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Heart (British Cardiac Society) Jul 2023Hypertrophic cardiomyopathy (HCM) is characterised by left ventricular hypertrophy (LVH), myocardial fibrosis, enhanced oxidative stress and energy depletion.... (Randomized Controlled Trial)
Randomized Controlled Trial
AIMS
Hypertrophic cardiomyopathy (HCM) is characterised by left ventricular hypertrophy (LVH), myocardial fibrosis, enhanced oxidative stress and energy depletion. Unbound/loosely bound tissue copper II ions are powerful catalysts of oxidative stress and inhibitors of antioxidants. Trientine is a highly selective copper II chelator. In preclinical and clinical studies in diabetes, trientine is associated with reduced LVH and fibrosis, and improved mitochondrial function and energy metabolism. Trientine was associated with improvements in cardiac structure and function in an open-label study in patients with HCM.
METHODS
The Efficacy and Mechanism of Trientine in Patients with Hypertrophic Cardiomyopathy (TEMPEST) trial is a multicentre, double-blind, parallel group, 1:1 randomised, placebo-controlled phase II trial designed to evaluate the efficacy and mechanism of action of trientine in patients with HCM. Patients with a diagnosis of HCM according to the European Society of Cardiology Guidelines and in New York Heart Association classes I-III are randomised to trientine or matching placebo for 52 weeks. Primary outcome is change in left ventricular (LV) mass indexed to body surface area, measured using cardiovascular magnetic resonance. Secondary efficacy objectives will determine whether trientine improves exercise capacity, reduces arrhythmia burden, reduces cardiomyocyte injury, improves LV and atrial function, and reduces LV outflow tract gradient. Mechanistic objectives will determine whether the effects are mediated by cellular or extracellular mass regression and improved myocardial energetics.
CONCLUSION
TEMPEST will determine the efficacy and mechanism of action of trientine in patients with HCM.
TRIAL REGISTRATION NUMBERS
NCT04706429 and ISRCTN57145331.
Topics: Humans; Trientine; Copper; Cardiomyopathy, Hypertrophic; Heart; Hypertrophy, Left Ventricular; Fibrosis
PubMed: 37137675
DOI: 10.1136/heartjnl-2022-322271 -
Journal of Clinical Medicine Jul 2023Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a... (Review)
Review
Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.
PubMed: 37510837
DOI: 10.3390/jcm12144722 -
American Journal of Translational... 2024Heart failure poses a significant threat to global public health within the realm of cardiovascular diseases. Its pathological progression involves various alterations... (Review)
Review
Heart failure poses a significant threat to global public health within the realm of cardiovascular diseases. Its pathological progression involves various alterations in cardiomyocytes, among which autophagy, a crucial intracellular degradation mechanism, plays a pivotal role. Autophagy facilitates the breakdown of damaged organelles and proteins, thereby maintaining cellular homeostasis. In the context of heart failure, autophagy coexists with apoptosis and necrosis, influencing myocardial hypertrophy and ventricular remodeling. However, its impact on heart failure manifests a dual nature: moderate autophagy aids in cardiac repair, whereas excessive autophagy may exacerbate ventricular remodeling and cell demise. This review delves into the fundamental biology of autophagy, elucidating its involvement in the pathological cascade of heart failure and its correlation with cardiac hypertrophy and ventricular remodeling. Furthermore, an analysis of the interplay between autophagy regulatory factors and heart failure sheds light on the potential therapeutic implications of autophagy in the prevention and management of heart failure. This exploration provides a theoretical foundation for novel treatment strategies in combating heart failure.
PubMed: 38883358
DOI: 10.62347/OBXQ9477 -
Journal of the American College of... Aug 2023Precapillary pulmonary hypertension (precPH) patients have altered right atrial (RA) function and right ventricular (RV) diastolic stiffness.
BACKGROUND
Precapillary pulmonary hypertension (precPH) patients have altered right atrial (RA) function and right ventricular (RV) diastolic stiffness.
OBJECTIVES
This study aimed to investigate RA function using pressure-volume (PV) loops, isolated cardiomyocyte, and histological analyses.
