Carvedilol therapy in pediatric patients with congestive heart failure: a study investigating clinical and pharmacokinetic parameters

Metabolic activation and cytotoxicity of carvedilol mediated by cytochrome P450s in vitro and in vivo

Carvedilol (CAR) is commonly administered in the treatment of essential hypertension. Current reports suggest that CAR therapy may elevate the risk of hepatotoxicity, occasionally progressing to liver injury. However, the underlying mechanisms of the toxicity remain poor understood. This study investigated CAR-associated hepatotoxicity through reactive metabolites formation. In the microsomal incubation mixture containing CAR (50 μM), four phase I metabolites (M1-M4) were detected. Upon the addition of glutathione (GSH), N-acetylcysteine (NAC), or cysteine as trapping agents, four GSH conjugates (M5-M8), four NAC conjugates (M9-M12), and four cysteine conjugates (M13-M16) were also detected. Chemical synthesis of 8-hydroxy CAR identified M1 as the primary oxidative metabolite of CAR. Following the administration of CAR (25 mg/kg), we detected GSH conjugate (M5) in bile, NAC conjugate (M9) in urine, and cysteine adduct (M13) in proteolytic mixture of liver tissues of rat. Furthermore, it was found that CYP3A4 dominated the metabolic activation of CAR. Additionally, CAR exhibited time-course changes and dose-dependent (0, 25, 50, and 100 mg/kg) protein adduction in rat liver tissues, as well as time- and concentration-dependent (0, 10, 25, 50 and 100 μM) inhibition of hepatocyte viability. Ketoconazole (KTZ) significantly decreased the susceptibility of hepatocytes to CAR-induced cytotoxicity. Collectively, these findings offer new insight into the hepatotoxicity mechanism associated with the metabolic activation of CAR.

Relationship between heart failure and intestinal inflammation in infants with congenital heart disease

OBJECTIVE

The association between heart failure (HF) and intestinal inflammation caused by a disturbed intestinal microbiota in infants with congenital heart disease (CHD) was investigated.

METHODS

Twenty infants with HF and CHD who were admitted to our hospital between October 2021 and March 2022 were included in this study. Twenty age- and sex-matched infants without HF at our hospital were selected as the control group. Faecal samples were obtained from each participant and analysed by enzyme-linked immunoassay and 16 S rDNA sequencing to assess intestinal inflammatory factors and the microbiota.

RESULTS

The levels of intestinal inflammatory factors, including IL-1β, IL-4, IL-6, IL-17 A and TNF-α, were greatly increased, while the levels of IL-10 were significantly decreased in the HF group compared to the control group (p < 0.05). The intestinal microbial diversity of patients in the HF group was markedly lower than that in the control group (p < 0.05). The abundance of Enterococcus was significantly increased in the HF group compared to the control group (p < 0.05), but the abundance of Bifidobacterium was significantly decreased in the HF group compared to the control group (p < 0.05). The diversity of the intestinal microbiota was negatively correlated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the intestinal tract but was positively correlated with that of IL-10. The abundance of Enterococcus was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the intestinal tract but was negatively correlated with that of IL-10. NT-proBNP was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the HF group but was negatively correlated with that of IL-10. The heart function score was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the HF group but was negatively correlated with that of IL-10.

CONCLUSIONS

Infants with CHD-related HF had a disordered intestinal microbiota, decreased diversity of intestinal microbes, increased levels of pathogenic bacteria and decreased levels of beneficial bacteria. The increased abundance of Enterococcus and the significant decrease in the diversity of the intestinal microbiota may exacerbate the intestinal inflammatory response, which may be associated with the progression of HF.

Influence of Age, Heart Failure and ACE Inhibitor Treatment on Plasma Renin Activity in Children: Insights from a Systematic Review and the European LENA Project

BACKGROUND

Plasma renin activity (PRA) has gained relevance as prognostic marker in adults with heart failure. The use of PRA as a clinically meaningful parameter in children and children with heart failure requires a thorough knowledge of the factors that influence PRA to correctly assess PRA levels. We aim to evaluate the influence of age, heart failure and angiotensin-converting enzyme inhibitor (ACEi) on PRA levels in children.

