scholarly journals A mouse model of heart failure with preserved ejection fraction due to chronic infusion of a low subpressor dose of angiotensin II

2015 ◽  
Vol 309 (5) ◽  
pp. H771-H778 ◽  
Author(s):  
Jessica A. Regan ◽  
Adolfo Gabriele Mauro ◽  
Salvatore Carbone ◽  
Carlo Marchetti ◽  
Rabia Gill ◽  
...  

Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome of HF symptoms associated with impaired diastolic function. Although it represents ∼50% of patients with HF, the mechanisms of disease are poorly understood, and therapies are generally ineffective in reducing HF progression. Animal models of HFpEF not due to pressure or volume overload are lacking, therefore limiting in-depth understanding of the pathophysiological mechanisms and the development of novel therapies. We hypothesize that a continuous infusion of low-dose angiotensin II (ATII) is sufficient to induce left ventricular (LV) diastolic dysfunction and HFpEF, without increasing blood pressure or inducing LV hypertrophy or dilatation. Osmotic pumps were implanted subcutaneously in 8-wk-old male mice assigned to the ATII (0.2 mg·kg−1·day−1) or volume-matched vehicle ( N = 8/group) for 4 wk. We measured systolic and diastolic arterial blood pressures through a tail-cuff transducer, LV dimensions and ejection fraction through echocardiography, and LV relaxation through pulsed-wave Doppler and LV catheterization. Myocardial fibrosis and cardiomyocyte cross-sectional area were measured. ATII infusion had no effects on systemic arterial blood pressure. ATII induced significant impairment in LV diastolic function, as measured by an increase (worsening) in LV isovolumetric relaxation time, myocardial performance index, isovolumetric relaxation time constant, and LV end-diastolic pressure without altering LV dimensions, mass, or ejection fraction. Chronic infusion of low-dose ATII recapitulates the HFpEF phenotype in the mouse, without increasing systemic arterial blood pressure. This mouse model may provide insight into the mechanisms of HFpEF.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jessica A Regan ◽  
Adolofo G Mauro ◽  
Salvatore Carbone ◽  
Carlo Marchetti ◽  
Eleonora Mezzaroma ◽  
...  

Background: Heart failure with preserved ejection fraction (HFpEF) is characterized by elevated left ventricular (LV) filling pressures due to impaired LV diastolic function. Low-dose infusion of angiotensin 2 (AT2) in the mouse induces a HFpEF phenotype without increasing blood pressure. AT2 infusion induces expression of Interleukin-18 (IL-18) in the heart. We therefore tested whether IL-18 mediated AT2-induced LV diastolic dysfunction in this model. Methods: We infused subcutaneously AT2 (0.2 mg/Kg/day) or a matching volume of vehicle via osmotic pumps surgically implanted in the interscapular space in adult wild-type (WT) male mice and IL-18 knock-out mice (IL-18KO). We also treated WT mice with daily intraperitoneal injections of recombinant murine IL-18 binding protein (IL-18bp, a naturally occurring IL-18 blocker) at 3 different doses (0.1, 0.3 and 1.0 mg/kg) or vehicle for 25 days starting on day 3. We performed a Doppler-echocardiography study before implantation and at 28 days to measure LV dimensions, mass, and systolic and diastolic function in all mice. LV catheterization was performed prior to sacrifice to measure LV end-diastolic pressure (LVEDP) using a Millar catheter. Results: AT2 induces a significant increase in isovolumetric relaxation time (IRT) and myocardial performance index (MPI) at Doppler echocardiography and elevation of LVEDP at catheterization, indicative of impaired LV diastolic function, in absence of any measurable effects on systolic blood pressure nor LV dimensions, mass, or systolic function. Mice with genetic deletion of IL-18 (IL-18 KO) or WT mice treated with IL-18bp had no significant increase in IRT, MPI or LVEDP with AT2 infusion. Conclusion: Genetic or pharmacologic IL-18 blockade prevent diastolic dysfunction in a mouse model of HFpEF induced by low dose AT2 infusion, suggesting a critical role of IL-18 in the pathophysiology of HFpEF.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Stefano Toldo ◽  
Carlo Marchetti ◽  
Aysar Al Husseini ◽  
Salvatore Carbone ◽  
Jessica Regan ◽  
...  

Introduction: Heart failure with preserved ejection fracture (HFpEF) is a clinical syndrome of HF symptoms associated with impaired diastolic function. Although it represents approximately 50% of all patients with HF, the mechanisms of disease are poorly understood, animal models of HFpEF not due pressure overload are lacking, and therapies for HFpEF are generally ineffective. Hypothesis: A continuous infusion of low dose of angiotensin II (ATII) may be sufficient to induce changes in left ventricular (LV) diastolic function without increasing blood pressure nor induce LV hypertrophy. Methods: Osmotic pumps were implanted subcutaneously in 8 week-old CD1 male mice randomly assigned to the ATII (200 ng/kg/day) or vehicle (N=8/group). Transthoracic echocardiography was performed at baseline and 4 weeks to measure LV dimensions, systolic and diastolic function. Aortic systolic and diastolic pressures (AoP), LV peak systolic and end-diastolic pressures (LVPSP, LVEDP) were measured at LV catheterization. Fibrosis was measured using Masson’s trichrome stain. The expression of Interleukin (IL)-18 mRNA levels, a cytokine associated with impaired cardiomyocyte relaxation, was measured at 4 weeks. Results: When compared to the baseline values or vehicle group, ATII infusion had no effects on AoP, LVPSP and HR, and had no effects on LV dimensions or mass, nor on LVEF (all P>0.2). ATII induced a significant impairment in LV diastolic function as measured by an increase (worsening) of the myocardial performance index (MPI), the LV isovolumetric relaxation time (IVRT) and of LVEDP (Figure). Cardiac expression of IL-18 mRNA was significantly increased 7-fold after ATII infusion (P<0.001), suggesting a potential mechanistic role of IL-18. Conclusion: Chronic infusion of low dose ATII recapitulates the HFpEF phenotype in the mouse, without increasing blood pressure. The use of this mouse model may help understanding the mechanisms leading to HFpEF syndrome in patients.


