Drugs for left ventricular remodeling in heart failure

Mathematical modelling of the influence of ACE I/D polymorphism on blood pressure and antihypertensive therapy

The angiotensin-converting enzyme (ACE) gene (ACE) insertion/deletion (I/D) polymorphism raises the possibility of personalising ACE inhibitor therapy to optimise its efficiency and reduce side effects in genetically distinct subgroups. However, the extent of its influence among these subgroups is unknown. Therefore, we extended our computational model of blood pressure regulation to investigate the effect of the ACE I/D polymorphism on haemodynamic parameters in humans undergoing antihypertensive therapy. The model showed that the dependence of blood pressure on serum ACE activity is a function of saturation and therefore, the lack of association between ACE I/D and blood pressure levels may be due to high ACE activity in specific populations. Additionally, in an extended model simulating the effects of different classes of antihypertensive drugs, we explored the relationship between ACE I/D and the efficacy of inhibitors of the renin-angiotensin-aldosterone system. The model predicted that the response of cardiovascular and renal parameters to treatment directly depends on ACE activity. However, significant differences in parameter changes were observed only between groups with high and low ACE levels, while different ACE I/D genotypes within the same group had similar changes in absolute values. We conclude that a single genetic variant is responsible for only a small fraction of heredity in treatment success and its predictive value is limited.

Electrocardiographic predictors of response to sacubitril/valsartan therapy in heart failure with reduced ejection fraction

BACKGROUND

Sacubitril/valsartan (SV) is currently recommended as a first-line therapy in patients with heart failure and reduced ejection fraction (HFrEF) due to its significant clinical and prognostic benefit; however, not all patients respond to therapy and predictors of clinical response to SV remain under-studied.

AIMS

To identify electrocardiographic (ECG) predictors of response to SV therapy in HFrEF patients.

METHODS

A retrospective analysis of a hospital heart failure registry was undertaken. Consecutive HFrEF patients (New York Heart Association class II-III) on maximal-dose SV were studied. Response to SV was defined as ≥10% relative improvement in left ventricular ejection fraction (LVEF) at 3-months post-maximal-dose therapy. Pre-therapy ECGs were retrospectively analyzed for axes and standard wave and interval durations. Logistic regression was used to estimate odds ratios and 95% confidence intervals for associations between predictors and therapeutic response. Backward stepwise regression was employed to develop a parsimonious model.

RESULTS

P-wave duration (PWD) 100-120 ms, PWD >120 ms, and QTc >460 ms were associated with response to SV on univariate analysis: OR 18.00 (4.45-122.90), 5.00 (1.47-20.42), and 3.10 (1.18-9.22), respectively. The preferred model that included the former two predictors in combination with pre-therapy creatinine, mineralocorticoid receptor antagonist use, and LVEF was highly selective (area under the ROC curve = 0.868).

CONCLUSIONS

Prolongation of both PWD and QTc interval on baseline ECG in HFrEF patients is predictive of therapeutic response to maximal-dose SV therapy and may indicate early cardiac remodeling that is highly amenable to reversal.

MicroRNA-30d-5p-A Potential New Therapeutic Target for Prevention of Ischemic Cardiomyopathy after Myocardial Infarction

(1) Background and Objective: MicroRNAs (miRs) are biomarkers for assessing the extent of cardiac remodeling after myocardial infarction (MI) and important predictors of clinical outcome in heart failure. Overexpression of miR-30d-5p appears to have a cardioprotective effect. The aim of the present study was to demonstrate whether miR-30d-5p could be used as a potential therapeutic target to improve post-MI adverse remodeling. (2) Methods and Results: MiR profiling was performed by next-generation sequencing to assess different expression patterns in ischemic vs. healthy myocardium in a rat model of MI. MiR-30d-5p was significantly downregulated (p < 0.001) in ischemic myocardium and was selected as a promising target. A mimic of miR-30d-5p was administered in the treatment group, whereas the control group received non-functional, scrambled siRNA. To measure the effect of miR-30d-5p on infarct area size of the left ventricle, the rats were randomized and treated with miR-30d-5p or scrambled siRNA. Histological planimetry was performed 72 h and 6 weeks after induction of MI. Infarct area was significantly reduced at 72 h and at 6 weeks by using miR-30d-5p (72 h: 22.89 ± 7.66% vs. 35.96 ± 9.27%, p = 0.0136; 6 weeks: 6.93 ± 4.58% vs. 12.48 ± 7.09%, p = 0.0172). To gain insight into infarct healing, scratch assays were used to obtain information on cell migration in human umbilical vein endothelial cells (HUVECs). Gap closure was significantly faster in the mimic-treated cells 20 h post-scratching (12.4% more than the scrambled control after 20 h; p = 0.013). To analyze the anti-apoptotic quality of miR-30d-5p, the ratio between phosphorylated p53 and total p53 was evaluated in human cardiomyocytes using ELISA. Under the influence of the miR-30d-5p mimic, cardiomyocytes demonstrated a decreased pp53/total p53 ratio (0.66 ± 0.08 vs. 0.81 ± 0.17), showing a distinct tendency (p = 0.055) to decrease the apoptosis rate compared to the control group. (3) Conclusion: Using a mimic of miR-30d-5p underlines the cardioprotective effect of miR-30d-5p in MI and could reduce the risk for development of ischemic cardiomyopathy.

Comparative Efficacy of Different Drugs for the Treatment of Dilated Cardiomyopathy: A Systematic Review and Network Meta-analysis

BACKGROUND AND OBJECTIVE

At present, the therapies of dilated cardiomyopathy concentrated on the symptoms of heart failure and related complications. The study is to evaluate the clinical efficacy of a combination of various conventional and adjuvant drugs in treating dilated cardiomyopathy via network meta-analysis.

METHODS

The study was reported according to the PRISMA 2020 statement. From inception through 27 June 2022, the PubMed, Embase, Cochrane library, and Web of Science databases were searched for randomized controlled trials on medicines for treating dilated cardiomyopathy. The quality of the included studies was evaluated according to the Cochrane risk of bias assessment. R4.1.3 and Revman5.3 software were used for analysis.

RESULTS

There were 52 randomized controlled trials in this study, with a total of 25 medications and a sample size of 3048 cases. The network meta-analysis found that carvedilol, verapamil, and trimetazidine were the top three medicines for improving left ventricular ejection fraction (LVEF). Ivabradine, bucindolol, and verapamil were the top 3 drugs for improving left ventricular end-diastolic dimension (LVEDD). Ivabradine, L-thyroxine, and atorvastatin were the top 3 drugs for improving left ventricular end-systolic dimension (LVESD). Trimetazidine, pentoxifylline, and bucindolol were the top 3 drugs for improving the New York Heart Association classification (NYHA) cardiac function score. Ivabradine, carvedilol, and bucindolol were the top 3 drugs for reducing heart rate (HR).

CONCLUSION

A combination of different medications and conventional therapy may increase the clinical effectiveness of treating dilated cardiomyopathy. Beta-blockers, especially carvedilol, can improve ventricular remodeling, cardiac function, and clinical efficacy in patients with dilated cardiomyopathy (DCM). Hence, they can be used if patients tolerate them. If LVEF and HR do not meet the standard, ivabradine can also be used in combination with other treatments. However, since the quality and number of studies in our research were limited, large sample size, multi-center, and high-quality randomized controlled trials are required to corroborate our findings.

