Mechanistic basis for potassium efflux-driven activation of the human NLRP1 inflammasome.

Nigericin, an ionophore derived from Streptomyces hygroscopicus, is arguably the most commonly used tool compound to study the NLRP3 inflammasome. Recent findings, however, showed that nigericin also activates the NLRP1 inflammasome in human keratinocytes. In this study, we resolve the mechanistic basis of nigericin-driven NLRP1 inflammasome activation. In multiple nonhematopoietic cell types, nigericin rapidly and specifically inhibits the elongation stage of the ribosome cycle by depleting cytosolic potassium ions. This activates the ribotoxic stress response (RSR) sensor kinase ZAKα, p38, and JNK, as well as the hyperphosphorylation of the NLRP1 linker domain. As a result, nigericin-induced pyroptosis in human keratinocytes is blocked by extracellular potassium supplementation, ZAKα knockout, or pharmacologic inhibitors of ZAKα and p38 kinase activities. By surveying a panel of ionophores, we show that electroneutrality of ion movement is essential to activate ZAKα-driven RSR and a greater extent of K+ depletion is necessary to activate ZAKα-NLRP1 than NLRP3. These findings resolve the mechanism by which nigericin activates NLRP1 in nonhematopoietic cell types and demonstrate an unexpected connection between RSR, perturbations of potassium ion flux, and innate immunity.

Identification of type 2 diabetes loci in 433,540 East Asian individuals.

Meta-analyses of genome-wide association studies (GWAS) have identified more than 240 loci that are associated with type 2 diabetes (T2D)1,2; however, most of these loci have been identified in analyses of individuals with European ancestry. Here, to examine T2D risk in East Asian individuals, we carried out a meta-analysis of GWAS data from 77,418 individuals with T2D and 356,122 healthy control individuals. In the main analysis, we identified 301 distinct association signals at 183 loci, and across T2D association models with and without consideration of body mass index and sex, we identified 61 loci that are newly implicated in predisposition to T2D. Common variants associated with T2D in both East Asian and European populations exhibited strongly correlated effect sizes. Previously undescribed associations include signals in or near GDAP1, PTF1A, SIX3, ALDH2, a microRNA cluster, and genes that affect the differentiation of muscle and adipose cells3. At another locus, expression quantitative trait loci at two overlapping T2D signals affect two genes-NKX6-3 and ANK1-in different tissues4-6. Association studies in diverse populations identify additional loci and elucidate disease-associated genes, biology, and pathways.

Investigating causal relationships between obesity and skin barrier function in a multi-ethnic Asian general population cohort.

BACKGROUND: Skin diseases impact significantly on the quality of life and psychology of patients. Obesity has been observed as a risk factor for skin diseases. Skin epidermal barrier dysfunctions are typical manifestations across several dermatological disturbances. OBJECTIVES: We aim to establish the association between obesity and skin physiology measurements and investigate whether obesity may play a possible causal role on skin barrier dysfunction. METHODS: We investigated the relationship of obesity with skin physiology measurements, namely transepidermal water loss (TEWL), skin surface moisture and skin pH in an Asian population cohort (n = 9990). To assess for a possible causal association between body mass index (BMI) and skin physiology measurements, we performed Mendelian Randomization (MR), along with subsequent additional analyses to assess the potential causal impact of known socioeconomic and comorbidities of obesity on TEWL. RESULTS: Every 1 kg/m2 increase in BMI was associated with a 0.221% (95%CI: 0.144-0.298) increase in TEWL (P = 2.82E-08), a 0.336% (95%CI: 0.148-0.524) decrease in skin moisture (P = 4.66E-04) and a 0.184% (95%CI: 0.144-0.224) decrease in pH (P = 1.36E-19), adjusting for age, gender, and ethnicity. Relationships for both TEWL and pH with BMI remained strong (Beta 0.354; 95%CI: 0.189-0.520 and Beta -0.170; 95%CI: -0.253 to -0.087, respectively) even after adjusting for known confounders, with MR experiments further supporting BMI's possible causal relationship with TEWL. Based on additional MR performed, none of the socioeconomic and comorbidities of obesity investigated are likely to have possible causal relationships with TEWL. CONCLUSION: We establish strong association of BMI with TEWL and skin pH, with MR results suggestive of a possible causal relationship of obesity with TEWL. It emphasizes the potential impact of obesity on skin barrier function and therefore opportunity for primary prevention.

