Abstract 266: Is the Col4a3 -/- Alport Mouse a Novel Model for Heart Failure With Preserved Ejection Fraction?

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Keyvan Yousefi ◽  
Wen Ding ◽  
Jayanti Singh ◽  
Lina Shehadeh

Heart failure with preserved ejection fraction (HFpEF) accounts for more than 50% of all HF cases. HFpEF patients manifest normal or mildly reduced left ventricle (LV) ejection fraction (LVEF), LV hypertrophy, diastolic dysfunction, myocardial stiffness, cardiac fibrosis, hypertension, nephropathy and sudden death. There is no appropriate animal model for HFpEF. The Alport Col4a3 -/- mouse, a model of nephropathy, hypertension and early death, develops a cardiovascular pathology that is yet to be well characterized. We elected to analyze the cardiovascular pathology of the Alport mouse and investigate any commonalities with HFpEF. Male Alport and wild type (WT) littermates of mixed background at 2 months of age were subjected to echocardiographic and 2D speckle tracking analyses and heart tissues were used for histopathological examinations (N=6 mice per group). Circulating Galectin-3, a marker of HFpEF, was measured by Elisa in plasma samples. Data are shown as mean±SEM. Normalized heart weight increased in Alport relative to WT mice - p<0.01, indicative of cardiac hypertrophy. Consistently, echocardiography showed interventricular septum (IVS) thickening -p<0.05. Reduced stroke volume p<0.01, and impaired global longitudinal and circumferential strain (GLS and GCS) indicated systolic dysfunction in Alport mice. No significant reduction in LVEF was observed. Alport mice developed diastolic dysfunction evidenced by a prolonged Isovolumetric relaxation time -P<0.05, and a reduced E/A, a marker of LV relaxation and stiffness -p<0.01. Elevated LV filling pressure and pulmonary artery wedge pressure were demonstrated by an increase in E/E’ - p<0.01. Galectin-3 increased in Alport relative to WT plasma (P<0.01). Alport hearts had more Fibronectin protein - P<0.05 and increased number of fibroblasts with “activated” phenotype as demonstrated by increased mass of rough endoplasmic reticulum in EM cross sections. Our study suggests that the cardiovascular pathologies of the Alport mouse are similar to HFpEF, specifically preserved ejection fraction, diastolic dysfunction, hypertension, early death and cardiac stiffness and fibrosis. Further study of this multi-factorial pathology may render the Alport mouse as a useful novel model for HFpEF.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Charles D Smart ◽  
Vineet Agrawal ◽  
Anna R Hemnes ◽  
Meena S Madhur

Deoxycorticosterone acetate (DOCA)-salt is a common hypertension model in mice and has recently been used to study heart failure with preserved ejection fraction (HFpEF) in rats. Our goal was to validate DOCA-salt as a mouse model of HFpEF and determine how DOCA-salt alters the cardiac immunological landscape to identify novel therapeutic targets for this disease. DOCA-salt mice underwent uninephrectomy, implantion of a DOCA pellet, and supplementation of the drinking water with 1% NaCl water for three weeks. Control mice underwent a sham procedure and received normal water. Compared to control mice, DOCA-salt mice exhibited elevated systolic BP, increased heart weight to body weight ratios (5.6 vs 7.1), increased lung wet to dry weight ratios (4.4 vs 4.8) indicative of pulmonary congestion, and decreased time to exhaustion upon treadmill exercise testing (23.0 vs. 18.5 seconds). On conscious echocardiography, DOCA-salt mice exhibited a preserved ejection fraction. Invasive hemodynamic studies revealed an increased tau constant (5.7 vs 8.2) and increased end-diastolic pressures in DOCA-salt mice (1.7 vs 2.6), consistent with diastolic dysfunction. CITE-seq, a novel technique to obtain transcriptomic and surface marker expression on single cells, was performed on a total of 4,359 and 7,600 cells sorted live CD45+ leukocytes from four sham and four DOCA-salt left ventricles, respectively. Unsupervised computational analysis revealed 29 clusters of immune cells. Six clusters containing natural killer, T lymphocyte and myeloid cell populations were overrepresented and five B cell clusters were underrepresented in DOCA-salt samples. Differential expression analysis of CD11b+CD64+ cardiac macrophages revealed transcriptional changes between groups with 146 significantly upregulated and 111 downregulated genes. Gene set enrichment analysis showed upregulation of leukocyte migration, response to type I interferon, and cytokine-mediated signaling pathways in DOCA-salt macrophages. In conclusion, the DOCA-salt mouse model recapitulates key features of HFpEF including diastolic dysfunction with preserved ejection fraction, cardiac hypertrophy, and pulmonary congestion and is associated with an altered cardiac immune cell profile.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Alejandro Chade ◽  
Maxx Williams ◽  
Jason Engel ◽  
Michael Hall