Three-dimensional echocardiographic assessment of left ventricular geometric changes following acute myocardial infarction

Acute ST-segment elevation myocardial infarction (STEMI) is associated with left ventricular (LV) structural and functional consequences. We aimed to elucidate LV geometric changes following STEMI using three-dimensional (3D) echocardiography (3DE) and to assess their functional implications using two-dimensional (2D) speckle tracking echocardiography (STE). The study included 71 patients with STEMI who underwent baseline and 6-month follow-up 2D- and 3DE. Measured parameters included LV dimensions, biplane volumes, wall motion assessment, 2D LV global longitudinal strain (GLS), and 3D LV volumes, sphericity index and systolic dyssynchrony index. According to 3DE, LV geometric changes were classified as, adverse remodeling, reverse remodeling, and minimal LV volumetric changes. The occurrence of in-hospital and follow-up major adverse cardiovascular events (MACE) was assessed among the study population. The incidence of developing adverse remodeling was 25.4% while that of reverse remodeling was 36.6%. Adverse remodeling patients had significantly higher in-hospital MACE. Reverse remodeling was associated with significantly improved GLS, that was less evident in those with minimal LV geometric changes, and non-significant improvement for adverse remodeling group. LV baseline 2D GLS significantly correlated with follow-up 3D volumes among both reverse and adverse remodeling groups. Female gender and higher absolute GLS change upon follow-up were significantly associated with reverse remodeling. ROC-derived cutoff for adverse remodeling reallocated a substantial number of patients from the minimal change group to the adverse remodeling. Following acute STEMI, two-dimensional GLS was associated with and potentially predictive of changes in LV volumes as detected by three-dimensional echocardiography.

Reviewing the Modern Therapeutical Options and the Outcomes of Sacubitril/Valsartan in Heart Failure

Sacubitril/valsartan (S/V) is a pharmaceutical strategy that increases natriuretic peptide levels by inhibiting neprilysin and regulating the renin-angiotensin-aldosterone pathway, blocking AT1 receptors. The data for this innovative medication are mainly based on the PARADIGM-HF study, which included heart failure with reduced ejection fraction (HFrEF)-diagnosed patients and indicated a major improvement in morbidity and mortality when S/V is administrated compared to enalapril. A large part of the observed favorable results is related to significant reverse cardiac remodeling confirmed in two prospective trials, PROVE-HF and EVALUATE-HF. Furthermore, according to a subgroup analysis from the PARAGON-HF research, S/V shows benefits in HFrEF and in many subjects having preserved ejection fraction (HFpEF), which indicated a decrease in HF hospitalizations among those with a left ventricular ejection fraction (LVEF) < 57%. This review examines the proven benefits of S/V and highlights continuing research in treating individuals with varied HF characteristics. The article analyses published data regarding both the safeness and efficacy of S/V in patients with HF, including decreases in mortality and hospitalization, increased quality of life, and reversible heart remodeling. These benefits led to the HF guidelines recommendations updating and inclusion of S/V combinations a key component of HFrEF treatment.

Role of Phospholipase C in Catecholamine-induced Increase in Myocardial Protein Synthesis

The activation of the α1-adrenoceptor-(α1-AR) by norepinephrine results in the G-protein (Gqα) mediated increase in the phosphoinositide-specific phospholipase C (PLC) activity. The byproducts of PLC hydrolytic activity, namely, 1,2-diacylglycerol and inositol-1,4,5-trisphosphate, are important downstream signal transducers for increased protein synthesis in the cardiomyocyte and the subsequent hypertrophic response. In this article, evidence is outlined to demonstrate the role of cardiomyocyte PLC isozymes in the catecholamine-induced increase in protein synthesis by using a blocker of α1-AR and an inhibitor of PLC. The discussion will be focused on the α1-AR-Gqα-PLC-mediated hypertrophic signaling pathway from the viewpoint that it may compliment the other β1-AR-Gs protein-adenylyl cyclase signal transduction mechanisms in the early stages of cardiac hypertrophy development, but may become more relevant at the late stage of cardiac hypertrophy. From the information provided here, it is suggested that some specific PLC isozymes may potentially serve as important targets for the attenuation of cardiac hypertrophy in the vulnerable patient population at-risk for heart failure.

Clinical Determinants and Prognosis of Left Ventricular Reverse Remodelling in Non-Ischemic Dilated Cardiomyopathy

Aims: Non-ischaemic dilated cardiomyopathy (NIDCM) is characterized by left ventricular (LV) chamber enlargement and systolic dysfunction in the absence of coronary artery disease. Left ventricular reverse remodelling (LVRR) is the ability of a dilated ventricle to restore its normal size, shape and function. We sought to determine the frequency, clinical predictors and prognostic implications of LVRR, in a cohort of heart failure (HF) patients with NIDCM. Methods: We conducted a multicentre observational, retrospective cohort study of patients with NIDCM, with prospective serial echocardiography evaluations. LVRR was defined as an increase of ≥15% in left ventricular ejection fraction (LVEF) or as a LVEF increase ≥ 10% plus reduction of LV end-systolic diameter index ≥ 20%. We used multivariable logistic regression analyses to identify the baseline clinical predictors of LVRR and evaluate the prognostic impact of LVRR. Results: LVRR was achieved in 42.5% of 527 patients with NIDCM during the first year of follow-up (median LVEF 49%, median change +22%), Alcoholic aetiology, HF duration, baseline LVEF and the absence of LBBB (plus NT-proBNP levels when in the model), were the strongest predictors of LVRR. During a median follow-up of 47 months, 134 patients died (25.4%) and 7 patients (1.3%) received a heart transplant. Patients with LVRR presented better outcomes, regardless of other clinical conditions. Conclusions: In patients with NIDCM, LVRR was frequent and was associated with improved prognosis. Major clinical predictors of LVRR were alcoholic cardiomyopathy, absence of LBBB, shorter HF duration, and lower baseline LVEF and NT-proBNP levels. Our study advocates for clinical phenotyping of non-ischaemic dilated cardiomyopathy and intense gold-standard treatment optimization of patients according to current guidelines and recommendations in specialized HF units.

Mechanisms for the development of heart failure and improvement of cardiac function by angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme (ACE) inhibitors, which prevent the conversion of angiotensin I to angiotensin II, are well-known for the treatments of cardiovascular diseases, such as heart failure, hypertension and acute coronary syndrome. Several of these inhibitors including captopril, enalapril, ramipril, zofenopril and imidapril attenuate vasoconstriction, cardiac hypertrophy and adverse cardiac remodeling, improve clinical outcomes in patients with cardiac dysfunction and decrease mortality. Extensive experimental and clinical research over the past 35 years has revealed that the beneficial effects of ACE inhibitors in heart failure are associated with full or partial prevention of adverse cardiac remodeling. Since cardiac function is mainly determined by coordinated activities of different subcellular organelles, including sarcolemma, sarcoplasmic reticulum, mitochondria and myofibrils, for regulating the intracellular concentration of Ca2+ and myocardial metabolism, there is ample evidence to suggest that adverse cardiac remodelling and cardiac dysfunction in the failing heart are the consequence of subcellular defects. In fact, the improvement of cardiac function by different ACE inhibitors has been demonstrated to be related to the attenuation of abnormalities in subcellular organelles for Ca2+-handling, metabolic alterations, signal transduction defects and gene expression changes in failing cardiomyocytes. Various ACE inhibitors have also been shown to delay the progression of heart failure by reducing the formation of angiotensin II, the development of oxidative stress, the level of inflammatory cytokines and the occurrence of subcellular defects. These observations support the view that ACE inhibitors improve cardiac function in the failing heart by multiple mechanisms including the reduction of oxidative stress, myocardial inflammation and Ca2+-handling abnormalities in cardiomyocytes.