METHODS

We conducted a systematic literature search to identify studies on PRA levels in healthy children and in children with heart failure. In addition, we analysed PRA data measured before (n = 35, aged 25 days-2.1 years), 4 hours after (n = 34) and within the first 8 days of enalapril treatment (n = 29) in children with heart failure from the European project Labeling of Enalapril from Neonates up to Adolescents (LENA).

RESULTS

Age has a profound effect on PRA levels in healthy children, as PRA levels in the literature are up to about 7 times higher in neonates than in older children. Children with heart failure younger than 6 months showed 3-4 times higher PRA levels than healthy peers in both the literature and the LENA studies. In the LENA studies, the ACEi enalapril significantly increased median predose PRA by a factor of 4.5 in children with heart failure after 4.7 ± 1.6 days of treatment (n = 29, p < 0.01). Prior to treatment with enalapril, LENA subjects with symptomatic heart failure (Ross score ≥3) had a significantly higher PRA than LENA subjects with asymptomatic heart failure of comparable age (Ross score ≤2, p < 0.05).

CONCLUSIONS

Age, heart failure and ACEi treatment have a notable influence on PRA and must be considered when assessing PRA as a clinically meaningful parameter.

CLINICAL TRIAL REGISTRATION

The trials are registered on the EU Clinical Trials Register (https://www.clinicaltrialsregister.eu).

TRIAL REGISTRATION NUMBERS

EudraCT 2015-002335-17, EudraCT 2015-002396-18.

N-Terminal Pro-B-Type Natriuretic Peptide as a Marker of Severity of Heart Failure in Children with Congenital Heart Diseases

N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been used as a tool for diagnosis, severity assessment and prognostication of congestive heart failure (CHF) in adults, with specific cut off values for diagnosis and denoting points of intervention. However, there is scarcity of paediatric literature regarding role of NT-proBNP as a marker of heart failure severity and prognostication. So, this study was done to assess the utility of NT-proBNP as a marker of severity of heart failure in children with congenital heart diseases. Single centre, prospective observational study. Children (1 month to 5 years), with congenital heart disease, admitted in the paediatric wards with varying severity of CHF were enrolled. Heart failure severity grading was done according to Laer modification of Ross Classification at the time of presentation to hospital and children were classified as having no/grade I CHF (score: 0-2); mild/grade II CHF (score 3-6); moderate/grade III CHF (score 7-9) or severe/grade IV CHF (score 10-12). NT-proBNP levels were measured within 24 h of admission. Eighty children with congenital heart disease were enrolled in this study. As per modified Ross Classification, 11 had grade I/No heart failure (13.7%), 32 children had grade II/mild heart failure (40%), 36 had grade III/moderate heart failure (45%) and only 1 had grade IV/severe heart failure (1.25%). The median NT-proBNP levels (IQR) in the above mentioned grades of heart failure were found to be 321.11 (211.1-411.78 pg/ml), 750.62 (474.62-995.2 pg/ml), 4159.61 (1440.59-11,857 pg/ml) and 11,320.34 pg/ml, respectively. Seven children (8.75%) expired. Median NT-proBNP value in seven children who died was significantly higher than those who survived [median (IQR): 11,681.01 pg/ml (10,092.72-14,754 pg/ml) vs 839.4 pg/ml (456.67-3288.09 pg/ml), p value < 0.001]. NT-proBNP level of 520.2 pg/ml predicted grade II (mild heart failure) or more severe grades of heart failure with Sensitivity, Specificity, Negative Predictive Value and Positive Predictive Value of 83%, 91%, 57.1% and 98%, respectively. NT-proBNP levels increase progressively with increasing severity of CHF and can be used as a marker of severity of heart failure in children with congenital heart disease presenting with CHF.

