mTOR Inhibition Prolongs Survival and Has Beneficial Effects on Heart Function After Onset of Lamin A/C Gene Mutation Cardiomyopathy in Mice.

BACKGROUND: Mutations in LMNA encoding nuclear envelope proteins lamin A/C cause dilated cardiomyopathy. Activation of the AKT/mTOR (RAC-α serine/threonine-protein kinase/mammalian target of rapamycin) pathway is implicated as a potential pathophysiologic mechanism. The aim of this study was to assess whether pharmacological inhibition of mTOR signaling has beneficial effects on heart function and prolongs survival in a mouse model of the disease, after onset of heart failure. METHODS: We treated male LmnaH222P/H222P mice, after the onset of heart failure, with placebo or either of 2 orally bioavailable mTOR inhibitors: everolimus or NV-20494, a rapamycin analog highly selective against mTORC1. We examined left ventricular remodeling, and the cell biological, biochemical, and histopathologic features of cardiomyopathy, potential drug toxicity, and survival. RESULTS: Everolimus treatment (n=17) significantly reduced left ventricular dilatation and increased contractility on echocardiography, with a 7% (P=0.018) reduction in left ventricular end-diastolic diameter and a 39% (P=0.0159) increase fractional shortening compared with placebo (n=17) after 6 weeks of treatment. NV-20494 treatment (n=15) yielded similar but more modest and nonsignificant changes. Neither drug prevented the development of cardiac fibrosis. Drug treatment reactivated suppressed autophagy and inhibited mTORC1 signaling in the heart, although everolimus was more potent. With regards to drug toxicity, everolimus alone led to a modest degree of glucose intolerance during glucose challenge. Everolimus (n=20) and NV-20494 (n=20) significantly prolonged median survival in LmnaH222P/H222P mice, by 9% (P=0.0348) and 11% (P=0.0206), respectively, compared with placebo (n=20). CONCLUSIONS: These results suggest that mTOR inhibitors may be beneficial in patients with cardiomyopathy caused by LMNA mutations and that further study is warranted.

Effect of epicatechin consumption on the inflammatory pathway and mitochondria morphology in PBMC from a R350P desminopathy patient: A case report.

Desminopathy R350P is a human myopathy that is characterized by the progressive loss of muscle fiber organization. This results in the loss of muscle size, mobility, and strength. In desminopathy, inflammation affects muscle homeostasis and repair, and contributes to progressive muscle deterioration. Mitochondria morphology was also suggested to affect desminopathy progression. Epicatechin (Epi)-a natural compound found in cacao-has been proposed to regulate inflammatory signaling and mitochondria morphology in human and animal models. Hence, we hypothesize chronic Epi consumption to improve inflammatory pathway and mitochondria morphology in the peripheral blood mononuclear cells (PBMCs) of a desminopathy R350P patient. We found that 12 weeks of Epi consumption partially restored TRL4 signaling, indicative of inflammatory signaling and mitochondria morphology in the desminopathy patient. Moreover, Epi consumption improved blood health parameters, including reduced HOMA-IR and IL-6 levels in the desminopathy patient. This indicates that Epi consumption could be a useful tool to slow disease progression in desminopathy patients.

Esculin targets TLR4 to protect against LPS-induced septic cardiomyopathy.

BACKGROUND: Esculin, a main active ingredient from Cortex fraxini, possesses biological activities such as anti-thrombosis, anti-inflammatory, and anti-oxidation effects. However, the effects of Esculin on septic cardiomyopathy remains unclear. This study aimed to explore the protective properties and mechanisms of Esculin in countering sepsis-induced cardiac trauma and dysfunction. METHODS AND RESULTS: In lipopolysaccharide (LPS)-induced mice model, Esculin could obviously improve heart injury and function. Esculin treatment also significantly reduced the production of inflammatory and apoptotic cells, the release of inflammatory cytokines, and the expression of oxidative stress-associated and apoptosis-associated markers in hearts compared to LPS injection alone. These results were consistent with those of in vitro experiments based on neonatal rat cardiomyocytes. Database analysis and molecular docking suggested that TLR4 was targeted by Esculin, as shown by stable hydrogen bonds formed between Esculin with VAL-308, ASN-307, CYS-280, CYS-304 and ASP-281 of TLR4. Esculin reversed LPS-induced upregulation of TLR4 and phosphorylation of NF-κB p65 in cardiomyocytes. The plasmid overexpressing TLR4 abolished the protective properties of Esculin in vitro. CONCLUSION: We concluded that Esculin could alleviate LPS-induced septic cardiomyopathy via binding to TLR4 to attenuate cardiomyocyte inflammation, oxidative stress and apoptosis.