Association of donor hypertension and outcomes in orthotopic heart transplantation

The present study examined the impact of donor hypertension on recipient survival and offer acceptance practices in the United States. This was a retrospective study of all patients undergoing OHT from 1995 to 2019 using the United Network for Organ Sharing and Potential Transplant Recipient file databases. Hypertensive donors were stratified by Short (0-5 years) and Prolonged (> 5 years) hypertension. Multivariable logistic regression was used to analyze offer acceptance practices while Cox proportional-hazards models were used to compare mortality across groups. Of 38,338 heart transplants meeting study criteria, 5662 were procured from hypertensive donors (69% Short and 31% Prolonged). After adjustment, Prolonged donor hypertension was associated with increased mortality (hazard ratio, HR, 1.31, 95% confidence interval, CI, 1.04-1.64), while recipients of Short donors experienced no decrement in post-transplant survival. Both Short and Prolonged hypertension were independently associated with decreased odds of offer acceptance (odds ratio, OR .92 95%CI: .88-.96 and OR .93 95%CI: .88-.99, respectively). While prolonged untreated hypertension in OHT donors is associated with a slight decrement in recipient survival, donors with ≤5 years of hypertension yielded similar outcomes. Donor hypertension was associated with reduced organ offer acceptance, highlighting a potential source of organ underutilization.

Exploring the mechanisms of action of gliflozines in heart failure and possible implications in pulmonary hypertension

Although results from two major trials trials have shown a clear benefit of gliflozines in the management of heart failure (HF) irrespective of diabetes status, the mechanism of cardiac benefits remains incompletely understood. Gliflozines have an osmotic diuretic effect that differs from that of other diuretic classes, resulting in greater electrolyte-free water clearance, and clinical studies have shown that intravascular volume depletion is rare and occurs at similar frequency in the gliflozines and placebo groups. As a consequence of the negligible effects on the blood volume and body's fluid balance compared to diuretics, gliflozines may limit the reflex neurohumoral stimulation and activation of renin-angiotensin-aldosterone system (RAAS). Since neurohormonal and RAAS activation in patients with HF reduced or ejection fraction (HFrEF and HFpEF) also leads to systemic and pulmonary arterial stiffening, pulmonary hypertension (PH) and PH-related right ventricular failure, gliflozines may lead to a mitigation of systemic and pulmonary arterial stiffening, which in turn can reduce the degree of PH associated with HFrEF or HFpEF, can improve the ventricular arterial coupling and can reduce the overload of the left and right ventricle, improving their function. The current review discusses the latest findings regarding the effects of SGLT2 inhibitors on heart failure with focus also on pulmonary hypertension, discussing the molecular mechanisms involved.

Plasma Concentrations of Extracellular Vesicles Are Decreased in Patients with Post-Infarct Cardiac Remodelling

Simple Summary

A heart attack may lead to the remodelling of the cardiac muscle, which negatively affects patient’s prognosis. At present, the mechanisms of cardiac remodelling remain unclear. In patients with heart attack, many body cells become activated and release small particles, called extracellular vesicles, which can either aggravate cardiac injury, or contribute to healing of heart muscle. In our study, we hypothesized that the concentrations of these small particles in plasma allow to determine which patients will experience remodelling of the cardiac muscle after the heart attach. We found that concentrations of extracellular vesicles from endothelial cells, erythrocytes and platelets, measured directly the heart attack, were lower in patients who developed cardiac remodelling 6 months later, compared to patients who had no remodelling. Vesicles from endothelial cells and erythrocytes allowed to determine remodelling independently of other clinical features. Hence, decreased concentrations of these vesicles may on one hand be a sign of inappropriate cardiac repair mechanisms, and on the other hand may allow to identify patients, who will develop cardiac remodelling after the heart attack.

Abstract

Background, the mechanisms underlying left ventricular remodelling (LVR) after acute myocardial infarction (AMI) remain obscure. In the course of AMI, blood cells and endothelial cells release extracellular vesicles (EVs). We hypothesized that changes in EV concentrations after AMI may underlie LVR. Methods, plasma concentrations of EVs from endothelial cells (CD146+), erythrocytes (CD235a+), leukocytes (CD45+), platelets (CD61+), activated platelets (P-selectin+), and EVs exposing phosphatidylserine after AMI were determined by flow cytometry in 55 patients with the first AMI. LVR was defined as an increase in left ventricular end-diastolic volume by 20% at 6 months after AMI, compared to baseline. Results, baseline concentrations of EVs from endothelial cells, erythrocytes and platelets were lower in patients who developed LVR (p ≤ 0.02 for all). Concentrations of EVs from endothelial cells and erythrocytes were independent LVR predictors (OR 8.2, CI 1.3–54.2 and OR 17.8, CI 2.3–138.6, respectively) in multivariate analysis. Combining the three EV subtypes allowed to predict LVR with 83% sensitivity and 87% specificity. Conclusions, decreased plasma concentrations of EVs from endothelial cells, erythrocytes and platelets predict LVR after AMI. Since EV release EVs contributes to cellular homeostasis by waste removal, decreased concentrations of EVs may indicate dysfunctional cardiac homeostasis after AMI, thus promoting LVR.

Epigenetic gene expression links heart failure to memory impairment

In current clinical practice, care of diseased patients is often restricted to separated disciplines. However, such an organ-centered approach is not always suitable. For example, cognitive dysfunction is a severe burden in heart failure patients. Moreover, these patients have an increased risk for age-associated dementias. The underlying molecular mechanisms are presently unknown, and thus, corresponding therapeutic strategies to improve cognition in heart failure patients are missing. Using mice as model organisms, we show that heart failure leads to specific changes in hippocampal gene expression, a brain region intimately linked to cognition. These changes reflect increased cellular stress pathways which eventually lead to loss of neuronal euchromatin and reduced expression of a hippocampal gene cluster essential for cognition. Consequently, mice suffering from heart failure exhibit impaired memory function. These pathological changes are ameliorated via the administration of a drug that promotes neuronal euchromatin formation. Our study provides first insight to the molecular processes by which heart failure contributes to neuronal dysfunction and point to novel therapeutic avenues to treat cognitive defects in heart failure patients.

Molecular imaging in nuclear cardiology: Pathways to individual precision medicine

Growth of molecular imaging bears potential to transform nuclear cardiology from a primarily diagnostic method to a precision medicine tool. Molecular targets amenable for imaging and therapeutic intervention are particularly promising to facilitate risk stratification, patient selection and exquisite guidance of novel therapies, and interrogation of systems-based interorgan communication. Non-invasive visualization of pathobiology provides valuable insights into the progression of disease and response to treatment. Specifically, inflammation, fibrosis, and neurohormonal signaling, central to the progression of cardiovascular disease and emerging therapeutic strategies, have been investigated by molecular imaging. As the number of radioligands grows, careful investigation of the binding properties and added-value of imaging should be prioritized to identify high-potential probes and facilitate translation to clinical applications. In this review, we discuss the current state of molecular imaging in cardiovascular medicine, and the challenges and opportunities ahead for cardiovascular molecular imaging to navigate the path from diagnosis to prognosis to personalized medicine.

Pathogenesis and pathophysiology of heart failure with reduced ejection fraction: translation to human studies

Heart failure represents the end result of different pathophysiologic processes, which culminate in functional impairment. Regardless of its aetiology, the presentation of heart failure usually involves symptoms of pump failure and congestion, which forms the basis for clinical diagnosis. Pathophysiologic descriptions of heart failure with reduced ejection fraction (HFrEF) are being established. Most commonly, HFrEF is centred on a reactive model where a significant initial insult leads to reduced cardiac output, further triggering a cascade of maladaptive processes. Predisposing factors include myocardial injury of any cause, chronically abnormal loading due to hypertension, valvular disease, or tachyarrhythmias. The pathophysiologic processes behind remodelling in heart failure are complex and reflect systemic neurohormonal activation, peripheral vascular effects and localised changes affecting the cardiac substrate. These abnormalities have been the subject of intense research. Much of the translational successes in HFrEF have come from targeting neurohormonal responses to reduced cardiac output, with blockade of the renin-angiotensin-aldosterone system (RAAS) and beta-adrenergic blockade being particularly fruitful. However, mortality and morbidity associated with heart failure remains high. Although systemic neurohormonal blockade slows disease progression, localised ventricular remodelling still adversely affects contractile function. Novel therapy targeted at improving cardiac contractile mechanics in HFrEF hold the promise of alleviating heart failure at its source, yet so far none has found success. Nevertheless, there are increasing calls for a proximal, 'cardiocentric' approach to therapy. In this review, we examine HFrEF therapy aimed at improving cardiac function with a focus on recent trials and emerging targets.

