Coronary atherosclerosis in unheralded sudden coronary death under age 50: histo-pathologic comparison with 'healthy' subjects dying out of hospital

Fucoxanthin alleviated atherosclerosis by regulating PI3K/AKT and TLR4/NFκB mediated pyroptosis in endothelial cells

Fucoxanthin, a type of natural xanthophyll carotenoid, is mainly present in seaweeds and various microalgae. This compound has been proved to possess multiple functions including antioxidation, anti-inflammation and anti-tumor. Atherosclerosis is widely deemed as a chronic inflammation disease, and as the basis of vascular obstructive disease. However, there is rare research about fucoxanthin's effects on atherosclerosis. In this study, we demonstrated that the plaque area of mice treated with fucoxanthin was significantly reduced compared to the group that did not receive fucoxanthin. In addition, Bioinformatics analysis showed that PI3K/AKT signaling might be involved in the protective effect of fucoxanthin, and this hypothesis was then verified in vitro endothelial cell experiments. Besides, our further results showed that endothelial cell mortality measured by TUNEL and flow cytometry was significantly increased in the oxidized low-density lipoprotein (ox-LDL) treatment group while significantly decreased in the fucoxanthin treatment group. In addition, the pyroptosis protein expression level in the fucoxanthin group was significantly lower than that in the ox-LDL group, which indicated that fucoxanthin improved the pyroptosis level of endothelial cells. Furthermore, it was revealed that TLR4/NFκB signaling were also participated in the protection of fucoxanthin on endothelial pyroptosis. Moreover, the protection of fucoxanthin on endothelial cell pyroptosis was abrogated when PI3K/AKT was inhibited or TLR4 was overexpressed, which further suggested the anti-pyroptosis effect of fucoxanthin was mediated through regulations of PI3K/AKT and TLR4/NFκB signaling.

Diagnostic Cardiac CT for the Improvement of Cardiovascular Event Prediction

BACKGROUND

The aim of the long-term Heinz Nixdorf Recall Study (observation period 20 years) was to establish the extent to which computed tomography (CT) improves the predictability of cardiovascular events relative to determination of risk factors alone.

METHODS

In the period 2000-2003, study staff examined 4355 probands (53% of them female) aged 45-75 years with no signs of cardiovascular disease. The Atherosclerotic Cardiovascular Disease (ASCVD) score was calculated on the basis of demographic data and cardiovascular risk factors. Cardiac CT was carried out over the same period and coronary artery calcification (CAC) was graded according to the Agatston score.

RESULTS

The median duration of follow-up was 18.2 years for men and 17.8 years for women. Myocardial infarction or stroke occurred in 458 (11%) of the 4154 participants with complete data. Overall, estimation of risk using a combination of ASCVD score and CAC grade was superior to the ASCVD score alone-even after 10 and 20 years. Classification into established risk categories improved by 12.2% (95% confidence interval: [5.3%; 18.1%]). In the highest ASCVD risk category, we observed occurrence of a cardiovascular event over 20 years for 14% [5.0%; 23.1%] of probands with a CAC score = 0 but for 34.2% [27.5%; 41.4%] of those with a CAC score ≥ 400. In the lowest ASCVD risk category, an event occurred in 2.4% [1.4%; 3.7%] of probands with a CAC score = 0 and in 23.5% [2.3%; 35.8%] of those with a CAC score ≥ 400.

CONCLUSION

Even after 20 years, individual risk prediction is improved by addition of CT-based determination of coronary artery calcification to the ASCVD score. Therefore, assessment of ASCVD risk factors should be complemented more widely by cardiac CT in the primary prevention of cardiovascular disease.

Comparison of the Agatston score acquired with photon-counting detector CT and energy-integrating detector CT: ex vivo study of cadaveric hearts

The purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50-150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-processing multimodality workplace. The best match with Sa36 was PCD-CT Qr36 images, at a monoenergetic level of 72 keV. Statistical analyses showed excellent correlation and agreement. The correlation and agreement with regards to the Agatston score (AS) between the two methods, for each position as well as between the two positions for each method, were assessed with the Spearman´s rank correlation. The correlation coefficient, rho, was 0.98 and 0.97 respectively 0.99 and 0.98. The corresponding agreements were investigated by means of Bland-Altman plots. High correlation and agreement was observed between the AS derived from the EID-CT and a PCD-CT. Both methods also demonstrated excellent reproducibility.

Relationship of age, atherosclerosis and angiographic stenosis using artificial intelligence

Objective

The study evaluates the relationship of coronary stenosis, atherosclerotic plaque characteristics (APCs) and age using artificial intelligence enabled quantitative coronary computed tomographic angiography (AI-QCT).

Methods

This is a post-hoc analysis of data from 303 subjects enrolled in the CREDENCE (Computed TomogRaphic Evaluation of Atherosclerotic Determinants of Myocardial IsChEmia) trial who were referred for invasive coronary angiography and subsequently underwent coronary computed tomographic angiography (CCTA). In this study, a blinded core laboratory analysing quantitative coronary angiography images classified lesions as obstructive (≥50%) or non-obstructive (<50%) while AI software quantified APCs including plaque volume (PV), low-density non-calcified plaque (LD-NCP), non-calcified plaque (NCP), calcified plaque (CP), lesion length on a per-patient and per-lesion basis based on CCTA imaging. Plaque measurements were normalised for vessel volume and reported as % percent atheroma volume (%PAV) for all relevant plaque components. Data were subsequently stratified by age <65 and ≥65 years.

Results

The cohort was 64.4±10.2 years and 29% women. Overall, patients >65 had more PV and CP than patients <65. On a lesion level, patients >65 had more CP than younger patients in both obstructive (29.2 mm³ vs 48.2 mm³; p<0.04) and non-obstructive lesions (22.1 mm³ vs 49.4 mm³; p<0.004) while younger patients had more %PAV (LD-NCP) (1.5% vs 0.7%; p<0.038). Younger patients had more PV, LD-NCP, NCP and lesion lengths in obstructive compared with non-obstructive lesions. There were no differences observed between lesion types in older patients.