Smokeless and combustible tobacco use among 148,944 South Asian adults: a cross-sectional study of South Asia Biobank.

INTRODUCTION: Tobacco use, in both smoking and smokeless forms, is highly prevalent among South Asian adults. The aims of the study were twofold: (1) describe patterns of SLT and combustible tobacco product use in four South Asian countries stratified by country and sex, and (2) assess the relationships between SLT and smoking intensity, smoking quit attempts, and smoking cessation among South Asian men. METHODS: Data were obtained from South Asia Biobank Study, collected between 2018 and 2022 from 148,944 men and women aged 18 years and above, living in Bangladesh, India, Pakistan, or Sri Lanka. Mixed effects multivariable logistic and linear regression were used to quantify the associations of SLT use with quit attempt, cessation, and intensity. RESULTS: Among the four South Asian countries, Bangladesh has the highest rates of current smoking (39.9% for male, 0.4% for female) and current SLT use (24.7% for male and 23.4% for female). Among male adults, ever SLT use was associated with a higher odds of smoking cessation in Bangladesh (OR, 2.88; 95% CI, 2.65, 3.13), India (OR, 2.02; 95% CI, 1.63, 2.50), and Sri Lanka (OR, 1.36; 95% CI, 1.14, 1.62). Ever SLT use and current SLT use was associated with lower smoking intensity in all countries. CONCLUSIONS: In this large population-based study of South Asian adults, rates of smoking and SLT use vary widely by country and gender. Men who use SLT products are more likely to abstain from smoking compared with those who do not.

Epigenome-wide association study of incident type 2 diabetes: a meta-analysis of five prospective European cohorts.

AIMS/HYPOTHESIS: Type 2 diabetes is a complex metabolic disease with increasing prevalence worldwide. Improving the prediction of incident type 2 diabetes using epigenetic markers could help tailor prevention efforts to those at the highest risk. The aim of this study was to identify predictive methylation markers for incident type 2 diabetes by combining epigenome-wide association study (EWAS) results from five prospective European cohorts. METHODS: We conducted a meta-analysis of EWASs in blood collected 7-10 years prior to type 2 diabetes diagnosis. DNA methylation was measured with Illumina Infinium Methylation arrays. A total of 1250 cases and 1950 controls from five longitudinal cohorts were included: Doetinchem, ESTHER, KORA1, KORA2 and EPIC-Norfolk. Associations between DNA methylation and incident type 2 diabetes were examined using robust linear regression with adjustment for potential confounders. Inverse-variance fixed-effects meta-analysis of cohort-level individual CpG EWAS estimates was performed using METAL. The methylGSA R package was used for gene set enrichment analysis. Confirmation of genome-wide significant CpG sites was performed in a cohort of Indian Asians (LOLIPOP, UK). RESULTS: The meta-analysis identified 76 CpG sites that were differentially methylated in individuals with incident type 2 diabetes compared with control individuals (p values <1.1 × 10-7). Sixty-four out of 76 (84.2%) CpG sites were confirmed by directionally consistent effects and p values <0.05 in an independent cohort of Indian Asians. However, on adjustment for baseline BMI only four CpG sites remained genome-wide significant, and addition of the 76 CpG methylation risk score to a prediction model including established predictors of type 2 diabetes (age, sex, BMI and HbA1c) showed no improvement (AUC 0.757 vs 0.753). Gene set enrichment analysis of the full epigenome-wide results clearly showed enrichment of processes linked to insulin signalling, lipid homeostasis and inflammation. CONCLUSIONS/INTERPRETATION: By combining results from five European cohorts, and thus significantly increasing study sample size, we identified 76 CpG sites associated with incident type 2 diabetes. Replication of 64 CpGs in an independent cohort of Indian Asians suggests that the association between DNA methylation levels and incident type 2 diabetes is robust and independent of ethnicity. Our data also indicate that BMI partly explains the association between DNA methylation and incident type 2 diabetes. Further studies are required to elucidate the underlying biological mechanisms and to determine potential causal roles of the differentially methylated CpG sites in type 2 diabetes development.