Optimal Heart Rate May Improve Systolic and Diastolic Function in Patients with Fontan Circulation

(1) Background: The optimal heart rate, at which the E-wave and A-wave stand adjacent without any overlaps in the Doppler transmitral flow echocardiography, is associated with maximum cardiac output and favorable clinical outcomes in adult patients with systolic heart failure. However, the clinical implication of the echocardiographic overlap length in patients with Fontan circulation remains unknown. We investigated the relationship between heart rate (HR) and hemodynamics in Fontan surgery patients with and without beta-blockers. (2) Methods and Results: A total of 26 patients (median age 1.8 years, 13 males) were enrolled. At baseline, the plasma N-terminal pro-B-type natriuretic peptide was 2439 ± 3483 pg/mL, the fraction area change was 33.5 ± 11.4%, the cardiac index was 3.55 ± 0.90 L/min/m², and the overlap length was 45.2 ± 59.0 msec. Overlap length was importantly decreased after the one-year follow-up (7.60 ± 78.57 msec, p = 0.0069). Positive correlations were noted between the overlap length and A-wave and E/A ratio (p = 0.0021 and p = 0.0046, respectively). Ventricular end-diastolic pressure was significantly correlated with the overlap length in non-beta-blocker patients (p = 0.0483). (3) Conclusion: Overlap length may reflect the status of ventricular dysfunction. Hemodynamic preservation at lower HR could be critical for cardiac reverse remodeling.

Heart rate reduction as a marker to optimize carvedilol treatment and enhance myocardial recovery in pediatric dilated cardiomyopathy

Introduction: An elevated heart rate is associated with an increased risk of death or cardiac transplant in children with dilated cardiomyopathy (DCM). Whether heart rate is a clinical marker to address therapy, is poorly investigated in children. Aim: To investigate the relationship between heart rate reduction (HRR) and left ventricular ejection fraction (LVEF) in DCM, treated with carvedilol. Methods: This is a multi center retrospective analysis conducted on all children with DCM (aged <18 years) between 2013 and 2020, with LVEF <40% and treated with carvedilol. Carvedilol was up titrated to the maximal tolerated dose or to 1 mg/kg/day. Echocardiographic data on left ventricular function and dimension were collected. The relationship between HRR and LVEF, left ventricular end-diastolic (LVEDd) and end-systolic diameter (LVESd) was assessed before and after HRR with carvedilol, using regression analysis. Results: 100 patients were enrolled (M: 51%; age 7 ± 8 years). The mean LVEF was 30.2 ± 10% before treatment and 43.7 ± 9.6% after treatment, at the maximum therapeutic dose (p < 0.0001). There was a positive relationship between HRR and increase in LVEF (R 2 = 0.06, p = 0.014). A HRR of >20% correlated with an improvement in LVEF >13%. At 3 years follow up, HRR demonstrated a significant reduction of LVESd (R2 = 0.1, p = 0.003) LVEDd (R2 = 0.07, p = 0.008) and LVEF recovery up to 15% (p < 0.0001). No deaths or heart transplant occurred during follow-up. Conclusion: This study demonstrates that HRR is safe and improvement in LVEF is related to the degree of HRR. The magnitude of LVEF improvement was enhanced by a major reduction in HR. It provides evidence that HRR could be used as a clinical marker to treat HF in children.

Enalapril and Enalaprilat Pharmacokinetics in Children with Heart Failure Due to Dilated Cardiomyopathy and Congestive Heart Failure after Administration of an Orodispersible Enalapril Minitablet (LENA-Studies)

Angiotensin-converting enzyme inhibitors (ACEI), such as enalapril, are a cornerstone of treatment for pediatric heart failure which is still used off-label. Using a novel age-appropriate formulation of enalapril orodispersible minitablets (ODMTs), phase II/III open-label, multicenter pharmacokinetic (PK) bridging studies were performed in pediatric patients with heart failure due to dilated cardiomyopathy (DCM) and congenital heart disease (CHD) in five participating European countries. Children were treated for 8 weeks with ODMTs according to an age-appropriate dosing schedule. The primary objective was to describe PK parameters (area under the curve (AUC), maximal concentration (Cmax), time to reach maximal concentration (t-max)) of enalapril and its active metabolite enalaprilat. Of 102 patients, 89 patients (n = 26, DCM; n = 63 CHD) were included in the primary PK endpoint analysis. Rate and extent of enalapril and its active metabolite enalaprilat were described and etiology and age could be identified as potential PK modifying factors. The dosing schedule appeared to be tolerated well and did not result in any significant drug-related serious adverse events. The PK analysis and the lack of severe safety events supports the applied age-appropriate dosing schedule for the enalapril ODMTs.