Conclusion

AI-QCT identifies a unique APC signature that differs by age and degree of stenosis and provides a foundation for AI-guided age-based approaches to atherosclerosis identification, prevention and treatment.

Cardiac computed tomographic evaluation of coronary artery calcification: A review

Vascular calcification is most commonly due to atherosclerosis. It has been well documented that absence of coronary calcification on a chest CT (CCT) is associated with low cardiovascular events and good prognosis. High CT calcium scores often result in a higher incidence of cardiovascular events and worse survival. In asymptomatic patients with an intermediate risk for coronary artery disease, numerous studies have shown Coronary Calcium Scoring (CCS) has prognostic relevance and incremental prognostic value over conventional risk stratification. CT detected calcium score plays important role in patient management. This article will review various CT based coronary artery calcium scoring methods.

Genetic variations in G-protein signal pathways influence progression of coronary artery calcification: Results from the Heinz Nixdorf Recall study

BACKGROUND AND AIMS

Coronary artery calcification (CAC) is one of the most sensitive and specific markers of coronary atherosclerosis and believed to be heritable. We hypothesized that functionally relevant single-nucleotide polymorphisms (SNPs) in the G-protein signal pathway, which have been previously related to coronary artery disease, are associated with CAC progression.

METHODS

3108 participants from the Heinz Nixdorf Recall study with CAC measurements at both baseline (CACb) and 5-year follow-up (CAC5y) were included. We genotyped SNPs rs1042714 (ADRB2), rs6026584 and rs12481583 (GNAS), and rs5443 (GNB3) and defined a priori risk alleles derived from literature data. Regression analyses were applied to measures of 5-year CAC progression, unadjusted, adjusted for age, sex, and adjusted for age, sex, log(CACb+1) as well as for cardiovascular risk factors.

RESULTS

The presence of one or more risk alleles was associated with a 26.9% (95% CI 5.5-52.4) increase in 5-year CAC progression (p = 0.011) and a 29.2% (95% CI 5.9-57.6) accelerated increase of CAC over the 5-year period compared to what was expected with respect to the baseline CAC percentile value (p = 0.012). Each of those risk alleles increased the 5-year CAC progression by 4.4% (95% CI 1.3-7.6, p = 0.006) and resulted in a 4.9% accelerated increase of CAC over the 5-year period (95% CI 1.6-8.4, p = 0.004). These unadjusted data did not change after adjustment.

CONCLUSIONS

Genetic variations in the G-protein signal pathway are associated with CAC progression in a cumulative fashion, indicating the importance of the pathway for genetic heritability in CAC progression and coronary artery disease.

Association of Rivaroxaban With Thromboembolic Events in Patients With Heart Failure, Coronary Disease, and Sinus Rhythm: A Post Hoc Analysis of the COMMANDER HF Trial

Importance

Whether anticoagulation benefits patients with heart failure (HF) in sinus rhythm is uncertain. The COMMANDER HF randomized clinical trial evaluated the effects of adding low-dose rivaroxaban to antiplatelet therapy in patients with recent worsening of chronic HF with reduced ejection fraction, coronary artery disease (CAD), and sinus rhythm. Although the primary end point of all-cause mortality, myocardial infarction, or stroke did not differ between rivaroxaban and placebo, there were numerical advantages favoring rivaroxaban for myocardial infarction and stroke.

Objective

To examine whether low-dose rivaroxaban was associated with reduced thromboembolic events in patients enrolled in the COMMANDER HF trial.

Design, Setting, and Participants

Post hoc analysis of the COMMANDER HF multicenter, randomized, double-blind, placebo-controlled trial in patients with CAD and worsening HF. The trial randomized 5022 patients postdischarge from a hospital or outpatient clinic after treatment for worsening HF between September 2013 and October 2017. Patients were required to be receiving standard care for HF and CAD and were excluded for a medical condition requiring anticoagulation or a bleeding history. Patients were randomized in a 1:1 ratio. Analysis was conducted from June 2018 and January 2019.

Intervention

Patients were randomly assigned to receive 2.5 mg of rivaroxaban given orally twice daily or placebo in addition to their standard therapy.

Main Outcomes and Measures

For this post hoc analysis, a thromboembolic composite was defined as either (1) myocardial infarction, ischemic stroke, sudden/unwitnessed death, symptomatic pulmonary embolism, or symptomatic deep venous thrombosis or (2) all of the previous components except sudden/unwitnessed deaths because not all of these are caused by thromboembolic events.

Results

Of 5022 patients, 3872 (77.1%) were men, and the overall mean (SD) age was 66.4 (10.2) years. Over a median (interquartile range) follow-up of 19.6 (11.7-30.8) months, fewer patients assigned to rivaroxaban compared with placebo had a thromboembolic event including sudden/unwitnessed deaths: 328 (13.1%) vs 390 (15.5%) (hazard ratio, 0.83; 95% CI, 0.72-0.96; P = .01). When sudden/unwitnessed deaths were excluded, the results analyzing thromboembolic events were similar: 153 (6.1%) vs 190 patients (7.6%) with an event (hazard ratio, 0.80; 95% CI, 0.64-0.98; P = .04).

Conclusions and Relevance

In this study, thromboembolic events occurred frequently in patients with HF, CAD, and sinus rhythm. Rivaroxaban may reduce the risk of thromboembolic events in this population, but these events are not the major cause of morbidity and mortality in patients with recent worsening of HF for which rivaroxaban had no effect. While consistent with other studies, these results require confirmation in prospective randomized clinical trials.

Trial Registration

ClinicalTrials.gov identifier: NCT01877915.