METHODS
RA PV loops were constructed in control subjects (n = 9) and precPH patients (n = 27) using magnetic resonance and catheterization data. RA stiffness (pressure rise during atrial filling) and right atrioventricular coupling index (RA minimal volume / RV end-diastolic volume) were compared in a larger cohort of patients with moderate (n = 39) or severe (n = 41) RV diastolic stiffness. Cardiomyocytes were isolated from RA tissue collected from control subjects (n = 6) and precPH patients (n = 9) undergoing surgery. Autopsy material was collected from control subjects (n = 6) and precPH patients (n = 4) to study RA hypertrophy, capillarization, and fibrosis.
RESULTS
RA PV loops showed 3 RA cardiac phases (reservoir, passive emptying, and contraction) with dilatation and elevated pressure in precPH. PrecPH patients with severe RV diastolic stiffness had increased RA stiffness and worse right atrioventricular coupling index. Cardiomyocyte cross-sectional area was increased 2- to 3-fold in precPH, but active tension generated by the sarcomeres was unaltered. There was no increase in passive tension of the cardiomyocytes, but end-stage precPH showed reduced number of capillaries per mm accompanied by interstitial and perivascular fibrosis.
CONCLUSIONS
RA PV loops show increased RA stiffness and suggest atrioventricular uncoupling in patients with severe RV diastolic stiffness. Isolated RA cardiomyocytes of precPH patients are hypertrophied, without intrinsic sarcomeric changes. In end-stage precPH, reduced capillary density is accompanied by interstitial and perivascular fibrosis.
Topics: Humans; Myocytes, Cardiac; Hypertension, Pulmonary; Atrial Fibrillation; Heart Atria; Atrial Appendage
PubMed: 37587582
DOI: 10.1016/j.jacc.2023.05.063 -
JAMA Cardiology Nov 2023Left ventricular (LV) hypertrophy contributes to the onset and progression of heart failure (HF), particularly for patients with pre-HF (stage B) for whom no treatment... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
Left ventricular (LV) hypertrophy contributes to the onset and progression of heart failure (HF), particularly for patients with pre-HF (stage B) for whom no treatment has yet proven effective to prevent transition to overt HF (stage C). The β3-adrenergic receptors (β3ARs) may represent a new target, as their activation attenuates LV remodeling.
OBJECTIVE
To determine whether activation of β3ARs by repurposing a β3AR agonist, mirabegron, is safe and effective in preventing progression of LV hypertrophy and diastolic dysfunction among patients with pre- or mild HF.
DESIGN, SETTING, AND PARTICIPANTS
The Beta3-LVH prospective, triple-blind, placebo-controlled phase 2b randomized clinical trial enrolled patients between September 12, 2016, and February 26, 2021, with a follow-up of 12 months. The trial was conducted at 10 academic hospitals in 8 countries across Europe (Germany, Poland, France, Belgium, Italy, Portugal, Greece, and the UK). Patients aged 18 years or older with or without HF symptoms (maximum New York Heart Association class II) were screened for the presence of LV hypertrophy (increased LV mass index [LVMI] of ≥95 g/m2 for women or ≥115 g/m2 for men) or maximum wall thickness of 13 mm or greater using echocardiography. Data analysis was performed in August 2022.
INTERVENTION
Participants were randomly assigned (1:1) to mirabegron (50 mg/d) or placebo, stratified by the presence of atrial fibrillation and/or type 2 diabetes, for 12 months.
MAIN OUTCOMES AND MEASURES
The primary end points were LVMI determined using cardiac magnetic resonance imaging and LV diastolic function (early diastolic tissue Doppler velocity [E/e'] ratio assessed using Doppler echocardiography) at 12 months. Patients with at least 1 valid measurement of either primary end point were included in the primary analysis. Safety was assessed for all patients who received at least 1 dose of study medication.