Explaining Heart Failure Hyper-mortality in Sub Saharan Africa: Global Genomic and Environmental Contribution Review

The annual heart failure (HF) mortality rate in Africa is 34% according to the INTERHF study. This is twice the world average of 16.5% and 3.7 times that of South America, 9%. We review evidence-based explanations for the Hyper-mortality of HF, by comparison of North American, Caribbean, Afro-Brazilian with Sub-Saharan African (SSA) nations profiles, and suggest amelioration. 1 year HF mortality rates in SSA ranged from 29% to 58%, and intra-hospital mortality rate from 8 to 26% (n = 8). A clustering of adverse genetic single nucleotide polymorphisms (SNP) predisposing to hypertension and/or left ventricular hypertrophy (LVH) in the black diaspora may contribute. A higher prevalence of HF with reduced Ejection Fraction (HF r EF) phenotype, which is associated with greater mortality is more common in SSA nations. Additionally, a worse co-morbidity burden, especially valvular regurgitations causing LV remodeling (LVR), chronic kidney disease (CKD), anemia, lung disease, infections, late presentation in NYHA III/IV, right ventricular disease (RVD) were also common in SSA. Geographic variation in SSA, HF risk factors and co-morbidity was observed. There was sub-optimal use of guideline directed medical therapy (GDMT) and intracardiac device (ICD) unavailability. Gross Domestic Product -per purchasing power parity (GDP-PPP), which is low in SSA, was inversely correlated both to higher intra-hospital mortality rate % (r = -0.73, r 2 = 0.54 p = 0.038) and higher 1 year HF mortality rate % (r = -0.62, r 2 = 0.38, = 0.098). Localized primary prevention, early detection and prompt treatment of hypertension, diabetes, rheumatic fever, early cardiac valve repair and use of cardiovascular polypill, optimal use of GDMT, national health insurance scheme are advocated to stem the dismal mortality and cost burden of HF.

Pharmacokinetic and pharmacodynamic considerations in the treatment of the elderly patient with hypertension

INTRODUCTION

Hypertension is an important risk factor for developing cardiovascular diseases. It is more prevalent in the elderly population. Recently updated American and European guidelines recommend treating every elderly patient with hypertension independent of age, starting with a low dose of antihypertensive drugs. However, little information is available on the optimal dosages of antihypertensive drugs to treat the elderly safely. Areas covered: Comorbidities, co-medication and frailty status can alter the clinical outcome of drug treatment and can cause adverse events in the elderly. Also, due to pharmacokinetic and pharmacodynamic changes the interpatient variability when using antihypertensive drugs is considerable. In this review, an overview is given on the extent to which the previously mentioned parameters are changed in elderly patients and what this means for the exposure to antihypertensive medication. Also, recommendations on the starting dose of the most frequently used antihypertensive drugs are given based on literature data. Expert opinion: We believe that recommendations on starting dosages followed by a stepwise increase of dosages will lead to improved blood pressure control and less adverse drug reactions in the elderly patient. This may improve adherence to antihypertensive therapy.

Beyond Reperfusion: Acute Ventricular Unloading and Cardioprotection During Myocardial Infarction

Heart failure is a major cause of morbidity and mortality around the world, and myocardial infarction is its leading cause. Myocardial infarction destroys viable myocardium, and this dead tissue is replaced by a non-contractile scar that results in impaired cardiac function and a significantly increased likelihood of the patient developing heart failure. Limiting infarct scar size has been the target of pre-clinical and clinical investigations for decades. However, beyond reperfusion, few therapies have translated into the clinic that limit its formation. New approaches are needed. This review will focus on new clinical and pre-clinical data demonstrating that acute ventricular unloading prior to reperfusion by means of percutaneous left ventricular support devices reduces ischemia-reperfusion injury and limits infarct scar size. Emphasis will be given to summarizing our current mechanistic understanding of this new therapeutic approach to treating myocardial infarction.

Efficacy of Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor-Neprilysin Inhibitors in the Treatment of Chronic Heart Failure: A Review of Landmark Trials

Heart failure (HF) is a multi-faceted clinical condition affecting up to 2% of the population in the developed world and is linked to significant morbidity and mortality, therefore posing a major public health concern. To this date, pharmacotherapy for HF has mainly focused on chronic HF with reduced ejection fraction (HFrEF), with angiotensin converting enzyme inhibitors (ACEi) being at the centre of the management plan, alongside angiotensin-receptor-blockers (ARBs), β-blockers (BB) and mineralocorticoid receptor antagonists (MRAs). A novel and recently approved therapy, however, involving angiotensin receptor-neprilysin inhibitors (ARNI), has shown very promising results and comparable to those of ACEi, which raises the question of whether ACEi should remain the first-line treatment option for HFrEF. In this review, the evidence regarding the clinical efficacy of ACEi and ARNI in the treatment of HFrEF is discussed, with emphasis placed on the major landmark trials.

Potential Usefulness of Losartan as an Antifibrotic Agent and Adjunct to Platelet-Rich Plasma Therapy to Improve Muscle Healing and Cartilage Repair and Prevent Adhesion Formation

Postoperative tissue fibrosis represents a major complication in orthopedics. Transforming growth factor beta 1 is a key molecule in the development of postoperative fibrosis. High concentrations of transforming growth factor beta 1 have also been implicated in various diseases. Agents that counteract the actions of transforming growth factor beta 1 have been investigated as potential antifibrotic medications and as adjunct treatment to platelet-rich plasma injections (increased amounts of transforming growth factor beta 1) to improve their effectiveness and/or safety profile. Losartan blocks transforming growth factor beta 1 action and has attracted special interest in orthopedic research that focuses on how to reduce the risk of postoperative fibrosis. [Orthopedics. 2018; 41(5):e591-e597.].

Comparison of ventricular tachyarrhythmia recurrence between ischemic cardiomyopathy and dilated cardiomyopathy: a retrospective study

Background

The use of an implantable cardioverter-defibrillator (ICD) has been established as an effective secondary prevention strategy for ventricular tachycardia (VT)/ventricular fibrillation (VF). However, few reports discuss the difference in clinical predictors for recurrent VT/VF between patients with ischemic cardiomyopathy (ICM) and patients with dilated cardiomyopathy (DCM).

Methods

From May 2004 to December 2015, 132 consecutive patients who had ICM (n = 94) or DCM (n = 38) and had received ICD implantation for secondary prevention were enrolled in this study. All anti-tachycardia events during follow-up were validated. The clinical characteristics and echocardiographic parameters were obtained for comparison. The incidence of recurrence of VT/VF, cardiovascular mortality, all-cause mortality, the change of left ventricular ejection fraction (LVEF) and LV volume were analyzed.

