lysophosphatidylcholines were mainly found in the lipoprotein-free fraction. The observed differences were not explained by the use of statins as confirmed in a second, independent cohort. CONCLUSIONS Reduced levels of four PC plasmalogens (PC33:1, PC33:2, PC33:3 and PC35:3) were identified as a putatively novel lipid signature for CAD and AMI.

Detection of significant coronary artery disease by noninvasive anatomical and functional imaging.

BACKGROUND The choice of imaging techniques in patients with suspected coronary artery disease (CAD) varies between countries, regions, and hospitals. This prospective, multicenter, comparative effectiveness study was designed to assess the relative accuracy of commonly used imaging techniques for identifying patients with significant CAD. METHODS AND RESULTS A total of 475 patients with stable chest pain and intermediate likelihood of CAD underwent coronary computed tomographic angiography and stress myocardial perfusion imaging by single photon emission computed tomography or positron emission tomography, and ventricular wall motion imaging by stress echocardiography or cardiac magnetic resonance. If ≥1 test was abnormal, patients underwent invasive coronary angiography. Significant CAD was defined by invasive coronary angiography as >50% stenosis of the left main stem, >70% stenosis in a major coronary vessel, or 30% to 70% stenosis with fractional flow reserve ≤0.8. Significant CAD was present in 29% of patients. In a patient-based analysis, coronary computed tomographic angiography had the highest diagnostic accuracy, the area under the receiver operating characteristics curve being 0.91 (95% confidence interval, 0.88-0.94), sensitivity being 91%, and specificity being 92%. Myocardial perfusion imaging had good diagnostic accuracy (area under the curve, 0.74; confidence interval, 0.69-0.78), sensitivity 74%, and specificity 73%. Wall motion imaging had similar accuracy (area under the curve, 0.70; confidence interval, 0.65-0.75) but lower sensitivity (49%, P<0.001) and higher specificity (92%, P<0.001). The diagnostic accuracy of myocardial perfusion imaging and wall motion imaging were lower than that of coronary computed tomographic angiography (P<0.001). CONCLUSIONS In a multicenter European population of patients with stable chest pain and low prevalence of CAD, coronary computed tomographic angiography is more accurate than noninvasive functional testing for detecting significant CAD defined invasively. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT00979199.

Higher macrophage superoxide anion production in coronary artery disease (CAD) patients with Type D personality

BACKGROUND Type D personality (Type D) is an independent psychosocial risk factor for poor cardiac prognosis and increased mortality in patients with cardiovascular disease (CVD), but the involved mechanisms are poorly understood. Macrophages play a pivotal role in atherosclerosis, the process underlying coronary artery disease (CAD). We investigated macrophage superoxide anion production in production in CAD patients with and without Type D. METHODS AND RESULTS We studied 20 male CAD patients with Type D (M:66.7±9.9years) and 20 age-matched male CAD patients without Type D (M:67.7±8.5years). Type D was measured using the DS14 questionnaire with the two subscales 'negative affectivity' and 'social inhibition'. We assessed macrophage superoxide anion production using the WST-1 assay. All analyses were controlled for potential confounders. CAD patients with Type D showed higher superoxide anion production compared to CAD patients without Type D (F(1,38)=15.57, p<0.001). Complementary analyses using the Type D subscales 'negative affectivity' and 'social inhibition', and their interaction as continuous measures, showed that both Type D subscales (negative affectivity: (ß=0.48, p=0.002, R(2)=0.227); social inhibition: (ß=0.46, p=0.003, R(2)=0.208)) and their interaction (ß=0.36, p=0.022, R(2)=0.130) were associated with higher WST-1 reduction scores. Results remained significant when controlling for classical CVD risk factors (i.e. body mass index, mean arterial blood pressure), atherosclerosis severity (i.e. intima media thickness, presence of carotid plaques), and psychological factors (depressive symptom severity, chronic stress). CONCLUSIONS Our results indicate higher macrophage superoxide anion production in CAD patients with Type D compared to those without Type D. This may suggest a mechanism contributing to increased morbidity and mortality in CAD patients with Type D.

Hyperoxia Exacerbates Myocardial Ischemia in the Presence of Acute Coronary Artery Stenosis in Swine.

