Heart failure

CircRNAs in diabetic cardiomyopathy

Diabetic cardiomyopathy is an important irreversible chronic cardiovascular complication in diabetic patients. This condition is described as early diastolic dysfunction, myocardial fibrosis, cardiac hypertrophy, systolic dysfunction and other complex pathophysiological events, which ultimately lead to heart failure. Despite these characteristics, the underlying mechanisms resulting in diabetic cardiomyopathy are still unknown. With the developments in molecular biotechnology, increasing evidence shows that circRNAs play critical roles in the pathogenesis of diabetic cardiomyopathy. The purpose of this review is to summarize recent studies on the role of circRNAs in the pathophysiological process to provide novel prevention and treatment strategies for diabetic cardiomyopathy, oxidative stress, inflammation, endothelial dysfunction, myocardial fibrosis and cell death in diabetic cardiomyopathy.

Harnessing the Benefits of Endogenous Hydrogen Sulfide to Reduce Cardiovascular Disease

Cardiovascular disease is the leading cause of death in the U.S. While various studies have shown the beneficial impact of exogenous hydrogen sulfide (H₂S)-releasing drugs, few have demonstrated the influence of endogenous H₂S production. Modulating the predominant enzymatic sources of H₂S-cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase-is an emerging and promising research area. This review frames the discussion of harnessing endogenous H₂S within the context of a non-ischemic form of cardiomyopathy, termed diabetic cardiomyopathy, and heart failure. Also, we examine the current literature around therapeutic interventions, such as intermittent fasting and exercise, that stimulate H₂S production.

The pyruvate-lactate axis modulates cardiac hypertrophy and heart failure

The metabolic rewiring of cardiomyocytes is a widely accepted hallmark of heart failure (HF). These metabolic changes include a decrease in mitochondrial pyruvate oxidation and an increased export of lactate. We identify the mitochondrial pyruvate carrier (MPC) and the cellular lactate exporter monocarboxylate transporter 4 (MCT4) as pivotal nodes in this metabolic axis. We observed that cardiac assist device-induced myocardial recovery in chronic HF patients was coincident with increased myocardial expression of the MPC. Moreover, the genetic ablation of the MPC in cultured cardiomyocytes and in adult murine hearts was sufficient to induce hypertrophy and HF. Conversely, MPC overexpression attenuated drug-induced hypertrophy in a cell-autonomous manner. We also introduced a novel, highly potent MCT4 inhibitor that mitigated hypertrophy in cultured cardiomyocytes and in mice. Together, we find that alteration of the pyruvate-lactate axis is a fundamental and early feature of cardiac hypertrophy and failure.

Role of quantitative myocardial blood flow and 13N-ammonia washout for viability assessment in ischemic cardiomyopathy

OBJECTIVE

Positron emission tomography (PET) integrating assessment of perfusion with 13N-ammonia (NH3) and viability with 18F-fluorodeoxyglucose (FDG) has high accuracy to identify viable, hibernating myocardium. We tested whether quantification of myocardial blood flow (MBF) and washout (k2) can predict myocardial viability using FDG as standard of reference.

METHODS

In 180 consecutive patients with ischemic cardiomyopathy, myocardium was categorized on a segment-level into normal, ischemic, hibernating, and scar. From dynamic images, stress MBF, rest MBF, and k2 were derived and myocardial flow reserve (MFR) and volume of distribution (VD) were calculated.

RESULTS

Across myocardial tissues, all parameters differed significantly. The area under the curve (AUC) was 0.564 (95% CI 0.527-0.601), 0.635 (0.599-0.671), 0.553 (0.516-0.591), 0.520 (0.482-0.559), and 0.560 (0.522-0.597) for stress MBF, rest MBF, MFR, k2, and VD. The generalized linear mixed model correctly classified 81% of scar as viable, hibernating myocardium. If the threshold of rest MBF to predict viability was set to 0.45 mL·min-1·g-1, sensitivity and specificity were 96% and 12%, respectively.

CONCLUSION

Quantitative NH3 PET parameters have low to moderate diagnostic performance to predict viability in ischemic cardiomyopathy. However, if rest MBF falls below 0.45 mL·min-1·g-1, viability testing by FDG-PET may be safely deferred.

Development of an ImmunoFET for Analysis of Tumour Necrosis Factor-α in Artificial Saliva: Application for Heart Failure Monitoring

Assessing tumour necrosis factor-α (TNF-α) levels in the human body has become an essential tool to recognize heart failure (HF). In this work, label-free, rapid, easy to use ImmunoFET based on an ion-sensitive field effect transistor (ISFET) was developed for the detection of TNF-α protein. Monoclonal anti-TNF-α antibodies (anti-TNF-α mAb) were immobilized on an ISFET gate made of silicon nitride (Si3N4) after salinization with 11-(triethoxysilyl) undecanal (TESUD). The obtained ISFET functionalized with the mAbs (ImmunoFET) was used to detect TNF-α protein in both phosphate buffer saline (PBS) and artificial saliva (AS). The change in the threshold voltage of the gate (∆VT) showed approximately linear dependency on the concentration of the antigens in the range 5–20 pg/mL for both matrixes. The cross-selectivity study showed that the developed ImmunoFET demonstrated to be selective towards TNF-α, when compared to other HF biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP), interleukin-10 (IL-10), and cortisol, even if further experiments have to be carried out for decreasing possible unspecific absorption phenomena. To the best of our knowledge, this is the first ImmunoFET that has been developed based on Si3N4 for TNF-α detection in AS by electrical measurement.

Possible association between eating behaviors and cardiovascular disease in the general population: Analysis of a nationwide epidemiological database

BACKGROUND AND AIMS

Epidemiological evidence on the relationship between eating behaviors, including breakfast skipping, late night dinner, and bedtime snacking, and cardiovascular disease (CVD) events among the general population is scarce. We sought to explore the association of eating behaviors with subsequent CVD using a nationwide epidemiological database.

METHODS AND RESULTS

Medical records of 1,941,125 individuals without prior history of CVD were extracted from the Japan Medical Data Center contracting with more than 60 insurers from multiple regions in Japan, mainly including employed working-age individuals. Skipping breakfast <3 times per week, late night dinner <3 times per week, and bedtime snacking <3 times per week were defined as optimal eating behaviors. Median age was 45 (interquartile range 39-53) years, and 1,138,676 were men. Median follow-up period was 978 (interquartile range 481-1790) days. Among them, 948,805 individuals (48.9%) had optimal eating behaviors, whereas 647,383 individuals (33.4%), 283,017 individuals (14.6%), and 61,920 individuals (3.2%) had single, double, and triple non-optimal eating behaviors, respectively. Individuals with non-optimal eating behaviors were younger and more likely to be men. Obesity and high waist circumference were more commonly observed in those with non-optimal eating behaviors. Multivariable Cox regression analysis showed that, compared with no non-optimal eating behavior, having non-optimal eating behaviors would have higher risk of myocardial infarction, angina pectoris, stroke, and heart failure. However, the dose-response relationship was not clear in the association between the number of non-optimal eating behaviors and incident CVD. Multivariable Cox regression analysis after multiple imputation for missing values also showed the association between non-optimal eating behaviors and incident CVD.

CONCLUSIONS

Using a nationwide epidemiological database, we found a possible relationship between eating behaviors including skipping breakfast, late night dinner, and bedtime snacking, and subsequent cardiovascular events among the general population, suggesting the potential importance of maintaining optimal eating behaviors for the primordial and primary CVD prevention in the general population.

Prognostic value of estimated plasma volume in patients with chronic systolic heart failure

Assessing congestion is challenging but important to patients with chronic heart failure (CHF). However, there are limited data regarding the association between estimated plasma volume status (ePVS) determined using hemoglobin/hematocrit data and outcomes in patients with stable CHF. We prospectively analyzed 231 patients; the median follow-up period was 35.6 months. We calculated ePVS at admission using the Duarte and Strauss formula, derived from hemoglobin and hematocrit ratios and divided patients into three groups. The primary outcome was a composite of all-cause mortality or heart failure rehospitalization. Among 274 patients (61.98 years of age, 2.3% male), the mean ePVS was 3.98±0.90 dL/g. The third ePVS tertile had a higher proportion of primary outcome (71.4%) than the first or second tertile (48.1% and 59.7%, respectively; p=0.013). On multivariable Cox analysis, after adjusting for potential confounders, higher ePVS remained significantly associated with increased rate of primary outcome (adjusted HR 1.567, 95% CI 1.267 to 1.936; p<0.001). Kaplan-Meier survival analyses showed that the occurrence of primary outcome, all-cause mortality and rehospitalization increased progressively from first to third tertiles (p=0.006, 0.014 and 0.001; respectively). In receiver operating characteristic analysis, the area under the curve of ePVS for primary outcome was 0.645. ePVS determined using hemoglobin and hematocrit was independently associated with clinical outcomes for patients with stable CHF. Our study thus further strengthens the evidence that ePVS has important prognostic value in patients with stable CHF.

Trial registration number ChiCTR-ONC-14004463.