Results

At a mean follow-up of 3.62 ± 2.93 years, 34 patients (36.2%) in the ICM group and 22 patients (57.9%) in the DCM group had a recurrence of VT/VF episodes (p = 0.032). The DCM group had a lower LVEF (p = 0.019), a larger LV end-diastolic volume (LVEDV) (p = 0.001), a higher prevalence of LVEDV >158 mL (p = 0.010), and a larger LV end-systolic volume (p = 0.010) than the ICM group. LVEDV >158 mL and no use of angiotensin-converting-enzyme inhibitor/angiotensin receptor blocker were independent predictors of recurrences of VT/VF in ICM patients but not in DCM patients. There were no difference in cardiovascular mortality and all-cause mortality between the ICM and DCM patients.

Conclusion

The DCM patients had a higher recurrence rate of VT/VF than did the ICM patients during long-term follow-up. An enlarged LV is an independent predictor of the recurrence of VT/VF in ICM patients receiving ICD for secondary prevention.

Increased risk of ventricular tachycardia and cardiovascular death in patients with myocarditis during the long-term follow-up: A national representative cohort from the National Health Insurance Research Database

The incidence of acute myocarditis complicated with ventricular tachycardia (VT) is unknown. This study aimed to investigate the association between myocarditis and the incidence of VT and mortality. We also aimed to determine the independent predictors that increased the VT risk in those patients. From 2000 to 2004, 13,250 patients with a history of myocarditis were identified from the Taiwan National Health Insurance Research Database. The same number of individuals without heart disease with a matched sex and underlying diseases were selected as the control group. The long-term risks of life-threatening ventricular arrhythmias and mortality in patients with a history of myocarditis were investigated by an adjusted Cox proportional hazards regression. After a mean follow-up of 10.4 ± 2.94 years (interquartile range: 12, 10.19-12), the myocarditis patients showed a higher incidence of new onset VT events compared with healthy controls (5.4% [519 per 100,000 person-year] in the myocarditis group vs, 0.47% [43 per 100,000 person-year] in the healthy controls; adjusted hazard ratio [HR]: 16.1, 95% confidence interval [CI]: 12.4-20.9; P < .001). A higher incidence of cardiovascular death was noted in the myocarditis group than healthy controls (6.52% vs 3.18%; HR: 2.42, 95% CI: 2.14-2.73; P < .001) after adjusting for the multivariate confounders including sex, age, underlying comorbidities, and medications. The results of this study suggested that there was higher incidence of life-threatening VT and mortality during the very long-term follow-up in patients with a history of myocarditis. Future work should focus on an in-depth risk stratification of VT in myocarditis patients.

Left ventricle remodeling predicts the recurrence of ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients for secondary prevention

BACKGROUND

Implantable cardioverter defibrillator (ICD) is an effective treatment for secondary prevention of ventricular tachycardia/ventricular fibrillation (VT/VF). Left ventricular (LV) remodeling may develop before ICD implant and over time. However, it remains unclear how LV remodeling affects subsequent risk for recurrence VT/VF in ICD recipients under optimal medical therapy.

METHODS

From May of 2004 to June of 2015, 144 patients received ICD implantation for secondary prevention were enrolled in this study. All information interrogated from ICD devices during follow-up or ICD therapy history (anti-tachycardia pacing and shock therapy) were reviewed and validated the occurrences of VT/VF.

RESULTS

At a mean follow-up of 1110.5 ± 860.6 days, 53 patients (36.8%) had recurrence of VT/VF episodes and 91 patients had no recurrence of VT/VF episode after ICD implant. Left ventricular end-diastolic volume (LVEDV) > 163.5 mL had significant predictive value for VT/VF recurrence (area under the curve: 0.602, p = 0.041). Moreover, the percentage of patients with LVEDV >163.5 mL was significantly higher in patients with recurrent VT/VF than patients without recurrent VT/VF (62.3 vs 40.0%, p = 0.010). Left ventricular ejection fraction ≤ 30% (p = 0.031), LVEDV > 163.5 mL (p = 0.012) and QRS width > 125 msec (p = 0.049) were significant predictors for VT/VF recurrence by univariate Cox regression analysis. However, only LVEDV > 163.5 mL (hazard ratio: 2.549, 95% confidence interval: 1.249 ~ 5.201, p = 0.010) and QRS width > 125 msec (hazard ratio: 2.173, 95% confidence interval: 1.030 ~ 4.586, p = 0.042) were independent predictors for recurrence of VT/VF after multivariable adjustment.

CONCLUSION

LV remodeling and QRS width > 125 msec were independent predictors for VT/VF recurrence in secondary prevention ICD recipients under optimal medical therapy, independent of LV ejection fraction.

A pathway and network review on beta-adrenoceptor signaling and beta blockers in cardiac remodeling

It is well established that cardiac remodeling plays a pivotal role in the development of heart failure, a leading cause of death worldwide. Meanwhile, sympathetic hyperactivity is an important factor in inducing cardiac remodeling. Therefore, an in-depth understanding of beta-adrenoceptor signaling pathways would help to find better ways to reverse the adverse remodeling. Here, we reviewed five pathways, namely mitogen-activated protein kinase signaling, Gs-AC-cAMP signaling, Ca(2+)-calcineurin-NFAT/CaMKII-HDACs signaling, PI3K signaling and beta-3 adrenergic signaling, in cardiac remodeling. Furthermore, we constructed a cardiac-remodeling-specific regulatory network including miRNA, transcription factors and target genes within the five pathways. Both experimental and clinical studies have documented beneficial effects of beta blockers in cardiac remodeling; nevertheless, different blockers show different extent of therapeutic effect. Exploration of the underlying mechanisms could help developing more effective drugs. Current evidence of treatment effect of beta blockers in remodeling was also reviewed based upon information from experimental data and clinical trials. We further discussed the mechanism of how beta blockers work and why some beta blockers are more potent than others in treating cardiac remodeling within the framework of cardiac remodeling network.

Predictors and outcome of sustained improvement in left ventricular function in dilated cardiomyopathy

BACKGROUND

Improvement in the left ventricular ejection fraction (LVEF) may occur in patients with dilated cardiomyopathy (DCM).

HYPOTHESIS

There are different implications of persistent versus transient improvement in LVEF among DCM patients receiving contemporary therapy.

METHODS

We studied 188 patients with nonischemic DCM. Persistent improvement in LVEF (PIEF) was defined as LVEF increase by at least 10% compared to baseline, and found in 2 separate echo-Doppler exams performed at least 12 months apart. Increased LVEF in echo 2, which was not sustained in echo 3, was defined as transient improvement in LVEF (TIEF).

RESULTS

Over an average follow-up of 6.8 years, PIEF occurred in 61 (33%) patients, predicting a better long-term outcome (P < 0.001) in a combined end-point comprising death, heart transplantation, or the need for a ventricular assist device. The TIEF group had an intermediate course and were closer to nonimprovers (P = 0.003 vs PIEF). Multivariate logistic regression identified the following independent predictors of PIEF: shorter disease duration, pregnancy-associated disease, left ventricular hypertrophy, and baseline LVEF ≤ 25%. A score to predict PIEF assigned 1 point to each of the following: disease duration < 3 years and no familial cardiomyopathy; pregnancy-associated presentation; basal LVEF ≤ 25%; and left ventricular wall thickness ≥ 12. A score of ≥ 3 was present in 44% of the patients, reliably predicting PIEF in 91% (P = 0.01).

CONCLUSIONS

Persistent improvement in LVEF is associated with improved long-term prognosis. Baseline clinical parameters can be used to identify patients likely to demonstrate PIEF, thereby allowing tailored management in this population.

