Profile of serum microRNAs in heart failure with reduced and preserved ejection fraction: Correlation with myocardial remodeling

Background and aims

Cardiomyocyte hypertrophy and interstitial fibrosis are key components of myocardial remodeling in Heart Failure (HF) with preserved (HFpEF) or reduced ejection fraction (HFrEF). MicroRNAs (miRNAs) are non-coding, evolutionarily conserved RNA molecules that may offer novel insights into myocardial remodeling. This study aimed to characterize miRNA expression in HFpEF (LVEF ≥  45%) and HFrEF (LVEF < 45%) and its association with myocardial remodeling.

Methods

Prospectively enrolled symptomatic HF patients (HFpEF:n = 36; HFrEF:n = 31) and controls (n = 23) underwent cardiac magnetic resonance imaging with T1-mapping and circulating miRNA expression (OpenArray system).

Results

13 of 188 miRNAs were differentially expressed between HF groups (11 downregulated in HFpEF). Myocardial extracellular volume (ECV) was increased in both HF groups (HFpEF 30 ± 5%; HFrEF 30 ± 3%; controls 26 ± 2%, p < 0.001). miR-128a-3p, linked to cardiac hypertrophy, fibrosis, and dysfunction, correlated positively with ECV in HFpEF (r = 0.60, p = 0.01) and negatively in HFrEF (r = - 0.51, p = 0.04). miR-423-5p overexpression, previously associated HF mortality, was inversely associated with LVEF (r = - 0.29, p = 0.04) and intracellular water lifetime (τ ic) (r = - 0.45, p < 0.05) in both HF groups, and with NT-proBNP in HFpEF (r = - 0.63, p < 0.01).

Conclusions

miRNA expression profiles differed between HF phenotypes. The differential expression and association of miR-128a-3p with ECV may reflect the distinct vascular, interstitial, and cellular etiologies of HF phenotypes.

Health literacy and diabetic retinopathy

Health literacy (HL) is defined as a cognitive and social skill that determines the motivation and ability of individuals to understand and use information to promote and maintain proper health. Inadequate HL has been associated with worse outcomes in diabetes control, poor self-care, and higher hospitalization rates for some chronic diseases. We hypothesized that HL influences the prevalence of diabetic retinopathy (DR) among individuals with type 2 diabetes mellitus (T2DM) and that inadequate glycemic control would mediate this association. This was a cross-sectional study carried out with 288 participants of the "Brazilian Diabetes Study" cohort. Inclusion criteria were people diagnosed with T2DM aged between 40 and 70 years and ability to read and write. In the adequate HL group, DR was found in 16.5% of participants and in the inadequate HL group, it was found in 32.8% (P=0.0081). Individuals with inadequate HL had a higher risk of having DR, and this association was still statistically significant after adjusting for HbA1c, low-density lipoprotein cholesterol, systolic blood pressure, and diastolic blood pressure. In conclusion, HL is related to DR without the mediation of classical clinical variables.

Impaired cardiac sympathetic innervation activity is associated with myocardial extracellular remodeling, functional capacity and biomarkers

Background

Despite recent advances in treatment, heart failure (HF) continues to be associated with high mortality rates. In this setting, 123iodine-meta-iodobenzylguanidine (123I-MIBG) scintigraphy emerges as a promising tool for the prediction of clinical outcomes in HF due to its ability to assess cardiac sympathetic innervation. However, 123I-MIBG scintigraphy's correlation with myocardial remodeling and cardiopulmonary exercise capacity has not yet been fully elucidated.

Objectives

To evaluate cardiac sympathetic activity through 123I-MIBG scintigraphy, and to analyze its correlation with myocardial remodeling and exercise capacity in HF patients.

Methods

Symptomatic HF patients (NYHA class II–III) stratified by LVEF as HFpEF (LVEF 45%) and HFrE'F (LVEF &lt;45%) and healthy controls were enrolled. HF patients were euvolemic under optimized treatment at the time of enrollment. All individuals underwent CMR with morphology/function and extracellular volume fraction (ECV) assessment, global longitudinal strain (GLS) by echocardiogram, cardiopulmonary exercise testing (CPET), cardiac sympathetic imaging 123I-MIBG scintigraphy (mIBG), and NT-proBNP.