Defining a therapeutic range for regeneration of ischemic myocardium via shock waves

Shockwave therapy (SWT) represents a promising regenerative treatment option for patients with ischemic cardiomyopathy. Although no side-effects have been described upon SWT, potential cellular damage at therapeutic energies has not been addressed so far. In this work, we aimed to define a therapeutic range for shock wave application for myocardial regeneration. We could demonstrate that SWT does not induce cellular damage beneath energy levels of 0.27 mJ/mm² total flux density. Endothelial cell proliferation, angiogenic gene expression and phosphorylation of AKT and ERK are enhanced in a dose dependent manner until 0.15 mJ/mm² energy flux density. SWT induces regeneration of ischemic muscle in vivo via expression of angiogenic gene expression, enhanced neovascularization and improved limb perfusion in a dose-dependent manner. Therefore, we provide evidence for a dose-dependent induction of angiogenesis after SWT, as well as the absence of cellular damage upon SWT within the therapeutic range. These data define for the first time a therapeutic range of SWT, a promising regenerative treatment option for ischemic cardiomyopathy.

Elevated plasma fatty acid-binding protein 3 is related to prolonged corrected QT interval and reduced ejection fraction in patients with stable angina

Background: Higher concentrations of plasma fatty acid-binding protein 3 (FABP3) play a role in the development of cardiovascular events, cerebrovascular deaths, and acute heart failure. However, little is known about the relationship between plasma FABP3 level and prolonged QT interval and reduced ejection fraction (EF). This study aimed to investigate the relationship between plasma FABP3 level and prolonged corrected QT (QTc) interval and reduced EF in patients with stable angina. Inflammatory cytokine and adipocytokine levels were also measured to investigate their associations with plasma FABP3. Methods: We evaluated 249 consecutive patients with stable angina. Circulating levels of FABP3 were measured by ELISA. In addition, 12-lead ECG and echocardiography recordings were obtained from each patient. Results: Multiple regression analysis showed that high-density lipoprotein cholesterol, high sensitivity C-reactive protein (hs-CRP), white blood cell (WBC) count, visfatin, adiponectin, FABP4, heart rate, QTc interval, left atrial diameter, left ventricular mass index, end-systolic volume, end-systolic volume index, fractional shortening, and EF were independently associated with FABP3 (all p<0.05). Patients with an abnormal QTc interval had a higher median plasma FABP3 level than those with a borderline and normal QTc interval. With increasing FABP3 tertiles, the patients had higher frequencies of abnormal QTc interval, left ventricular systolic dysfunction, and all-cause mortality, incrementally lower EF, higher WBC count, and higher levels of hs-CRP, visfatin, adiponectin, and FABP4. Conclusion: This study indicates that plasma FABP3 may act as a surrogate parameter of prolonged QTc interval and reduced EF in patients with stable angina, partially through the effects of inflammation or cardiomyocyte injury. Further studies are required to elucidate whether plasma FABP3 plays a role in the pathogenesis of QTc prolongation and reduced EF.

Drug-Therapy Problems and Predictors among Hospitalized Heart-Failure Patients: A Prospective Observational Study

BACKGROUND

Heart-failure patients are at high risk of experiencing drug-therapy problems, owing to polypharmacy, comorbidities, and usually advanced age. Drug-therapy problems can lead to poor clinical outcomes, increased health-care costs and decreased quality of life, and thus strategies for identifying, resolving, and preventing them are urgently needed. Therefore, this study aimed at investigating the incidence and predictors of drug-therapy problems among hospitalized heart-failure patients.

METHODS

This hospital-based prospective observational study was conducted from February 1 to May 31, 2014 at Jimma University Specialized Hospital. Patients of either sex aged 18 years and above with chronic heart failure and complete medical records were enrolled. Patients with high-output heart failure, <1 day of hospital stay, unwilling to give written informed consent, and unconscious without caregivers were excluded. Data were collected from medication charts, laboratory reports, patients/caregivers, morning multidisciplinary meetings, and ward rounds. Multivariate binary logistic regression analysis was done to identify independent predictors of drug-therapy problems.

RESULTS

A total of 104 heart-failure patients (mean age 51.20±15.66 years, females 51.9%) were consecutively enrolled, and 95 (91.3%) had experienced at least one drug-therapy problem (total 268, mean 2.82±1.39 encounters per patient). Of these problems, 45.5% were the need for additional drugs, followed by noncompliance (22.0%), inappropriate dosing (9.3%), unnecessary drugs (9.0%), ineffective drugs (8.2%), and adverse drug reactions (6.0%). None of the independent variables was found to be an independent predictor of having at least one drug-therapy problem. However, the number of clinical/pharmacological risk factors (AOR 7.93), female sex (AOR 3.24), and length of hospital stay (AOR 12.98) were predictors of noncompliance.

CONCLUSION

Patients suffered from a large number of drug-therapy problems. Drugs with survival benefit were underused. Noncompliance and the need for additional drug therapy were the most frequently identified drug-therapy problems. Numbers of clinical/pharmacological risk factors, length of hospital stay, and female sex were identified as predictors for noncompliance.

Study of Cellular Aging in a Cohort of Patients with Heart Failure

INTRODUCTION

Cellular senescence and fibrosis are important phenomena in the development of heart failure (HF). These processes are closely related to telomeric length (TL).

AIM

To assess cellular senescence in HF through the study of TL in peripheral blood mononuclear cells (PBMCs).

METHODS

Using real-time PCR, TL was measured in PBMCs from 20 patients diagnosed with HF, aged between 51 and 77 years (50% males). Ten patients had HF with reduced ejection fraction (HFrEF) and ten had preserved EF (HFpEF). TL was measured in 20 healthy controls matched by age and gender. Obtained values were compared with an internal control, the 36B4 gene, which never modifies its expression, and correlated with the clinical parameters.

RESULTS

TL mean was 1327 in patients with HF (95% CI 1309-1344) compared to 1286 (95% CI 1264-1308) in controls (p = 0.005). No differences were found when studying the correlation of telomere size with subgroups by gender, left ventricle ejection fraction (LVEF), presence of ischemic heart disease, smoking, Chronic Obstructive Pulmonary Disease (COPD), NYHA stage, degree of renal function or number of hospital admissions in the previous year. A significant and negative correlation was found between age and renal function (r = - 0.544, p < 0.05), as well as LVEF and NT-proBNP values (ρ = - 0.475, p < 0.05).

CONCLUSIONS

TL is shorter in patients with HF when compared with age and gender balanced controls. The shortening of TL is independent of age, gender and degree of kidney function, and does not correlate with LVEF decrease or functional status.

Favorable effects of peritoneal dialysis in patients with refractory heart failure and overhydration

BACKGROUND

Patients with refractory to optimal pharmacological treatment heart failure (HF) require frequent hospitalization. Peritoneal dialysis (PD) has been part of the management of such patients mainly for promoting ultrafiltration and management of overhydration independently of kidney function. The aim of this study was to evaluate the efficacy of PD, especially the use of icodextrin solutions and intermittent PD, in the hospitalization rate and cardiac functional status of patients with HF.

METHODS

We conducted a retrospective study involving patients with New York Heart Association (NYHA) class IV HF and preserved renal function (estimated glomerular filtration rate (eGFR) > 25 ml/min), who were refractory to conservative treatment. Clinical data on weight loss, hospitalization rate before and after PD initiation, cardiac functional status, and technique complications during a 6-month observational period were analyzed.

RESULTS

PD treatment was performed in 32 patients with a mean age of 63.8 ± 11.9 years and a follow-up of 20.78 ± 14.24 months. Hospitalizations were significantly reduced from 20.7 ± 13.7 to 7.7 ± 8.9 days/patients at 6 months. All patients showed improvement in NYHA class as well as in left ventricular ejection fraction. Overall, eGFR showed a significant decrease but only six patients reached end-stage renal disease. Complications included 18 cases of peritonitis. PD was well tolerated and no patient dropped out of the method. Survival rate reached 72% at 12 months but mortality rate was high with 23 patients dying at 16.65 ± 12.3 months after the initiation of treatment. Patients survival was not influenced by the type of PD modality or weight reduction achieved.

CONCLUSIONS

PD showed to be a viable option for the treatment of patients with refractory HF leading to a better cardiac functional status and diminishing the number of hospital admissions.

Critical role of glutamine metabolism in cardiomyocytes under oxidative stress

BACKGROUND

Metabolic remodeling in cardiomyocytes is deeply associated with the pathogenesis of heart failure (HF). Glutaminolysis is an anaplerotic pathway that incorporates α-ketoglutarate (αKG) derived from glutamine into the tricarboxylic acid (TCA) cycle. It is well known that cancer cells depend on glutamine for their increased energy demand and proliferation; however, the physiological roles of glutamine metabolism in failing hearts remain unclear.

OBJECTIVE

To investigate the regulatory mechanisms and biological effects of glutamine metabolism in oxidative stress-induced failing myocardium.

METHODS AND RESULTS

The intracellular levels of glutamine, glutamate, and αKG were significantly decreased by H₂O₂ stimulation in rat neonatal cardiomyocytes (RNCMs). To better understand the metabolic flux in failing myocardium, we performed a stable isotope tracing study and found that glutaminolysis was upregulated in RNCMs under oxidative stress. Consistent with this, the enzymatic activity of glutaminase (Gls), which converts glutamine to glutamate, was augmented in RNCMs treated with H₂O₂. These findings suggest that glutamine anaplerosis is enhanced in cardiomyocytes under oxidative stress to compensate for the reduction of αKG. Furthermore, the inhibition of Gls reduced cardiac cell viability, ATP production, and glutathione (GSH) synthesis in RNCMs with H₂O₂ stimulation. Finally, we evaluated the effects of αKG on failing myocardium and observed that dimethyl α-ketoglutarate (DMKG) suppressed oxidative stress-induced cell death likely due to the enhancement of intracellular ATP and GSH levels.