Efficacy and Tolerability of Ivabradine for Cardiomyopathy in Patients with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is an intractable X-linked myopathy caused by dystrophin gene mutations. Patients with DMD suffer from progressive muscle weakness, inevitable cardiomyopathy, increased heart rate (HR), and decreased blood pressure (BP). The aim of this study was to clarify the efficacy and tolerability of ivabradine treatment for DMD cardiomyopathy.A retrospective analysis was performed in 11 patients with DMD, who received ivabradine treatment for more than 1 year. Clinical results were analyzed before (baseline), 6 months after, and 12 months after the ivabradine administration.The initial ivabradine dose was 2.0 ± 1.2 mg/day and the final dose was 5.6 ± 4.0 mg/day. The baseline BP was 95/64 mmHg. A non-significant BP decrease to 90/57 mmHg was observed at 1 month but it recovered to 97/62 mmHg at 12 months after ivabradine administration. The baseline HR was 93 ± 6 bpm and it decreased to 74 ± 12 bpm at 6 months (P = 0.011), and to 77 ± 10 bpm at 12 months (P = 0.008). A linear correlation (y = 2.2x + 5.1) was also observed between the ivabradine dose (x mg/day) and HR decrease (y bpm). The baseline LVEF was 38 ± 12% and it significantly increased to 42 ± 9% at 6 months (P = 0.011) and to 41 ± 11% at 12 months (P = 0.038). Only 1 patient with the lowest BMI of 11.0 kg/m2 and BP of 79/58 mmHg discontinued ivabradine treatment at 6 months, while 1-year administration was well-tolerated in the other 10 patients.Ivabradine decreased HR and increased LVEF without lowering BP, suggesting it can be a treatment option for DMD cardiomyopathy.

Successful Management of a Pregnant Patient with Danon Cardiomyopathy.

A 25-year-old woman with left ventricular (LV) dysfunction became pregnant during the diagnostic period. Decompensated heart failure with frequent ventricular arrhythmias necessitated hospitalization in the 21st week of pregnancy. Under careful monitoring, diuretics and sotalol were added to her ongoing treatment of carvedilol and spironolactone due to the risk of hemodynamic collapse. An emergency cesarean section was performed in the 32nd week after the detection of rapid nonsustained ventricular tachycardia. Subsequent genetic testing revealed that the LV dysfunction was associated with Danon cardiomyopathy. This case highlights the importance of careful pregnancy management with LV dysfunction along with early genetic testing.

Spontaneous Remission Without Steroid Therapy in Isolated Cardiac Sarcoidosis with Severe Left Ventricular Systolic Dysfunction.

Spontaneous remission is often observed in extracardiac cases of sarcoidosis, such as skin sarcoidosis. However, for cardiac sarcoidosis (CS), the prognosis is unfavorable. Although corticosteroids are the first-line treatment for CS, data regarding the natural history of isolated CS are limited. We describe a rare case of isolated CS with severe left ventricular systolic dysfunction that improved without steroid therapy.

Nanomedicine alleviates doxorubicin-induced cardiotoxicity and enhances chemotherapy synergistic chemodynamic therapy.