RESULTS
Of the 380 patients screened, 296 were enrolled in the trial. There were 147 patients randomized to mirabegron (116 men [79%]; mean [SD] age, 64.0 [10.2] years) and 149 to placebo (112 men [75%]; mean [SD] age, 62.2 [10.9] years). All patients were included in the primary intention-to-treat analysis. At 12 months, the baseline and covariate-adjusted differences between groups included a 1.3-g/m2 increase in LVMI (95% CI, -0.15 to 2.74; P = .08) and a -0.15 decrease in E/e' (95% CI, -0.69 to 0.4; P = .60). A total of 213 adverse events (AEs) occurred in 82 mirabegron-treated patients (including 31 serious AEs in 19 patients) and 215 AEs occurred in 88 placebo-treated patients (including 30 serious AEs in 22 patients). No deaths occurred during the trial.
CONCLUSIONS
In this study, mirabegron therapy had a neutral effect on LV mass or diastolic function over 12 months among patients who had structural heart disease with no or mild HF symptoms.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT02599480.
Topics: Female; Humans; Male; Middle Aged; Adrenergic Agonists; Diabetes Mellitus, Type 2; Heart Failure; Hypertrophy, Left Ventricular; Prospective Studies; Aged
PubMed: 37728907
DOI: 10.1001/jamacardio.2023.3003 -
Biomedicine & Pharmacotherapy =... Sep 2023Left ventricular hypertrophy leads to heart failure, a serious medical condition associated with high rates of hospitalization and mortality. Limited success with the...
Left ventricular hypertrophy leads to heart failure, a serious medical condition associated with high rates of hospitalization and mortality. Limited success with the existing pharmacological treatments necessitates the development of mechanisms-based new therapies to better control the progression from left ventricular hypertrophy to heart failure. The current work investigated the pharmacological potentials and mechanisms of naturally occurring cinnamic acid in the treatment of left ventricular hypertrophy and heart failure. The in vitro findings reveal that cinnamic acid attenuates the hypertrophic responses and mitochondrial dysfunction in the phenylephrine (PE)-stimulated cardiomyocytes. Furthermore, cinnamic acid offsets PE-induced increases in N-methyladenosine (mA) RNA modification and reductions in the expression of the key mA demethylase FTO in cardiomyocytes. Most importantly, FTO knockdown abrogates anti-hypertrophic and mitochondrial protective effects of cinnamic acid in the PE-stimulated cardiomyocytes. The in vivo results further demonstrate that cinnamic acid mitigates left ventricular hypertrophy, left ventricular systolic dysfunction and ultrastructural impairment of cardiomyocyte mitochondria and myofibrils in the mice subjected to transverse aortic constriction (TAC)-induced pressure overload. Moreover, FTO knockdown abolishes these beneficial effects of cinnamic acid in the TAC mice. In conclusion, the work here demonstrates for the first time that cinnamic acid is effective at mitigating pressure overload-induced left ventricular hypertrophy and heart failure in part by modulating the expression of FTO and the level of FTO-dependent mA RNA modification in cardiomyocytes. These novel findings warrant further evaluation of cinnamic acid as a pharmacological agent/component to complement the existing treatment of pressure overload-mediated left ventricular hypertrophy and heart failure.
Topics: Mice; Animals; Hypertrophy, Left Ventricular; Myocytes, Cardiac; Heart Failure; Phenylephrine; RNA; Mice, Inbred C57BL; Disease Models, Animal; Alpha-Ketoglutarate-Dependent Dioxygenase FTO
PubMed: 37453198
DOI: 10.1016/j.biopha.2023.115168 -
Heart Failure Reviews Sep 2023Studies over recent years have redeveloped our understanding of uremic cardiomyopathy, defined as left ventricular hypertrophy, congestive heart failure, and associated... (Review)
Review
Studies over recent years have redeveloped our understanding of uremic cardiomyopathy, defined as left ventricular hypertrophy, congestive heart failure, and associated cardiac hypertrophy plus other abnormalities that result from chronic kidney disease and are often the cause of death in affected patients. Definitions of uremic cardiomyopathy have conflicted and overlapped over the decades, complicating the body of published evidence, and making comparison difficult. New and continuing research into potential risk factors, including uremic toxins, anemia, hypervolemia, oxidative stress, inflammation, and insulin resistance, indicates the increasing interest in illuminating the pathways that lead to UC and thereby identifying potential targets for intervention. Indeed, our developing understanding of the mechanisms of UC has opened new frontiers in research, promising novel approaches to diagnosis, prognosis, treatment, and management. This educational review highlights advances in the field of uremic cardiomyopathy and how they may become applicable in practice by clinicians. Pathways to optimal treatment with current modalities (with hemodialysis and angiotensin-converting enzyme inhibitors) will be described, along with proposed steps to be taken in research to allow evidence-based integration of developing investigational therapies.