CONCLUSION

Our study demonstrates that under oxidative stress, glutaminolysis is upregulated to compensate for the loss of αKG and its replenishment into the TCA cycle, thereby exerting cardioprotective effects by maintaining ATP and GSH levels. Modulation of glutamine metabolism in failing hearts might provide a new therapeutic strategy for HF.

Myocardial ischemia and coronary disease in heart failure

Heart failure is a complex clinical syndrome and represents the final path of numerous heart diseases. Coronary artery disease is recognized as the primary risk factor for heart failure development, being the main etiological factor in more than 50% of heart failure patients in North America and Europe. Regardless of overt coronary artery disease, myocardial ischemia is a common finding in failing hearts, likely due to structural or functional coronary circulation alterations. Ischemia is a self-propagating process which irreversibly impairs the cardiac function and negatively impacts prognosis. Thus, a better and thorough understanding of myocardial ischemia pathophysiology in heart failure would likely lead to significantly improved outcomes in these patients. This review aims to describe the mechanisms of myocardial ischemia and coronary artery disease in heart failure, focusing on coronary circulation dysfunctions due to increased parietal stress or non-obstructive coronary disease, and discussing the association and management of coronary artery disease in patients with heart failure.

cGMP Signaling and Modulation in Heart Failure

Cyclic GMP (cGMP) represents a classic intracellular second messenger molecule. Over the past 2 decades, important discoveries have identified that cGMP signaling becomes deranged in heart failure (HF) and that cGMP and its main kinase effector, protein kinase G, generally oppose the biological abnormalities contributing to HF, in experimental studies. These findings have influenced the design of clinical trials of cGMP-augmenting drugs in HF patients. At present, the trial results of cGMP-augmenting therapies in HF remain mixed. As detailed in this review, strong evidence now exists that protein kinase G opposes pathologic cardiac remodeling through regulation of diverse biological processes and myocardial substrates. Potential reasons for the failures of cGMP-augmenting drugs in HF may be related to biological mechanisms opposing cGMP or because of certain features of clinical trials, all of which are discussed.

Downregulation of FOXO6 alleviates hypoxia-induced apoptosis and oxidative stress in cardiomyocytes by enhancing Nrf2 activation via upregulation of SIRT6

Forkhead box protein O6 (FOXO6) has been recently identified as a novel regulator of oxidative stress in multiple pathological processes. However, whether FOXO6 participates in the regulation of oxidative stress of myocardial infarction is unclear. The present study was performed to evaluate the potential role of FOXO6 in regulating hypoxia-induced apoptosis and oxidative stress in cardiomyocytes in vitro. Our results demonstrated that FOXO6 expression was highly elevated in cardiomyocytes exposed to hypoxia. Downregulation of FOXO6 expression by the siRNA-mediated gene knockdown in hypoxia-exposed cardiomyocytes increased cell viability, while repressing apoptosis and reactive oxygen species (ROS) production. In contrast, overexpression of FOXO6 enhanced the sensitivity of cardiomyocytes to hypoxia-induced injury. Further, in-depth research revealed that knockdown of FOXO6 promoted the expression of sirtuin6 (SIRT6) and enhanced the activation of nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signaling. Moreover, SIRT6 inhibition markedly blocked the FOXO6 knockdown-induced promotion effect on Nrf2 activation. In addition, Nrf2 inhibition partially reversed the FOXO6 knockdown-mediated protective effect against hypoxia-induced cardiomyocyte injury. Taken together, the findings of our study demonstrate that knockdown of FOXO6 is capable of protecting cardiomyocytes from hypoxia-induced apoptosis and oxidative stress by enhancing Nrf2 activation via upregulation of SIRT6. Our study highlights a potential role of FOXO6 in myocardial infarction and suggests it as an attractive target for cardioprotection.

Impacts of Comorbid Chronic Obstructive Pulmonary Disease and Congestive Heart Failure on Prognosis of Critically Ill Patients

Background

Comorbid congestive heart failure (CHF) was associated with worse prognosis in patients with chronic obstructive pulmonary disease (COPD), while few studies specially investigated critically ill patients. This study investigated the associations between comorbid COPD with or without CHF and prognosis of patients admitted to intensive care units (ICU).

Methods

We conducted a retrospective cohort study in the Medical Information Mart for Intensive Care III database. Adult ICU patients were included and categorized as patients without COPD and CHF, patients with COPD but without CHF, patients with CHF but without COPD, and patients with both COPD and CHF. The study outcomes were 28-day mortality and 90-day mortality after ICU admission. Kaplan–Meier curves were plotted to estimate the survival distributions between groups and multivariable Cox regression analyses were employed to evaluate the associations between comorbid COPD and/or CHF and the study outcomes.

Results

A total of 29,589 patients were included with 20,507 patients without COPD and CHF, 1575 patients with COPD, 6190 patients with CHF, and 1317 patients with both COPD and CHF. The highest 28-day mortality rate and 90-day mortality rate were found in patients with both COPD and CHF (15.95% and 25.74%, respectively), while patients with COPD and patients with CHF had similar mortality rates, also observed in Kaplan–Meier curves. Compared with patients without COPD or CHF, comorbid COPD or CHF both significantly increased the risk of 28-day mortality and 90-day mortality, but comorbid COPD and CHF together was associated with the highest risk of mortality (hazard ratio 1.55 (95% confidence interval (CI) 1.33–1.80) and 1.25 (95% CI 1.16–1.35) for 28-day mortality and 90-day mortality, respectively), while no significant interaction between COPD and CHF was found.

Conclusion

ICU patients with comorbid COPD or CHF both experienced greater mortalities, while these two risk factors seemed to play an independent role.

Isoproterenol-induced hypertrophy of neonatal cardiac myocytes and H9c2 cell is dependent on TRPC3-regulated CaV1.2 expression

Ca_V1.2 and transient receptor potential canonical channel 3 (TRPC3) are two proteins known to have important roles in pathological cardiac hypertrophy; however, such roles still remain unclear. A better understanding of these roles is important for furthering the clinical understanding of heart failure. We previously reported that Trpc3-knockout (KO) mice are resistant to pathologic hypertrophy and that their Ca_V1.2 protein expression is reduced. In this study, we aimed to examine the relationship between these two proteins and characterize their role in neonatal cardiomyocytes. We measured Ca_V1.2 expression in the hearts of wild-type (WT) and Trpc3^-/- mice, and examined the effects of Trpc3 knockdown and overexpression in the rat cell line H9c2. We also compared the hypertrophic responses of neonatal cardiomyocytes cultured from Trpc3^-/- mice to a representative hypertrophy-causing drug, isoproterenol (ISO), and measured the activity of nuclear factor of activated T cells 3 (NFAT3) in neonatal cardiomyocytes (NCMCs). We inhibited the L-type current with nifedipine, and measured the intracellular calcium concentration using Fura-2 with 1-oleoyl-2-acetyl-sn-glycerol (OAG)-induced Ba²⁺ influx. When using the Trpc3-mediated Ca²⁺ influx, both intracellular calcium concentration and calcium influx were reduced in Trpc3-KO myocytes. Not only was the expression of Ca_V1.2 greatly reduced in Trpc3-KO cardiac lysate, but the size of the Ca_V1.2 currents in NCMCs was also greatly reduced. When NCMCs were treated with Trpc3 siRNA, it was confirmed that the expression of Ca_V1.2 and the intracellular nuclear transfer activity of NFAT decreased. In H9c2 cells, the ISO activated- and verapamil inhibited- Ca²⁺ influxes were dramatically attenuated by Trpc3 siRNA treatment. In addition, it was confirmed that both the expression of Ca_V1.2 and the size of H9c2 cells were regulated according to the expression and activation level of TRPC3. We found that after stimulation with ISO, cell hypertrophy occurred in WT myocytes, while the increase in size of Trpc3-KO myocytes was greatly reduced. These results suggest that not only the cell hypertrophy process in neonatal cardiac myocytes and H9c2 cells were regulated according to the expression level of Ca_V1.2, but also that the expression level of Ca_V1.2 was regulated by TRPC3 through the activation of NFAT.

Usefulness of Peritoneal Ultrafiltration in Patients with Diuretic Resistant Heart Failure without End-Stage Renal Disease

AIM

This study aimed to explore the role of peritoneal ultrafiltration (UF) in cardiorenal syndrome (CRS) patients for fluid and metabolic control.

BACKGROUND

Peritoneal UF is safely and efficiently used for the management of CRS. It has been shown to provide efficient UF in hypervolemic patients.

METHODS

Thirty (20 males and 10 females) CRS patients were treated by peritoneal dialysis (PD) and UF. The baseline data of the patients (demographics, causes of heart failure, the presence of pacemaker or implantable cardioverter-defibrillator, the need for extracorporeal UF or paracentesis or thoracentesis, comorbidity, drugs, left ventricular ejection fraction [LVEF] and pulmonary artery systolic pressure [PAPs], pericardial effusion, physical examination, body weight, NYHA class, dialysis regime, urine output, N-terminal pro-B-type natriuretic peptide [NT-proBNP] level, hemoglobin, estimated glomerular filtration rate [eGFR], and other routine biochemical determinations) were recorded at the onset, every 6 months, and then annually. Echocardiograms were performed at baseline and after 6 and 12 months. The time points of complications associated with PD, the need for hemodialysis, the day of death, and causes of death were documented.