Doxorubicin (DOX) is widely used in clinic as a broad-spectrum chemotherapy drug, which can enhance the efficacy of chemodynamic therapy (CDT) by interfering tumor-related metabolize to increase H2O2 content. However, DOX can induce serious cardiomyopathy (DIC) due to its oxidative stress in cardiomyocytes. Eliminating oxidative stress would create a significant opportunity for the clinical application of DOX combined with CDT. To address this issue, we introduced sodium ascorbate (AscNa), the main reason is that AscNa can be catalyzed to produce H2O2 by the abundant Fe3+ in the tumor site, thereby enhancing CDT. While the content of Fe3+ in heart tissue is relatively low, so the oxidation of AscNa had tumor specificity. Meanwhile, due to its inherent reducing properties, AscNa could also eliminate the oxidative stress generated by DOX, preventing cardiotoxicity. Due to the differences between myocardial tissue and tumor microenvironment, a novel nanomedicine was designed. MoS2 was employed as a carrier and CDT catalyst, loaded with DOX and AscNa, coating with homologous tumor cell membrane to construct an acid-responsive nanomedicine MoS2-DOX/AscNa@M (MDA@M). In tumor cells, AscNa enhances the synergistic therapy of DOX and MoS2. In cardiomyocytes, AscNa could effectively reduce the cardiomyopathy induced by DOX. Overall, this study enhanced the clinical potential of chemotherapy synergistic CDT.

C-terminal fragment of fibroblast growth factor 23 improves heart function in murine models of high intact fibroblast growth factor 23.

Cardiovascular disease (CVD) is the major cause of death in chronic kidney disease (CKD) and is associated with high circulating fibroblast growth factor (FGF)23 levels. It is unresolved whether high circulating FGF23 is a mere biomarker or pathogenically contributes to cardiomyopathy. It is also unknown whether the C-terminal FGF23 peptide (cFGF23), a natural FGF23 antagonist proteolyzed from intact FGF23 (iFGF23), retards CKD progression and improves cardiomyopathy. We addressed these questions in three murine models with high endogenous FGF23 and cardiomyopathy. First, we examined wild-type (WT) mice with CKD induced by unilateral ischemia-reperfusion and contralateral nephrectomy followed by a high-phosphate diet. These mice were continuously treated with intraperitoneal implanted osmotic minipumps containing either iFGF23 protein to further escalate FGF23 bioactivity, cFGF23 peptide to block FGF23 signaling, vehicle, or scrambled peptide as negative controls. Exogenous iFGF23 protein given to CKD mice exacerbated pathological cardiac remodeling and CKD progression, whereas cFGF23 treatment improved heart and kidney function, attenuated fibrosis, and increased circulating soluble Klotho. WT mice without renal insult placed on a high-phosphate diet and homozygous Klotho hypomorphic mice, both of whom develop moderate CKD and clear cardiomyopathy, were treated with cFGF23 or vehicle. Mice treated with cFGF23 in both models had improved heart and kidney function and histopathology. Taken together, these data indicate high endogenous iFGF23 is not just a mere biomarker but pathogenically deleterious in CKD and cardiomyopathy. Furthermore, attenuation of FGF23 bioactivity by cFGF23 peptide is a promising therapeutic strategy to protect the kidney and heart from high FGF23 activity.NEW & NOTEWORTHY There is a strong correlation between cardiovascular morbidity and high circulating fibroblast growth factor 23 (FGF23) levels, but causality was never proven. We used a murine chronic kidney disease (CKD) model to show that intact FGF23 (iFGF23) is pathogenic and contributes to both CKD progression and cardiomyopathy. Blockade of FGF23 signaling with a natural proteolytic product of iFGF23, C-terminal FGF23, alleviated kidney and cardiac histology, and function in three separate murine models of high endogenous FGF23.

Naringenin protects against septic cardiomyopathy in mice by targeting HIF-1α.