BACKGROUND Current guidelines limit the use of high oxygen tension after return of spontaneous circulation after cardiac arrest, focusing on neurological outcome and mortality. Little is known about the impact of hyperoxia on the ischemic heart. Oxygen is frequently administered and is generally expected to be beneficial. This study seeks to assess the effects of hyperoxia on myocardia oxygenation in the presence of severe coronary artery stenosis in swine. METHODS AND RESULTS In 22 healthy pigs, we surgically attached a magnetic resonance compatible flow probe to the left anterior descending coronary artery (LAD). In 11 pigs, a hydraulic occluder was inflated distal to the flow probe. After increasing PaO2 to >300 mm Hg, LAD flow decreased in all animals. In 8 stenosed animals with a mean fractional flow reserve of 0.64±0.02, hyperoxia resulted in a significant decrease of myocardial signal intensity in oxygenation-sensitive cardiovascular magnetic resonance images of the midapical segments of the LAD territory. This was not seen in remote myocardium or in the other 8 healthy animals. The decreased signal intensity was accompanied by a decrease in circumferential strain in the same segments. Furthermore, ejection fraction, cardiac output, and oxygen extraction ratio declined in these animals. Changing PaCO2 levels did not have a significant effect on any of the parameters; however, hypercapnia seemed to nonsignificantly attenuate the hyperoxia-induced changes. CONCLUSIONS Ventilation-induced hyperoxia may decrease myocardial oxygenation and lead to ischemia in myocardium subject to severe coronary artery stenosis.

Preprocedural High-Sensitivity Cardiac Troponin T and Clinical Outcomes in Patients With Stable Coronary Artery Disease Undergoing Elective Percutaneous Coronary Intervention.

BACKGROUND Cardiac troponin detected by new-generation, highly sensitive assays predicts clinical outcomes among patients with stable coronary artery disease (SCAD) treated medically. The prognostic value of baseline high-sensitivity cardiac troponin T (hs-cTnT) elevation in SCAD patients undergoing elective percutaneous coronary interventions is not well established. This study assessed the association of preprocedural levels of hs-cTnT with 1-year clinical outcomes among SCAD patients undergoing percutaneous coronary intervention. METHODS AND RESULTS Between 2010 and 2014, 6974 consecutive patients were prospectively enrolled in the Bern Percutaneous Coronary Interventions Registry. Among patients with SCAD (n=2029), 527 (26%) had elevated preprocedural hs-cTnT above the upper reference limit of 14 ng/L. The primary end point, mortality within 1 year, occurred in 20 patients (1.4%) with normal hs-cTnT versus 39 patients (7.7%) with elevated baseline hs-cTnT (P<0.001). Patients with elevated hs-cTnT had increased risks of all-cause (hazard ratio 5.73; 95% confidence intervals 3.34-9.83; P<0.001) and cardiac mortality (hazard ratio 4.68; 95% confidence interval 2.12-10.31; P<0.001). Preprocedural hs-TnT elevation remained an independent predictor of 1-year mortality after adjustment for relevant risk factors, including age, sex, and renal failure (adjusted hazard ratio 2.08; 95% confidence interval 1.10-3.92; P=0.024). A graded mortality risk was observed across higher tertiles of elevated preprocedural hs-cTnT, but not among patients with hs-cTnT below the upper reference limit. CONCLUSIONS Preprocedural elevation of hs-cTnT is observed in one fourth of SCAD patients undergoing elective percutaneous coronary intervention. Increased levels of preprocedural hs-cTnT are proportionally related to the risk of death and emerged as independent predictors of all-cause mortality within 1 year. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT02241291.

Human internal thoracic arteries from diabetic patients are resistant to endothelial dysfunction

The aim of this analysis was to compare vasoreactive properties of internal thoracic arteries (ITA) grafts from diabetic (DM) to those of non-diabetic (ND) patients. Ring segments of ITA, taken from patients undergoing coronary artery bypass grafting, were suspended in organ bath chambers filled with modified Krebs-Henseleit solution and contractile responses to potassium chloride (KCl), noradrenaline (NA), endothelin-1 (ET-l), and endothelium-dependent relaxant responses to acetylcholine (ACH) were recorded isometrically. The receptor-mediated agonists NA and ET-1 stimulated ITA from both groups within similar concentration ranges while ITA from DM patients proved to be significantly more sensitive to KCl than ITA from ND. Furthermore, maximal contractile responses indicated that KCl (3.79 +/- 0.30 g, n = 7 in DM and 2.50 +/- 0.23 g, n = 29 in ND, P < 0.05) evoked significantly higher responses in ITA from DM as compared to the ND control group while both NA and ET-l stimulated ITA from both groups with similar efficacies. Endothelium-dependent relaxant responses to ACH proved to be similar in both groups when expressed as percentages of the pre-existing tone. The present data support the contention that in comparison to ND controls arteries from DM patients are more sensitive to depolarization but endothelial dysfunction is less frequent in human ITA than expected from observations in systemic vascular beds.

