Effects of Triiodothyronine Treatment in an Animal Model of Heart Failure with Preserved Ejection Fraction

Background: Low levels of triiodothyronine (T3) are common in patients with heart failure (HF). Our aim was to evaluate the effects of supplementation with low and replacement doses of T3 in an animal model of HF with preserved ejection fraction (HFpEF). Methods: We evaluated four groups: ZSF1 Lean (n = 8, Lean-Ctrl), ZSF1 Obese (rat model of metabolic-induced HFpEF, n = 13, HFpEF), ZSF1 Obese treated with a replacement dose of T3 (n = 8, HFpEF-T3high), and ZSF1 Obese treated with a low-dose of T3 (n = 8, HFpEF-T3low). T3 was administered in drinking water from weeks 13 to 24. The animals underwent anthropometric and metabolic assessments, echocardiography, and peak effort testing with maximum O2 consumption (VO2max) determination at 22 weeks, and a terminal hemodynamic evaluation at 24 weeks. Afterwhile myocardial samples were collected for single cardiomyocyte evaluation and molecular studies. Results: HFpEF animals showed lower serum and myocardial thyroid hormone levels than Lean-Ctrl. Treatment with T3 did not normalize serum T3 levels, but increased myocardial T3 levels to normal levels in the HFpEF-T3high group. Body weight was significantly decreased in both the T3-treated groups, comparing with HFpEF. An improvement in glucose metabolism was observed only in HFpEF-T3high. Both the treated groups had improved diastolic and systolic function in vivo, as well as improved Ca2+ transients and sarcomere shortening and relaxation in vitro. Comparing with HFpEF animals, HFpEF-T3high had increased heart rate and a higher rate of premature ventricular contractions. Animals treated with T3 had higher myocardial expression of calcium transporter ryanodine receptor 2 (RYR2) and α-myosin heavy chain (MHC), with a lower expression of β-MHC. VO2max was not influenced by treatment with T3. Myocardial fibrosis was reduced in both the treated groups. Three animals died in the HFpEF-T3high group. Conclusions: Treatment with T3 was shown to improve metabolic profile, myocardial calcium handling, and cardiac function. While the low dose was well-tolerated and safe, the replacement dose was associated with increased heart rate, and increased risk of arrhythmias and sudden death. Modulation of thyroid hormones may be a potential therapeutic target in HFpEF; however, it is important to take into account the narrow therapeutic window of T3 in this condition.

Mobile Application for Improvement of Self-Management of Type 2 Diabetes: Usability Pilot Test

We intend to evaluate the usability of a mobile app developed for the self-management of T2DM. A pilot usability cross-sectional study was performed with a convenience sample of 6 smartphone users aged 45 years. Participants performed tasks autonomously in a mobile app to assess if users could complete them and filled out a usability and satisfaction questionnaire. About half of the tasks had a successful completion rate. The result of the usability questionnaire was 64/100, below the acceptable value, but the satisfaction value was considered good. This study was fundamental as it allowed us to verify which improvements should be implemented in the next version of the app, contributing to its better acceptance.

The thromboxane receptor antagonist NTP42 promotes beneficial adaptation and preserves cardiac function in experimental models of right heart overload

Background

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary artery pressure leading to right ventricular (RV) failure. While current PAH therapies improve patient outlook, they show limited benefit in attenuating RV dysfunction. Recent investigations demonstrated that the thromboxane (TX) A₂ receptor (TP) antagonist NTP42 attenuates experimental PAH across key hemodynamic parameters in the lungs and heart. This study aimed to validate the efficacy of NTP42:KVA4, a novel oral formulation of NTP42 in clinical development, in preclinical models of PAH while also, critically, investigating its direct effects on RV dysfunction.

Methods

The effects of NTP42:KVA4 were evaluated in the monocrotaline (MCT) and pulmonary artery banding (PAB) models of PAH and RV dysfunction, respectively, and when compared with leading standard-of-care (SOC) PAH drugs. In addition, the expression of the TP, the target for NTP42, was investigated in cardiac tissue from several other related disease models, and from subjects with PAH and dilated cardiomyopathy (DCM).

Results

In the MCT-PAH model, NTP42:KVA4 alleviated disease-induced changes in cardiopulmonary hemodynamics, pulmonary vascular remodeling, inflammation, and fibrosis, to a similar or greater extent than the PAH SOCs tested. In the PAB model, NTP42:KVA4 improved RV geometries and contractility, normalized RV stiffness, and significantly increased RV ejection fraction. In both models, NTP42:KVA4 promoted beneficial RV adaptation, decreasing cellular hypertrophy, and increasing vascularization. Notably, elevated expression of the TP target was observed both in RV tissue from these and related disease models, and in clinical RV specimens of PAH and DCM.