Abstract Background and Aims Patients with chronic kidney disease (CKD) have a significantly higher cardiovascular risk that non-CKD patients, and over 50% of CKD patients die of cardiovascular events. We recently developed a model of CKD that displays major pathological features of clinical CKD: GFR of about 60 ml/min (stage 2-3a), significant renal inflammation, fibrosis, microvascular dysfunction and remodeling, and hypertension. The current study aims to define the cardiac phenotype of this model and, if cardiac abnormalities are present, the potential pathological traits involved. Method CKD was induced in 6 pigs via bilateral renovascular disease and dyslipidemia and observed for 14 weeks. After 14 weeks, renal hemodynamics (RBF, GFR) were quantified using multi-detector CT and echocardiographic assessment (morphology and function) performed using ultrasound-doppler. Mean arterial pressure (MAP) was continuously measured by telemetry. Blood was collected to measure circulating inflammatory cytokines (TNF-α, MCP-1, IL-6) and biomarkers of heart failure (ANP, BNP, NT-proBNP). Animals were then euthanized and kidneys and hearts collected for ex vivo studies. Normal pigs were used as time-matched controls. Results Loss of renal function in CKD was accompanied by left ventricular hypertrophy, left atrial dilatation, diastolic dysfunction (E/A ratio) with preserved ejection fraction (pEF), elevated ANP, BNP, and NT-proBNP, and hypertension (average MAP of 131.2 mm/Hg, p&lt;0.05 vs. normal). CKD also increased renal (but not cardiac) mRNA expression of TNF-α, MCP-1, IL-6, accompanied by increased circulating inflammatory cytokines (Figure). Conclusion This study shows that CKD in the swine model leads to cardiac hypertrophy and diastolic dysfunction (with pEF) and increased biomarkers of heart failure, meeting the criteria for a potential novel model of heart failure with pEF (HFpEF). Our data also suggest that hypertension and inflammatory mediators (possibly originated in the kidney) target the heart and may contribute to HFpEF pathophysiology. HFpEF is considered the largest unmet need in cardiology with no specific treatments and associates with CKD in about 50% of cases. Thus, our study offers a promising new experimental platform to increase our understanding of CKD-HFpEF and to test new treatments in a translational fashion.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Claire L Curl ◽  
Vennetia R Danes ◽  
James R Bell ◽  
Antonia J Raaijmakers ◽  
Wendy T Ip ◽  
...  

Diagnosis of heart failure with preserved ejection fraction (HFpEF) is becoming the prevalent form of disease type. Established treatments for heart failure with reduced ejection fraction (HFrEF) have proven minimally effective for HFpEF. This may reflect differences in underlying cardiomyocyte pathophysiology. In HFrEF cardiomyocyte phenotype is characterized by impaired contractile response and diminished systolic Ca 2+ levels. Studies of intact HFpEF-derived cardiomyocytes are lacking. Progress in understanding the etiology of HFpEF has been impeded by limited availability of appropriate pre-clinical models. Our goal was to validate and characterize a new rodent model of HFpEF, the ‘Hypertrophic Heart Rat’ (HHR), undertaking longitudinal investigations to delineate the associated cardiac and cardiomyocyte pathophysiology. The selectively inbred HHR strain exhibits adult cardiac enlargement (without hypertension) and premature mortality (40% at age 50 weeks) compared to the control ‘Normal Heart Rat’ (NHR). Echo analyses established that cardiac hypertrophy was characterized in vivo by maintained systolic parameters (i.e. ejection fraction at 85-90% control) with marked diastolic dysfunction (i.e. increased E/E’). Diastolic dysfunction was detectable in young adult HHR, as an early disease marker. Histological examination identified regions of focal reparative fibrosis in HHR hearts, most prominent in the transverse midwall area of the left ventricle adjacent to the interventricular septum. Evaluation of cardiomyocyte function using left ventricular myocytes isolated from hearts of 30 week (prefailing ) HHR revealed a hypercontractile phenotype with high Ca 2+ operational levels and arrhythmogenic vulnerability. HHR cardiomyocytes exhibited dramatically increased L-type Ca 2+ channel current density (almost 2-fold), and molecular analyses identified hyperphosphorylation of key sarcoplasmic reticulum Ca 2+ regulatory proteins, without change in total phospho-titin. These findings strongly support the contention that HFpEF and HFrEF can have different underlying cardiomyocyte phenotypes. New directions for HFpEF therapies are indicated, and the HHR provides a new model for preclinical HFpEF investigations.