Myocardial dysfunction is a prevalent complication of sepsis (septic cardiomyopathy) with a high mortality rate and limited therapeutic options. Naringenin, a natural flavonoid compound with anti-inflammatory and antioxidant properties, holds promise as a potential treatment for sepsis-induced myocardial dysfunction. This study investigated the pharmacological effects of naringenin on septic cardiomyopathy. In vivo and in vitro experiments demonstrated that naringenin improved cardiomyocyte damage. Network pharmacology and database analysis revealed that HIF-1α is a key target protein of naringenin. Elevated expression of HIF-1α was observed in damaged cardiomyocytes, and the HIF-1α inhibitor effectively protected against LPS-induced cardiomyocyte damage. Molecular docking studies confirmed the direct binding between naringenin and HIF-1α protein. Importantly, our findings demonstrated that naringenin did not provide additional attenuation of cardiomyocyte injury on the biases of HIF-1α inhibitor treatment. In conclusion, this study proves that naringenin protects against septic cardiomyopathy through HIF-1α signaling. Naringenin is a promising therapeutic candidate for treating septic cardiomyopathy.

MG53: A new protagonist in the precise treatment of cardiomyopathies.

Cardiomyopathies (CMs) are highly heterogeneous progressive heart diseases characterised by structural and functional abnormalities of the heart, whose intricate pathogenesis has resulted in a lack of effective treatment options. Mitsugumin 53 (MG53), also known as Tripartite motif protein 72 (TRIM72), is a tripartite motif family protein from the immuno-proteomic library expressed primarily in the heart and skeletal muscle. Recent studies have identified MG53 as a potential cardioprotective protein that may play a crucial role in CMs. Therefore, the objective of this review is to comprehensively examine the underlying mechanisms mediated by MG53 responsible for myocardial protection, elucidate the potential role of MG53 in various CMs as well as its dominant status in the diagnosis and prognosis of human myocardial injury, and evaluate the potential therapeutic value of recombinant human MG53 (rhMG53) in CMs. It is expected to yield novel perspectives regarding the clinical diagnosis and therapeutic treatment of CMs.

Outcomes of Octogenarian Patients Treated with Tafamidis for Transthyretin Amyloid Cardiomyopathy.

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) benefit from disease-modifying agents such as tafamidis. However, the survival benefit of tafamidis in elderly patients (age ≥80 years) is not reported. This study aimed to assess the survival of patients with ATTR-CM aged 80 years and older who were treated with tafamidis compared with patients aged <80 years. We conducted a retrospective analysis of patients with ATTR-CM who underwent tafamidis treatment, aged 45 to 97 years at the time of diagnosis between January 1, 2008, and May 31, 2021. A total of 484 patients were included, with 208 in the ≥80 years group and 276 in the <80 years group. The cohort was followed up for mortality outcomes, and hazard ratios with 95% confidence intervals were calculated. After a median follow-up of 18.5 months, 72 deaths were recorded in the entire cohort. Kaplan-Meier curves showed no differences in survival probability between the 2 groups at 30 months (p for log-rank test = 0.76). The survival rates for patients aged ≥80 years who underwent treatment at 1, 2, 3, 4, and 5 years were 94.7%, 86.0%, 77.0%, 77.0%, and 38.5%, respectively. The corresponding rates for patients aged <80 years who underwent treatment were 93.2, 84.8, 74.4, 68.2, and 64.6%, respectively. In the multivariable analysis, the hazard ratio (95% confidence interval) of the mortality comparing treatment patients aged ≥80 years with those aged <80 years was 0.81 (0.41 to 1.61). In conclusion, tafamidis treatment is associated with similar reductions in mortality in older and younger patients with ATTR-CM.

Tolerability and effectiveness of beta-blockers in patients with cardiac amyloidosis: A systematic review and meta-analysis.