Conclusion

This study shows that, through antagonism of TP signaling, NTP42:KVA4 attenuates experimental PAH pathophysiology, not only alleviating pulmonary pathologies but also reducing RV remodeling, promoting beneficial hypertrophy, and improving cardiac function. The findings suggest a direct cardioprotective effect for NTP42:KVA4, and its potential to be a disease-modifying therapy in PAH and other cardiac conditions.

OR19-2 Treatment of Heart Failure with Preserved Ejection Fraction (HFpEF) with Low and High Dose of Triiodothyronine: an Animal Model of Metabolic Syndrome with HFpEF

Introduction

Low levels of triiodothyronine (T3) are common in patients with heart failure (HF). It has been proposed that the decreased levels of T3 contribute to metabolic and cardiac dysfunction in HF. We aimed to evaluate the effects of treatment with low dose and high dose of T3 in an animal model of HF with preserved ejection fraction (HFpEF).

Materials and Methods

We evaluated four groups: ZSF1 Lean (Lean-Ctrl, n=8), ZSF1 obese (rat model of metabolic syndrome with HFpEF, HFpEF-Ctrl, n=13), ZSF1 obese supplemented with a replacement dose of T3 (initially 0.04mg/ml, increased to 0.06mg/ml after 4 weeks; HFpEF-T3high, n=8), and ZSF1 Obese supplemented with a low-dose of T3 (0.03mg/mL; HFpEF-T3low, n=8). T3 was supplemented in drinking water from week 13 to 24. The animals were submitted to anthropometric and metabolic evaluation, echocardiography, VO2max evaluation, hemodynamic evaluation, single cardiomyocyte evaluation, and myocardial tissue collection at 24 weeks.

Results

HFpEF-Ctrl animals had lower serum and myocardial thyroid hormone levels than Lean-Ctrl. Treatment with low dose and high dose of T3 did not correct serum T3 levels, but increased myocardial T3 levels, with normalization of myocardial T3 levels in the HFpEF-T3high group. In comparison to HFpEF-Ctrl, body weight was significantly decreased in HFpEF-T3low and HFpEF-T3high groups (616±39g, 572±24g and 535±18g respectively, p<0.001). An improvement in glucose metabolism was observed only in HFpEF-T3high, with a decreased AUC of glucose during OGTT and insulin tolerance test. Both treated groups presented an improvement in diastolic function (with decreased isovolumetric relaxation time) and systolic function (with increased peak systolic velocity and decreased ejection time) comparing to HFpEF-Ctrl. These results were supported by enhanced Ca2+ transients during diastole and sarcomere relaxation. Comparing with HFpEF-Ctrl, animals treated with T3 had higher myocardial expression of the calcium transporter RYR2, of the transcriptional coactivator PGC-1α, and of the α-myosin heavy chain (MHC), with a lower expression of β-MHC. VO2max was improved with low-dose and high-dose T3 compared with HFpEF-Ctrl. Comparing with HFpEF-Ctrl, heart rate was increased with high-dose (277.9±30.2 vs 313.5±35.8, p=0.049) but not significantly with low-dose (277.9±30.2 vs 299.8±30.9 bpm, p=0.13). Mortality was increased in the HFpEF-T3high comparing with the other groups (no animals died during the protocol in the Lean-Ctrl, HFpEF-Ctrl and HFpEF-T3low groups; three animals had sudden death in the HFpEF-T3high group).

Conclusion

Treatment with T3 improves metabolic function, myocardial calcium handling, diastolic and systolic function, and exercise capacity in this animal model of HFpEF. While the low dose was well tolerated and safe, the high dose was associated with increased heart rate and a higher risk of sudden death. Modulation of thyroid hormones may be a potential therapeutic target in HFpEF; however such approaches must take into account a narrow therapeutic window of T3 in HFpEF.

Presentation: Monday, June 13, 2022 11:15 p.m. - 11:30 a.m.

RF36 | PSUN101 Liver and Adipose Tissue Effects of Triiodothyronine Treatment in an Animal Model of Metabolic Syndrome

Introduction

Metabolic syndrome (MS) associates to obesity and non-alcoholic fatty liver disease (NAFLD). Besides its high and rising prevalence, the therapeutical options are scarce. Studies show that thyroid hormones (TH) may ameliorate hepatic function and hepatic and extra-hepatic lipid deposition.