2010 ◽  
Vol 6 (2) ◽  
pp. 33 ◽  
Author(s):  
Christopher R deFilippi ◽  
G Michael Felker ◽  
◽  

For many with heart failure, including the elderly and those with a preserved ejection fraction, both risk stratification and treatment are challenging. For these large populations and others there is increasing recognition of the role of cardiac fibrosis in the pathophysiology of heart failure. Galectin-3 is a novel biomarker of fibrosis and cardiac remodelling that represents an intriguing link between inflammation and fibrosis. In this article we review the biology of galectin-3, recent clinical research and its application in the management of heart failure patients.


2018 ◽  
Vol 26 (6) ◽  
pp. 613-623 ◽  
Author(s):  
Aisha Gohar ◽  
Rogier F Kievit ◽  
Gideon B Valstar ◽  
Arno W Hoes ◽  
Evelien E Van Riet ◽  
...  

Background The prevalence of undetected left ventricular diastolic dysfunction is high, especially in the elderly with comorbidities. Left ventricular diastolic dysfunction is a prognostic indicator of heart failure, in particularly of heart failure with preserved ejection fraction and of future cardiovascular and all-cause mortality. Therefore we aimed to develop sex-specific diagnostic models to enable the early identification of men and women at high-risk of left ventricular diastolic dysfunction with or without symptoms of heart failure who require more aggressive preventative strategies. Design Individual patient data from four primary care heart failure-screening studies were analysed (1371 participants, excluding patients classified as heart failure and left ventricular ejection fraction <50%). Methods Eleven candidate predictors were entered into logistic regression models to be associated with the presence of left ventricular diastolic dysfunction/heart failure with preserved ejection fraction in men and women separately. Internal-external cross-validation was performed to develop and validate the models. Results Increased age and β-blocker therapy remained as predictors in both the models for men and women. The model for men additionally consisted of increased body mass index, moderate to severe shortness of breath, increased pulse pressure and history of ischaemic heart disease. The models performed moderately and similarly well in men (c-statistics range 0.60–0.75) and women (c-statistics range 0.51–0.76) and the performance improved significantly following the addition of N-terminal pro b-type natriuretic peptide (c-statistics range 0.61–0.80 in women and 0.68–0.80 in men). Conclusions We provide an easy-to-use screening tool for use in the community, which can improve the early detection of left ventricular diastolic dysfunction/heart failure with preserved ejection fraction in high-risk men and women and optimise tailoring of preventive interventions.


2021 ◽  
Vol 24 (4) ◽  
pp. 304-314
Author(s):  
M. A. Manukyan ◽  
A. Y. Falkovskaya ◽  
V. F. Mordovin ◽  
T. R. Ryabova ◽  
I. V. Zyubanova ◽  
...  