Food environment and diabetes mellitus in South Asia: A geospatial analysis of health outcome data.

BACKGROUND: The global epidemic of type 2 diabetes mellitus (T2DM) renders its prevention a major public health priority. A key risk factor of diabetes is obesity and poor diets. Food environments have been found to influence people's diets and obesity, positing they may play a role in the prevalence of diabetes. Yet, there is scant evidence on the role they may play in the context of low- and middle-income countries (LMICs). We examined the associations of food environments on T2DM among adults and its heterogeneity by income and sex. METHODS AND FINDINGS: We linked individual health outcome data of 12,167 individuals from a network of health surveillance sites (the South Asia Biobank) to the density and proximity of food outlets geolocated around their homes from environment mapping survey data collected between 2018 and 2020 in Bangladesh and Sri Lanka. Density was defined as share of food outlets within 300 m from study participant's home, and proximity was defined as having at least 1 outlet within 100 m from home. The outcome variables include fasting blood glucose level, high blood glucose, and self-reported diagnosed diabetes. Control variables included demographics, socioeconomic status (SES), health status, healthcare utilization, and physical activities. Data were analyzed in ArcMap 10.3 and STATA 15.1. A higher share of fast-food restaurants (FFR) was associated with a 9.21 mg/dl blood glucose increase (95% CI: 0.17, 18.24; p < 0.05). Having at least 1 FFR in the proximity was associated with 2.14 mg/dl blood glucose increase (CI: 0.55, 3.72; p < 0.01). A 1% increase in the share of FFR near an individual's home was associated with 8% increase in the probability of being clinically diagnosed as a diabetic (average marginal effects (AMEs): 0.08; CI: 0.02, 0.14; p < 0.05). Having at least 1 FFR near home was associated with 16% (odds ratio [OR]: 1.16; CI: 1.01, 1.33; p < 0.05) and 19% (OR: 1.19; CI: 1.03, 1.38; p < 0.05) increases in the odds of higher blood glucose levels and diagnosed diabetes, respectively. The positive association between FFR density and blood glucose level was stronger among women than men, but the association between FFR proximity and blood glucose level was stronger among men as well as among those with higher incomes. One of the study's key limitations is that we measured exposure to food environments around residency geolocation; however, participants may source their meals elsewhere. CONCLUSIONS: Our results suggest that the exposure to fast-food outlets may have a detrimental impact on the risk of T2DM, especially among females and higher-income earners. Policies should target changes in the food environments to promote better diets and prevent T2DM.

Reference equations for evaluation of spirometry function tests in South Asia, and among South Asians living in other countries.

BACKGROUND: There are few data to support accurate interpretation of spirometry data in South Asia, a major global region with a high reported burden of chronic respiratory disease. METHOD: We measured lung function in 7453 healthy men and women aged ≥18 years, from Bangladesh, North India, South India, Pakistan and Sri Lanka, as part of the South Asia Biobank study. First, we assessed the accuracy of existing equations for predicting normal forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC ratio. Then, we used our data to derive (n=5589) and internally validate (n=1864) new prediction equations among South Asians, with further external validation among 339 healthy South Asians living in Singapore. RESULTS: The Global Lung Initiative (GLI) and National Health and Nutrition Examination Survey consistently overestimated expiratory volumes (best fit GLI-African American, mean±sd z-score: FEV1 -0.94±1.05, FVC -0.91±1.10; n=7453). Age, height and weight were strong predictors of lung function in our participants (p<0.001), and sex-specific reference equations using these three variables were highly accurate in both internal validation (z-scores: FEV1 0.03±0.99, FVC 0.04±0.97, FEV1/FVC -0.03±0.99) and external validation (z-scores: FEV1 0.31±0.99, FVC 0.24±0.97, FEV1/FVC 0.16±0.91). Further adjustment for study regions improves the model fit, with highest accuracy for estimation of region-specific lung function in South Asia. CONCLUSION: We present improved equations for predicting lung function in South Asians. These offer the opportunity to enhance diagnosis and management of acute and chronic lung diseases in this major global population.