2017 ◽  
Vol 122 (2) ◽  
pp. 376-385 ◽  
Author(s):  
Silvana Roberto ◽  
Gabriele Mulliri ◽  
Raffaele Milia ◽  
Roberto Solinas ◽  
Virginia Pinna ◽  
...  

The aim of the present investigation was to assess the role of cardiac diastole on the hemodynamic response to metaboreflex activation. We wanted to determine whether patients with diastolic function impairment showed a different hemodynamic response compared with normal subjects during this reflex. Hemodynamics during activation of the metaboreflex obtained by postexercise muscle ischemia (PEMI) was assessed in 10 patients with diagnosed heart failure with preserved ejection fraction (HFpEF) and in 12 age-matched healthy controls (CTL). Subjects also performed a control exercise-recovery test to compare data from the PEMI test. The main results were that patients with HFpEF achieved a similar mean arterial blood pressure (MAP) response as the CTL group during the PEMI test. However, the mechanism by which this response was achieved was markedly different between the two groups. Patients with HFpEF achieved the target MAP via an increase in systemic vascular resistance (+389.5 ± 402.9 vs. +80 ± 201.9 dynes·s−1·cm−5 for HFpEF and CTL groups respectively), whereas MAP response in the CTL group was the result of an increase in cardiac preload (−1.3 ± 5.2 vs. 6.1 ± 10 ml in end-diastolic volume for HFpEF and CTL groups, respectively), which led to a rise in stroke volume and cardiac output. Moreover, early filling peak velocities showed a higher response in the CTL group than in the HFpEF group. This study demonstrates that diastolic function is important for normal hemodynamic adjustment to the metaboreflex. Moreover, it provides evidence that HFpEF causes hemodynamic impairment similar to that observed in systolic heart failure. NEW & NOTEWORTHY This study provides evidence that diastolic function is important for normal hemodynamic responses during the activation of the muscle metaboreflex in humans. Moreover, it demonstrates that diastolic impairment leads to hemodynamic consequences similar to those provoked by systolic heart failure. In both cases the target blood pressure is obtained mainly by means of exaggerated vasoconstriction than by a flow-mediated mechanism.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
P Huang ◽  
C Liu

Abstract Background Lower systolic blood pressure (SBP) at admission or discharge was associated with poor outcomes in patients with heart failure and preserved ejection fraction (HFpEF). However, the optimal long-term SBP for HFpEF was less clear. Purpose To examine the association of long-term SBP and all-cause mortality among patients with HFpEF. Methods We analyzed participants from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) study. Participants had at least two SBP measurements of different times during the follow-up were included. Long-term SBP was defined as the average of all SBP measurements during the follow-up. We stratified participants into four groups according to long-term SBP: &lt;120mmHg, ≥120mmHg and &lt;130mmHg, ≥130mmHg and &lt;140mmHg, ≥140mmHg. Multivariable adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality associated with SBP level. To assess for nonlinearity, we fitted restricted cubic spline models of long-term SBP. Sensitivity analyses were conducted by confining participants with history of hypertension or those with left ventricular ejection fraction≥50%. Results The 3338 participants had a mean (SD) age of 68.5 (9.6) years; 51.4% were women, and 89.3% were White. The median long-term SBP was 127.3 mmHg (IQR 121–134.2, range 77–180.7). Patients in the SBP of &lt;120mmHg group were older age, less often female, less often current smoker, had higher estimated glomerular filtration rate, less often had history of hypertension, and more often had chronic obstructive pulmonary disease and atrial fibrillation. After multivariable adjustment, long-term SBP of 120–130mmHg and 130–140mmHg was associated with a lower risk of mortality during a mean follow-up of 3.3 years (HR 0.65, 95% CI: 0.49–0.85, P=0.001; HR 0.66, 95% CI 0.50–0.88, P=0.004, respectively); long-term SBP of &lt;120mmHg had similar risk of mortality (HR 1.03, 95% CI: 0.78–1.36, P=0.836), compared with long-term SBP of ≥140mmHg. Findings from restricted cubic spline analysis demonstrate that there was J-shaped association between long-term SBP and all-cause mortality (P=0.02). These association was essentially unchanged in sensitivity analysis. Conclusions Among patients with HFpEF, long-term SBP showed a J-shaped pattern with all-cause mortality and a range of 120–140 mmHg was significantly associated with better outcomes. Future randomized controlled trials need to evaluate optimal long-term SBP goal in patients with HFpEF. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): China Postdoctoral Science Foundation Grant (2019M660229 and 2019TQ0380)


2016 ◽  
Vol 29 (8) ◽  
pp. 1001-1007 ◽  
Author(s):  
Sante D. Pierdomenico ◽  
Anna M. Pierdomenico ◽  
Francesca Coccina ◽  
Domenico Lapenna ◽  
Ettore Porreca

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.


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