Revascularization Treatment of Emergency Patients with Acute ST-Segment Elevation Myocardial Infarction in Switzerland: Results from a Nationwide, Cross-Sectional Study in Switzerland for 2010-2011

BACKGROUND: Cardiovascular diseases are the leading cause of death worldwide and in Switzerland. When applied, treatment guidelines for patients with acute ST-segment elevation myocardial infarction (STEMI) improve the clinical outcome and should eliminate treatment differences by sex and age for patients whose clinical situations are identical. In Switzerland, the rate at which STEMI patients receive revascularization may vary by patient and hospital characteristics. AIMS: To examine all hospitalizations in Switzerland from 2010-2011 to determine if patient or hospital characteristics affected the rate of revascularization (receiving either a percutaneous coronary intervention or a coronary artery bypass grafting) in acute STEMI patients. DATA AND METHODS: We used national data sets on hospital stays, and on hospital infrastructure and operating characteristics, for the years 2010 and 2011, to identify all emergency patients admitted with the main diagnosis of acute STEMI. We then calculated the proportion of patients who were treated with revascularization. We used multivariable multilevel Poisson regression to determine if receipt of revascularization varied by patient and hospital characteristics. RESULTS: Of the 9,696 cases we identified, 71.6% received revascularization. Patients were less likely to receive revascularization if they were female, and 80 years or older. In the multivariable multilevel Poisson regression analysis, there was a trend for small-volume hospitals performing fewer revascularizations but this was not statistically significant while being female (Relative Proportion = 0.91, 95% CI: 0.86 to 0.97) and being older than 80 years was still associated with less frequent revascularization. CONCLUSION: Female and older patients were less likely to receive revascularization. Further research needs to clarify whether this reflects differential application of treatment guidelines or limitations in this kind of routine data.

[Manifestation and course of coronary heart disease in men and women--consequences for diagnosis and treatment]

Gender related issues in manifestation, diagnosis and treatment of coronary artery disease are important but still not well recognized. Women are more likely to present late after first symptoms of myocardial infarction. Myocardial infarction is more often unrecognized. In regard to complications after myocardial infarctions ventricular tachycardia and cardiac arrest are more frequent and women are also more likely to develop heart failure or cardiogenic shock. The reason for this is most probably the fact that women presenting with myocardial infarction are of older age and have a higher incidence of co-morbidities. Thrombolysis and coronary angioplasty are less often performed in women in the setting of myocardial infarction. However there is a clear trend toward improvement of this situation during the last years. The reopening rate of occluded coronary arteries with thrombolysis and with coronary angioplasty is similar in women compared to men. Perioperative risk with aorto-coronary bypass surgery is higher in women, which can not be fully explained by higher age and co-morbidities. However 10 years survival rate after aorto-coronary bypass-surgery is similar for men and women, although occlusion of venous grafts is seen more often in women. The benefit of structured cardiac rehabilitation after an acute event is similar for younger and older women and as good as in men. Positive effects of cardiac rehabilitation include increased physical performance, reduction of body fat, improvement of lipid-profiles and an improvement of the psychosocial situation and quality of life.

Should intentional endovascular stent-graft coverage of the left subclavian artery be preceded by prophylactic revascularisation?

Thoracic endovascular aortic repair (TEVAR) has emerged as a promising therapeutic alternative to conventional open aortic replacement but it requires suitable proximal and distal landing zones for stent-graft anchoring. Many aortic pathologies affect in the immediate proximity of the left subclavian artery (LSA) limiting the proximal landing zone site without proximal vessel coverage. In patients in whom the distance between the LSA and aortic lesion is too short, extension of the landing zone can be obtained by covering the LSA's origin with the endovascular stent graft (ESG). This manoeuvre has the potential for immediate and delayed neurological and vascular symptoms. Some authors, therefore, propose prophylactic revascularisation of the LSA by transposition or bypass, while others suggest prophylactic revascularisation only under certain conditions, and still others see no requirement for prophylactic revascularisation in anticipation of LSA ostium coverage. In this review about LSA revascularisation in TEVAR patients with coverage of the LSA, we searched the electronic databases MEDLINE and EMBASE historically until the end date of May 2010 with the search terms left subclavian artery, covering, endovascular, revascularisation and thoracic aorta. We have gathered the most complete scientific evidence available used to support the various concepts to deal with this issue. After a review of the current available literature, 23 relevant articles were found, where we have identified and analysed three basic treatment concepts for LSA revascularisation in TEVAR patients (prophylactic, conditional prophylactic and no prophylactic LSA revascularisation). The available evidence supports prophylactic revascularisation of the LSA before ESG LSA coverage when preoperative imaging reveals abnormal supra-aortic vascular anatomy or pathology. We further conclude that elective patients undergoing planned coverage of the LSA during TEVAR should receive prophylactic LSA transposition or LSA-to-left-common-carotid-artery (LCCA) bypass surgery to prevent severe neurological complications, such as paraplegia or brain stem infarction.