RESULTS

Mean age was 69 ± 8 years (range 49-84 years). The average PD duration was 18.25 ± 14.87 months. According to the CKD-EPI, initial mean GFR was 34.34 ± 11.9 mL/min/1.73 m2 (range 16.57-59.0), and this increased to 45.48 ± 26.04, 45.10 ± 28.58, and 41.10 ± 25.68 mL/min/1.73 m2 in the third, sixth, and twelfth months, respectively. There was a significant increase in the first 3 months and a significant decrease between the third and twelfth months (respectively, p = 0.018 and p = 0.043). There was no difference in eGFR levels between baseline and the end of the first year (p = 0.217). In the first 3 months, there was a significant decline in urea levels to 79.38 ± 36.65 from 109.92 ± 42.44 mg/dL and this was maintained until the end of the first year of PD therapy (after 3 months, p = 0.002; after 1 year, p = 0.024). However, there was no significant change in creatinine levels within the first year (p = 0.312). There was a significant increase in hemoglobin level up to the end of the first year of PD (after 3 months, p = 0.000; after 12 months, p = 0.013). There was a marked decrease in NT-proBNP levels in the first 6 months (p = 0.011). Functional capacity (according to NYHA classification) improved in all patients by the third month of PD treatment (p < 0.001). This early improvement was maintained in many patients during the following 12 months (p < 0.001). There was a marked decrease in NT-proBNP levels in the first 6 months (p = 0.011). At the end of the first year, there was an approximate 15% reduction in NT-proBNP levels (p = 0.647). Hospitalizations decreased to 6 ± 15 days/patient-year (range 18-122 days) from 62 ± 24 days/patient-year (p = 0.000).

CONCLUSION

Peritoneal UF is a treatment method that maintains renal function and electrolyte balance, improves cardiac function, and reduces hospitalizations in CRS patients. We observed that this treatment significantly increased functional capacity and quality of life and significantly reduced hospital admissions.

In vitro controlled release of extracellular vesicles for cardiac repair from poly(glycerol sebacate) acrylate-based polymers

Cell therapy to restore cardiac function in chronic heart failure has been extensively studied. However, its therapeutic value is limited due to poor cell engraftment and survival and the therapeutic outcomes have been attributed to paracrine secretions such as extracellular vesicles (EV). The direct use of EV is an attractive therapeutic strategy and it has been shown that the kinetics of delivery of the EV to the targeted tissue may impact the outcomes. However, there are currently no technologies to deliver EV to the heart in a controlled and tunable manner. The objective of this study was to design a controlled release system, based on a photocurable adhesive polymer, to locally deliver EV to the cardiac tissue. We have first demonstrated that the adhesive polymer, PGSA-g-EG, did not impact the EV bioactivity in vitro and was biocompatible in vivo when tested in a rat model. Importantly, the polymer remained attached to the heart surface for at least 1 month. We have then evaluated and optimized the in vitro release kinetics of the EV from the PGSA-g-EG polymer. Freeze-dried EV formulations were developed to tune the release kinetics and maximize the loading in the polymeric material. Moreover, despite the instability of the EV in aqueous medium at 37°C, the PGSA-g-EG polymer was able to release bioactive EV for at least 14 days. Overall, these results suggest that the PGSA-g-EG is a suitable material to promote the controlled delivery of bioactive EV over an extended period of time. STATEMENT OF SIGNIFICANCE: Extracellular vesicles (EV) are an investigational class of therapeutics that has shown promise to restore cardiac function following an ischemic event. Furthermore, its translation to the clinics is expected to pose less regulatory challenges than cell-based therapies. However, EV therapeutic outcomes are likely to be impacted by the route of administration and the kinetics of delivery to the target tissue. Therefore, there is a need for biomaterial-based technologies to deliver, in a controlled and tunable manner, EV to the heart. The present study describes the use of PGSA-g-EG polymer as an adhesive cardiac patch with potential to enable the controlled delivery of bioactive EV over an extended period of time to the cardiac tissue.

Oestrogen Receptor β Activation Protects Against Myocardial Infarction via Notch1 Signalling

Purpose

Oestrogen receptor β is believed to exert a cardioprotective effect against ischaemic injury. Nonetheless, the mechanism underlying its protective action remains to be fully elucidated. Recently, increased attention has been focused on Notch1 signalling for ameliorating cardiac ischaemic injury. Here, we hypothesised that oestrogen receptor β activation attenuates myocardial infarction (MI)-induced cardiac damage by modulating the Notch1 signalling pathway.

Methods

Male C57BL/6 mice were used to establish an MI model through the ligation of the anterior descending branch of the left coronary artery. Two chemical drugs, 2,3-Bis(4-hydroxyphenyl)-propionitrile (DPN) and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-s-phenylglycine t-butyl ester (DAPT), a specific inhibitor of Notch1 signalling) were administered via intraperitoneal injection to change oestrogen receptor β and Notch1 activities. Immunohistochemistry, western blot analysis, enzyme-linked immunosorbent assay (Elisa) assessment and echocardiography were used in this study to analyse cardiac oxidative stress, apoptosis, infraction volume, fibrosis and cardiac function.

Results

DPN-mediated oestrogen receptor β activation effectively protected cardiomyocytes from MI-induced oxidative damage and apoptosis. Furthermore, oestrogen receptor β activation reduced the infarct size and lowered the levels of myocardial enzymes in the serum, thereby leading to greater overall cardiac function improvement. Ischaemic injury–induced myocardial fibrosis was attenuated by oestrogen receptor β activation. Nevertheless, all of these cardioprotective effects of oestrogen receptor β activation were almost abrogated by DAPT administration, i.e. DAPT attenuated the anti-oxidative and anti-apoptotic effects and the decrease in infarct and fibrotic areas and reversed cardiac functional recovery. The levels of phospho-phosphatidylinositol-3-kinase (PI3K) and phospho-protein kinase B (Akt) were increased after DPN administration, and this change was reversed after DAPT was administered.

Conclusions

All of these new findings indicate that oestrogen receptor β activation is effective in ameliorating MI-induced cardiac dysfunction by enhancing Notch1 signalling and that PI3K/Akt signalling is the downstream mediator.

Electronic supplementary material

The online version of this article (10.1007/s10557-020-06949-3) contains supplementary material, which is available to authorized users.

The Partial Support of the Left Ventricular Assist Device Shifts the Systemic Cardiac Output Curve Upward in Proportion to the Effective Left Ventricular Ejection Fraction in Pressure-Volume Loop

Left ventricular assist device (LVAD) has been saving many lives in patients with severe left ventricular (LV) failure. Recently, a minimally invasive transvascular LVAD such as Impella enables us to support unstable hemodynamics in severely ill patients. Although LVAD support increases total LV cardiac output (CO_TLV) at the expense of decreases in the native LV cardiac output (CO_NLV), the underlying mechanism determining CO_TLV remains unestablished. This study aims to clarify the mechanism and develop a framework to predict CO_TLV under known LVAD flow (CO_LVAD). We previously developed a generalized framework of circulatory equilibrium that consists of the integrated CO curve and the VR surface as common functions of right atrial pressure (P_RA) and left atrial pressure (P_LA). The intersection between the integrated CO curve and the VR surface defines circulatory equilibrium. Incorporating LVAD into this framework indicated that LVAD increases afterload, which in turn decreases CO_NLV. The total LV cardiac output (CO_TLV) under LVAD support becomes CO_TLV = CO_NLV+EF_e · CO_LVAD, where EF_e is effective ejection fraction, i.e., E_es/(E_es+E_a). E_es and E_a represent LV end-systolic elastance (E_es) and effective arterial elastance (E_a), respectively. In other words, LVAD shifts the total LV cardiac output curve upward by EF_e · CO_LVAD. In contrast, LVAD does not change the VR surface or the right ventricular CO curve. In six anesthetized dogs, we created LV failure by the coronary ligation of the left anterior descending artery and inserted LVAD by withdrawing blood from LV and pumping out to the femoral artery. We determined the parameters of the CO curve with a volume-change technique. We then changed the CO_LVAD stepwise from 0 to 70–100 ml/kg/min and predicted hemodynamics by using the proposed circulatory equilibrium. Predicted CO_TLV, P_RA, and P_LA for each step correlated well with those measured (SEE; 2.8 ml/kg/min 0.17 mmHg, and 0.65 mmHg, respectively, r²; 0.993, 0.993, and 0.965, respectively). The proposed framework quantitatively predicted the upward-shift of the total CO curve resulting from the synergistic effect of LV systolic function and LVAD support. The proposed framework can contribute to the safe management of patients with LVAD.

Mitochondrial CaMKII causes adverse metabolic reprogramming and dilated cardiomyopathy

Despite the clear association between myocardial injury, heart failure and depressed myocardial energetics, little is known about upstream signals responsible for remodeling myocardial metabolism after pathological stress. Here, we report increased mitochondrial calmodulin kinase II (CaMKII) activation and left ventricular dilation in mice one week after myocardial infarction (MI) surgery. By contrast, mice with genetic mitochondrial CaMKII inhibition are protected from left ventricular dilation and dysfunction after MI. Mice with myocardial and mitochondrial CaMKII overexpression (mtCaMKII) have severe dilated cardiomyopathy and decreased ATP that causes elevated cytoplasmic resting (diastolic) Ca2+ concentration and reduced mechanical performance. We map a metabolic pathway that rescues disease phenotypes in mtCaMKII mice, providing insights into physiological and pathological metabolic consequences of CaMKII signaling in mitochondria. Our findings suggest myocardial dilation, a disease phenotype lacking specific therapies, can be prevented by targeted replacement of mitochondrial creatine kinase or mitochondrial-targeted CaMKII inhibition.