Impact of socioeconomic status on coronary artery calcification

Background

Low socioeconomic status is associated with an increased risk of coronary artery disease, but few studies have investigated the potential link between living in an area with a low versus a high socioeconomic status and coronary artery calcification, a marker of subclinical coronary artery disease.

Design

The design of this study was a cross-sectional study.

Methods

We evaluated 1067 participants with no history of coronary artery disease from the pilot phase of the Swedish CArdioPulmonary bioImage Study (SCAPIS). Men and women aged 50–64 years were recruited from three high-socioeconomic status ( n = 541) and three low-socioeconomic status ( n = 526) areas in the city of Gothenburg (550,000 inhabitants). The coronary artery calcification score was assessed with the Agatston method using computed tomography, with individuals classified into either no coronary calcification ( n = 625; mean age, 57 years) or any coronary artery calcification ( n = 442; mean age, 59 years (men, 68.5%)).

Results

Coronary artery calcification was present in 244 (46.3%) and 198 (36.6%) individuals from the low- and high-socioeconomic status areas, respectively. Participants from the low-socioeconomic status areas had a significantly higher risk factor burden. In a multivariable logistic regression model with adjustment for age, sex and cardiovascular risk factors, the odds for coronary artery calcification were not significantly higher among persons living in low-socioeconomic status areas (odds ratio = 1.18, 95% confidence interval = 0.87–1.60).

Conclusion

In this relatively small cross-sectional study, we observed an association between living in a low-socioeconomic status area and coronary artery calcification. However, this was mostly explained by higher levels of cardiovascular disease risk factors, indicating that the effect of socioeconomic status on the atherosclerotic process works through an increased burden of cardiovascular disease risk factors.

Echocardiographic calcification score in patients with low/intermediate cardiovascular risk

PURPOSE

Calcification of aortic valve and mitral annulus is associated with cardiovascular risk factors, morbidity and mortality. Assessment of cardiac calcification with echocardiography is feasible, however, only few structured scoring systems have been established so far with limited prognostic data. This study aimed to evaluate an echocardiographic calcification score (echo-CCS) in patients with low/intermediate cardiovascular risk.

METHODS

Digitally stored echocardiography studies of 151 patients (median age 64, 49.7% male) from February 2008 to December 2009 were retrospectively reviewed for calcifications of the aortic valve, aortic root, mitral annulus, papillary muscles and ventricular septum. A calcification score ranging from 0 to 5 was assigned to every patient and its relation to computed tomography calcium score, coronary stenosis and ESC SCORE was assessed. Follow-up data were collected from 149 patients (98.7%) with a median of 6.2 years. Logistic regression and Kaplan-Meier analysis were performed to assess the association of the echo-CCS with significant coronary artery disease (≥ 50% stenosis) and risk for cardiac events and all-cause mortality.

RESULTS

An association of the echo-CCS with the ESC SCORE (ρ = 0.5; p < 0.001) and a good correlation of the echo-CCS with the Agatston score (ρ = 0.73; p < 0.001) can be observed. Univariate regressions revealed that echo-CCS is a significant predictor for cardiac events [OR = 5.1 (CI: 1.7-15.0); p = 0.003], coronary intervention [OR = 2.8 (CI: 1.3-5.7); p = 0.006], hospitalisation for cardiac symptoms [OR = 2.0 (CI: 1.2-3.4); p = 0.007], all-cause mortality [OR = 2.6 (CI: 1.3-5.5); p = 0.01] and significant CAD [OR = 3.2 (CI: 1.9-5.4); p < 0.001].

CONCLUSIONS

We demonstrated the prevalence of an easily obtainable, radiation-free calcification score in patients with low/intermediate cardiovascular risk. The strong association with CT-calcium scoring may evoke its potential as an alternative method in CV risk assessment.

A Comparative Study of Coronary Atherosclerosis in Young and Old

INTRODUCTION

Atherosclerotic coronary artery disease is an important cause of sudden and unexpected deaths in the young people. It is assumed that thrombosis and plaque hemorrhage are commonly associated with sudden deaths from coronary atherosclerosis in the young. In this study, we compared the histological patterns of atherosclerosis in young and old populations to see whether an association exists between the histological pattern of atherosclerosis in the young and thrombosis or plaque hemorrhage.

METHODS AND RESULTS

All autopsy cases of coronary atherosclerosis in young people (aged younger than 40 years) in comparison with an equal number of randomly selected older people (older than 65 years) over a period of 4 and a half years in the Provincial Forensic Pathology Unit of the Ontario Forensic Pathology Service in Toronto, Canada, were reviewed to characterize the gross and histologic appearance. There were 28 cases of atherosclerosis in young people ("the young"). Twenty-three (82%) of the young had eccentric atherosclerosis compared with 11 (39%) of the old. An inflammatory response was seen in all 28 (100%) of the young in comparison with 17 (61%) of the old. Thirteen (47%) of the young compared with 3 (11%) of the old had thrombosis, whereas 9 (32%) of the young and 17 (61%) of the old had plaque hemorrhage. Pultaceous debris was the principal component in 11 atherosclerotic plaques (39%) in the young, followed by foam cells in 7 (25%). In the older group, pultaceous debris was the principal component in 18 (64%) followed by dense fibrous tissue in 5 (18%).

CONCLUSIONS

The morphology in coronary atherosclerosis of the young is significantly different from the old. Coronary atherosclerosis in the young commonly shows an eccentric distribution with associated inflammation. Thrombosis is commoner among the young, whereas plaque hemorrhage is commoner among the old.

Sudden cardiac death associated with premature atheroma in the young: an autopsy study emphasising single-vessel lesions

Aims This is the first autopsy study in the United Kingdom to analyse the demographic and pathological characteristics of atheroma associated with sudden cardiac death in young people.