Results

Eighty individuals were recruited allocated into the following groups: HFpEF (n=33, 59.42±12.63 years, LVEF: 59.82±9.87, NT-proBNP: 409.40±693.37, H2FPEF-score: 5±2), HFrEF (n=28, 53.93±11.40 years; LVEF: 29.81±8.67, NT-proBNP: 1662,34±2016,73) and healthy controls (42.65±13.96 years, LVEF: 65.27±4.73, NT-proBNP: 44,43±33,28) were enrolled. While ECV was elevated in HF groups (HFpEF: 0.32±0.05%, HFrEF: 0.31±0.41% and controls: 0.26±0.03, p&lt;0.05), adjusted maximum oxygen consumption (VO2max) was markedly reduced vs. controls (HFpEF: 18.58±6.29mL/kg/min, HFrEF: 17.60±3.89mL/kg/min, controls: 29.73±9.98mL/kg/min, p&lt;0.001). The MIBG heart-to-mediastinum ratio at 4 hours (H/M) was significantly lower in HF compared with controls (HFpEF: 1.59±0.25, HFrEF: 1.45±0.15 and controls: 1.92±0.25, p&lt;0.001). Interestingly, the H/M ratio was more impaired with HFrEF compared to HFpEF (Fig. 1A). As a result, the mean myocardial washout rate was increased in HF patients (HFrEF 36.38±14.35, HFpEF 29.92±18.33 vs. controls 8.0±27.01, p&lt;0.001). In addition, considering all HF patients, H/M was inversely associated with ECV (R: −0.45, p&lt;0.001, Fig. 1B), NT-proBNP (R: −0.55, p&lt;0.001) and VO2max (R: −0.27, p: &lt;0.024, Fig. 1C). GLS was inversely associated with H/M in HFrEF but not HFpEF (HFrEF: R: −0.535, p&lt;0.001 and HFpEF: R: −0.036, p=NS, Fig. 1D).

Conclusion

Cardiac sympathetic activity assessed by 123I-MIBG was abnormal in patients with HF with reduced and preserved EF as compared to controls. H/M, a validated marker for cardiac sympathetic activity, showed a strong correlation with markers of functional capacity and myocardial remodeling. Sympathetic innervation appears to be a limiting factor for global longitudinal strain in HFrEF, while in HFpEF longitudinal strain is independent of sympathetic activity

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The São Paulo Research Foundation

Diffuse Myocardial Fibrosis and Cardiomyocyte Diameter Are Associated With Heart Failure Symptoms in Chagas Cardiomyopathy

Background

Chronic Chagas cardiomyopathy (CCC) constitutes the most life-threatening consequence of the Trypanosoma cruzi infection. Our goal was to test in CCC the associations of the myocardial tissue phenotype with cardiac dysfunction, and heart failure (HF) severity, using cardiac magnetic resonance (CMR).

Methods

We performed a prospective observational cohort of patients with consecutive CCC with a CMR protocol, including ventricular function, myocardial T1, and late gadolinium enhancement (LGE). Extracellular volume (ECV), and intracellular water lifetime, τic, a measure of cardiomyocyte diameter, were compared to CCC disease progression, including Rassi score and New York Heart Association (NYHA) class. An exploratory prognostic analysis was performed to investigate the association of both ECV and τic with CV death.

Results

A total of 37 patients with intermediate-to-high-risk CCC were enrolled (Chagas Rassi score ≥7, mean left ventricle (LV) ejection fraction (EF) 32 ± 16%). Myocardial ECV (0.40 ± 0.07) was correlated with Rassi score (r = 0.43; P = 0.009), higher NYHA class, and LV EF (r = -0.51; P = 0.0015). τic decreased linearly with NYHA class (P = 0.007 for non-parametric test of linear trend) and showed a positive association with LV EF (r = 0.47; P = 0.004). Over a median follow-up of 734 days (range: 6-2,943 days), CV death or cardiac transplantation occurred in 10 patients. The Rassi score (heart rate [HR] = 1.3; 95% CI = [1.0, 1.8]; P = 0.028) and ECV (HR = 3.4 for 0.1 change, 95% CI = [1.1, 11.0], P = 0.039) were simultaneously associated with CV death.

Conclusion

In patients with intermediate-to-high-risk CCC, an expanded ECV and regression of cardiomyocyte diameter were associated with worsening systolic function and HF severity, respectively. The exploratory analysis indicates that ECV may have a prognostic value to identify patients with CCC at a higher risk for cardiovascular events.