Topics: Humans; Uremia; Cardiomyopathies; Heart Failure; Hypertrophy, Left Ventricular; Cardiomegaly
PubMed: 37173614
DOI: 10.1007/s10741-023-10318-1 -
BioRxiv : the Preprint Server For... Nov 2023Friedreich's ataxia (FA) is an inherited neurodegenerative disorder that causes progressive nervous system damage resulting in impaired muscle coordination. FA is the...
BACKGROUND
Friedreich's ataxia (FA) is an inherited neurodegenerative disorder that causes progressive nervous system damage resulting in impaired muscle coordination. FA is the most common autosomal recessive form of ataxia and is caused by an expansion of the DNA triplet guanine-adenine-adenine (GAA) in the first intron of the Frataxin gene (FXN), located on chromosome 9q13. In the unaffected population, the number of GAA repeats ranges from 6 to 27 repetitions. In FA patients, GAA repeat expansions range from 44 to 1,700 repeats which decreases frataxin protein expression. Frataxin is a mitochondrial protein essential for various cellular functions, including iron metabolism. Reduced frataxin expression is thought to negatively affect mitochondrial iron metabolism, leading to increased oxidative damage. Although FA is considered a neurodegenerative disorder, FA patients display heart disease that includes hypertrophy, heart failure, arrhythmias, conduction abnormalities, and cardiac fibrosis.
OBJECTIVE
In this work, we investigated whether abnormal Ca handling machinery is the molecular mechanism that perpetuates cardiac dysfunction in FA.
METHODS
We used the frataxin knock-out (FXN-KO) mouse model of FA as well as human heart samples from donors with FA and from unaffected donors. ECG and echocardiography were used to assess cardiac function in the mice. Expression of calcium handling machinery proteins was assessed with proteomics and western blot. In left ventricular myocytes from FXN-KO and FXN-WT mice, the IonOptix system was used for calcium imaging, the seahorse assay was utilized to measure oxygen consumption rate (OCR), and confocal imaging was used to quantify the mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS).
RESULTS
We found that major contractile proteins, including SERCA2a and Ryr2, were downregulated in human left ventricular samples from deceased donors with FA compared to unaffected donors, similar to the downregulation of these proteins in the left ventricular tissue from FXN-KO compared to FXN-WT. On the ECG, the RR, PR, QRS, and QTc were significantly longer in the FXN-KO mice compared to FXN-WT. The ejection fraction and fractional shortening were significantly decreased and left ventricular wall thickness and diameter were significantly increased in the FXN-KO mice versus FXN-WT. The mitochondrial membrane potential Δψm was depolarized, ROS levels were elevated, and OCR was decreased in ventricular myocytes from FXN-KO versus FXN-WT.
CONCLUSION
The development of left ventricular contractile dysfunction in FA is associated with reduced expression of calcium handling proteins and mitochondrial dysfunction.
PubMed: 38014032
DOI: 10.1101/2023.11.09.566141 -
Hypertension (Dallas, Tex. : 1979) Nov 2023Left ventricular hypertrophy is a bipolar response, starting as an adaptive response to the hemodynamic challenge, but over time develops maladaptive pathology partly...
BACKGROUND
Left ventricular hypertrophy is a bipolar response, starting as an adaptive response to the hemodynamic challenge, but over time develops maladaptive pathology partly due to microvascular rarefaction and impaired coronary angiogenesis. Despite the profound influence on cardiac function, the mechanotransduction mechanisms that regulate coronary angiogenesis, leading to heart failure, are not well known.