Epigenomes of Human Hearts Reveal New Genetic Variants Relevant for Cardiac Disease and Phenotype.

RATIONALE: Identifying genetic markers for heterogeneous complex diseases such as heart failure is challenging and requires prohibitively large cohort sizes in genome-wide association studies to meet the stringent threshold of genome-wide statistical significance. On the other hand, chromatin quantitative trait loci, elucidated by direct epigenetic profiling of specific human tissues, may contribute toward prioritizing subthreshold variants for disease association. OBJECTIVE: Here, we captured noncoding genetic variants by performing epigenetic profiling for enhancer H3K27ac chromatin immunoprecipitation followed by sequencing in 70 human control and end-stage failing hearts. METHODS AND RESULTS: We have mapped a comprehensive catalog of 47 321 putative human heart enhancers and promoters. Three thousand eight hundred ninety-seven differential acetylation peaks (FDR [false discovery rate], 5%) pointed to pathways altered in heart failure. To identify cardiac histone acetylation quantitative trait loci (haQTLs), we regressed out confounding factors including heart failure disease status and used the G-SCI (Genotype-independent Signal Correlation and Imbalance) test1 to call out 1680 haQTLs (FDR, 10%). RNA sequencing performed on the same heart samples proved a subset of haQTLs to have significant association also to gene expression (expression quantitative trait loci), either in cis (180) or through long-range interactions (81), identified by Hi-C (high-throughput chromatin conformation assay) and HiChIP (high-throughput protein centric chromatin) performed on a subset of hearts. Furthermore, a concordant relationship between the gain or disruption of TF (transcription factor)-binding motifs, inferred from alternative alleles at the haQTLs, implied a surprising direct association between these specific TF and local histone acetylation in human hearts. Finally, 62 unique loci were identified by colocalization of haQTLs with the subthreshold loci of heart-related genome-wide association studies datasets. CONCLUSIONS: Disease and phenotype association for 62 unique loci are now implicated. These loci may indeed mediate their effect through modification of enhancer H3K27 acetylation enrichment and their corresponding gene expression differences (bioRxiv: https://doi.org/10.1101/536763). Graphical Abstract: A graphical abstract is available for this article.

Sex Differences in Right Ventricular Systolic Function and All-Cause Mortality in Tricuspid Regurgitation.

INTRODUCTION: Sex differences have been poorly studied in patients with right-sided heart valve disease. The principal aim of the current study was to explore the impact of sex differences on right ventricular (RV) hemodynamics and all-cause mortality in patients with moderate or severe tricuspid regurgitation (TR). METHODS: This is a retrospective study of 209 patients with significant TR. All patients were clinically profiled at baseline and underwent a transthoracic echocardiogram. The cohort was followed up for clinical events for a median duration of 80 months (mean ± SD 69.4 ± 33.4 months). RESULTS: There were 117 women with a mean (± SD) age of 72.6 ± 13 years and 92 men with a mean (± SD) age of 70.8 ± 15.8 years. There were no sex differences between the individual measures of RV systolic function (tricuspid annular plane systolic excursion [TAPSE], systolic pulmonary artery pressure, and RV S'), but overall RV systolic dysfunction (TAPSE <16 mm and/or RV S' <10 cm/s) and left ventricular ejection fraction <50% were more common in men. Mean (± SD) RV wall tension (RV WT) was 3,170 ± 1,220 mm Hg × mm in women and 3,817 ± 1,499 mm Hg × mm in men (p = 0.002). There was no difference in all-cause mortality between women and men (Log-Rank p = 0.528). Age and increased RV WT were independent predictors of all-cause mortality both in women (hazard ratio [HR] 2.61) and men (HR 3.01). CONCLUSIONS: In this cohort of patients with significant TR, women more frequently had preserved RV systolic function than men. There was no sex-difference in all-cause mortality. An increased RV WT and higher age were independent predictors of all-cause mortality in both women and men.

Clinical significance and prognostic value of ST segment depression on ECG during exercise treadmill test in asymptomatic patients with moderate or severe aortic stenosis.