Aim

To evaluate the effects of triiodothyronine (T3) treatment in high and low dose on the liver and adipose tissue of an animal model of metabolic syndrome (ZSF1 rats).

Material and methods

Four groups of animals were evaluated: 1) ZSF1 lean rats (Ln, used as controls; n=8); 2) untreated ZSF1 obese rats (Ob; animal model of MS; n=10); 3) ZSF1 obese rats treated with high dose T3 (hT3; initially 0.04mg/mL and 0.06mg/mL after 4 weeks; n=5); 4) ZSF1 obese rats treated with low dose T3 (lT3; 0.03mg/mL; n=5). We performed anthropometric and oral glucose tolerance testing (OGTT). Tissues and blood were collected at the 24th week of age for histological evaluation and assessing the levels of thyroid hormones.

Results

The animals from hT3 and lT3 groups had similar weights and both were significantly heavier (tibial length/weight ratio of 14.7±0.6 and 14.1±0.7g/mm respectively) than Ln (10.7±0.6g/mm, p<0.01). The rats from lT3 group were also significantly lighter than Ob (15.3±1.0g/mm, p=0.042). Fasting glucose of hT3 (118.6±36.0mg/dL) was lower comparing to Ob (228.1±58.6mg/dL, p<0.01) and to lT3 (207.2±69.8mg/dL, p=0.048) and similar to Ln (82.1±9.1mg/dL, p=1.00). The evaluation of the area under the curve (AUC) of OGTT is in agreement with these results.

The histological evaluation of the liver showed a ratio between lipids and surrounding tissue significantly lower in the treated groups (hT3 0.35±0.1 and lT3 0.34±0.1) compared to Ob (0.89±0.2, p<0.01) and similar to Ln (0.14±0.1, p=0.106 and p=0.124, respectively). The ratio between glycogen and surrounding tissue was not different between treated animals and either Ob or Ln.

Concerning the adipose tissue, adipocyte area was similar between treated animals (hT3 7435±1031mm² and lT3 6899±554mm², p=1.00) and was significantly lower compared to Ob (9037±789mm², p<0.01) and higher compared to Ln (2771±754mm², p<0.01). The area of fibrosis was similar between hT3 and lT3 (7.7±1.1mm and 6.6±0. 5mm, respectively, p=1. 00), higher when comparing both groups with Ln (2.4±1.3mm, p<0.01) and lower when comparing both groups with Ob (13.5±2.2mm, p<0.01).

Conclusion

Treatment of obese ZSF1 animals with T3 improved the glycemic profile, and lipid and fibrous deposition in the liver and adipose tissue. The usage of low dose T3 does not seem different from high dose concerning these effects and might be associated with fewer adverse events. TH may, in the future, become an option when treating patients with MS and NAFLD.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 12:42 p.m. - 12:47 p.m.

Gastric microbiome profile throughout gastric carcinogenesis: beyond helicobacter

BACKGROUND

Gastric dysbiosis has been hinted as a potential cause of gastric cancer. However, changes in microbiome throughout the major stages of gastric carcinogenesis remain mostly unknown.

OBJECTIVE

To describe gastric microbiome at different stages, analysing for the first time dysbiosis specifically in patients with early gastric cancer (EGC).

METHODS

Cross-sectional study including patients (n = 77) with endoscopically and histologically confirmed normal stomachs (controls; n = 25), advanced atrophic gastritis with intestinal metaplasia (IM; n = 18) and EGC (n = 34). Endoscopic biopsies from antrum and corpus (n = 154) were analyzed. Next-generation sequencing was performed characterizing microbial communities down to the species level based on full-length 16SrRNA gene profiling.

RESULTS

Significant differences were found in the microbiome profile between the groups. Firmicutes were more frequent (p = .012) and Proteobacteria were less frequent (p = .04) both in the IM and EGC when comparing to controls. Relative frequency of Helicobacter pylori, when present, was much higher in the controls (83%) when comparing to the other groups (IM 1%, EGC 27%; p = .006), being the dominant bacteria only in the controls. Dysbiosis was present already and more significantly at the IM stage, with two bacteria progressively increasing from controls to IM then to cancer: Gemella from 1.48 to 3.9% (p = .014); and Streptococcus from 19.3 to 33.7% (p = .04), being the EGC dominant bacteria.