METHODS

An observational retrospective study of referred cases of sudden cardiac death in the young (⩽35 years) associated with premature atheroma was carried out.

RESULTS

In total, 46 cases were referred, with a median age of 30 years (27, 32); 72% of the referred cases were male, with a mean body mass index of 30 kg/m2. Circumstances of death were as follows: at rest (n=21), exertion (n=7), in bed (n=7), related to drugs/alcohol (n=4), and unknown (n=7). A previous cardiac history was provided in 10 cases. A history of class A/B drug use was found in eight cases. There was macroscopic evidence of infarction in 10 cases (acute, n=3 and chronic, n=7). Microscopically, 10 cases demonstrated contraction band necrosis, 11 acute infarction, and 11 chronic infarction. Single-vessel disease predominated (n=28). The left anterior descending coronary artery was involved in 39/46 cases. Thrombosis was seen in 16 cases, mainly due to erosion; one case showed dual pathology with arrhythmogenic right ventricular cardiomyopathy and another showed left ventricular hypertrophy.

CONCLUSIONS

This study highlights premature atheroma mainly in a single vessel in young people with or without evidence of ischaemic damage in the ventricle. Dual pathology may occur. The role of arrhythmias and channelopathies are important considerations. Premature atheroma should prompt investigation for dyslipidaemias in family members.

Coronary atherosclerosis evaluation among Iranian patients with zero coronary calcium score in computed tomography coronary angiography

BACKGROUND

Coronary artery calcification (CAC) is a specific indicator of and a sensitive marker for the atherosclerotic disease process. However, calcium scoring may miss noncalcified plaques with clinical importance. The present study aimed to identify the presence and extent of coronary plaques in computed tomography coronary angiography (CTCA) in patients with a zero CAC score and the secondary endpoint was to evaluate the association between coronary risk factors and the presence of noncalcified plaques.

MATERIALS AND METHODS

In a retrospective descriptive-analytic study, a total of 2000 consecutive patients who undergone CTCA between September 2012 and September 2014 at Alzahra Hospital in Isfahan, Iran were analyzed. Three hundred and eighty-five patients with a zero calcium score were included in the study. The demographic information and coronary artery disease (CAD), risk factors including diabetes mellitus (DM), hypertension, hyperlipidemia, smoking, and family history of CAD, were obtained from the questionnaire. Furthermore, the presence of plaques and extent of stenosis were evaluated in patients with zero CAC score.

RESULTS

Of the 385 patients with a zero calcium score, 16 (4.2%) had atherosclerotic plaques. Among them, 6 (1.6%) had significant (>50%) coronary stenosis, and 10 (2.6%) had no significant (<50%) coronary stenosis. Hyperlipidemia, DM, and smoking were significantly associated with obstructive CAD. Furthermore, in patients with zero calcium score, DM, hyperlipidemia, and smoking had odds ratios of 5.9, 14, and 32.5 for the development of coronary artery plaques, respectively.

CONCLUSION

Although, CAC scoring is a noninvasive and valuable method to evaluate CAD; but zero CAC score does not absolutely exclude the CAD, especially in the presence of risk factors such as diabetes, hyperlipidemia, and smoking.

Cardiac CT angiography for evaluation of acute chest pain

Chest pain is the second most common emergency department (ED) presentation in the United States. Cardiac computed tomography angiography (CCTA) now plays an important role in the evaluation of patients with suspected acute coronary syndrome in the ED setting. In this article, we review the available techniques focused on the use of CCTA to evaluate patients fosr coronary atherosclerosis for timely triage of acute chest pain.

Coronary CT angiography in managing atherosclerosis

Invasive coronary angiography (ICA) was the only method to image coronary arteries for a long time and is still the gold-standard. Technology of noninvasive imaging by coronary computed-tomography angiography (CCTA) has experienced remarkable progress during the last two decades. It is possible to visualize atherosclerotic lesions in the vessel wall in contrast to “lumenography” performed by ICA. Coronary artery disease can be ruled out by CCTA with excellent accuracy. The degree of stenoses is, however, often overestimated which impairs specificity. Atherosclerotic lesions can be characterized as calcified, non-calcified and partially calcified. Calcified plaques are usually quantified using the Agatston-Score. Higher scores are correlated with worse cardiovascular outcome and increased risk of cardiac events. For non-calcified or partially calcified plaques different angiographic findings like positive remodelling, a large necrotic core or spotty calcification more frequently lead to myocardial infarctions. CCTA is an important tool with increasing clinical value for ruling out coronary artery disease or relevant stenoses as well as for advanced risk stratification.

Association between tissue characteristics of coronary plaque and distal embolization after coronary intervention in acute coronary syndrome patients: insights from a meta-analysis of virtual histology-intravascular ultrasound studies

Background and Objectives

The predictive value of plaque characteristics assessed by virtual histology-intravascular ultrasound (VH-IVUS) including fibrous tissue (FT), fibrofatty (FF), necrotic core (NC) and dense calcium (DC) in identifying distal embolization after percutaneous coronary intervention (PCI) is still controversial. We performed a systematic review and meta-analysis to summarize the association of pre-PCI plaque composition and post-PCI distal embolization in acute coronary syndrome patients.

Methods

Studies were identified in PubMed, OVID, EMBASE, the Cochrane Library, the Current Controlled Trials Register, reviews, and reference lists of relevant articles. A meta-analysis using both fixed and random effects models with assessment of study heterogeneity and publication bias was performed.

Results

Of the 388 articles screened, 10 studies with a total of 872 subjects (199 with distal embolization and 673 with normal flow) met the eligibility of our study. Compared with normal flow groups, significant higher absolute volume of NC [weighted mean differences (WMD): 5.79 mm³, 95% CI: 3.02 to 8.55 mm³; p<0.001] and DC (WMD: 2.55 mm³, 95% CI: 0.22 to 4.88 mm³; p = 0.03) were found in acute coronary syndrome patients with distal embolization. Further subgroup analysis demonstrated that the predictive value of tissue characteristics in determining distal embolization was correlated to clinical scenario of the patients, definition of distal embolization, and whether the percutaneous aspiration thrombectomy was applied.