MAP kinase kinase kinase-2 (MEKK2) regulates hypertrophic remodeling of the right ventricle in hypoxia-induced pulmonary hypertension

Pulmonary hypertension (PH) results in pressure overload of the right ventricle (RV) of the heart, initiating pathological RV remodeling and ultimately leading to right heart failure. Substantial research indicates that signaling through the MAPK superfamily mediates pathological cardiac remodeling. These considerations led us to test the hypothesis that the regulatory protein MAPKKK-2 (MEKK2) contributes to RV hypertrophy in hypoxia-induced PH. Transgenic mice with global knockout of MEKK2 (MEKK2(-/-) mice) and age-matched wild-type (WT) mice were exposed to chronic hypobaric hypoxia (10% O(2), 6 wk) and compared with animals under normoxia. Exposure to chronic hypoxia induced PH in WT and MEKK2(-/-) mice. In response to PH, WT mice showed RV hypertrophy, demonstrated as increased ratio of RV weight to body weight, increased RV wall thickness at diastole, and increased cardiac myocyte size compared with normoxic control animals. In contrast, each of these measures of RV hypertrophy seen in WT mice after chronic hypoxia was attenuated in MEKK2(-/-) mice. Furthermore, chronic hypoxia elicited altered programs of hypertrophic and inflammatory gene expression consistent with pathological RV remodeling in WT mice; MEKK2 deletion selectively inhibited inflammatory gene expression compared with WT mice. The actions of MEKK2 were mediated in part through regulation of the abundance and phosphorylation of its effector, ERK5. In conclusion, signaling by MEKK2 contributes to RV hypertrophy and altered myocardial inflammatory gene expression in response to hypoxia-induced PH. Therapies targeting MEKK2 may protect the myocardium from hypertrophy and pathological remodeling in human PH.

Minimally invasive injectable short nanofibers of poly(glycerol sebacate) for cardiac tissue engineering

Myocardial tissue lacks the ability to appreciably regenerate itself following myocardial infarction (MI) which ultimately results in heart failure. Current therapies can only retard the progression of disease and hence tissue engineering strategies are required to facilitate the engineering of a suitable biomaterial to repair MI. The aim of this study was to investigate the in vitro properties of an injectable biomaterial for the regeneration of infarcted myocardium. Fabrication of core/shell fibers was by co-axial electrospinning, with poly(glycerol sebacate) (PGS) as core material and poly-L-lactic acid (PLLA) as shell material. The PLLA was removed by treatment of the PGS/PLLA core/shell fibers with DCM:hexane (2:1) to obtain PGS short fibers. These PGS short fibers offer the advantage of providing a minimally invasive injectable technique for the regeneration of infarcted myocardium. The scaffolds were characterized by SEM, FTIR and contact angle and cell-scaffold interactions using cardiomyocytes. The results showed that the cardiac marker proteins actinin, troponin, myosin heavy chain and connexin 43 were expressed more on short PGS fibers compared to PLLA nanofibers. We hypothesized that the injection of cells along with short PGS fibers would increase cell transplant retention and survival within the infarct, compared to the standard cell injection system.

Electrocardiographic QRS duration reflects right ventricular remodeling in patients undergoing corrective surgery for isolated tricuspid regurgitation: a comparative study with cardiac magnetic resonance imaging

BACKGROUND

The role of electrocardiogram (ECG) is unclear for the longitudinal follow-up of patients who undergo corrective surgery for isolated severe tricuspid regurgitation (TR).

HYPOTHESIS

This study sought to investigate the usefulness of changes in QRS duration of ECG after TR surgery in predicting right ventricular (RV) reverse remodeling as determined by cardiac magnetic resonance imaging (CMR).

METHODS

We enrolled 30 consecutive TR patients (27 women, aged 57.8 ± 9.6 years) who had undergone prior left-sided valve surgery. A computer-assisted analysis was performed for objective calculation of QRS duration before and after surgery.

RESULTS

At a median CMR follow-up of 27.5 months postsurgery, QRS duration was cut by 14.6%, from 110.4 ± 14.6 msec to 96.9 ± 11.9 msec (P < 0.001), while CMR showed a decrease in RV end-diastolic volume index (RV-EDVI) from 179.5 ± 59.7 to 119.1 ± 30.4 mL/m(2) (P < 0.001). QRS duration correlated significantly with RV-EDVI and RV end-systolic volume index (r = 0.65, P < 0.001 and r = 0.53, P < 0.001, respectively), and a percent change in QRS duration was significantly correlated with a percent change in RV-EDVI (r = 0.40, P = 0.03). When significant RV reverse remodeling was defined as a reduction in RV-EDVI ≥20% following TR surgery, the sensitivity and specificity for significant RV reverse remodeling were 75% and 78%, respectively, with a 9% reduction in QRS duration (P = 0.01, area underneath the receiver operator curve [AUC] = 0.81).

CONCLUSIONS

The extent of changes in postoperative QRS duration can be used as a useful, inexpensive, and simple index reflecting the occurrence of significant RV reverse remodeling in patients undergoing corrective TR surgery.

G protein-coupled receptor kinase 2 in patients with acute myocardial infarction

Lymphocyte G protein-coupled receptor kinase 2 (GRK2) levels are increased in patients with chronic heart failure, and in this condition, they correlate with cardiac function. The aim of this study was to assess the prognostic role of GRK2 during acute cardiac dysfunction in humans. A study was designed to investigate the role of GRK2 levels in patients with acute coronary syndromes. Lymphocyte GRK2 levels were examined at admission and after 24 and 48 hours in 42 patients with acute coronary syndromes, 32 with ST-segment elevation myocardial infarction and 10 with unstable angina as a control group. Echocardiographic parameters of systolic and diastolic function and left ventricular remodeling were evaluated at admission and after 2 years. GRK2 levels increased during ST-segment elevation myocardial infarction and were associated with worse systolic and diastolic function. This association held at 2-year follow-up, when GRK2 was correlated with the ejection fraction and end-systolic volume, indicating a prognostic value for GRK2 levels during acute ST-segment elevation myocardial infarction. In conclusion, lymphocyte GRK2 levels increase during acute myocardial infarction and are associated with worse cardiac function. Taken together, these data indicate that GRK2 could be predictive of ventricular remodeling after myocardial infarction and could facilitate the tailoring of appropriate therapy for high-risk patients.

Effect of left ventricular reverse remodeling on long-term prognosis after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and β blockers in patients with idiopathic dilated cardiomyopathy

It remains unknown whether left ventricular (LV) reverse remodeling (LVRR) after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and β blockers is correlated with prognosis in patients with idiopathic dilated cardiomyopathy. Forty-two patients with idiopathic dilated cardiomyopathy treated with the therapy were studied. Complete left ventricular reverse remodeling was defined as LV end-diastolic dimension ≤ 55 mm and fractional shortening ≥ 25% at the last echocardiographic assessment. The incidence of complete LVRR was significantly higher in patients who survived than in those who died or underwent heart transplantation. Patients were divided into 3 groups: death or transplantation, alive with complete LVRR, and alive without complete LVRR. Although patients who died or underwent transplantation did not show any LV improvements, those with complete LVRR showed significant improvements at 1 to 6 months after starting the therapy. Patients without complete LVRR also showed small but significant improvements at 1 to 6 months. The decrease in LV end-systolic dimension from the initial value to that at 1 to 6 months was an independent determinant of future cardiac death or transplantation. In conclusion, complete LVRR is related to favorable prognosis in patients with idiopathic dilated cardiomyopathy. The extent of left ventricular reverse remodeling at 1 to 6 months after starting the therapy is predictive of long-term prognosis.