Objectives. In patients with asymptomatic moderate or severe aortic stenosis (AS), exercise testing is used for evaluating the need for aortic valve intervention. Expert opinions about the clinical significance and prognostic value of ST segment depression on electrocardiography (ECG) during exercise testing in AS is conflicting and there are no large studies exploring this issue. We aimed to explore the association of ST segment depression >5 mm during exercise treadmill test (ETT) with all-cause mortality, aortic valve replacement (AVR) or cardiac-related hospitalization. Design. We performed a retrospective analysis of prospectively collected data of a total of 315 patients (mean age 65 ± 12 years, 67% men) with asymptomatic moderate (n = 209; 66%) or severe (n = 106; 34%) AS. All patients underwent clinical evaluation, echocardiography and ETT. Results. During a mean follow-up of 34.9 ± 34.6 months, 29 (9%) patients died and 235 (74%) underwent AVR. The prevalence of ST segment depression (>5 mm) was 13% (n = 41) in the total study population and was comparable in patients with revealed symptoms (17.6%, n = 16) versus without revealed symptoms (11.3%, n = 25; p = .132). ST segment depression on ETT was strongly associated with aortic valve area. In univariate Cox regression analysis, ST segment depression was not associated with cardiac related hospitalizations (HR 1.65; 95% CI 0.89-3.10, p = .113), all-cause mortality (HR 1.37; 95% CI 0.47-3.98, p = .564) or AVR (HR 1.30; 95% CI 0.89-1.91, p = .170). Conclusion. In patients with moderate or severe AS, ST segment depression during ETT is non-specific, carries no prognostic risk and should be used with caution in the clinical interpretation of exercise test.

Echocardiographic features of left ventricular recess, cleft, diverticulum, and aneurysm: A systematic review.

A pouch protruding into the wall of the left ventricle (LV) may be either a recess, cleft, diverticulum, or aneurysm. Being aware of these anomalies is essential to make accurate diagnosis and guide management decisions. Standard multimodality imaging of the heart enables detailed characterizations of LV fissures and outpouchings. They often present as an incidental finding on echocardiography, and the clinical significance can be difficult to address. We provide an overview of echocardiographic features of LV recess, cleft, diverticulum, pseudoaneurysms/aneurysms, and non-compaction based upon review of the literature as well as present some relevant clinical cases from our echocardiography labs.

Meta-analysis of up to 622,409 individuals identifies 40 novel smoking behaviour associated genetic loci.

Smoking is a major heritable and modifiable risk factor for many diseases, including cancer, common respiratory disorders and cardiovascular diseases. Fourteen genetic loci have previously been associated with smoking behaviour-related traits. We tested up to 235,116 single nucleotide variants (SNVs) on the exome-array for association with smoking initiation, cigarettes per day, pack-years, and smoking cessation in a fixed effects meta-analysis of up to 61 studies (up to 346,813 participants). In a subset of 112,811 participants, a further one million SNVs were also genotyped and tested for association with the four smoking behaviour traits. SNV-trait associations with P < 5 × 10-8 in either analysis were taken forward for replication in up to 275,596 independent participants from UK Biobank. Lastly, a meta-analysis of the discovery and replication studies was performed. Sixteen SNVs were associated with at least one of the smoking behaviour traits (P < 5 × 10-8) in the discovery samples. Ten novel SNVs, including rs12616219 near TMEM182, were followed-up and five of them (rs462779 in REV3L, rs12780116 in CNNM2, rs1190736 in GPR101, rs11539157 in PJA1, and rs12616219 near TMEM182) replicated at a Bonferroni significance threshold (P < 4.5 × 10-3) with consistent direction of effect. A further 35 SNVs were associated with smoking behaviour traits in the discovery plus replication meta-analysis (up to 622,409 participants) including a rare SNV, rs150493199, in CCDC141 and two low-frequency SNVs in CEP350 and HDGFRP2. Functional follow-up implied that decreased expression of REV3L may lower the probability of smoking initiation. The novel loci will facilitate understanding the genetic aetiology of smoking behaviour and may lead to the identification of potential drug targets for smoking prevention and/or cessation.

First-phase ejection fraction by cardiovascular magnetic resonance predicts outcomes in aortic stenosis.