Reagent integration and controlled release for multiplexed nucleic acid testing in disposable thermoplastic 2D microwell arrays

The seamless integration of reagents into microfluidic devices can serve to significantly reduce assay complexity and cost for disposable diagnostics. In this work, the integration of multiplexed reagents into thermoplastic 2D microwell arrays is demonstrated using a scalable pin spotting technique. Using a simple and low-cost narrow-bore capillary spotting pin, high resolution deposition of concentrated reagents within the arrays of enclosed nanoliter-scale wells is achieved. The pin spotting method is further employed to encapsulate the deposited reagents with a chemically modified wax layer that serves to prevent disruption of the dried assay components during sample introduction through a shared microchannel, while also enabling temperature-controlled release after sample filling is complete. This approach supports the arbitrary patterning and release of different reagents within individual wells without crosstalk for multiplexed analyses. The performance of the in-well spotting technique is characterized using on-chip rolling circle amplification to evaluate its potential for nucleic acid-based diagnostics.

Noninvasive imaging assessment of rehabilitation therapy in heart failure with preserved and reduced left ventricular ejection fraction (IMAGING-REHAB-HF): design and rationale

Background:

Studies have shown significant benefits of exercise therapy in heart failure (HF) with a reduced ejection fraction (HFrEF) and HF with a preserved ejection fraction (HFpEF). The mechanisms responsible for the beneficial effect of exercise in HFrEF and HFpEF are still unclear. We hypothesized that the effect of exercise on myocardial remodeling may explain its beneficial effect.

Methods:

IMAGING-REHAB-HF is a single-center, randomized, controlled clinical trial using cardiac magnetic resonance imaging, vasomotor endothelial function, cardiac sympathetic activity imaging and serum biomarkers to compare the effect of exercise therapy in HFpEF (LVEF ≥ 45%) and HFrEF (LVEF < 45%). Subjects will be assessed at baseline and after 4 months. The exercise program will consist of three 60-min exercise sessions/week. The primary endpoints are the effect of exercise on myocardial extracellular volume (ECV), left ventricular (LV) systolic function, LV mass, LV mass-to-volume and LV cardiomyocyte volume. Secondary endpoints include the effect of exercise on vasomotor endothelial function, cardiac sympathetic activity and plasmatic biomarkers. Patients will be allocated in a 2:1 fashion to supervised exercise program or usual care. A total sample size of 90 patients, divided into two groups according to LVEF:HFpEF group (45 patients:30 in the intervention arm and 15 in the control arm) and HFrEF group (45 patients:30 in the intervention arm and 15 in the control arm) – will be necessary to achieve adequate power.

Conclusion:

This will be the first study to evaluate the benefits of a rehabilitation program on cardiac remodeling in HF patients. The unique design of our study may provide unique data to further elucidate the mechanisms involved in reverse cardiac remodeling after exercise in HFpEF and HFrEF patients.

Rapid real-time PCR and high resolution melt analysis in a self-filling thermoplastic chip

A microfluidic platform designed for point-of-care PCR-based nucleic acid diagnostics is described. Compared to established microfluidic PCR technologies, the system is unique in its ability to achieve exceptionally rapid PCR amplification in a low cost thermoplastic format, together with high temperature accuracy enabling effective validation of reaction product by high resolution melt analysis performed in the same chamber as PCR. In addition, the system employs capillary pumping for automated loading of sample into the reaction chamber, combined with an integrated hydrophilic valve for precise self-metering of sample volumes into the device. Using the microfluidic system to target a mutation in the G6PC gene, efficient PCR from human genomic DNA template is achieved with cycle times as low as 14 s, full amplification in 8.5 min, and final melt analysis accurately identifying the desired amplicon.

Elevated serum uric acid is associated with vascular inflammation but not coronary artery calcification in the healthy octogenarians: the Brazilian study on healthy aging

BACKGROUND

There is a limited data on the association between serum uric acid (SUA) and cardiovascular disease (CVD) among the very elderly population.

AIMS

We evaluated the association of SUA, highly sensitive C-reactive protein (hs-CRP, a marker of vascular and systemic inflammation), and coronary artery calcification (CAC, a marker of subclinical CVD) in a cohort of Brazilian octogenarians (≥80 years) free from known clinical CVD.

METHODS

208 individuals were included and evaluated for an association between increasing tertiles of SUA, elevated hs-CRP (>3 mg/dL), the presence and burden of CAC (CAC > 0 and CAC > 400).