METHODS
We subjected endothelial-specific knockout mice of mechanically activated ion channel, TRPV4 (transient receptor potential cation channel subfamily V member 4; TRPV4) to pressure overload via transverse aortic constriction and examined cardiac function, cardiomyocyte hypertrophy, cardiac fibrosis, and apoptosis. Further, we measured microvascular density and underlying TRPV4 mechanotransduction mechanisms using human microvascular endothelial cells, extracellular matrix gels of varying stiffness, unbiased RNA sequencing, small interfering RNA, Western blot, quantitative-PCR, and confocal immunofluorescence techniques.
RESULTS
We demonstrate that endothelial-specific deletion of TRPV4 preserved cardiac function, cardiomyocyte structure, and reduced cardiac fibrosis compared with TRPV4 mice, 28 days post-transverse aortic constriction. Interestingly, comprehensive RNA sequencing analysis revealed an upregulation of proangiogenic factors (VEGFα [vascular endothelial growth factor α], NOS3 [nitric oxide synthase 3], and FGF2 [fibroblast growth factor 2]) with concomitant increase in microvascular density in TRPV4 hearts after transverse aortic constriction compared with TRPV4. Further, an increased expression of VEGFR2 (vascular endothelial growth factor receptor 2) and activation of the YAP (yes-associated protein) pathway were observed in TRPV4 hearts. Mechanistically, we found that downregulation of TRPV4 in endothelial cells induced matrix stiffness-dependent activation of YAP and VEGFR2 via the Rho/Rho kinase/large tumor suppressor kinase pathway.
CONCLUSIONS
Our results suggest that endothelial TRPV4 acts as a mechanical break for coronary angiogenesis, and uncoupling endothelial TRPV4 mechanotransduction attenuates pathological cardiac hypertrophy by enhancing coronary angiogenesis.
Topics: Animals; Humans; Mice; Cardiomegaly; Disease Models, Animal; Endothelial Cells; Hypertrophy, Left Ventricular; Mechanotransduction, Cellular; Mice, Inbred C57BL; Mice, Knockout; Myocytes, Cardiac; TRPV Cation Channels; Vascular Endothelial Growth Factor A
PubMed: 37702061
DOI: 10.1161/HYPERTENSIONAHA.123.21528 -
International Journal of Cardiology Jul 2023The assessment of late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) by cardiac magnetic resonance (CMR) as diagnostic and prognostic maker in...
BACKGROUND
The assessment of late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) by cardiac magnetic resonance (CMR) as diagnostic and prognostic maker in Fabry disease is advancing. We aimed to investigate the impact of clinical characteristics and CMR findings on cardiac outcome in patients with FD.
METHODS
In this study 55 patients with genetically confirmed FD and available CMR imaging were included. The primary endpoint was defined as a composite of cardiac events including cardiac death, new occurrence of atrial fibrillation, heart failure, ventricular tachycardia and bradycardia requiring device insertion.
RESULTS
During a median follow-up of 4.9 years (IQR 3.7-5.9), 9 patients (16.3%) reached the primary cardiac end point. The global amount of LGE was associated with an increased risk for primary endpoint in the univariate analysis (HR 1.4 per 10% increase in LGE, p = 0.002). However maximal wall thickness (MWT) was the sole independent predictor of the primary endpoint in a stepwise logistic regression model (HR 9.8 per mm increase in MWT, p < 0.0001). Kaplan-Meier analysis revealed significant difference in event free survival rate between patients with and without LVH (Long-rank p = 0.006) and in patients with and without LGE (Long-rank p < 0.001). Patients without LVH and LGE were free of adverse cardiac events.
CONCLUSION
LVH and LGE detected by CMR were associated with adverse cardiac events in FD. In particular maximal wall thickness can be useful in cardiac risk stratification of FD patients.
Topics: Humans; Fabry Disease; Contrast Media; Gadolinium; Heart; Hypertrophy, Left Ventricular; Prognosis; Arrhythmias, Cardiac; Magnetic Resonance Spectroscopy; Predictive Value of Tests; Magnetic Resonance Imaging, Cine; Ventricular Function, Left; Risk Factors
PubMed: 37044180
DOI: 10.1016/j.ijcard.2023.04.016