Small intestinal submucosa gel as a potential scaffolding material for cardiac tissue engineering

Cardiac tissue engineering typically utilizes protein-rich scaffolding materials and growth factors to improve cardiac tissue function in vitro and in vivo. The objectives of this preliminary study were (i) to investigate the potential of porcine small intestinal submucosa gel (SIS gel) in cardiac tissue engineering and (ii) to compare the function of tissues based on either SIS gel or Matrigel, a tumor-derived benchmark material. Neonatal rat cardiac cells were combined with either SIS gel or Matrigel and cultured on porous elastomeric scaffolds composed of poly(glycerol sebacate) for 13days. Tissue function was assessed by measuring contraction rates twice daily. Tissue morphology was compared qualitatively by hematoxylin and eosin staining. Normalized troponin T expression (troponin T:DNA) was compared using image analysis. SIS gel constructs contracted at significantly higher rates than Matrigel constructs on days 8-11. Normalized troponin T expression was significantly higher in SIS gel constructs compared with Matrigel constructs. In summary, this research demonstrated that: (i) SIS gel can be used to create contractile engineered cardiac tissue; (ii) SIS gel produced engineered cardiac tissues with a more physiological contraction rate and higher phenotypic protein expression based on the basic in vitro examinations performed in this study.

Cardiac ultrasound helps for differentiating the causes of acute dyspnea with available B-type natriuretic peptide tests

INTRODUCTION

The aim of this study was to evaluate the role of cardiac ultrasound in diagnosing acute heart failure (AHF) in patients with acute dyspnea with available plasma B-type natriuretic peptide (BNP) level.

METHODS

Patients with acute dyspnea presenting to the emergency department (ED) of a tertiary medical center were prospectively enrolled. The enrolled 84 patients received both BNP tests and cardiac ultrasound studies and were classified into AHF and non-heart failure groups.

RESULTS

Plasma BNP levels were higher in the AHF group (1236 ± 1123 vs 354 ± 410 pg/mL; P < .001). The AHF group had larger left ventricular end-diastolic dimension (LVEDD; 32 ± 7 vs 27 ± 4 mm/m(2); P < .001) and worse left ventricular ejection fraction (52% ± 18% vs 64% ± 15%; P = .003). Multiple logistic regression analysis showed that both BNP levels more than 100 pg/mL and LVEDD were independent predictors for AHF. In patients with plasma BNP levels within gray zone of 100 to 500 pg/mL, LVEDD was larger in the AHF group than that in the non-heart failure group (29 ± 4 vs 26 ± 4 mm/m(2); P = .044).

CONCLUSION

Both LVEDD by cardiac ultrasound and BNP levels can help emergency physicians independently diagnose AHF in the ED. In patients with plasma BNP levels within 100 to 500 pg/mL, cardiac ultrasound can help differentiate heart failure or not.

Poor sleep and impaired self-care: towards a comprehensive model linking sleep, cognition, and heart failure outcomes

BACKGROUND

Persons with heart failure (HF) have significantly lower sleep quantity and quality than persons without HF. The purpose of this article is to propose a conceptual model describing how poor sleep may contribute to inadequate self-care and untoward outcomes in persons with HF.

AIMS

Our overarching hypothesis is that sleep affects self-care and outcomes through its effects on cognition. Building on the work of others, we outline a conceptual model that illustrates that even transient sleep disruption prevents sleep-related restorative processes and contributes to cognitive dysfunction-especially in the 25-50% of HF patients with existing cognitive impairment. Poor sleep may be sufficient to impair cognition to a level that interferes with higher order functions involved in effective HF self-care practices. Through these mechanisms, inadequate sleep may contribute to poor outcomes such as low health-related quality of life and greater risk of unplanned hospitalization.

CONCLUSION

The proposed model (1) bridges physical, neuropsychological and behavioral phenomena, (2) suggests a mechanism by which poor sleep affects daytime behavior, and (3) is empirically testable. Exploring factors that interfere with sleep may improve self-care and outcomes in persons with HF.

Effect of early versus late AT(1) receptor blockade with losartan on postmyocardial infarction ventricular remodeling in rabbits

To characterize the temporal activation of the renin-angiotensin system after myocardial infarction (MI) in rabbits, we examined cardiac ANG II type 1 receptor (AT(1)R) expression and ANG II levels from 3 h to 35 days. The effects of losartan (12.5 mg.kg(-1).day(-1)) on functional and histomorphometric parameters when treatment was initiated early (3 h) and late (day 15) post-MI and maintained for different periods of time [short term (4 days), midterm (20 days), and long term (35 days)] were also studied. AT(1)R expression increased in the MI zone at 15 and 35 days (P < 0.05). ANG II levels increased (P < 0.05) in the non-MI zone at 24 h and in the MI zone as well as in plasma at 4 days and then progressively decreased until 35 days. The survival rate was significantly lower in untreated MI and early long-term-treated animals. Diastolic pressure-volume curves in MI at 35 and 56 days shifted to the right (P < 0.05). This shift was even more pronounced in long-term-treated groups (P < 0.05). Contractility decreased (P < 0.05 vs. sham) in the untreated and long-term-treated groups and was attenuated in the midterm-treated group. The early administration of losartan reduced RAM 11-positive macrophages from 4.15 +/- 0.05 to 3.05 +/- 0.02 cells/high-power field (HPF; P < 0.05) and CD45 RO-positive lymphocytes from 2.23 +/- 0.05 to 1.48 +/- 0.01 cells/HPF (P < 0.05) in the MI zone at 4 days. Long-term treatment reduced the scar collagen (MI: 70.50 +/- 2.35% and MI + losartan: 57.50 +/- 2.48, P < 0.05), determined the persistency of RAM 11-positive macrophages (3.02 +/- 0.13 cells/HPF) and CD45 RO-positive lymphocytes (2.77 +/- 0.58 cells/HPF, P < 0.05 vs. MI), and reduced the scar thinning ratio at 35 days (P < 0.05). Consequently, the temporal expressions of cardiac AT(1)R and ANG II post-MI in rabbits are different from those described in other species. Long-term treatment unfavorably modified post-MI remodeling, whereas midterm treatment attenuated this harmful effect. The delay in wound healing (early reduction and late persistency of inflammatory infiltrate) and adverse remodeling observed in long-term-treated animals might explain the unfavorable effect observed in rabbits.

Atenolol is inferior to metoprolol in improving left ventricular function and preventing ventricular remodeling in dogs with heart failure

OBJECTIVES

beta-Blockers are standard therapy for patients with heart failure (HF). This study compared the effects of chronic monotherapy with 2 different beta(1)-selective adrenoceptor blockers, namely atenolol and metoprolol succinate, on left ventricular (LV) function and remodeling in dogs with coronary microembolization-induced HF [LV ejection fraction (EF) 30-40%].

METHODS

Twenty HF dogs were randomized to 3 months of therapy with atenolol (50 mg once daily, n = 6), metoprolol succinate (100 mg, once daily, n = 7) or to no therapy (control, n = 7). LV EF and volumes were measured before initiating therapy and after 3 months of therapy. The change (Delta) in EF and volumes between measurements before and after therapy was calculated and compared among study groups.

RESULTS

In controls, EF decreased and end-systolic volume increased. Atenolol prevented the decrease in EF and the increase in ESV. In contrast, metoprolol succinate significantly increased EF and decreased end-systolic volume. DeltaEF was significantly higher and Deltaend-systolic volume significantly lower in metoprolol succinate-treated dogs compared to atenolol-treated dogs (EF: 6.0 +/- 0.86% vs. 0.8 +/- 0.85%, p < 0.05; end-systolic volume: -4.3 +/- 0.81 ml vs. -1 +/- 0.52 ml, p <0.05).

CONCLUSIONS

In HF dogs, chronic therapy with atenolol does not elicit the same LV function and remodeling benefits as those achieved with metoprolol succinate.

Intracoronary autologous bone marrow stem cells transfer for patients with acute myocardial infarction: a meta-analysis of randomised controlled trials

BACKGROUND

Conflicting results existed now on the clinical utility of intracoronary bone marrow stem cells (BMSC) transfer for acute myocardial infarction (AMI). This study sought to analyze the efficacy and safety of autologous BMSC transfer in patients with AMI by performing a meta-analysis based on published randomised controlled trials.