CONCLUSIONS

Our results confirm Helicobacter pylori dominancy in non-atrophic stomachs and progressive dysbiosis throughout gastric carcinogenesis. Gemella but particularly Streptococcus is significantly increased in patients with EGC. Specific modulation of these bacteria may change gastric cancer risk.

Fat Quality Matters: Distinct Proteomic Signatures Between Lean and Obese Cardiac Visceral Adipose Tissue Underlie its Differential Myocardial Impact

BACKGROUND/AIMS

Heart failure with preserved ejection fraction (HFpEF) is recognised as an important cause of cardiovascular mortality and morbidity, accounting for approximately 50% of heart failure cases. Metabolic-related complications, such as obesity, have been associated with the pathophysiology of this complex syndrome. The anatomic proximity between cardiac visceral adipose tissue (CVAT) and the myocardium has been drawing attention due to its potential pathogenic role in cardiac diseases. Thus, we aimed to characterise the phenotypic and proteomic differences between CVAT from ZSF1 lean (control) and ZSF1 obese (HFpEF) rats as well as to evaluate the myocardial impact of conditioned media derived from CVAT of these 2 groups.

METHODS

CVAT of 20-weeks-old lean and obese ZSF1 rats was collected for: 1) 24h DMEM incubation to obtain conditioned media, 2) separation of proteins to mass spectrometry identification, 3) adipokines' expression, 4) adipocytes cross-sectional area assessment. Organotypic cultures were prepared from 7 days-old Wistar Han cardiac explants and incubated for 24h with the conditioned media. After incubation, cross-section area of cardiomyocytes and fibrosis were evaluated. Cardiomyocytes were isolated from Wistar Han and incubated with conditioned media for viability studies.

RESULTS

CVAT from lean rats presented a higher expression of uncoupling protein-1 (UCP-1) protein, associated with a multilocular appearance and an increased expression of brown adipose tissue markers. Contrarily, CVAT from obese rats revealed a white adipose tissue-like phenotype accompanied by hypertrophy of adipocytes. The analysis of the CVAT proteome reinforced the phenotypic differences between lean and obese CVAT, showing enrichment of proteins involved in triglyceride metabolic processes in obese CVAT. In contrast, mitochondrial proteins were prominent in lean CVAT, further suggesting a brown adipose tissue-like phenotype. The twenty-four hours-long incubation of myocardial organo-cultures with conditioned media obtained from CVAT obese (CM-obese) rats significantly reduced cell viability, induced cardiomyocytes hypertrophy and fibrosis, in stark contrast with the incubation with the conditioned media from lean rats CVAT (CM-lean). Furthermore, the deleterious effect imposed by CM-obese was associated with a pro-inflammatory profile, characterised by an increased expression of several pro-inflammatory adipokines.

CONCLUSION

Obesity promotes alterations in CVAT proteome signature, structure, composition and secretome, translating into dramatic myocardial consequences.

Disturbed cardiac mitochondrial and cytosolic calcium handling in a metabolic risk-related rat model of heart failure with preserved ejection fraction

AIM

Calcium ions play a pivotal role in matching energy supply and demand in cardiac muscle. Mitochondrial calcium concentration is lower in animal models of heart failure with reduced ejection fraction (HFrEF), but limited information is available about mitochondrial calcium handling in heart failure with preserved ejection fraction (HFpEF).

METHODS

We assessed mitochondrial Ca²⁺ handling in intact cardiomyocytes from Zucker/fatty Spontaneously hypertensive F1 hybrid (ZSF1)-lean (control) and ZSF1-obese rats, a metabolic risk-related model of HFpEF. A mitochondrially targeted Ca²⁺ indicator (MitoCam) was expressed in cultured adult rat cardiomyocytes. Cytosolic and mitochondrial Ca²⁺ transients were measured at different stimulation frequencies. Mitochondrial respiration and swelling, and expression of key proteins were determined ex vivo.

RESULTS

At rest, mitochondrial Ca²⁺ concentration in ZSF1-obese was larger than in ZSF1-lean. The diastolic and systolic mitochondrial Ca²⁺ concentrations increased with stimulation frequency, but the steady-state levels were larger in ZSF1-obese. The half-widths of the contractile responses, the resting cytosolic Ca²⁺ concentration and the decay half-times of the cytosolic Ca²⁺ transients were higher in ZSF1-obese, likely because of a lower SERCA2a/phospholamban ratio. Mitochondrial respiration was lower, particularly with nicotinamide adenine dinucleotide (NADH) (complex I) substrates, and mitochondrial swelling was larger in ZSF1-obese.