OBJECTIVE: This systematic review aimed to assess the tolerability of patients with cardiac amyloidosis (CA) to beta-blockers (BBs) and evaluate its association with adverse outcomes. METHODS: We performed a comprehensive search from January 1, 2000 to October 20, 2023. Studies examining BB use and tolerance or the relationship between BB use and outcomes in patients with CA were included. Pooled adjusted hazard ratios (aHRs) for all-cause mortality were calculated using random- and fixed-effects models. RESULTS: Eight observational studies involving 4002 patients with CA (87.5% with transthyretin CA [ATTR-CA] and 12.5% with immunoglobulin light chain CA [AL-CA]) were assessed. BBs were used by 52.5% of the patients. However, 26.3% of the patients discontinued BBs because of hypotension, bradycardia, or fatigue. Regarding the association between BB use and all-cause death, four studies were identified that included 2874 patients with ATTR-CA and 16 patients with AL-CA. The meta-analysis revealed no apparent relationship between BB use and all-cause mortality (pooled aHR = 0.78, 95% confidence interval (CI) = 0.40-1.51). Two studies on patients with ATTR-CA found no impact of BB use on all-cause mortality in the subgroup with left ventricular ejection fraction (LVEF) > 40%, but conflicting results exist for those with LVEF ≤40% (pooled aHR = 0.78, 95% CI = 0.40-1.54). CONCLUSION: The limited number of observational studies that predominantly enrolled patients with ATTR-CA showed that BBs were used in almost half of the patients with CA, with varying tolerability. However, no significant association was observed between BB use and all-cause mortality.

Molecular mechanisms and emerging therapies in wild-type transthyretin amyloid cardiomyopathy.

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is an underrecognized cause of heart failure due to misfolded wild-type transthyretin (TTRwt) myocardial deposition. The development of wild-type TTR amyloid fibrils is a complex pathological process linked to the deterioration of homeostatic mechanisms owing to aging, plausibly implicating multiple molecular mechanisms. The components of amyloid transthyretin often include serum amyloid P, proteoglycans, and clusterin, which may play essential roles in the localization and elimination of amyloid fibrils. Oxidative stress, impaired mitochondrial function, and perturbation of intracellular calcium dynamics induced by TTR contribute to cardiac impairment. Recently, tafamidis has been the only drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of ATTRwt-CM. In addition, small interfering RNAs and antisense oligonucleotides for ATTR-CM are promising therapeutic approaches and are currently in phase III clinical trials. Newly emerging therapies, such as antibodies targeting amyloid, inhibitors of seed formation, and CRISPR‒Cas9 technology, are currently in the early stages of research. The development of novel therapies is based on progress in comprehending the molecular events behind amyloid cardiomyopathy. There is still a need to further advance innovative treatments, providing patients with access to alternative and effective therapies, especially for patients diagnosed at a late stage.

Effects of SGLT2 inhibitors on cardiac function and health status in chronic heart failure: a systematic review and meta-analysis.

PURPOSE: Numerous clinical studies have explored sodium-glucose cotransporter 2 inhibitor (SGLT2i) in patients with chronic heart failure (CHF), with or without type 2 diabetes mellitus (T2DM), and SGLT2i were proved to significantly reduce CHF hospitalization, cardiovascular death, cardiovascular mortality, all-cause mortality and myocardial infarction in patients with or without T2DM. However, only a limited few have investigated the effects of SGLT-2i on HF disease-specific health status and cardiac function. This meta-analysis aims to assess the effects of SGLT2i on disease-specific health status and cardiac function in CHF patients. METHODS: A comprehensive search was conducted of trials by searching in PubMed, EMBASE, CENTRAL, Scopus, and Web of Science, and two Chinese databases (CNKI and Wanfang), Clinical Trials ( http://www. CLINICALTRIALS: gov ) were also searched. RESULTS: A total of 18 randomized controlled trials (RCTs) involving 23,953 participants were included in the meta-analysis. The effects of SGLT2 inhibitors were compared with control or placebo groups in CHF with or without T2DM. The SGLT2 inhibitors group exhibited a significant reduction in pro b-type natriuretic peptide (NT-proBNP) levels by 136.03 pg/ml (95% confidence interval [CI]: -253.36, - 18.70; P = 0.02). Additionally, a greater proportion of patients in the SGLT2 inhibitors group showed a ≥ 20% decrease in NT-proBNP (RR = 1.45, 95% CI [0.92, 2.29], p = 0.072). However, no statistically significant difference was observed for the effects on B-type natriuretic peptide (BNP). The use of SGLT-2 inhibitors led to a noteworthy improvement in LVEF by 2.79% (95% CI [0.18, 5.39];P = 0.036). In terms of health status, as assessed by the Kansas City Cardiomyopathy Questionnaire (KCCQ) and 6-minute walk distance, SGLT2 inhibitors led to a significant improvement in KCCQ clinical summary (KCCQ-CS) score (WMD = 1.7, 95% CI [1.67, 1.73], P < 0.00001), KCCQ overall summary (KCCQ-OS) score (WMD = 1.73, 95% CI [0.94, 2.52], P < 0.00001), and KCCQ total symptom (KCCQ-TS) score (WMD = 2.88, 95% CI [1.7, 4.06], P < 0.00001). Furthermore, the occurrence of KCCQ-CS and KCCQ-OS score increases ≥ 5 points had relative risks (RR) of 1.25 (95% CI [1.11, 1.42], P < 0.00001) and 1.15 (95% CI [1.09, 1.22], P < 0.00001), respectively. Overall, SGLT2 inhibitors increased the 6-minute walk distance by 23.98 m (95% CI [8.34, 39.62]; P = 0.003) compared to control/placebo from baseline. CONCLUSIONS: The SGLT2 inhibitors treatment offers an effective strategy for improving NT-proBNP levels, Kansas City Cardiomyopathy Questionnaire scores and 6-minute walk distance in CHF with or without T2DM. These findings indicate that SGLT2i improve cardiac function and health status in CHF with or without T2DM, and provide valuable guidance for clinicians making treatment decisions for patients with CHF.