Conclusion

Our study that pooled current evidence showed that plaque components were closely related to the distal embolization after PCI, especially the absolute volume of NC and DC, supporting further studies with larger sample size and high-methodological quality.

Assessment of atherosclerosis in chronic granulomatous disease

BACKGROUND

Patients with chronic granulomatous disease (CGD) experience immunodeficiency because of defects in the phagocyte NADPH oxidase and the concomitant reduction in reactive oxygen intermediates. This may result in a reduction in atherosclerotic injury.

METHODS AND RESULTS

We prospectively assessed the prevalence of cardiovascular risk factors, biomarkers of inflammation and neutrophil activation, and the presence of magnetic resonance imaging and computed tomography quantified subclinical atherosclerosis in the carotid and coronary arteries of 41 patients with CGD and 25 healthy controls in the same age range. Univariable and multivariable associations among risk factors, inflammatory markers, and atherosclerosis burden were assessed. Patients with CGD had significant elevations in traditional risk factors and inflammatory markers compared with control subjects, including hypertension, high-sensitivity C-reactive protein, oxidized low-density lipoprotein, and low high-density lipoprotein. Despite this, patients with CGD had a 22% lower internal carotid artery wall volume compared with control subjects (361.3±76.4 mm(3) versus 463.5±104.7 mm(3); P<0.001). This difference was comparable in p47(phox)- and gp91(phox)-deficient subtypes of CGD and independent of risk factors in multivariate regression analysis. In contrast, the prevalence of coronary arterial calcification was similar between patients with CGD and control subjects (14.6%, CGD; 6.3%, controls; P=0.39).

CONCLUSIONS

The observation by magnetic resonance imaging and computerized tomography of reduced carotid but not coronary artery atherosclerosis in patients with CGD despite the high prevalence of traditional risk factors raises questions about the role of NADPH oxidase in the pathogenesis of clinically significant atherosclerosis. Additional high-resolution studies in multiple vascular beds are required to address the therapeutic potential of NADPH oxidase inhibition in cardiovascular diseases.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01063309.

Risk loci for coronary artery calcification replicated at 9p21 and 6q24 in the Heinz Nixdorf Recall Study

Background

Atherosclerosis is the primary cause of coronary heart disease (CHD), preceding the onset of cardiovascular disease by decades in most cases. Here we examine the association between single nucleotide polymorphisms (SNPs) integrated on Metabochip and coronary artery calcification (CAC), a valid risk factor for CHD, in an unselected, population-based German cohort.

Methods

The Metabochip is a custom iSELECT array containing >195,000 SNPs that was designed to support large-scale follow-up of putative associations for metabolic and cardiovascular-associated traits. We used generalized linear regression models to explore the impact of Metabochip SNPs on quantitative CAC in 4,329 participants.

Results

The 9p21 variant, rs1537373, was most strongly associated (Beta = 0.30; 95% confidence interval (CI) = 0.21-0.39; p = 4.05x10^-11) with quantitative CAC. The second strongest association with CAC was with rs9349379 in the phosphatase and actin regulator 1 gene, PHACTR1, (Beta = 0.30; 95% CI = 0.22-0.40; p = 4.67x10^-11). Both SNPs remained nominally significant in dichotomized analyses for the presence of any CAC (odds ratio_rs1537373 (OR) = 1.19; 95% CI = 1.07-1.31; p = 0.001 and OR_rs9349379 = 1.26; 95% CI = 1.14-1.40); p = 1.5x10^-5). Fine mapping of the 9p21 and PHACTR1 gene region revealed several other SNPs that were strongly associated with CAC.

Conclusion

We demonstrate that SNPs near 9p21 and in PHACTR1 that have previously been shown to be associated with CHD are strongly associated with CAC in the Heinz Nixdorf Recall Study cohort. Our findings suggest that the 9p21 and 6q24 loci might be involved in cardiac outcome via promoting development of atherosclerosis in the coronary arteries.

Pheidippides redux: reducing risk for acute cardiac events during marathon running

Prolonged strenuous exercise such as marathon running transiently increases the absolute and relative risk for sudden cardiac death. A 17-fold increase in the latter over resting baseline in previously sedentary middle-aged men is reduced due to cardioprotection from training in experienced marathon runners. Exertional rhabdomyolysis as a common occurrence during the race is accompanied by neutrophilia and elevated biomarkers of inflammation, including interleukin-6 and C-reactive protein. A hemostatic imbalance with prothrombotic effects includes in vivo platelet activation during the race. Suggesting a pathogenic role for these findings, plaque rupture due to atherothrombosis triggers acute exertional cardiac events, including sudden death, in low-risk runners as in high-risk patients such as those with diabetes mellitus. Strategies including prophylactic aspirin are considered to decrease the risk for acute cardiac events.

Women have less severe and extensive coronary atherosclerosis in fatal cases of ischemic heart disease: an autopsy study

OBJECTIVE

The study aims to evaluate sex differences in extent and severity of coronary artery disease (CAD) and myocardial findings at autopsy among young people with fatal ischemic heart disease (IHD).

BACKGROUND

Women with acute coronary syndrome are less likely than men to display obstructive CAD at angiography. This suggests unique mechanisms of acute coronary syndrome exist in women or may reflect prehospital death of women with the most severe CAD.

METHODS

Reports of autopsies by the Office of the Chief Medical Examiner of New York City on people aged 21 to 54 years who died between January 1, 2006, and December 31, 2008, were reviewed. A total of 639 cases of death due to atherosclerotic or arteriosclerotic cardiovascular disease according to the medical examiner were analyzed. Significant CAD was defined as ≥75% cross-sectional area stenosis in an epicardial vessel or ≥50% left main.