CONCLUSION

The free mitochondrial calcium concentration is higher in HFpEF owing to alterations in mitochondrial and cytosolic Ca²⁺ handling. This coupling between cytosolic and mitochondrial Ca²⁺ levels may compensate for myocardial ATP supply in vivo under conditions of mild mitochondrial dysfunction. However, if mitochondrial Ca²⁺ concentration is sustainedly increased, it might trigger mitochondrial permeability transition pore opening.

Stretch-induced compliance: a novel adaptive biological mechanism following acute cardiac load

Aims

The heart is constantly challenged with acute bouts of stretching or overload. Systolic adaptations to these challenges are known but adaptations in diastolic stiffness remain unknown. We evaluated adaptations in myocardial stiffness due to acute stretching and characterized the underlying mechanisms.

Methods and results

Left ventricles (LVs) of intact rat hearts, rabbit papillary muscles and myocardial strips from cardiac surgery patients were stretched. After stretching, there was a sustained >40% decrease in end-diastolic pressure (EDP) or passive tension (PT) for 15 min in all species and experimental preparations. Stretching by volume loading in volunteers and cardiac surgery patients resulted in E/E' and EDP decreases, respectively, after sustained stretching. Stretched samples had increased myocardial cGMP levels, increased phosphorylated vasodilator-stimulated phosphoprotein phosphorylation, as well as, increased titin phosphorylation, which was reduced by prior protein kinase G (PKG) inhibition (PKGi). Skinned cardiomyocytes from stretched and non-stretched myocardia were studied. Skinned cardiomyocytes from stretched hearts showed decreased PT, which was abrogated by protein phosphatase incubation; whereas those from non-stretched hearts decreased PT after PKG incubation. Pharmacological studies assessed the role of nitric oxide (NO) and natriuretic peptides (NPs). PT decay after stretching was significantly reduced by combined NP antagonism, NO synthase inhibition and NO scavenging, or by PKGi. Response to stretching was remarkably reduced in a rat model of LV hypertrophy, which also failed to increase titin phosphorylation.

Conclusions

We describe and translate to human physiology a novel adaptive mechanism, partly mediated by titin phosphorylation through cGMP-PKG signalling, whereby myocardial compliance increases in response to acute stretching. This mechanism may not function in the hypertrophic heart.

Characterization of biventricular alterations in myocardial (reverse) remodelling in aortic banding-induced chronic pressure overload

Aortic Stenosis (AS) is the most frequent valvulopathy in the western world. Traditionally aortic valve replacement (AVR) has been recommended immediately after the onset of heart failure (HF) symptoms. However, recent evidence suggests that AVR outcome can be improved if performed earlier. After AVR, the process of left ventricle (LV) reverse remodelling (RR) is variable and frequently incomplete. In this study, we aimed at detecting mechanism underlying the process of LV RR regarding myocardial structural, functional and molecular changes before the onset of HF symptoms. Wistar-Han rats were subjected to 7-weeks of ascending aortic-banding followed by a 2-week period of debanding to resemble AS-induced LV remodelling and the early events of AVR-induced RR, respectively. This resulted in 3 groups: Sham (n = 10), Banding (Ba, n = 15) and Debanding (Deb, n = 10). Concentric hypertrophy and diastolic dysfunction (DD) were patent in the Ba group. Aortic-debanding induced RR, which promoted LV functional recovery, while cardiac structure did not normalise. Cardiac parameters of RV dysfunction, assessed by echocardiography and at the cardiomyocyte level prevailed altered after debanding. After debanding, these alterations were accompanied by persistent changes in pathways associated to myocardial hypertrophy, fibrosis and LV inflammation. Aortic banding induced pulmonary arterial wall thickness to increase and correlates negatively with effort intolerance and positively with E/e′ and left atrial area. We described dysregulated pathways in LV and RV remodelling and RR after AVR. Importantly we showed important RV-side effects of aortic constriction, highlighting the impact that LV-reverse remodelling has on both ventricles.

Characterization of liver changes in ZSF1 rats, an animal model of metabolic syndrome

BACKGROUND

The non-alcoholic fatty liver disease is the hepatic counterpart of the metabolic syndrome. ZSF1 rats are a metabolic syndrome animal model in which liver changes have not been described yet.

AIM

The characterization of liver histological and innate immunity changes in ZSF1 rats.