RESULTS

The median hs-CRP was 1.9 (IQR = 1.0-3.4) mg/L and mean SUA was 5.3 (±1.4) mg/dL. The overall prevalence of elevated hs-CRP (>3 mg/dL) was 31 %. A significant increase in the prevalence of hs-CRP was noted across the higher SUA tertiles (p < 0.001) with 3.4 times the odds of having elevated hs-CRP in the highest SUA tertile (3.40; CI = 1.27-9.08). No association was noted with either the CAC presence and/or CAC burden (CAC > 0 or CAC > 400) across the increasing SUA tertiles.

DISCUSSION

In the healthy octogenarians, higher SUA levels are associated with vascular inflammation (hs-CRP) but not with coronary atherosclerosis (CAC); markers for the subclinical CVD.

Beyond BMI: The "Metabolically healthy obese" phenotype & its association with clinical/subclinical cardiovascular disease and all-cause mortality -- a systematic review

Background

A subgroup has emerged within the obese that do not display the typical metabolic disorders associated with obesity and are hypothesized to have lower risk of complications. The purpose of this review was to analyze the literature which has examined the burden of cardiovascular disease (CVD) and all-cause mortality in the metabolically healthy obese (MHO) population.

Methods

Pubmed, Cochrane Library, and Web of Science were searched from their inception until December 2012. Studies were included which clearly defined the MHO group (using either insulin sensitivity and/or components of metabolic syndrome AND obesity) and its association with either all cause mortality, CVD mortality, incident CVD, and/or subclinical CVD.

Results

A total of 20 studies were identified; 15 cohort and 5 cross-sectional. Eight studies used the NCEP Adult Treatment Panel III definition of metabolic syndrome to define “metabolically healthy”, while another nine used insulin resistance. Seven studies assessed all-cause mortality, seven assessed CVD mortality, and nine assessed incident CVD. MHO was found to be significantly associated with all-cause mortality in two studies (30%), CVD mortality in one study (14%), and incident CVD in three studies (33%). Of the six studies which examined subclinical disease, four (67%) showed significantly higher mean common carotid artery intima media thickness (CCA-IMT), coronary artery calcium (CAC), or other subclinical CVD markers in the MHO as compared to their MHNW counterparts.

Conclusions

MHO is an important, emerging phenotype with a CVD risk between healthy, normal weight and unhealthy, obese individuals. Successful work towards a universally accepted definition of MHO would improve (and simplify) future studies and aid inter-study comparisons. Usefulness of a definition inclusive of insulin sensitivity and stricter criteria for metabolic syndrome components as well as the potential addition of markers of fatty liver and inflammation should be explored. Clinicians should be hesitant to reassure patients that the metabolically benign phenotype is safe, as increased risk cardiovascular disease and death have been shown.

The prevalence of the metabolically healthy obese phenotype in an aging population and its association with subclinical cardiovascular disease: The Brazilian study on healthy aging

BACKGROUND

Current literature has elucidated a new phenotype, metabolically healthy obese (MHO), with risks of cardiovascular disease similar to that of normal weight individuals. Few studies have examined the MHO phenotype in an aging population, especially in association with subclinical CVD.

RESEARCH DESIGN AND METHODS

This cross sectional study population consisted of 208 octogenarians and older. Anthropometrics, biochemical, and radiological parameters were measured to assess obesity, metabolic health (assessed by the National Cholesterol Education Program -Adult Treatment Panel (NCEP-ATP III) criteria), and subclinical measures of CVD.

RESULTS

The prevalence of MHO was 13.5% (N = 28). No significant association with MHO was noted for age, coronary artery calcium score, cIMT, or hs-CRP > 3 mg/dl (p = NS).

CONCLUSIONS

Our results suggest that the MHO phenotype exists in the elderly; however, subclinical CVD measures were not different in sub-group analysis suggesting traditional metabolic risk factor algorithms may not be accurate in the very elderly.

A systematic review: burden and severity of subclinical cardiovascular disease among those with nonalcoholic fatty liver; should we care?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging disease and a leading cause of chronic liver disease. The prevalence in the general population is approximately 15-30% and it increases to 70-90% in obese or diabetic populations. NAFLD has been linked to increased cardiovascular disease (CVD) risk. It is therefore critical to evaluate the relationship between markers of subclinical CVD and NAFLD.

METHOD

An extensive search of databases; including the National Library of Medicine and other relevant databases for research articles meeting inclusion criteria: observational or cohort, studies in adult populations and clearly defined NAFLD and markers of subclinical CVD.