Relationship of thyroid dysfunction with cardiovascular diseases: updated review on heart failure progression

Heart disease remains the leading cause of death globally. Heart failure (HF) is a clinical syndrome that results from impairment of the ability of the ventricle to fill with or eject blood. Over the past two decades, accumulated evidence has revealed the contribution of thyroid hormones to cardiovascular (CV) events, exerting their action through genomic and non-genomic pathways within the cardiomyocytes. The pivotal role of thyroid hormones in maintaining cardiac homeostasis has been observed in previous investigations which suggest that the CV system is adversely impacted by fluctuations in thyroid hormone levels, such as those that occur in hypothyroidism, hyperthyroidism, and low triiodothyronine syndrome (LT₃S). Thyroid dysfunction has direct effects on myocardial contractility, systolic and diastolic blood pressure, heart mass, heart rate, ejection fraction, and heart output, which may ultimately lead to HF. Recent clinical data have shown that thyroid hormone replacement therapy for hypothyroid patients appears to provide the potential for reducing CV events. Therefore, this review aims to address the impact of thyroid hormone dysfunction on pathophysiological mechanisms contributing to the development and progression of HF.

Sex differences in cardiovascular actions of the renin-angiotensin system

Cardiovascular disease (CVD) remains a worldwide public health concern despite decades of research and the availability of numerous targeted therapies. While the intrinsic physiological mechanisms regulating cardiovascular function are similar between males and females, marked sex differences have been established in terms of CVD onset, pathophysiology, manifestation, susceptibility, prevalence, treatment responses and outcomes in animal models and clinical populations. Premenopausal females are generally protected from CVD in comparison to men of similar age, with females tending to develop cardiovascular complications later in life following menopause. Emerging evidence suggests this cardioprotection in females is, in part, attributed to sex differences in hormonal regulators, such as the renin-angiotensin system (RAS). To date, research has largely focused on canonical RAS pathways and shown that premenopausal females are protected from cardiovascular derangements produced by activation of angiotensin II pathways. More recently, a vasodilatory arm of the RAS has emerged that is characterized by angiotensin-(1-7) [(Ang-(1-7)], angiotensin-converting enzyme 2 and Mas receptors. Emerging studies provide evidence for a shift towards these cardioprotective Ang-(1-7) pathways in females, with effects modulated by interactions with estrogen. Despite well-established sex differences, female comparison studies on cardiovascular outcomes are lacking at both the preclinical and clinical levels. Furthermore, there are no specific guidelines in place for the treatment of cardiovascular disease in men versus women, including therapies targeting the RAS. This review summarizes current knowledge on sex differences in the cardiovascular actions of the RAS, focusing on interactions with gonadal hormones, emerging data for protective Ang-(1-7) pathways and potential clinical implications for established and novel therapies.

Development of Cardiac Regenerative Medicine Using Human iPS Cell-derived Cardiomyocytes

Heart failure is a life-threatening disease prevalent worldwide. Cardiac transplantation is the last resort for patients with severe heart failure, but donor shortages represent a critical issue. Cardiac regenerative therapy is beneficial, but it is currently unsuitable as a substitute for cardiac transplantation. Human induced pluripotent stem cells (hiPSCs) are excellent sources for the generation of terminally differentiated cells. The preparation of a large number of pure cardiomyocytes (CMs) is the major premise for translational studies. To control the quality of the generated CMs, an efficient differentiation method, purification strategy, and mass-scale culture must be developed. Metabolic purification and large-scale culture systems have been established, and pure hiPSC-derived CMs of clinical grade are now available for translational research. The most critical challenge in cell therapy is the engraftment of transplanted cells. To overcome the low engraftment ratio of single CMs, aggregations of CMs are developed as cardiac spheroids. A cardiac transplantation device with domed tips and lateral holes has been developed for the transplantation of cardiac spheroids. Large animal models are necessary as the next step in the process toward clinical application. The transplant device has successfully been used to inject cardiac spheroids uniformly into myocardial layers in swine, and this approach is progressing toward clinical use. Remaining issues include immunological rejection and arrhythmia, which will require further investigation to establish safe and effective transplantation. This review summarizes the present status and future challenges of cardiac regenerative therapies.

Prognostic Value of Quantitative Metrics From Positron Emission Tomography in Ischemic Heart Failure

OBJECTIVES

The aim of this study was to investigate the prognostic and clinical value of quantitative positron emission tomographic (PET) metrics in patients with ischemic heart failure.

BACKGROUND

Although myocardial flow reserve (MFR) is a strong predictor of cardiac risk in patients without heart failure, it is unknown whether quantitative PET metrics improve risk stratification in patients with ischemic heart failure.

METHODS

The study included 254 patients referred for stress and rest myocardial perfusion imaging and viability testing using PET. Major adverse cardiac event(s) (MACE) consisted of death, resuscitated sudden cardiac death, heart transplantation, acute coronary syndrome, hospitalization for heart failure, and late revascularization.

RESULTS

MACE occurred in 170 patients (67%) during a median follow-up of 3.3 years. In a multivariate Cox proportional hazards model including multiple quantitative PET metrics, only MFR predicted MACE significantly (p = 0.013). Beyond age, symptom severity, diabetes mellitus, previous myocardial infarction or revascularization, 3-vessel disease, renal insufficiency, ejection fraction, as well as presence and burden of ischemia, scar, and hibernating myocardium, MFR was strongly associated with MACE (adjusted hazard ratio per increase in MFR by 1: 0.63; 95% confidence interval: 0.45 to 0.91). Incorporation of MFR into a risk assessment model incrementally improved the prediction of MACE (likelihood ratio chi-square test [16] = 48.61 vs. chi-square test [15] = 39.20; p = 0.002).

CONCLUSIONS

In this retrospective analysis of a single-center cohort, quantitative PET metrics of myocardial blood flow all improved risk stratification in patients with ischemic heart failure. However, in a hypothesis-generating analysis, MFR appears modestly superior to the other metrics as a prognostic index.

In Experimental Dilated Cardiomyopathy Heart Failure and Survival Are Adversely Affected by a Lack of Sexual Interactions

Nearly one in three people in the U.S. will develop heart failure (HF), characterized by fluid retention (edema) in the lungs and elsewhere. This leads to difficult breathing, deterioration of physical capacity, restriction of normal activities and death. There is little data about the safety and effects of sexual interactions in patients with HF. We tested whether a lack of sexual interactions affected pathophysiological outcomes in a pre-clinical mouse model of dilated cardiomyopathy that recapitulates the progressive stages of human HF. Male mice were randomly given access to, or deprived from, sexual interactions with female mice, which were confirmed by videography and generation of offspring. Cohousing with access to sexual interactions markedly prolonged survival, while cohousing without access to sexual activity did not. Sexual interactions improved systolic function, reduced HF-associated edema, altered transcription of heart contractile protein genes and decreased plasma testosterone levels. To determine whether testosterone levels contributed to survival, testosterone levels were experimentally reduced. Reduction of testosterone levels significantly prolonged survival. Taken together, in mice with dilated cardiomyopathy, sexual activity altered cardiac contractile gene transcription, improved systolic function, reduced edema and prolonged survival which may be in part due to lower testosterone levels.

Echocardiographic Diagnosis of Postcapillary Pulmonary Hypertension: A RIGHT1 Substudy

Background: Pulmonary hypertension is observed in 70% of patients with left ventricular (LV) dysfunction. Right heart catheterization is the gold standard for a complete evaluation of Pulmonary Hypertension (PH); however, echocardiography represents a powerful initial diagnostic tool. The aim of our study was to evaluate the accuracy of echocardiography for the diagnosis of postcapillary PH, i.e., due to increased left ventricular filling pressures. Methods and Results: We recruited patients with a diagnosis of PH from the RIGHT1 study (Right heart invasive and echocardiographic hemodynamic evaluation in Turin 1). Transthoracic echocardiography was performed within 60 min of cardiac catheterization. High LV filling pressures were defined by a pulmonary arterial wedge pressure (PAWP) greater than 15 mmHg. We assessed numerous morphological and functional features of LV, and their association with PAWP. 128 patients were diagnosed with PH. We observed a significant association between PAWP, the left atrial volume indexed by BSA (LAVi, R2 = 0.27; p < 0.0001) and the E/e’ ratio (R2 = 0.27; p < 0.0001). With these parameters, we implemented a diagnostic algorithm to identify high ventricular filling pressures in PH patients. The application of this algorithm could help identify patients with a diagnosis of postcapillary PH due to high ventricular filling pressures (E/E’ > 15). Conclusions: The echocardiographic parameters with the best association with PAWP in PH patients are E/e’ and LAVi. For these patients, our diagnostic algorithm could improve the diagnostic precision for the definition of subgroups.