RESULTS

Women were less likely to have obstructive CAD (63% vs 77% of men, P = .002). There was pathologic evidence of myocardial infarction (MI) in 43% of cases, 17% of which had nonobstructive CAD. Frequency of MI did not vary by sex overall (38% of women vs 45% of men, P = .18) or among those without significant CAD (23% vs 29%, P = .45).

CONCLUSIONS

Among young people determined at autopsy to have died of IHD, fewer women had obstructive CAD, consistent with angiographic data in other IHD syndromes. Pathologic evidence of MI may exist in the absence of obstructive CAD.

Etiology of sudden death in the community: results of anatomical, metabolic, and genetic evaluation

BACKGROUND

Identifying persons at risk for sudden cardiac death (SCD) is challenging. A comprehensive evaluation may reveal clues about the clinical, anatomical, genetic, and metabolic risk factors for SCD.

METHODS

Seventy-one patients who had SCD (25-60 years old) without an initially apparent cause of death were evaluated at the Hennepin County Medical Examiner's office (Minneapolis, MN) from August 2001 to July 2004. We reviewed their clinic records conducted next-of-kin interviews and performed autopsy, laboratory testing, and genetic analysis for mutations in genes associated with the long QT syndrome.

RESULTS

Mean age was 49.5 +/- 7 years, 86% were male, and 2 subjects had history of coronary heart disease (CHD). Coronary risk factors were highly prevalent in comparison to individuals of the same age group in this community (eg, smoking 61%, hypertension 27%, hyperlipidemia 25%) but inadequately treated. On autopsy, 80% of the subjects had high-grade coronary stenoses. Acute coronary lesions and previous silent myocardial infarction (MI) were found in 27% and 34%, respectively. Furthermore, 32% of the subjects had recently smoked cigarettes, and 50% had ingested analgesics. Possible deleterious mutations of the ion channel genes were detected in 5 subjects (7%). Of these, 4 were in the sodium channel gene SCN5A.

CONCLUSIONS

Most of the persons who had SCD in the community had severe subclinical CHD, including undetected previous MI. Traditional coronary risk factors were prevalent and undertreated. Mutations in the long QT syndrome genes were detected in a few subjects. These findings imply that improvements in the detection and treatment of subclinical CHD in the community are needed to prevent SCD.

Focus on collagen: in vitro systems to study fibrogenesis and antifibrosis state of the art

Fibrosis represents a major global disease burden, yet a potent antifibrotic compound is still not in sight. Part of the explanation for this situation is the difficulties that both academic laboratories and research and development departments in the pharmaceutical industry have been facing in re-enacting the fibrotic process in vitro for screening procedures prior to animal testing. Effective in vitro characterization of antifibrotic compounds has been hampered by cell culture settings that are lacking crucial cofactors or are not holistic representations of the biosynthetic and depositional pathway leading to the formation of an insoluble pericellular collagen matrix. In order to appreciate the task which in vitro screening of antifibrotics is up against, we will first review the fibrotic process by categorizing it into events that are upstream of collagen biosynthesis and the actual biosynthetic and depositional cascade of collagen I. We point out oversights such as the omission of vitamin C, a vital cofactor for the production of stable procollagen molecules, as well as the little known in vitro tardy procollagen processing by collagen C-proteinase/BMP-1, another reason for minimal collagen deposition in cell culture. We review current methods of cell culture and collagen quantitation vis-à-vis the high content options and requirements for normalization against cell number for meaningful data retrieval. Only when collagen has formed a fibrillar matrix that becomes cross-linked, invested with ligands, and can be remodelled and resorbed, the complete picture of fibrogenesis can be reflected in vitro. We show here how this can be achieved. A well thought-out in vitro fibrogenesis system represents the missing link between brute force chemical library screens and rational animal experimentation, thus providing both cost-effectiveness and streamlined procedures towards the development of better antifibrotic drugs.

Progression and observational frequency of atheromatous plaques in autopsied coronary arteries

Background and Objectives

Virtual histology-intravascular ultrasound (VH-IVUS) studies on early-stage fibroatheroma, the probable precursor lesion of progression to thin-cap fibroatheroma (TCFA), have only rarely been done in man. We investigated the progression and observational frequency of fibroatheromas, and compared plaque components between early-stage and advance-staged fibroatheromas in the general population.

Subjects and Methods

We assessed coronary fibroatheromas using VH-IVUS and histopathologic analysis of 109 coronary lesions from 40 autopsied cases that were not due to sudden cardiac death (NSCD cases). Fibroatheromas were grouped into early fibroatheroma, late fibroatheroma, thick-cap fibroatheroma (TkCFA), and thin-cap fibroatheroma.

Results

Mean patient age was 45±11 years old and 71% were males. Of 109 lesions, 27% were early fibroatheromas, 53% late fibroatheromas, 9% TkCFA, and 11% TCFA. VH-IVUS showed that there was relatively less fibrotic and fibrofatty plaque and more dense calcium deposits as fibroatheromas progressed. Furthermore, the relative amounts of fibrotic and fibrofatty plaque decreased (r=0.773, p<0.001 and r=0.538, p<0.001, respectively) as the necrotic core increased, while the relative area of dense calcium increased (r=0.665, p<0.001) as the size of the necrotic core increased.

Conclusion

Of NSCD cases in Korea, 27% were early fibroatheromas, 53% were late fibroatheromas, 9% were TkCFA, and 11% were TCFA. Advance-staged fibroatheromas show more necrotic core volume and more dense calcium than small, early-stage fibroatheromas.