Drug Treatment of Heart Failure in Children: Gaps and Opportunities

Medical therapy for pediatric heart failure is based on a detailed mechanistic understanding of the underlying causes, which are diverse and unlike those encountered in most adult patients. Diuresis and improved perfusion are the immediate goals of care in the child with acute decompensated heart failure. Conversion to maintenance oral therapy for heart failure is based on the results of landmark studies in adults, as well as recent pediatric clinical trials and heart failure guidelines. There will continue to be an important role for newer drugs, some of which are in active trials in adults, and some of which are already approved for use in children. The need to plan for clinical trials in children during drug development for heart failure is emphasized.

Utility of perinatal natriuretic peptide for predicting neonatal heart failure

BACKGROUND

We evaluated the significance of perinatal plasma natriuretic peptide (NP) levels in neonates with congenital heart defects (CHDs) or arrhythmias and determined whether measurement of perinatal plasma NP levels and echocardiographic assessment in utero could predict heart failure after birth.

METHODS

The study was conducted between 2012 and 2016 to evaluate the correlation of perinatal atrial NP (ANP) and brain NP (BNP) levels at birth with the modified Ross score after birth and the cardiovascular profile (CVP) score before birth.

RESULTS

A total of 122 singletons with CHDs or arrhythmias and 27 controls were analyzed. Neonatal blood sampling was performed at a median of 0.7 h (range, 0.1-1.5) after birth. The neonatal plasma ANP and BNP levels shortly after birth were significantly higher than those in the umbilical artery (UA) plasma. The ANP and BNP levels in UA and neonatal blood were correlated with the modified Ross score. The neonatal plasma ANP and BNP levels and the modified Ross scores were inversely correlated with the CVP score in neonates with CHDs or arrhythmias. The area under the receiver operating characteristic curve of UA ANP levels for predicting neonatal heart failure was highest among those for the CVP score, perinatal plasma ANP and BNP levels, and their combinations.

CONCLUSIONS

The plasma ANP and BNP levels increased markedly shortly after birth. Assessment of the UA plasma ANP level at birth and the CVP score in utero may be utilized to predict neonatal heart failure.

Real-World Use of Carvedilol in Children With Dilated Cardiomyopathy: Long-Term Effect on Survival and Ventricular Function

BACKGROUND

Carvedilol is recommended for chronic heart failure (HF) treatment in children. However, the ideal dosage and administration are not standardized, and data on its long-term effects are lacking. This study aimed to assess the effect of a high dosage regimen of carvedilol on cardiac outcomes in children with HF.

METHODS

We conducted a retrospective cohort study including all children with HF and dilated cardiomyopathy. We analyzed medical records before starting treatment, at 1 and 3 years after reaching the maximum therapeutic dosage. All data were compared with a historical control group. Kaplan-Meier analysis and Cox proportional hazard regression have been used to evaluate the effect of high dosage carvedilol therapy. The main outcome was a composite of all-cause mortality and heart transplant.

RESULTS

One hundred thirty-five were included in the study and 65 treated with a high dosage of carvedilol regimen (up to 1 mg/kg/day). Heart rate reduction (mean reduction 30%, p < 0.0001) and ejection fraction improvement (32 ± 9.4 vs. 45. ± 10.1%, p < 0.0001) were statistically significant in those. Long-term survival and freedom from heart transplant were significantly improved in those treated with high dosage carvedilol therapy (p = 0.00001).

CONCLUSIONS

Treatment with the high dosage of carvedilol, in addition to standard HF therapy, significantly improves ventricular function and survival in children with dilated cardiomyopathy and chronic HF.

Efficacy and safety of propranolol in infants with heart failure due to moderate-to-large ventricular septal defect (VSD-PHF study) - A prospective randomized trial

AIMS

The utility of beta-blocker therapy in infants with heart failure (HF) due to significant left-to-right shunt lesions is not known. The study aimed to assess the efficacy and safety of propranolol in infants with HF due to moderate-to-large ventricular septal defect (VSD).

METHODS

The prospective randomized trial included 80 infants with HF and moderate-to-large VSD, randomly allocated to receive either conventional therapy alone (n = 40) or propranolol plus conventional therapy (n = 40). The primary endpoint was a composite of all-cause mortality, hospitalization for HF and/or chest infection, and referral for surgery. The secondary clinical outcomes were the individual components of the composite endpoint. In addition, the patients were followed up to detect safety outcomes, for example, bronchospasm, bradyarrhythmia, and worsening HF symptoms.