Association between the number of hospital admissions and in-hospital outcomes in patients with heart failure

Readmission to the hospital is a major issue in clinical care for patients with heart failure (HF). However, the impact of the number of hospital admissions due to worsened HF is not fully understood. We sought to clarify the association between the number of hospital admissions due to worsened HF and patient outcomes. We studied 331,259 patients (median age was 81 years, and 175,286 patients (52.9%) were men) hospitalized for HF between January 2010 and March 2018 using the Japanese Diagnosis Procedure Combination Database, a national inpatient database. Patients were categorized into five groups based on the number of times they were admitted: once (n = 264,583), twice (n = 42,385), three times (n = 13,205), four times (n = 5347), and five or more times (n = 5739). The patients with larger numbers of admissions were more likely to have comorbidities and to use inotropic agents. The interval period between hospitalizations was shortened with an increasing number of hospital admissions, whereas the length of hospital stay was prolonged with an increasing number of hospital admissions. Multivariable logistic regression analysis fitted with a generalized estimating equation showed that an increased number of hospital admissions was independently associated with higher in-hospital mortality. In conclusion, readmission to the hospital due to worsened HF was still common, and in-hospital mortality was higher in those with larger numbers of readmissions, suggesting a clinical significance of the number of readmissions in patients with HF.

Manipulation of beta-adrenergic receptor in pressure-overloaded murine hearts mimics adverse and reverse cardiac remodeling

Transverse aortic constriction (TAC) has been widely used to create pressure overload induced heart failure in mice. However, this conventional model has some limitations such as low reproducibility and long creation period of cardiac failure. In order to establish a highly reproducible cardiac failure model that mimics adverse cardiac remodeling (ACR) we combined pressure overload and beta-adrenergic receptor stimuli using isoproterenol (ISO) and explored the optimal TAC model by changing the durations of TAC and the doses of ISO. Thus we constructed a suitable model for ACR with an effective combination of 3-week TAC and subsequent one-week ISO (3 mg/kg/day) infusion. Using RNA-Seq analyses, we identified that the up-regulated genes were mainly related to fibrosis including Fbn1, C1qtnf6 and Loxl2; and that the down-regulated genes were associated with mitochondrial function including Uqcrc1, Ndufs3, and Idh2 in failing hearts of our ACR model. Next, we followed the changes in cardiac function after ceasing ISO infusion. Left ventricular function gradually recovered after cessation of ISO, suggesting cardiac reverse remodeling (CRR). Gene expression signatures of hearts, which exhibited CRR, were almost identical to that of TAC hearts without ISO. In conclusion, our new model exhibits a transition to ACR and subsequent CRR with high reproducibility. This murine model might add new insights into the experiments of heart failure technically as well as scientifically.

Primary Prevention of Heart Failure in Women

The incidence of heart failure (HF) is increasing, particularly among women, and constitutes a rapidly growing public health problem. The primary prevention of HF in women should involve targeted, sex-specific strategies to increase awareness, promote a heart healthy lifestyle, and improve treatments that optimally control the risk factors for HF with reduced ejection fraction and HF with preserved ejection fraction. Epidemiological and pathophysiological differences in both HF subtypes strongly suggest that sex-specific preventive strategies and risk factor reduction may be particularly beneficial. However, significant gaps in sex-specific knowledge exist and are impeding preventive efforts. To overcome these limitations, women need to be adequately represented in HF research, sex differences must be prospectively investigated, and effective sex-specific interventions should be incorporated into clinical practice guidelines. This review summarizes the existing evidence that supports the primary prevention of HF in women and identifies potential strategies that are most likely to be effective in reducing the burden of HF among women.

Temporal trends and predictors of inhospital death in patients hospitalised for heart failure in Germany

AIMS

We investigated trends in incidence, case fatality rate, patient characteristics and adverse inhospital events of patients hospitalised for heart failure in Germany.

METHODS AND RESULTS

The German nationwide inpatient sample (2005-2016) was used for this analysis. Patients hospitalised due to heart failure were selected for analysis. Temporal trends in the incidence of hospitalisations, case fatality rate and treatments were analysed and predictors of inhospital death were identified. The analysis comprised a total number of 4,539,140 hospitalisations (52.0% women, 81.0% aged ≥70 years) due to heart failure. Although hospitalisations increased from 381 (2005) to 539 per 100,000 population (2016) (β estimate 0.06, 95% confidence interval (CI) 0.06 to 0.07, P < 0.001) in parallel with median age and prevalence of comorbidities, the inhospital case fatality rate decreased from 11.1% to 8.1% (β estimate -0.36, 95% CI -0.37 to -0.35, P < 0.001) and the rate of major adverse cardiovascular and cerebrovascular events (β estimate -0.24, 95% CI -0.25 to -0.23, P < 0.001) decreased from 12.7% to 10.3%. Age 70 years and older (odds ratio (OR) 2.60, 95% CI 2.57 to 2.63, P < 0.001) and cancer (OR 1.93, 95% CI 1.91 to 1.96, P < 0.001) were independent predictors of inhospital death.

CONCLUSION

Hospitalisations for heart failure increased in Germany from 2005 to 2016, whereas the major adverse cardiovascular and cerebrovascular event rate and inhospital case fatality rate decreased during this period despite higher patient age and increasing prevalence of comorbidities.

Heart failure patients with atrial fibrillation benefit from remote patient management: insights from the TIM-HF2 trial

Aims

Atrial fibrillation (AF) is a frequent comorbidity in patients with heart failure (HF). HF patients with AF are characterized by high morbidity and increased risk of hospitalizations. We assessed the effects of remote patient management (RPM) in HF patients with AF compared with usual care (UC) in the TIM‐HF2 trial.

Methods and results

For this post‐hoc analysis, AF status at randomization was assessed in 1537 patients with HF. The primary outcome was the percentage of days lost due to unplanned cardiovascular hospital admissions or death of any cause.

Around 966 patients had sinus rhythm (SR) and 571 had AF. The analysis showed a significant interaction between heart rhythm and all‐cause mortality (P for interaction = 0.001). AF patients had more days lost due to unplanned cardiovascular hospitalization than SR patients (7.53%, CI 6.01–9.05 vs. 4.90%, CI 3.98–5.82, ratio 1.54, P = 0.004) and higher all‐cause mortality (11.9%, CI 9.4–14.9 vs. 8.5%, CI 6.8–10.4, HR 0.66, CI 0.47–0.94, P = 0.029). Patients with AF randomized to RPM had significantly less days lost due to unplanned cardiovascular hospital admissions or all‐cause death (5.64%, CI 3.81–7.48) than patients with AF randomized to UC (9.37%, CI 6.98–11.76, ratio 0.60, P = 0.015). No difference was seen in SR patients (UC: 5.25%, CI 3.93–6.58, RPM: 4.55%, CI 3.27–5.83, ratio 0.87, P = 0.452). All‐cause mortality in AF patients was reduced with 9.2% (CI 6.1–13.2) in the RPM group compared with 14.5% (CI 10.7–18.1) in the UC group (HR 0.60, CI 0.36–1.00, P = 0.050).

Conclusions

For patients with atrial fibrillation at study entry, RPM was associated with increased days alive out of hospital. Our results identify HF patients with atrial fibrillation as a promising target population for RPM.

Characteristics of Acute Gout Flare in Patients Initiated on Intravenous Bumetanide for Acute Heart Failure Exacerbation

Background

Heart failure is a clinical syndrome with significant morbidity, mortality, and financial burden. These factors are magnified in patients with associated comorbidities. Therefore, addressing such conditions is critical in decreasing healthcare costs and improving patient outcomes.

Gout is a major comorbidity in patients with heart failure. Acute gout flares that occur in the context of acute heart failure exacerbations (AHFE) form an independent risk factor for increased readmissions or death. In this study, we characterized the frequency and outcomes of acute gout flares in patients treated with intravenous (IV) bumetanide for AHFE.

Methods

This single-center retrospective cohort study included 130 adult patients admitted in a tertiary-care hospital between August 2016 and June 2018. Chart review identified patients who were hospitalized for AHFE with International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code I50, received IV bumetanide, and developed an acute gout flare. Data were analyzed using the chi-square test for categorical variables and the two-sample t-test for continuous variables.

Results

The annualized frequency of acute gout while receiving IV bumetanide for AHFE was 7.17%. Chronic gout patients who were on colchicine and/or allopurinol while hospitalized were less likely to develop acute gout while receiving IV bumetanide for AHFE compared with those taking neither medication (p-value =0.002). There was no significant difference in length of stay or 30-day readmissions between those who developed acute gout and those who did not.

Conclusions

Acute gout flares occur with a notable frequency in patients hospitalized for AHFE who are administered IV bumetanide. It is important to continue patients’ outpatient gout regimens in an effort to mitigate acute gout flares during this time.

Sepsis With Preexisting Heart Failure: Management of Confounding Clinical Features

Preexisting heart failure (HF) in patients with sepsis is associated with worse clinical outcomes. Core sepsis management includes aggressive volume resuscitation followed by vasopressors (and potentially inotropes) if fluid is inadequate to restore perfusion; however, large fluid boluses and vasoactive agents are concerning amid the cardiac dysfunction of HF. This review summarizes evidence regarding the influence of HF on sepsis clinical outcomes, pathophysiologic concerns, resuscitation targets, hemodynamic interventions, and adjunct management (ie, antiarrhythmics, positive pressure ventilatory support, and renal replacement therapy) in patients with sepsis and preexisting HF. Patients with sepsis and preexisting HF receive less fluid during resuscitation; however, evidence suggests traditional fluid resuscitation targets do not increase the risk of adverse events in HF patients with sepsis and likely improve outcomes. Norepinephrine remains the most well-supported vasopressor for patients with sepsis with preexisting HF, while dopamine may induce more cardiac adverse events. Dobutamine should be used cautiously given its generally detrimental effects but may have an application when combined with norepinephrine in patients with low cardiac output. Management of chronic HF medications warrants careful consideration for continuation or discontinuation upon development of sepsis, and β-blockers may be appropriate to continue in the absence of acute hemodynamic decompensation. Optimal management of atrial fibrillation may include β-blockers after acute hemodynamic stabilization as they have also shown independent benefits in sepsis. Positive pressure ventilatory support and renal replacement must be carefully monitored for effects on cardiac function when HF is present.