BACKGROUND: First-phase ejection fraction (EF1; the ejection fraction measured during active systole up to the time of maximal aortic flow) measured by transthoracic echocardiography (TTE) is a powerful predictor of outcomes in patients with aortic stenosis. We aimed to assess whether cardiovascular magnetic resonance (CMR) might provide more precise measurements of EF1 than TTE and to examine the correlation of CMR EF1 with measures of fibrosis. METHODS: In 141 patients with at least mild aortic stenosis, we measured CMR EF1 from a short-axis 3D stack and compared its variability with TTE EF1, and its associations with myocardial fibrosis and clinical outcome (aortic valve replacement (AVR) or death). RESULTS: Intra- and inter-observer variation of CMR EF1 (standard deviations of differences within and between observers of 2.3% and 2.5% units respectively) was approximately 50% that of TTE EF1. CMR EF1 was strongly predictive of AVR or death. On multivariable Cox proportional hazards analysis, the hazard ratio for CMR EF1 was 0.93 (95% confidence interval 0.89-0.97, p = 0.001) per % change in EF1 and, apart from aortic valve gradient, CMR EF1 was the only imaging or biochemical measure independently predictive of outcome. Indexed extracellular volume was associated with AVR or death, but not after adjusting for EF1. CONCLUSIONS: EF1 is a simple robust marker of early left ventricular impairment that can be precisely measured by CMR and predicts outcome in aortic stenosis. Its measurement by CMR is more reproducible than that by TTE and may facilitate left ventricular structure-function analysis.

Alcohol consumption is associated with widespread changes in blood DNA methylation: Analysis of cross-sectional and longitudinal data.

DNA methylation may be one of the mechanisms by which alcohol consumption is associated with the risk of disease. We conducted a large-scale, cross-sectional, genome-wide DNA methylation association study of alcohol consumption and a longitudinal analysis of repeated measurements taken several years apart. Using the Illumina HumanMethylation450 BeadChip, DNA methylation was measured in blood samples from 5606 Melbourne Collaborative Cohort Study (MCCS) participants. For 1088 of them, these measures were repeated using blood samples collected a median of 11 years later. Associations between alcohol intake and blood DNA methylation were assessed using linear mixed-effects regression models. Independent data from the London Life Sciences Prospective Population (LOLIPOP) (N = 4042) and Cooperative Health Research in the Augsburg Region (KORA) (N = 1662) cohorts were used to replicate associations discovered in the MCCS. Cross-sectional analyses identified 1414 CpGs associated with alcohol intake at P < 10-7 , 1243 of which had not been reported previously. Of these novel associations, 1078 were replicated (P < .05) using LOLIPOP and KORA data. Using the MCCS data, we also replicated 403 of 518 previously reported associations. Interaction analyses suggested that associations were stronger for women, non-smokers, and participants genetically predisposed to consume less alcohol. Of the 1414 CpGs, 530 were differentially methylated (P < .05) in former compared with current drinkers. Longitudinal associations between the change in alcohol intake and the change in methylation were observed for 513 of the 1414 cross-sectional associations. Our study indicates that alcohol intake is associated with widespread changes in DNA methylation across the genome. Longitudinal analyses showed that the methylation status of alcohol-associated CpGs may change with alcohol consumption changes in adulthood.

APOC3 genetic variation, serum triglycerides, and risk of coronary artery disease in Asian Indians, Europeans, and other ethnic groups.

BACKGROUND: Hypertriglyceridemia has emerged as a critical coronary artery disease (CAD) risk factor. Rare loss-of-function (LoF) variants in apolipoprotein C-III have been reported to reduce triglycerides (TG) and are cardioprotective in American Indians and Europeans. However, there is a lack of data in other Europeans and non-Europeans. Also, whether genetically increased plasma TG due to ApoC-III is causally associated with increased CAD risk is still unclear and inconsistent. The objectives of this study were to verify the cardioprotective role of earlier reported six LoF variants of APOC3 in South Asians and other multi-ethnic cohorts and to evaluate the causal association of TG raising common variants for increasing CAD risk. METHODS: We performed gene-centric and Mendelian randomization analyses and evaluated the role of genetic variation encompassing APOC3 for affecting circulating TG and the risk for developing CAD. RESULTS: One rare LoF variant (rs138326449) with a 37% reduction in TG was associated with lowered risk for CAD in Europeans (p = 0.007), but we could not confirm this association in Asian Indians (p = 0.641). Our data could not validate the cardioprotective role of other five LoF variants analysed. A common variant rs5128 in the APOC3 was strongly associated with elevated TG levels showing a p-value 2.8 × 10- 424. Measures of plasma ApoC-III in a small subset of Sikhs revealed a 37% increase in ApoC-III concentrations among homozygous mutant carriers than the wild-type carriers of rs5128. A genetically instrumented per 1SD increment of plasma TG level of 15 mg/dL would cause a mild increase (3%) in the risk for CAD (p = 0.042). CONCLUSIONS: Our results highlight the challenges of inclusion of rare variant information in clinical risk assessment and the generalizability of implementation of ApoC-III inhibition for treating atherosclerotic disease. More studies would be needed to confirm whether genetically raised TG and ApoC-III concentrations would increase CAD risk.