Use of Technetium-99m-Pyrophosphate Single-Photon Emission Computed Tomography/Computed Tomography in Monitoring Therapeutic Changes of Eplontersen in Patients With Hereditary Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: Hereditary transthyretin amyloid cardiomyopathy (hATTR-CM) is a progressive and fatal disease. Recent evidence indicates that bone scintigraphy may serve as a tool to monitor the effectiveness of hATTR-CM treatment. The objective of this study was to examine how eplontersen therapy influences the semiquantitative uptake of technetium-99m-pyrophosphate in individuals diagnosed with hATTR-CM. METHODS AND RESULTS: We retrospectively analyzed a prospective cohort from the NEURO-TTRansform trial, including patients with hATTR-CM receiving eplontersen (45 mg/4 weeks). A control group comprised patients with hATTR-CM who had not received eplontersen, inotersen, tafamidis, or patisiran. Technetium-99m-pyrophosphate single-photon emission computed tomography/computed tomography was conducted at baseline and during follow-up. Thirteen patients with hATTR-CM were enrolled, with 6 receiving eplontersen and 7 serving as the control group. The median follow-up time was 544 days. The eplontersen group exhibited a significant decrease in volumetric heart and lung ratio (3.774 to 2.979, P=0.028), whereas the control group showed no significant change (4.079 to 3.915, P=0.237). Patients receiving eplontersen demonstrated a significantly greater reduction in volumetric heart and lung ratio compared with the control group (-20.7% versus -3.4%, P=0.007). CONCLUSIONS: The volumetric heart and lung ratio used to quantify technetium-99m-pyrophosphate uptake showed a significant reduction subsequent to eplontersen treatment in individuals diagnosed with hATTR-CM. These findings suggest the potential efficacy of eplontersen in treating hATTR-CM and highlight the value of technetium-99m-pyrophosphate single-photon emission computed tomography/computed tomography as a tool for monitoring therapeutic effectiveness.

Feasibility of PiB positron emission tomography/computed tomography for treatment monitoring with Tafamidis in a patient with transthyretin cardiac amyloidosis.

We present a 77-year-old woman with wild-type ATTR cardiac amyloidosis (ATTR-CA) who presented with dyspnea, arrhythmia, and elevated NT-pro BNP. Initial imaging including cardiac MRI, PYP scintigraphy, PiB PET/CT and NaF PET/CT revealed cardiac abnormalities. Tafamidis treatment was initiated. After 14 months, symptomatic improvement and reduced NT-pro BNP were observed. Cardiac MRI and PYP scintigraphy showed no significant change and increased NaF accumulation, while PiB PET/CT showed decreased amyloid deposition, suggesting that it may be superior to NaF PET/CT in assessing the therapeutic effect of tafamidis in ATTR-CA.