Safety and efficacy of direct Cardiac Shockwave Therapy in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting (the CAST-HF trial): study protocol for a randomized controlled trial

BACKGROUND

Coronary artery diseases (CAD) remains a severe socio-economic burden in the Western world. Coronary obstruction and subsequent myocardial ischemia result in progressive replacement of contractile myocardium with dysfunctional, fibrotic scar tissue. Post-infarctional remodeling is causal for the concomitant decline of left-ventricular function and the fatal syndrome of heart failure. Available neurohumoral treatment strategies aim at the improvement of symptoms. Despite extensive research, therapeutic options for myocardial regeneration, including (stem)-cell therapy, gene therapy, cellular reprogramming or tissue engineering, remain purely experimental. Thus, there is an urgent clinical need for novel treatment options for inducing myocardial regeneration and improving left-ventricular function in ischemic cardiomyopathy. Shockwave Therapy (SWT) is a well-established regenerative tool that is effective for the treatment of chronic tendonitis, long-bone non-union and wound-healing disorders. In preclinical trials, SWT regenerated ischemic myocardium via the induction of angiogenesis and the reduction of fibrotic scar tissue, resulting in improved left-ventricular function.

METHODS/DESIGN

In this prospective, randomized controlled, single-blind, monocentric study, 80 patients with reduced left-ventricular ejection fraction (LVEF≤ 40%) are subjected to coronary-artery bypass-graft surgery (CABG) surgery and randomized in a 1:1 ratio to receive additional cardiac SWT (intervention group; 40 patients) or CABG surgery with sham treatment (control group; 40 patients). This study aims to evaluate (1) the safety and (2) the efficacy of cardiac SWT as adjunctive treatment during CABG surgery for the regeneration of ischemic myocardium. The primary endpoints of the study represent (1) major cardiac events and (2) changes in left-ventricular function 12 months after treatment. Secondary endpoints include 6-min Walk Test distance, improvement of symptoms and assessment of quality of life.

DISCUSSION

This study aims to investigate the safety and efficacy of cardiac SWT during CABG surgery for myocardial regeneration. The induction of angiogenesis, decrease of fibrotic scar tissue formation and, thus, improvement of left-ventricular function could lead to improved quality of life and prognosis for patients with ischemic heart failure. Thus, it could become the first clinically available treatment strategy for the regeneration of ischemic myocardium alleviating the socio-economic burden of heart failure.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03859466. Registered on 1 March 2019.

Quantification of DNA Damage in Different Tissues in Rats with Heart Failure

Background

Chronic heart failure (CHF) is a complex syndrome which comprises structural and functional alterations in the heart in maintaining the adequate blood demand to all tissues. Few investigations sought to evaluate oxidative DNA damage in CHF.

Objective

To quantify the DNA damage using the comet assay in left ventricle (LV), lungs, diaphragm, gastrocnemius and soleus in rats with CHF.

Methods

Twelve male Wistar rats (300 to 330 g) were selected for the study: Sham (n = 6) and CHF (n = 6). The animals underwent myocardial infarction by the ligation of the left coronary artery. After six weeks, the animals were euthanized. It was performed a cell suspension of the tissues. The comet assay was performed to evaluate single and double strand breaks in DNA. Significance level (p) considered < 0.05.

Results

The CHF group showed higher values of left ventricle end-diastolic pressure (LVEDP), pulmonary congestion, cardiac hypertrophy and lower values of maximal positive and negative derivatives of LV pressure, LV systolic pressure (p < 0.05). CHF group showed higher DNA damage (% tail DNA, tail moment and Olive tail moment) compared to Sham (p < 0.001). The tissue with the highest damage was the soleus, compared to LV and gastrocnemius in CHF group (p < 0.05).

Conclusion

Our results indicates that the CHF affects all tissues, both centrally and peripherically, being more affected in skeletal muscle (soleus) and is positively correlated with LV dysfunction.

Stimulating pro-reparative immune responses to prevent adverse cardiac remodelling: consensus document from the joint 2019 meeting of the ESC Working Groups of cellular biology of the heart and myocardial function

Cardiac injury may have multiple causes, including ischaemic, non-ischaemic, autoimmune, and infectious triggers. Independent of the underlying pathophysiology, cardiac tissue damage induces an inflammatory response to initiate repair processes. Immune cells are recruited to the heart to remove dead cardiomyocytes, which is essential for cardiac healing. Insufficient clearance of dying cardiomyocytes after myocardial infarction (MI) has been shown to promote unfavourable cardiac remodelling, which may result in heart failure (HF). Although immune cells are integral key players of cardiac healing, an unbalanced or unresolved immune reaction aggravates tissue damage that triggers maladaptive remodelling and HF. Neutrophils and macrophages are involved in both, inflammatory as well as reparative processes. Stimulating the resolution of cardiac inflammation seems to be an attractive therapeutic strategy to prevent adverse remodelling. Along with numerous experimental studies, the promising outcomes from recent clinical trials testing canakinumab or colchicine in patients with MI are boosting the interest in novel therapies targeting inflammation in cardiovascular disease patients. The aim of this review is to discuss recent experimental studies that provide new insights into the signalling pathways and local regulators within the cardiac microenvironment promoting the resolution of inflammation and tissue regeneration. We will cover ischaemia- and non-ischaemic-induced as well as infection-related cardiac remodelling and address potential targets to prevent adverse cardiac remodelling.

Cell-based therapies for the treatment of myocardial infarction: lessons from cardiac regeneration and repair mechanisms in non-human vertebrates

Ischemic cardiomyopathy is the cardiovascular condition with the highest impact on the Western population. In mammals (humans included), prolonged ischemia in the ventricular walls causes the death of cardiomyocytes (myocardial infarction, MI). The loss of myocardial mass is soon compensated by the formation of a reparative, non-contractile fibrotic scar that ultimately affects heart performance. Despite the enormous clinical relevance of MI, no effective therapy is available for the long-term treatment of this condition. Moreover, since the human heart is not able to undergo spontaneous regeneration, many researchers aim at designing cell-based therapies that allow for the substitution of dead cardiomyocytes by new, functional ones. So far, the majority of such strategies rely on the injection of different progenitor/stem cells to the infarcted heart. These cardiovascular progenitors, which are expected to differentiate into cardiomyocytes de novo, seldom give rise to new cardiac muscle. In this context, the most important challenge in the field is to fully disclose the molecular and cellular mechanisms that could promote active myocardial regeneration after cardiac damage. Accordingly, we suggest that such strategy should be inspired by the unique regenerative and reparative responses displayed by non-human animal models, from the restricted postnatal myocardial regeneration abilities of the murine heart to the full ventricular regeneration of some bony fishes (e.g., zebrafish). In this review article, we will discuss about current scientific approaches to study cardiac reparative and regenerative phenomena using animal models.

Asymptomatic hyperuricemia and incident congestive heart failure in elderly patients without comorbidities

BACKGROUND AND AIMS

Although hyperuricemia is associated with congestive heart failure (CHF), hyperuricemic patients frequently have other comorbidities. Thus, it is difficult to distinguish the role of hyperuricemia from that of other comorbid conditions in CHF. The aim of this study was to evaluate the association between hyperuricemia and CHF in elderly patients without comorbidities.

METHODS AND RESULTS

Subjects aged ≥65 years were analyzed at enrollment (2009-2012) and during the 4-year follow-up period at the Kangjian Community Health Center of Shanghai. Subjects were excluded if they had hypertension, diabetes mellitus, preexisting cardiovascular disease, hyperlipidemia, overweight or obesity, a history of gout or hyperuricemia and were taking medication for their condition, or chronic kidney disease. The primary outcome of this study was to investigate the impact of asymptomatic hyperuricemia on incident CHF. We used Cox regression to estimate the hazard ratio (HR) for incident CHF events between hyperuricemic (defined as an SUA level >7 mg/dL in men and ≥6 mg/dL in women) and normouricemic subjects. A total of 2749 subjects (70.9 ± 6.0 years) were followed for 47.4 ± 3.6 months. Asymptomatic hyperuricemia was associated with an increased cumulative incidence of incident CHF events (6.5% versus 3.1%, odds ratio [OR] = 2.15, 95% confidence index [CI]: 1.39-3.33, p = 0.001). After adjusting for confounding factors, including baseline eGFR, hyperuricemia independently predicted the risk of incident CHF events (HR = 2.34, 95% CI: 1.50-3.63, p < 0.001).

CONCLUSION

Asymptomatic hyperuricemia was a valuable biomarker for predicting the development of incident CHF in elderly patients without comorbidities.

High-mobility group box 1 fragment suppresses adverse post-infarction remodeling by recruiting PDGFRα-positive bone marrow cells

OBJECTIVES

High-mobility group box 1 protein (HMGB1) fragment enhances bone marrow-derived mesenchymal stem cell (BM-MSC) recruitment to damaged tissue to promote tissue regeneration. This study aimed to evaluate whether systemic injection of HMGB1 fragment could promote tissue repair in a rat model of myocardial infarction (MI).