Relationship between LDL, HDL, blood pressure and atheroma progression in the coronaries

PURPOSE OF REVIEW

To highlight clinical trials that have employed coronary artery imaging to evaluate the impact of medical therapies that target established cardiovascular risk factors.

RECENT FINDINGS

High resolution imaging of the entire vessel wall permits assessment of changes in the full extent of coronary atherosclerosis. Intensive lowering of LDL cholesterol and systolic blood pressure are associated with the greatest benefit in terms of slowing disease progression. Therapeutic approaches that promote the biological activity of HDL have the potential to promote regression of atherosclerotic plaque. Targeting inflammatory cascades may also have a beneficial effect on the extent and composition of coronary plaque.

SUMMARY

Intensive modification of established risk factors has a profound impact on the natural history of atheroma progression.

Oxysterols in heart failure

Oxysterols are biologically active molecules that result from the oxidation of cholesterol. Several oxysterols are found in macrophages and macrophage-derived 'foam cells' in atherosclerotic tissue. Lipophilic oxysterols penetrate cell membranes and, therefore, their concentrations can reach harmful levels in endothelial and smooth muscle cells located in close proximity to the atherosclerotic plaques or inflammatory zones. New findings suggest that the effects of oxysterols on cardiomyocytes can lead to cell hypertrophy and death. This may make oxysterols one of the major factors precipitating morbidity in atherosclerosis-induced cardiac diseases and inflammation-induced heart complications. The pathological actions of oxysterols on muscle cells were shown to depend on dysfunctional Ca(2+) signaling; however, the mechanisms of the effects remain to be elucidated. Understanding the effects of oxysterols could lead to therapies that modulate malfunction of cardiomyocytes. This review discusses the experimental findings and the relevance of oxysterols to heart failure, and suggests strategies for important future investigations.

Predictors of resuscitation outcome in a swine model of VF cardiac arrest: A comparison of VF duration, presence of acute myocardial infarction and VF waveform

INTRODUCTION

Factors that affect resuscitation to a perfusing rhythm (ROSC) following ventricular fibrillation (VF) include untreated VF duration, acute myocardial infarction (AMI), and possibly factors reflected in the VF waveform. We hypothesized that resuscitation of VF to ROSC within 3min is predicted by the VF waveform, independent of untreated VF duration or presence of acute MI.

METHODS

AMI was induced by the occlusion of the left anterior descending coronary artery. VF was induced in normal (N=30) and AMI swine (N=30). Animals were resuscitated after untreated VF of brief (2min) or prolonged (8min) duration. VF waveform was analyzed before the first shock to compute the amplitude-spectral area (AMSA) and slope.

RESULTS

Unadjusted predictors of ROSC within 3min included untreated VF duration (8min vs 2min; OR 0.11, 95%CI 0.02-0.54), AMI (AMI vs normal; OR 0.11, 95%CI 0.02-0.54), AMSA (highest to lowest tertile; OR 15.5, 95%CI 1.7-140), and slope (highest to lowest tertile; OR 12.7, 95%CI 1.4-114). On multivariate regression, untreated VF duration (P=0.011) and AMI (P=0.003) predicted ROSC within 3min. Among secondary outcome variables, favorable neurological status at 24h was only predicted by VF duration (OR 0.22, 95% CI 0.05-0.92).

CONCLUSIONS

In this swine model of VF, untreated VF duration and AMI were independent predictors of ROSC following VF cardiac arrest. AMSA and slope predicted ROSC when VF duration or the presence of AMI were unknown. Importantly, the initial treatment of choice for short duration VF is defibrillation regardless of VF waveform.

Atherosclerotic progression attenuates the expression of Nogo-B in autopsied coronary artery: pathology and virtual histology intravascular ultrasound analysis

The relation of Nogo-B to atherosclerotic plaque progression is not well understood. Thus, the purpose of this study was to assess the expression of Nogo-B in fibroatheromas (FA) of different stages, classified using virtual histology intravascular ultrasound (VH-IVUS) analysis in 19 autopsied cases of non-sudden cardiac death. VH-IVUS imaging analysis was performed 30 mm from the ostium of each coronary artery. VH-IVUS revealed 11 early FAs (34.5+/-8.3 yr), 12 late FAs (42.6+/-16.6 yr), 8 thick-cap FAs (TkCFAs) (46.4+/-11.1 yr), and 6 thin-cap FAs (TCFAs) (51.8+/-6.8 yr). TkCFAs and TCFAs were defined as advanced FA. FA progression advanced with age (P=0.04). VH-IVUS analysis of small, early FAs showed smaller necrotic cores and relatively less calcium compared to more advanced FAs with large necrotic cores (P<0.001). Histopathology and immunohistochemical stains demonstrated that early or late FAs had smaller necrotic cores, less empty space of decalcification, and greater Nogo-B expression compared to advanced FAs (vs. early FA, P=0.013; vs. late FA, P=0.008, respectively). These findings suggest that FA progression is inversely associated with Nogo-B expression. Local reduction of Nogo-B may contribute to plaque formation and/or instability.

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a 'negative autopsy' in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.

Preshock cardiopulmonary resuscitation worsens outcome from circulatory phase ventricular fibrillation with acute coronary artery obstruction in swine

BACKGROUND

Some clinical studies have suggested that chest compressions before defibrillation improve survival in cardiac arrest because of prolonged ventricular fibrillation (VF; ie, within the circulatory phase). Animal data have also supported this conclusion, and we have previously demonstrated that preshock chest compressions increase the VF median frequency and improve the likelihood of a return of spontaneous circulation in normal swine. We hypothesized that chest compressions before defibrillation in a swine model of acute myocardial ischemia would also increase VF median frequency and improve resuscitation outcome.