RESULTS

The addition of propranolol therapy to the conventional medications did not result in significant improvement in the primary composite endpoint (32.50% vs. 52.50%; P = 0.07). There was a trend toward improvement, but the study is underpowered for this important question. However, propranolol therapy significantly decreased the risk of hospitalization (12.50% vs. 32.50%; P = 0.03) and worsening of Ross HF class (5.41% vs. 28.21%; P = 0.01) as compared to conventional therapy (estimated number needed to treat = 5). Propranolol did not result in any significant safety concerns in these infants except bronchospasm in an infant.

CONCLUSIONS

Propranolol therapy in infants with significant left-to-right shunt may prevent worsening in HF symptoms and hospitalization and is well tolerated. However, it does not reduce mortality or need for surgery.

Carvedilol improves left ventricular diastolic dysfunction in patients with transfusion-dependent thalassemia

Background:

Iron overload cardiomyopathy is the most common cause of death in patients with transfusion-dependent thalassemia.

Aim:

The aim of this study was to determine the efficacy of carvedilol treatment in patients with transfusion-dependent thalassemia who had left ventricular diastolic dysfunction.

Methods:

Eighteen patients with transfusion-dependent thalassemia who had left ventricular diastolic dysfunction were enrolled. All patients had normal left ventricular systolic function and were given carvedilol with the target dose of 0.8 mg/kg/day. Ventricular function and the level of cardiac iron were assessed by echocardiography and magnetic resonance imaging at 0, 3, and 6 months.

Results:

The median age of the patients was 19 years (range 13–25 years). Four patients had severe left ventricular Grade III diastolic dysfunction and fourteen patients had Grade II diastolic dysfunction. The grade of left ventricular diastolic dysfunction was improved at 3 months after the carvedilol treatment. The Doppler parameters, including pulmonary vein atrial reversal velocity, pulmonary vein atrial reversal duration, and the difference of pulmonary vein atrial reversal and the mitral valve atrial contraction wave duration at 3 months after the carvedilol treatment, were significantly lower than these parameters before the treatment.

Conclusions:

Among patients with transfusion-dependent thalassemia who had left ventricular diastolic dysfunction without systolic dysfunction, treatment with carvedilol for 3 months was associated with improvement in Doppler parameters of left ventricular diastolic function. However, this finding and its clinical significance need to be confirmed in further double-blind controlled studies.

Current and Future Drug and Device Therapies for Pediatric Heart Failure Patients: Potential Lessons from Adult Trials

This review discusses the potential drug and device therapies for pediatric heart failure (HF) due to reduced systolic function. It is important to realize that most drugs that are used in pediatric HF are extrapolated from adult cardiology practices or consensus guidelines based on expert opinion rather than on evidence from controlled clinical trials. It is difficult to conclude whether the drugs that are well established in adult HF trials are also beneficial for children because of tremendous heterogeneity in the mechanism of HF in children and variations in the pharmacokinetics and pharmacodynamics of drugs from birth to adolescence. The lessons learned from adult trials can guide pediatric cardiologists to design clinical trials of the newer drugs that are in the pipeline to study their efficacy and safety in children with HF. This paper's focus is that the reader should specifically think through the pathophysiological mechanism of HF and the mode of action of drugs for the selection of appropriate pharmacotherapy. We review the drug and device trials in adults with HF to highlight the knowledge gap that exists in the pediatric HF population.

Medical management of pediatric heart failure

Pediatric heart failure is a complex, heterogenous syndrome that occurs relatively rarely in children, but carries a high burden of morbidity and mortality. This article reflects on the current state of medical therapy for both acute and chronic pediatric heart failure, based on expert consensus guidelines, and the extrapolation of data from trials performed in adults. For the management of acute heart failure specifically, we rely on an initial assessment of the perfusion and volume status of a patient, to guide medical therapy. This paradigm was adapted from adult studies that demonstrated increased morbidity and mortality in heart failure patients whose hemodynamics or examination findings were consistent with a PCWP >18 mmHg and a CI ≤2.2 L/min/m². The cornerstone of treatment in the acute setting therefore relies on achieving a euvolemic state with adequate cardiac output. In the chronic setting, patients are typically maintained on a regimen of an angiotensin converting enzyme inhibitor, a beta-blocker, and spironolactone. For those with refractory heart failure, intravenous milrinone therapy has become a mainstay of bridging children to cardiac transplantation. The pediatric-specific data driving these clinical practices are limited and often times, conflicting. The future of pediatric heart failure depends on collaboration, quality improvement, and a commitment to pediatric-specific indications for new medical and device therapies.