METHODS

HMGB1 (n = 14) or phosphate buffered saline (n = 12, control) was administered to MI rats for 4 days. Cardiac performance and left ventricular remodeling were evaluated using ultrasonography and immunostaining. BM-MSC recruitment to damaged tissue in green fluorescent protein-bone marrow transplantation (GFP-BMT) models was evaluated using immunostaining.

RESULTS

At four weeks post-treatment, the left ventricular ejection fraction was significantly improved in the HMGB1 group compared to that in the control. Interstitial fibrosis and cardiomyocyte hypertrophy were also significantly attenuated in the HMGB1 group compared to the control. In the peri-infarction area, VEGF-A mRNA expression was significantly higher and TGFβ expression was significantly attenuated in the HMGB1 group than in the control. In GFP-BMT rats, GFP+/PDGFRα+ cells were significantly mobilized to the peri-infarction area in the HMGB1 group compared to that in the control, leading to the formation of new vasculature. In addition, intravital imaging revealed that more GFP+/PDGFRα+ cells were recruited to the peri-infarction area in the HMGB1 group than in the control 12 h after treatment.

CONCLUSIONS

Systemic administration of HMGB1 induced angiogenesis and reduced fibrosis by recruiting PDGFRα+ mesenchymal cells from the bone marrow, suggesting that HMGB1 administration might be a new therapeutic approach for heart failure after MI.

A high-content, in vitro cardiac fibrosis assay for high-throughput, phenotypic identification of compounds with anti-fibrotic activity

A key feature in the pathogenesis of heart failure is cardiac fibrosis, but effective treatments that specifically target cardiac fibrosis are currently not available. A major impediment to progress has been the lack of reliable in vitro models with sufficient throughput to screen for activity against cardiac fibrosis. Here, we established cell culture conditions in micro-well format that support extracellular deposition of mature collagen from primary human cardiac fibroblasts - a hallmark of cardiac fibrosis. Based on robust biochemical characterization we developed a high-content phenotypic screening platform, that allows for high-throughput identification of compounds with activity against cardiac fibrosis. Our platform correctly identifies compounds acting on known cardiac fibrosis pathways. Moreover, it can detect anti-fibrotic activity for compounds acting on targets that have not previously been reported in in vitro cardiac fibrosis assays. Taken together, our experimental approach provides a powerful platform for high-throughput screening of anti-fibrotic compounds as well as discovery of novel targets to develop new therapeutic strategies for heart failure.

Back to Basics: Key Physical Examinations and Theories in Patients with Heart Failure

Heart failure (HF) is a leading cause of hospitalization. Suitable pharmacologic management is critical. Distinct physical findings such as congestion and peripheral hypoperfusion need to be considered in selecting pharmacologic therapy. By applying the pretest probability and likelihood ratios of unique physical findings of HF to a Markov model, a definite posttest probability can be obtained. This article focuses on the findings of S3, jugular venous pressure, proportional pulse pressure, bendopnea, trepopnea, and various heart murmurs. Incorporating statistical precision in physical assessments, diagnoses of HF can be further refined, providing a sophisticated approach to evaluate patients hemodynamics status noninvasively.

Selective targeting of ubiquitination and degradation of PARP1 by E3 ubiquitin ligase WWP2 regulates isoproterenol-induced cardiac remodeling

The elevated expression of poly(ADP-ribose) polymerase-1 (PARP1) and increased PARP1 activity, namely, poly(ADP-ribosyl)ation (PARylation), have been observed in cardiac remodeling, leading to extreme energy consumption and myocardial damage. However, the mechanisms underlying the regulation of PARP1 require further study. WWP2, a HECT-type E3 ubiquitin ligase, is highly expressed in the heart, but its function there is largely unknown. Here, we clarified the role of WWP2 in the regulation of PARP1 and the impact of this regulatory process on cardiac remodeling. We determined that the knockout of WWP2 specifically in myocardium decreased the level of PARP1 ubiquitination and increased the effects of isoproterenol (ISO)-induced PARP1 and PARylation, in turn aggravating ISO-induced myocardial hypertrophy, heart failure, and myocardial fibrosis. Similar findings were obtained in a model of ISO-induced H9c2 cells with WWP2 knockdown, while the reexpression of WWP2 significantly increased PARP1 ubiquitination and decreased PAPR1 and PARylation levels. Mechanistically, coimmunoprecipitation results identified that WWP2 is a novel interacting protein of PARP1 and mainly interacts with its BRCT domain, thus mediating the degradation of PARP1 through the ubiquitin-proteasome system. In addition, lysine 418 (K418) and lysine 249 (K249) were shown to be of critical importance in regulating PARP1 ubiquitination and degradation by WWP2. These findings reveal a novel WWP2-PARP1 signal transduction pathway involved in controlling cardiac remodeling and may provide a basis for exploring new strategies for treating heart disorders related to cardiac remodeling.

Collagen biomaterial for the treatment of myocardial infarction: an update on cardiac tissue engineering and myocardial regeneration

Myocardial infarction (MI) remains one of the leading cause of mortality over the world. However, current treatments are more palliative than curative, which only stall the progression of the disease, but not reverse the disease. While stem cells or bioactive molecules therapy is promising, the limited survival and engraftment of bioactive agent due to a hostile environment is a bottleneck for MI treatment. In order to maximize the utility of stem cells and bioactive molecules for myocardial repair and regeneration, various types of biomaterials have been developed. Among them, collagen-based biomaterial is widely utilized for cardiac tissue engineering and regeneration due to its optimal physical and chemical properties. In this review, we summarize the properties of collagen-based biomaterial. Then, we discuss collagen-based biomaterial currently being applied to treat MI alone, or together with stem cells and/or bioactive molecules. Finally, the delivery system of collagen-based biomaterial will also be discussed.

Chemokines profile in patients with chronic heart failure treated with cardiac resynchronization therapy

PURPOSE

Inflammatory mechanisms have been suggested to play a role in the heart failure with reduced ejection fraction (HF-REF) development, but the role of chemokines is largely unknown. Cardiac resynchronization therapy (CRT) may reverse the HF-REF course. We aimed to evaluate selected chemokines concentrations in HF-REF patients and their relationship with disease severity and clinical response to CRT.

MATERIALS AND METHODS

The study included 37 patients (64.1 ± 11.04 years, 6 females) with HF-REF subjected to CRT, controlled prior to implantation and after 6 months. The control population included 26 healthy volunteers (63.9 ± 8.1 years, 8 females). Serum chemokines concentrations were determined using multiplex method.

RESULTS

HF-REF patients were characterized by the higher baseline MIF, NAP-2 and PF4 concentrations and lower Axl, BTC, IL-9, and IL-18 BPa concentrations comparing to controls. After 6 months of CRT only NAP-2 concentration decreased significantly in comparison to the baseline values.

CONCLUSIONS

HF-REF patients present altered chemokines profile compared to the control group. The CRT-related alleviation of HF-REF causes only slight changes in the chemokines concentrations especially in the platelet-associated ones. The precise chemokines role in the HF-REF pathogenesis and their prognostic value remains to be established.

The (pro)renin receptor in health and disease

The (pro)renin receptor ((P)RR) was first identified as a single-transmembrane receptor in human kidneys and initially attracted attention owing to its potential role as a regulator of the tissue renin-angiotensin system (RAS). Subsequent studies found that the (P)RR is widely distributed in organs throughout the body, including the kidneys, heart, brain, eyes, placenta and the immune system, and has multifaceted functions in vivo. The (P)RR has roles in various physiological processes, such as the cell cycle, autophagy, acid-base balance, energy metabolism, embryonic development, T cell homeostasis, water balance, blood pressure regulation, cardiac remodelling and maintenance of podocyte structure. These roles of the (P)RR are mediated by its effects on important biological systems and pathways including the tissue RAS, vacuolar H⁺-ATPase, Wnt, partitioning defective homologue (Par) and tyrosine phosphorylation. In addition, the (P)RR has been reported to contribute to the pathogenesis of diseases such as fibrosis, hypertension, pre-eclampsia, diabetic microangiopathy, acute kidney injury, cardiovascular disease, cancer and obesity. Current evidence suggests that the (P)RR has key roles in the normal development and maintenance of vital organs and that dysfunction of the (P)RR is associated with diseases that are characterized by a disruption of the homeostasis of physiological functions.

Biomechanics of infarcted left Ventricle-A review of experiments

Myocardial infarction (MI) is one of leading diseases to contribute to annual death rate of 5% in the world. In the past decades, significant work has been devoted to this subject. Biomechanics of infarcted left ventricle (LV) is associated with MI diagnosis, understanding of remodelling, MI micro-structure and biomechanical property characterizations as well as MI therapy design and optimization, but the subject has not been reviewed presently. In the article, biomechanics of infarcted LV was reviewed in terms of experiments achieved in the subject so far. The concerned content includes experimental remodelling, kinematics and kinetics of infarcted LVs. A few important issues were discussed and several essential topics that need to be investigated further were summarized. Microstructure of MI tissue should be observed even carefully and compared between different methods for producing MI scar in the same animal model, and eventually correlated to passive biomechanical property by establishing innovative constitutive laws. More uniaxial or biaxial tensile tests are desirable on MI, border and remote tissues, and viscoelastic property identification should be performed in various time scales. Active contraction experiments on LV wall with MI should be conducted to clarify impaired LV pumping function and supply necessary data to the function modelling. Pressure-volume curves of LV with MI during diastole and systole for the human are also desirable to propose and validate constitutive laws for LV walls with MI.