METHODS AND RESULTS

Twenty-six swine were subjected to balloon occlusion of the left anterior descending coronary artery for 2 hours. The balloon was removed and VF was induced and untreated for 8 minutes. Swine were then treated with up to 3 stacked defibrillation shocks (n=13, shock-first group) or 3 minutes of chest compressions before shock (n=13, preshock cardiopulmonary resuscitation group). In the preshock cardiopulmonary resuscitation group, median frequency was increased from 7.0+/-0.8 to 13.9+/-1.6 Hz after chest compressions (P=0.002). Despite the improved median frequency in the preshock cardiopulmonary resuscitation group, 24-hour survival with favorable neurological status was significantly worse in the preshock cardiopulmonary resuscitation group (1/13) compared with the shock-first group (8/13, P=0.01).

CONCLUSIONS

In a swine model of prolonged VF in acute myocardial ischemia, 24-hour survival with favorable neurological status was more likely when defibrillation was performed first without preceding chest compressions. Myocardial substrate is an important factor in determining the optimal resuscitation strategy.

MRI detects increased coronary wall thickness in asymptomatic individuals: the multi-ethnic study of atherosclerosis (MESA)

PURPOSE

To evaluate the use of coronary wall MRI as a measure of atherosclerotic disease burden in an asymptomatic population free of clinical cardiovascular disease. Coronary wall magnetic resonance imaging (MRI) is a noninvasive method for evaluation of arterial wall remodeling associated with atherosclerosis.

MATERIALS AND METHODS

Asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA) study were studied using black blood MRI. MRI-assessed coronary wall thickness was compared with computed tomography calcium score, carotid intimal-medial thickness, and risk factors for coronary artery disease.

RESULTS

Eighty-eight arterial segments were evaluated in 38 MESA participants (mean age, 61.3+/-8.7 years). The maximum coronary wall thickness was greater for participants with two or more cardiovascular risk factors than for those with one or no risk factors (2.59+/-0.33 mm vs. 2.36+/-0.30 mm, respectively, P=0.05.) For participants with zero calcium score, the mean and maximum coronary wall thickness for subjects with two or more risk factors for coronary artery disease were greater than the wall thickness for subjects with one or no risk factors (mean thickness: 1.95+/-0.17 mm vs. 1.7+/-0.19 mm; maximum thickness: 2.67+/-0.24 mm vs. 2.32+/-0.27 mm, respectively, P<0.05). Subjects with increased carotid intimal-medial thickness also had increased coronary artery wall thickness (P<0.05).

CONCLUSION

Coronary artery wall MRI detects increased coronary wall thickness in asymptomatic individuals with subclinical markers of atherosclerotic disease and in individuals with zero calcium score.

Unstable coronary plaques and cardiac events in myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits: questions and quandaries

PURPOSE OF REVIEW

Use of suitable animal models is essential for investigation of the mechanisms underlying cardiac events and development of the therapeutic strategies; however, ideal animal models that can recapitulate human coronary atherosclerosis and subsequent acute myocardial infarction are still lacking. In this article, we review the insights learned from myocardial infarction-prone Watanabe heritable hyperlipidemic (designated as WHHLMI) rabbits and discuss the possibility of using this model for the study of human acute coronary syndromes.

RECENT FINDINGS

The vulnerable plaques of human coronary arteries are histologically characterized by a large lipid core and a thin fibrous cap with inflammatory cells. Recent studies have revealed that inflammatory cells and inflammatory mediators (such as cytokines and matrix metalloproteinases) play an important role in the plaque rupture.

SUMMARY

We developed the WHHLMI rabbit that shows spontaneous myocardial infarction caused by coronary atherosclerosis. The coronary lesions of WHHLMI rabbits have features of fatty streaks, fibrous plaques, and fibroatheromatous plaques. Some plaques contain a lipid core and a thin fibrous cap similar to human vulnerable plaques. In spite of this, the plaque rupture is not observed in WHHLMI rabbits, suggesting that other additional factors such as mechanical stress are required to trigger the rupture. WHHLMI rabbits may become an important means for elucidating the possible mechanisms of plaque rupture by exposing the plaques to additional risk factors beyond hyperlipidemia.

Type I collagen induces tissue factor expression and matrix metalloproteinase 9 production in human primary monocytes through a redox-sensitive pathway

BACKGROUND

Tissue factor (TF), the main trigger of coagulation cascade, is a major component of the atherosclerotic plaque. Matrix metalloproteinases (MMPs) are recognized as key mediators of extracellular matrix remodeling during inflammation. It was recently emphasized that both TF and MMP-9 were overexpressed in atherosclerotic plaques, suggesting a role of both molecules in plaque instability and thrombogenicity.

OBJECTIVE

The present study was designed to determine whether human monocytes could co-express TF and MMP-9 when the cells interact with type I collagen, a major component of the extracellular matrix and atherosclerotic plaque.

METHODS

Human monocytes were isolated by elutriation and incubated in collagen I-coated plates. Tissue factor and MMP-9 expression were examined using real-time reverse transcription-polymerase chain reaction, flow cytometry, western blot and zymography. The activation of nuclear factor-kappa B (NF-kappaB) and the role of reactive oxygen species (ROS) in TF and MMP-9 production was studied using gel shift experiments, antioxidants pyrrolidine dithiocarbamate (PDTC) and N-acetyl-cysteine (NAC), and apocynin (a specific inhibitor of the NADPH oxidase).

RESULTS

Type I collagen induced TF expression and increased MMP-9 production. In addition, the pro-inflammatory tumor necrosis factor-alpha (TNF-alpha), produced in response to collagen I, increased MMP-9 production. PDTC and NAC inhibited NF-kappaB activation during monocyte interaction with collagen I. Finally, both antioxidants and apocynin decreased the expression of TF, TNF-alpha, and MMP-9.

CONCLUSIONS

These results indicate a new mechanism in the monocyte expression of TF and MMP-9 in response to collagen I involving a ROS-dependent pathway linked to the activation of the NADPH oxidase.