RESULTS

Twenty-seven studies were included in the review; 16 (59%) presented the association of NAFLD and carotid intima-media thickness (CIMT), 7 (26%) the association with coronary calcification and 7 (26%) the effect on endothelial dysfunction and 6 (22%) influence on arterial stiffness. CIMT studies showed significant increases among NAFLD patients compared to controls. These were independent of traditional risk factors and metabolic syndrome. The association was similar in coronary calcification studies. The presence of NAFLD is associated with the severity of the calcification. Endothelial dysfunction and arterial stiffness showed significant independent associations with NAFLD. Two studies argued the associations were not significant; however, these studies were limited to diabetic populations.

CONCLUSION

There is evidence to support the association of NAFLD with subclinical atherosclerosis independent of traditional risk factors and metabolic syndrome. However, there is need for future longitudinal studies to review this association to ascertain causality and include other ethnic populations.

Laser-Induced Forward Transfer-printing of focused ion beam pre-machined crystalline magneto-optic yttrium iron garnet micro-discs

We present femtosecond laser-induced forward transfer of focused ion beam pre-machined discs of crystalline magneto-optic yttrium iron garnet (YIG) films. Debris-free circular micro-discs with smooth edges and surface uniformity have been successfully printed. The crystalline nature of the printed micro-discs has not been altered by the LIFT printing process, as was confirmed via micro-Raman measurements.

LDL particle subspecies are distinct in their capacity to mediate free cholesterol efflux via the SR-BI/Cla-1 receptor

The human scavenger receptor SR-BI/Cla-1 promotes efflux of free cholesterol from cells to both high-density and low-density lipoproteins (HDL, LDL). SR-BI/Cla-1-mediated cholesterol efflux to HDL is dependent on particle size, lipid content and apolipoprotein conformation; in contrast, the capacity of LDL subspecies to accept cellular cholesterol via this receptor is indeterminate. Cholesterol efflux assays were performed with CHO cells stably transfected with Cla-1 cDNA. Expression of Cla-1 in CHO cells induced elevation in total cholesterol efflux to plasma, LDL and HDL. Such Cla-1-specific efflux was abrogated by addition of anti-Cla-1 antibody. LDL were fractionated into five subspecies either on the basis of hydrated density or size. Among LDL subfractions, small dense LDL (sdLDL) were 1.5-to 3-fold less active acceptors for Cla-1-mediated cellular cholesterol efflux. Equally, sdLDL markedly reduced Cla-1-specific cholesterol efflux to large buoyant LDL in a dose-dependent manner. Conversely, sdLDL did not influence efflux to HDL(2). These findings provide evidence that LDL particles are heterogeneous in their capacity to promote Cla-1-mediated cholesterol efflux. Relative to HDL(2), large buoyant LDL may constitute physiologically-relevant acceptors for cholesterol efflux via Cla-1.

Cellular cholesterol efflux mediated by HDL isolated from subjects with low HDL levels and coronary artery disease

OBJECTIVE

The aim of this study was to verify whether HDL particles isolated from patients with coronary artery disease (CAD) and low HDL-C had diminished ability to promote cholesterol efflux from cultured cells compared with HDL isolated from subjects without CAD and with normal HDL-C.

METHODS

Smooth muscle cells isolated from human aortas cultured and radiolabeled with H-cholesterol were loaded with cholesterol and incubated with increasing concentrations of HDL isolated from 13 CAD patients with low HDL-C (CAD group) or from 5 controls without CAD (C group). Efflux of cellular cholesterol was measured by cellular depletion of radiolabeled cholesterol and by the appearance of H-cholesterol into experimental medium expressed as a percentage of total labeled cholesterol.

RESULTS

Cholesterol efflux increased with the amount of HDL present in the medium, and no difference was found between groups at various HDL protein concentrations: efflux was 28 +/- 6.3% (C) and 25.5 +/- 8.9% (CAD) with 25 microg/mL; 34 +/- 4.3% (C) and 31.9 +/- 6.6% (CD) with 50 micro g/mL and 39.5 +/- 3.5% (C) and 37.1 +/- 4.4% (CAD) with 100 micro g/mL, HDL.

CONCLUSION

Because the HDL fraction of CAD patients with low HDL-C have normal ability to extract cholesterol from cells of the vessel wall, it is suggested that low HDL-C atherogenicity should be ascribed to diminished concentrations of HDL particles rather than to the qualitative properties of the HDL fraction.