METHODS

A systematic literature search of PubMed, MEDLINE, BIOSIS, EMBASE, and Cochrane EBM databases during the period of 1990-2007 was made, objective being the randomised controlled trials in patients with AMI who underwent primary percutaneous coronary intervention (PCI) and received intracoronary BMSC transfer, and were followed up for at least 3 months.

RESULTS

A total of 6 trials with 525 patients were available for analysis. The pooled statistics showed the mean increase in left ventricular ejection fraction (LVEF) from baseline was 7.05% in BMSC group (p=0.01), whereas only 2.46% in control group (p=0.02), and the effect on the absolute change in LVEF was an increase of 4.77% compared with the control (95% confidence interval [CI] 1.42% to 8.12%; p=0.005). The similar effect on left ventricular (LV) end-diastolic dimensions was demonstrated in inter-group comparison (standardized mean difference [SMD]=-0.15, 95%CI -0.50 to 0.20; p=0.41). The incidence of major adverse cardiac events was also similar in two groups but in favor of BMSC group (relative risk [RR]=0.85, 95%CI, 0.61 to 1.19; p=0.34).

CONCLUSIONS

Post PCI BMSC transplantation in patients with AMI significantly increases LVEF but has no effects on LV remodeling, and there is not an incremental effect on the occurrence of major adverse cardiac events in the observed period.

Left ventricular remodelling in patients with moderate systolic dysfunction after myocardial infarction: favourable effects of exercise training and predictive role of N-terminal pro-brain natriuretic peptide

AIMS

To investigate the effects of exercise training (ET) on left ventricular (LV) volumes, cardiopulmonary functional capacity and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in postinfarction patients with moderate LV dysfunction.

METHODS

Sixty-one postinfarction patients were randomized into two groups: group T [n=30, LV ejection fraction (EF) 41.6+/-11.3%, mean+/-SD] entered a 6-month ET programme, whereas group C (n=31, EF 42.0+/-7.6%, P=NS) did not. NT-proBNP assay, Doppler-echocardiography and cardiopulmonary exercise test were performed upon enrolment and at sixth months.

RESULTS

At sixth months, trained patients showed an improvement in workload (+26%, P<0.001), Vo2peak (+31%, P<0.001), LV end-diastolic volume index (LVEDVI; -9%, P<0.001), a reduction in NT-proBNP (-71%, P<0.001) and a significant correlation between changes in NT-proBNP and in LVEDVI (r=0.858, P<0.001). Baseline NT-proBNP correlated with changes in LVEDVI in both trained (r=0.673, P<0.001) and untrained (r=0.623, P<0.001) patients. Group C showed unfavourable LVEDVI dilation (+8%, P<0.001; T vs. C group, P<0.001) and a smaller reduction in NT-proBNP (-40%, P<0.001; T vs. C group, P<0.001).

CONCLUSIONS

Six month ET induced a favourable LV remodelling and a marked fall in NT-proBNP that could predict LV remodelling in postinfarction patients with moderate LV dysfunction.

Location and density of alpha- and beta-adrenoreceptor sub-types in myocardium after mechanical left ventricular unloading

BACKGROUND

We hypothesized that not all subtypes of alpha- and beta-adrenoreceptors undergo similar upregulation and redistribution in human myocardium after mechanical unloading with an assist device.

METHODS

We obtained core biopsy samples of the left ventricle in 19 patients before and after removal of a Jarvik or Thoratec left ventricular assist device (LVAD) to study the effect of mechanical unloading on the distribution of alpha- and beta-adrenoreceptors. Fresh, embedded tissue sections were incubated with receptor blockers and antibodies before the fluorescent labeling of receptors. Images were obtained by fluorescence deconvolution microscopy, and composite tissue renditions were made from the stacked images. Multiple adrenoreceptor subtypes were studied.

RESULTS

We saw a reversal of myocyte hypertrophy in all patients, but the upregulation of receptors was not seen in all post-LVAD tissue samples. Furthermore, we noted receptor relocalization from an initial punctate/clumped pattern to a normal homogeneous distribution in many patients. Significant differences were seen in the distribution of beta(2)- and alpha(1)-receptors and in alpha(1A) subtypes.

CONCLUSIONS

In this study we show not only the expected reversal of myocyte hypertrophy and the increase in adrenoreceptors after ventricular unloading, but also the relocalization of specific receptor subtypes.

Urotensin-II and cardiovascular remodeling

Urotensin-II (U-II), a cyclic undecapeptide, and its receptor, UT, have been linked to vascular and cardiac remodeling. In patients with coronary artery disease (CAD), it has been shown that U-II plasma levels are significantly greater than in normal patients and the severity of the disease is increased proportionally to the U-II plasma levels. We showed that U-II protein and mRNA levels were significantly elevated in the arteries of patients with coronary atherosclerosis in comparison to healthy arteries. We observed U-II expression in endothelial cells, foam cells, and myointimal and medial vSMCs of atherosclerotic human coronary arteries. Recent studies have demonstrated that U-II acts in synergy with mildly oxidized LDL inducing vascular smooth muscle cell (vSMC) proliferation. Additionally, U-II has been shown to induce cardiac fibrosis and cardiomyocyte hypertrophy leading to cardiac remodeling. When using a selective U-II antagonist, SB-611812, we demonstrated a decrease in cardiac dysfunction including a reduction in cardiomyocyte hypertrophy and cardiac fibrosis. These findings suggest that U-II is undoubtedly a potential therapeutic target in treating cardiovascular remodeling.

Chronic cardiac resynchronization therapy and reverse ventricular remodeling in a model of nonischemic cardiomyopathy

While cardiac resynchronization therapy (CRT) has been shown to reduce morbidity and mortality in heart failure (HF) patients, the fundamental mechanisms for the efficacy of CRT are poorly understood. The lack of understanding of these basic mechanisms represents a significant barrier to our understanding of the pathogenesis of HF and potential recovery mechanisms. Our purpose was to determine cellular mechanisms for the observed improvement in chronic HF after CRT. We used a canine model of chronic nonischemic cardiomyopathy. After 15 months, dogs were randomized to continued RV tachypacing (untreated HF) or CRT for an additional 9 months. Six minute walk tests, echocardiograms, and electrocardiograms were done to assess the functional response to therapy. Left ventricular (LV) midmyocardial myocytes were isolated to study electrophysiology and intracellular calcium regulation. Compared to untreated HF, CRT improved HF-induced increases in LV volumes, diameters and mass (p<0.05). CRT reversed HF-induced prolongations in LV myocyte repolarization (p<0.05) and normalized HF-induced depolarization (p<0.03) of the resting membrane potential. CRT improved HF-induced reductions in calcium (p<0.05). CRT did not attenuate the HF-induced increases in LV interstitial fibrosis. Using a translational approach in a chronic HF model, CRT significantly improved LV structure; this was accompanied by improved LV myocyte electrophysiology and calcium regulation. The beneficial effects of CRT may be attributable, in part, to improved LV myocyte function.

Device therapy for remodeling in congestive heart failure

Heart failure is a progressive condition which begins after an inciting event that leads to neurohormonal activation and cardiac remodeling. Medical therapy with beta-blockers and angiotensin-converting enzyme inhibitors has been shown to attenuate neurohormonal changes and left ventricular remodeling. Despite optimal medical therapy, patients often progress, and other therapeutic modalities have been sought to interrupt and reverse the process of remodeling. Various devices have been developed and entered into clinical trials with the intent of promoting reverse remodeling by directly altering the mechanical properties or shape of the left ventricle. This article reviews devices currently undergoing clinical trials.