BACKGROUND: It is expected that a steady increase in the incidence of diabetes and resistant hypertension (RHTN), along with an increase in life expectancy, will lead to a noticeable increase in the proportion of patients with heart failure with preserved ejection fraction (HFpEF). At the same time, data on the frequency of HFpEF in a selective group of patients with RHTN in combination with diabetes are still lacking, and the pathophysiological and molecular mechanisms of its formation have not been yet studied sufficiently.AIM: To assess the features of the development HFpEF in diabetic and non-diabetic patients with RHTN, as well as to determine the factors associated with HFpEF.MATERIALS AND METHODS: In the study were included 36 patients with RHTN and type 2 diabetes mellitus (DM) (mean age 61.4 ± 6.4 years, 14 men) and 33 patients with RHTN without diabetes, matched by sex, age and level of systolic blood pressure (BP). All patients underwent baseline office and 24-hour BP measurement, echocardiography with assess diastolic function, lab tests (basal glycemia, HbA1c, creatinine, aldosterone, TNF-alpha, hsCRP, brain naturetic peptide, metalloproteinases of types 2, 9 (MMP-2, MMP-9) and tissue inhibitor of MMP type 1 (TIMP-1)). HFpEF was diagnosed according to the 2019 AHA/ESC guidelines.RESULTS: The frequency of HFpEF was significantly higher in patients with RHTN with DM than those without DM (89% and 70%, respectively, p=0.045). This difference was due to a higher frequency of such major functional criterion of HFpEF as E/e’≥15 (p=0.042), as well as a tendency towards a higher frequency of an increase in left atrial volumes (p=0.081) and an increase in BNP (p=0.110). Despite the comparable frequency of diastolic dysfunction in patients with and without diabetes (100% and 97%, respectively), disturbance of the transmitral blood flow in patients with DM were more pronounced than in those without diabetes. Deterioration of transmitral blood flow and pseudo-normalization of diastolic function in diabetic patients with RHTN have relationship not only with signs of carbohydrate metabolism disturbance, but also with level of pulse blood pressure, TNF-alfa, TIMP-1 and TIMP-1 / MMP-2 ratio, which, along with the incidence of atherosclerosis, were higher in patients with DM than in those without diabetes.CONCLUSIONS: Thus, HFpEF occurs in the majority of diabetic patients with RHTN. The frequency of HFpEF in patients with DN is significantly higher than in patients without it, which is associated with more pronounced impairments of diastolic function. The progressive development of diastolic dysfunction in patients with diabetes mellitus is associated not only with metabolic disorders, but also with increased activity of chronic subclinical inflammation, profibrotic state and high severity of vascular changes.


2018 ◽  
Vol 124 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Michinari Hieda ◽  
Erin Howden ◽  
Shigeki Shibata ◽  
Takashi Tarumi ◽  
Justin Lawley ◽  
...  

The beat-to-beat dynamic Starling mechanism (DSM), the dynamic modulation of stroke volume (SV) because of breath-by-breath changes in left-ventricular end-diastolic pressure (LVEDP), reflects ventricular-arterial coupling. The purpose of this study was to test whether the LVEDP-SV relationship remained impaired in heart failure with preserved ejection fraction (HFpEF) patients after normalization of LVEDP. Right heart catheterization and model-flow analysis of the arterial pressure waveform were performed while preload was manipulated using lower-body negative pressure to alter LVEDP. The DSM was compared at similar levels of LVEDP between HFpEF patients ( n = 10) and age-matched healthy controls ( n = 12) (HFpEF vs. controls: 10.9 ± 3.8 vs. 11.2 ± 1.3 mmHg, P = 1.00). Transfer function analysis between diastolic pulmonary artery pressure (PAD) representing dynamic changes in LVEDP vs. SV index was applied to obtain gain and coherence of the DSM. The DSM gain was significantly lower in HFpEF patients than in the controls, even at a similar level of LVEDP (0.46 ± 0.19 vs. 0.99 ± 0.39 ml·m−2·mmHg−1, P = 0.0018). Moreover, the power spectral density of PAD, the input variability, was greater in the HFpEF group than the controls (0.75 ± 0.38 vs. 0.28 ± 0.26 mmHg2, P = 0.01). Conversely, the power spectral density of SV index, the output variability, was not different between the groups ( P = 0.97). There was no difference in the coherence, which confirms the reliability of the linear transfer function between the two groups (0.71 ± 0.13 vs. 0.77 ± 0.19, P = 0.87). The DSM gain in HFpEF patients is impaired compared with age-matched controls even at a similar level of LVEDP, which may reflect intrinsic LV diastolic dysfunction and incompetence of ventricular-arterial coupling. NEW & NOTEWORTHY The beat-to-beat dynamic Starling mechanism (DSM), the dynamic modulation of stroke volume because of breath-by-breath changes in left-ventricular end-diastolic pressure (LVEDP), reflects ventricular-arterial coupling. Although the DSM gain is impaired in heart failure with preserved ejection fraction (HFpEF) patients, it is not clear whether this is because of higher LVEDP or left-ventricular diastolic dysfunction. The DSM gain in HFpEF patients is severely impaired, even at a similar level of LVEDP, which may reflect intrinsic left-ventricular diastolic dysfunction.


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