METHODS

Five groups of rats were included (n = 7 each group): healthy Wistar-Kyoto control rats (Ctrl), hypertensive ZSF1 lean (Ln), ZSF1 obese rats with a normal diet (Ob), ZSF1 obese rates with a high-fat diet (Ob-HFD), and ZSF1 obese rats with low-intensity exercise training (Ob-Ex). The animals were sacrificed at 20 weeks of age, their livers were collected for: a) measurements of the area of steatosis, fibrosis and inflammation (histomorphological analysis); and b) innate immunity (toll-like receptor [TLR] 2, TLR4, peroxisome proliferator-activated receptor γ [PPARγ], toll interacting protein [TOLLIP]) and inflammatory marker (tumor necrosis factor-alpha [TNFα], interleukin 1 [IL-1]) expression analysis by real-time PCR.

RESULTS

Ob, Ob-HFD and Ob-Ex were significantly heavier than Ln and Ctrl animals. Ob, Ob-HFD and Ob-Ex animals had impaired glucose tolerance and insulin resistance. ZSF1 Ob, Ob-HFD and Ob-Ex presented a higher degree of steatosis (3,5x; p < 0.05) than Ctrl or ZSF1 Ln rats. Steatohepatitis and fibrosis were not observed in any of the groups. No differences in expression were observed between Ctrl, Ln and Ob animals (except for the significantly higher expression of TOLLIP observed in the Ob vs Ln comparison). Ob-HFD and Ob-Ex rats showed increased expression of PPARγ and TOLLIP as compared to other groups. However, both groups also showed increased expression of TLR2 and TLR4. Nevertheless, this did not translate into a differential expression of TNFα or IL-1 in any of the groups.

CONCLUSION

The ZSF1 model is associated with liver steatosis but not with steatohepatitis or a significantly increased expression of innate immunity or inflammation markers.

Frailty Syndrome: Visceral Adipose Tissue and Frailty in Patients with Symptomatic Severe Aortic Stenosis

BACKGROUND/OBJECTIVES

In patients with severe aortic stenosis (AS), frailty is a clinically relevant measure of increased vulnerability that should be included in the preoperative risk assessment. Bioelectrical impedance analysis (BIA) derived phase angle (PA) reflects cell membrane integrity and function. Few studies are available on the relative contribution of adiposity distribution on frailty, and about the influences of frailty and visceral obesity in PA value. Therefore, we aimed to evaluate associations among frailty, visceral fat depots and PA in patients with symptomatic severe AS.

METHODS

In a cohort of patients with symptomatic severe AS and preserved ejection fraction, we examined the associations between frailty, visceral fat depots and bioelectrical impedance analysis (BIA) derived phase angle (PA); and between visceral fat and PA. Frailty was defined according the Fried et al. scale criteria and the body fat distribution was determined by multidetector computed tomography and by BIA.

RESULTS

Of the fifty-five included patients, 26 were frail (47%). Adjusting for age and gender, frailty was associated with indexed epicardial adipose tissue volume (EATVi) (the odds of frailty increased 4.1-fold per additional 100 cm3/m2 of EAT [95% confidence interval (CI) of 1.03 to 16.40, p=0.04] and with PA (OR of 0.50, 95% CI, 0.26 to 0.97, p=0.04), but not with body mass index (BMI), waist circumference (WC), indexed total, visceral and subcutaneous abdominal fat areas (TAFAi, VAFAi and SAFAi) nor with indexed mediastinal adipose tissue volume (MATVi). In an age and gender adjusted linear model, PA was inversely correlated with EATVi (β=-0.008, 95% CI, -0.016 to -0.001, p=0.03), but not with BMI, WC, nor with MATVi, VAFAi, SAFAi and TAFAi.

CONCLUSIONS

In patients with symptomatic severe AS, EATVi is associated with frailty, independently of age and gender, but not with MAFVi or VAFAi. Moreover, frailty and EATVi are associated with impaired cell membrane integrity and function assessed by PA.

Animal models of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function is impaired. Although it now represents over 50 % of all patients with heart failure, the mechanisms of HFpEF remain understood, precluding effective therapy. Understanding the pathophysiology of HFpEF has been restricted by both limited access to human myocardial biopsies and by the lack of animal models that fully mimic human pathology. Animal models are valuable research tools to clarify subcellular and molecular mechanisms under conditions where the comorbidities and other confounding factors can be precisely controlled. Although most of the heart failure animal models currently available represent heart failure with reduced ejection fraction, several HFpEF animal models have been proposed. However, few of these fulfil all the features present in human disease. In this review we will provide an overview of the currently available models to study HFpEF from rodents to large animals as well as present advantages and disadvantages of these models.