Left atrial volume index predicts adverse events in asymptomatic moderate or severe aortic stenosis.

OBJECTIVE: In aortic stenosis (AS), chronic pressure overload on left ventricle (LV) leads to LV hypertrophy, impaired relaxation, increased chamber stiffness, fibrosis and left atrial (LA) dilatation. An enlarged LA may be a marker of longstanding diastolic dysfunction (DD) and more advanced disease in AS. We aimed to assess the impact of LA volume index (LAVI) on events in patients with moderate or severe AS. METHODS: A total of 324 patients (mean age 69 ± 13 years, 61% men) were included. LA volume was measured by biplane Simpson's method using apical four- and two-chamber views and indexed to body surface area. An increased LAVI was defined as > 34 ml/m2 . RESULTS: The mean EF was 64 ± 8%, LAVI 35 ± 14 ml/m2 and flow rate 244 ± 70 ml/s. The number of total events was 275 (85%): 243 (75%) aortic valve replacement and 32 (10%) deaths. Mean follow-up 23.7 ± 23.8 months (median 15.2 months). An increased LAVI (45% [n = 145]) was associated with adverse events (HR 1.86; 95% CI 1.24-2.82, p = 0.003) independent of age, smoking, diabetes, atrial fibrillation, LV ejection fraction, LV mass, aortic valve area, and low flow rate (<200 ml/s). In the same multivariate model, when increased LAVI was replaced by E/e' ratio ≥14 cm, no association was found between E/e' ratio ≥14 cm and adverse events (HR 1.18; 95% CI .78-1.78, p = 0.430). CONCLUSION: LAVI was an independent predictor of adverse events in patients with moderate or severe AS and preserved ejection fraction. Including LAVI in the risk assessment of AS patients may further improve risk stratification.

The electrocardiogram: Still a useful marker for LV fibrosis in aortic stenosis.

Left ventricular (LV) strain on the electrocardiogram (ECG) (down-sloping, convex ST-segment depression with asymmetric T-wave inversion in leads V5 and V6) reflects fibrosis as a result of subendocardial ischemia. It is associated with a significantly increased risk of cardiovascular events independent of the presence of LV hypertrophy on the echocardiogram or cardiac magnetic resonance (CMR) scan. Ongoing studies of early aortic valve replacement in asymptomatic patients with severe aortic stenosis are using ECG changes as a marker of possible fibrosis shown by midwall late gadolinium enhancement on CMR. However, until these studies report, it is still reasonable to respond to LV strain on the ECG by tightening control of systemic hypertension and consider intervention in cases where indications are otherwise in borderline.

First phase ejection fraction in aortic stenosis: A useful new measure of early left ventricular systolic dysfunction.

In aortic stenosis (AS), a left ventricular (LV) ejection fraction (EF) <50% or symptoms are class I indications for aortic valve intervention. However, an EF <50% may be too conservative since subendocardial fibrosis may already have developed. An earlier marker of LV systolic dysfunction is therefore needed and first phase EF (EF1) is a promising new candidate. It is the EF measured over early systole to the point of maximum transaortic blood flow. It may be low in the presence of preserved total LV EF since the heart may compensate by recruiting myosin motors in later systole. The EF1 is inversely related to the grade of AS and directly related to markers of subendocardial fibrosis like late gadolinium enhancement on cardiac magnetic resonance scanning. A reduced EF1 (<25%) predicts adverse clinical events better that total EF and global longitudinal strain. We suggest that it is worth exploring as an indication for surgery in patients with asymptomatic severe AS.

