Myocardial tissue tagging with cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) is currently the gold standard for assessing both global and regional myocardial function. New tools for quantifying regional function have been recently developed to characterize early myocardial dysfunction in order to improve the identification and management of individuals at risk for heart failure. Of particular interest is CMR myocardial tagging, a non-invasive technique for assessing regional function that provides a detailed and comprehensive examination of intra-myocardial motion and deformation. Given the current advances in gradient technology, image reconstruction techniques, and data analysis algorithms, CMR myocardial tagging has become the reference modality for evaluating multidimensional strain evolution in the human heart. This review presents an in depth discussion on the current clinical applications of CMR myocardial tagging and the increasingly important role of this technique for assessing subclinical myocardial dysfunction in the setting of a wide variety of myocardial disease processes

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.

OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis

An ethnic predilection for fetal echogenic intracardiac focus identified during targeted midtrimester ultrasound examination: A retrospective review

BACKGROUND: Echogenic intracardiac focus (EIF) has been identified as a common ultrasound finding in association with fetal aneuploidy. Little is known about the association of this soft marker aneuploidy in various ethnic groups. Although it is commonly thought Asians in general have a higher incidence of EIF, it is unknown whether this also applies to Japanese as a subpopulation. The purpose of this study is to determine the antenatal incidence and postnatal significance of EIF observed during sonography in Japanese patients. METHODS: A cohort of Japanese patients who underwent ultrasound screening from 1997 to 1999 in the ultrasound unit at the New York University School of Medicine was identified. Variables included age, gestational age, serum markers, and the presence or absence of aneuploidy. Patients with first degree paternal or maternal Japanese ancestry were included for analysis. Examinations were performed between 14 and 24 weeks gestation. The prevalence of EIF was calculated. The control group was based on previously published data in the U.S (7.3% prevalence). RESULTS: A total of 154 subjects were identified, 148 were available for final analysis. Twenty-two fetuses had an EIF, 19 (86.4%) left-sided, 3 (13.6%) right-sided. Seventeen patients had other sonographic markers associated with aneuploidy. The mean maternal age at diagnosis was 30.7 ± 3.9 years and the mean gestational age was 19.8 ± 1.6 weeks. The prevalence of EIF was 14.8%. Compared to published population prevalence, there was a statistically significant difference (p < 0.005). No abnormal karyotypes were found. CONCLUSION: Asians of Japanese origin may have a higher prevalence of echogenic intracardiac foci, thus affecting the positive predictive value of this sonographic marker for aneuploidy

Gene-centric meta-analyses for central adiposity traits in up to 57 412 individuals of European descent confirm known loci and reveal several novel associations

Waist circumference (WC) and waist-to-hip ratio (WHR) are surrogate measures of central adiposity that are associated with adverse cardiovascular events, type 2 diabetes and cancer independent of body mass index (BMI). WC and WHR are highly heritable with multiple susceptibility loci identified to date. We assessed the association between SNPs and BMI-adjusted WC and WHR and unadjusted WC in up to 57 412 individuals of European descent from 22 cohorts collaborating with the NHLBIs Candidate Gene Association Resource (CARe) project. The study population consisted of women and men aged 2080 years. Study participants were genotyped using the ITMAT/Broad/CARE array, which includes 50 000 cosmopolitan tagged SNPs across 2100 cardiovascular-related genes. Each trait was modeled as a function of age, study site and principal components to control for population stratification, and we conducted a fixed-effects meta-analysis. No new loci for WC were observed. For WHR analyses, three novel loci were significantly associated (P 2.4 10(6)). Previously unreported rs2811337-G near TMCC1 was associated with increased WHR ( SE, 0.048 0.008, P 7.7 10(9)) as was rs7302703-G in HOXC10 ( 0.044 0.008, P 2.9 10(7)) and rs936108-C in PEMT ( 0.035 0.007, P 1.9 10(6)). Sex-stratified analyses revealed two additional novel signals among females only, rs12076073-A in SHC1 ( 0.10 0.02, P 1.9 10(6)) and rs1037575-A in ATBDB4 ( 0.046 0.01, P 2.2 10(6)), supporting an already established sexual dimorphism of central adiposity-related genetic variants. Functional analysis using ENCODE and eQTL databases revealed that several of these loci are in regulatory regions or regions with differential expression in adipose tissue

Gene-centric meta-analyses for central adiposity traits in up to 57 412 individuals of European descent confirm known loci and reveal several novel associations

Waist circumference (WC) and waist-to-hip ratio (WHR) are surrogate measures of central adiposity that are associated with adverse cardiovascular events, type 2 diabetes and cancer independent of body mass index (BMI). WC and WHR are highly heritable with multiple susceptibility loci identified to date. We assessed the association between SNPs and BMI-adjusted WC and WHR and unadjusted WC in up to 57 412 individuals of European descent from 22 cohorts collaborating with the NHLBIs Candidate Gene Association Resource (CARe) project. The study population consisted of women and men aged 2080 years. Study participants were genotyped using the ITMAT/Broad/CARE array, which includes 50 000 cosmopolitan tagged SNPs across 2100 cardiovascular-related genes. Each trait was modeled as a function of age, study site and principal components to control for population stratification, and we conducted a fixed-effects meta-analysis. No new loci for WC were observed. For WHR analyses, three novel loci were significantly associated (P 2.4 10(6)). Previously unreported rs2811337-G near TMCC1 was associated with increased WHR ( SE, 0.048 0.008, P 7.7 10(9)) as was rs7302703-G in HOXC10 ( 0.044 0.008, P 2.9 10(7)) and rs936108-C in PEMT ( 0.035 0.007, P 1.9 10(6)). Sex-stratified analyses revealed two additional novel signals among females only, rs12076073-A in SHC1 ( 0.10 0.02, P 1.9 10(6)) and rs1037575-A in ATBDB4 ( 0.046 0.01, P 2.2 10(6)), supporting an already established sexual dimorphism of central adiposity-related genetic variants. Functional analysis using ENCODE and eQTL databases revealed that several of these loci are in regulatory regions or regions with differential expression in adipose tissue