Pharmacokinetics, efficacy and convulsive dose of articaine hydrochloride in goat kids.

OBJECTIVE: To investigate the pharmacokinetics, efficacy and convulsive dose of articaine hydrochloride in goat kids. STUDY DESIGN: Experimental prospective study. ANIMALS: A total of 18 (n = 6 animals per experiment) male Saanen goat kids (2-4 weeks old). METHODS: The study consisted of three experiments. The first determined the pharmacokinetics of articaine following intravenous administration of articaine hydrochloride (8 mg kg-1). The second experiment investigated the anaesthetic efficacy and pharmacokinetics following cornual nerve block using 1.5% articaine hydrochloride. Anaesthesia of horn buds was evaluated using the response to pinprick test. Non-compartmental analysis was used. The final experiment determined the convulsive dose of articaine and its corresponding plasma concentration following intravenous infusion of articaine hydrochloride (4 mg kg-1 minute-1). Data are shown as mean ± standard deviation. RESULTS: The mean terminal half-life (t1/2λz), mean volume of distribution at steady state (Vdss) and mean plasma clearance (CL) of articaine following intravenous administration were 0.66 hour, 3.81 L kg-1 and 5.33 L hour-1 kg-1, respectively. After cornual nerve block, the mean maximum plasma concentration of articaine was 587 ng mL-1 at 0.22 hour and its mean t1/2λz was 1.26 hours. Anaesthesia of horn buds was observed within 4 minutes following cornual nerve block. The mean dose required to produce convulsions was 16.24 mg kg-1 and mean convulsive plasma concentrations of articaine and articainic acid were 9905 and 1517 ng mL-1, respectively. CONCLUSIONS: Intravenous administration of 8 mg kg-1 of articaine hydrochloride did not cause any adverse effects. Pharmacokinetic data suggest that articaine was rapidly eliminated and cleared. Cornual nerve block using 1.5% articaine hydrochloride alleviated the response to the acute nociceptive stimulus during disbudding. CLINICAL RELEVANCE: Articaine hydrochloride appears to be a safe and effective local anaesthetic for disbudding in goat kids.

Serum metabolic signatures of coronary and carotid atherosclerosis and subsequent cardiovascular disease.

AIMS: To characterize serum metabolic signatures associated with atherosclerosis in the coronary or carotid arteries and subsequently their association with incident cardiovascular disease (CVD). METHODS AND RESULTS: We used untargeted one-dimensional (1D) serum metabolic profiling by proton nuclear magnetic resonance spectroscopy (1H NMR) among 3867 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), with replication among 3569 participants from the Rotterdam and LOLIPOP studies. Atherosclerosis was assessed by coronary artery calcium (CAC) and carotid intima-media thickness (IMT). We used multivariable linear regression to evaluate associations between NMR features and atherosclerosis accounting for multiplicity of comparisons. We then examined associations between metabolites associated with atherosclerosis and incident CVD available in MESA and Rotterdam and explored molecular networks through bioinformatics analyses. Overall, 30 1H NMR measured metabolites were associated with CAC and/or IMT, P = 1.3 × 10-14 to 1.0 × 10-6 (discovery) and P = 5.6 × 10-10 to 1.1 × 10-2 (replication). These associations were substantially attenuated after adjustment for conventional cardiovascular risk factors. Metabolites associated with atherosclerosis revealed disturbances in lipid and carbohydrate metabolism, branched chain, and aromatic amino acid metabolism, as well as oxidative stress and inflammatory pathways. Analyses of incident CVD events showed inverse associations with creatine, creatinine, and phenylalanine, and direct associations with mannose, acetaminophen-glucuronide, and lactate as well as apolipoprotein B (P < 0.05). CONCLUSION: Metabolites associated with atherosclerosis were largely consistent between the two vascular beds (coronary and carotid arteries) and predominantly tag pathways that overlap with the known cardiovascular risk factors. We present an integrated systems network that highlights a series of inter-connected pathways underlying atherosclerosis.