Clinical Pharmacokinetics of Enalapril and Enalaprilat in Pediatric Patients-A Systematic Review

Purpose: Enalapril has an established safety and efficacy in adults and is used in hypertension, heart failure, and renal failure. In pediatric patients, enalapril is labeled for children with hypertension and used off label in children with heart failure. The systematic literature search aims to assess the current knowledge about enalapril and its active metabolite enalaprilat pharmacokinetics in children as a basis for dose delineation for pediatric patients with heart failure. Methods: A systematic literature review was performed in the PubMed database using relevant keywords. Dose normalization of relevant pharmacokinetic parameters of the identified studies was done for comparison between different diseases and pediatric age groups. Results: The literature search has resulted in three pediatric pharmacokinetic studies of enalapril out of which Wells et al. reported about children with hypertension and Nakamura et al., and Llyod et al. presented data for pediatric heart failure patients. The area under the curve values of enalaprilat in hypertensive pediatric patients increased with respect to the age groups and showed maturation of body functions with increasing age. Dose normalized comparison with the heart failure studies revealed that although the pediatric heart failure patients of > 20 days of age showed the area under the curve a similar to that of hypertensive patients, two pediatric patients of very early age (<20 days) were presented with 5-6-fold higher area under the curve values. Conclusion: Data related to the pharmacokinetics of enalapril and enalaprilat in hypertensive patients and few data for young heart failure children are available. Comparison of dose normalized exposition of the active metabolite enalaprilat indicated similarities between heart failure and hypertensive patients and a potentially high exposition of premature patients but substantially more pharmacokinetic studies are required to have reliable and robust enalapril as well as enalaprilat exposures especially in pediatric patients with heart failure as a basis for any dose delineation.

Low-volume LC-MS/MS method for the pharmacokinetic investigation of carvedilol, enalapril and their metabolites in whole blood and plasma: Application to a paediatric clinical trial

Evidence-based pharmacotherapy with carvedilol and enalapril in children suffering from heart failure is insufficient owing to limited pharmacokinetic data. Although a few data sets regarding enalapril, its metabolite enalaprilat and carvedilol in children have been published, pharmacokinetic data on carvedilol metabolites are missing. However, for both drug substances, their active metabolites contribute substantially to drug efficacy. As data can hardly be derived from adults owing to the unknown impacts of enzymatic maturation and ontogeny during childhood, customised assays are important to facilitate paediatric evidence-based pharmacotherapy. Considering ethical paediatric constraints, a low-volume liquid chromatography coupled to mass spectrometry (LC-MS/MS) assay was developed using whole blood or plasma for the quantification of enalapril, enalaprilat, carvedilol, O-desmethyl carvedilol, 4- and 5-hydroxyphenyl carvedilol as well as 3- and 8-hydroxy carvedilol. To facilitate broader applications in adults, the elderly and children, a wide calibration range-between 0.024/0.049 and 50.000 ng/ml-was achieved with good linearity (r ≥ 0.995 for all analytes). In compliance with international bioanalytical guidelines, accuracy, precision, sensitivity and internal standard normalised matrix effects were further successfully validated with the exception of those for 3-hydroxy carvedilol, which was therefore assessed semi-quantitatively. Distinct haematocrits did not impact matrix effects or recoveries when analysing whole blood. Blood-to-plasma ratios were determined for all analytes to form the basis for pharmacokinetic modelling. Finally, incurred sample reanalysis of paediatric samples confirmed the reproducibility of the developed low-volume LC-MS/MS method during study sample analysis. The assay facilitates the reliable generation of important data and contributes towards a safe drug therapy in children.

Update of Pediatric Heart Failure

Pediatric heart failure (PHF) affects 0.87 to 7.4 per 100,000 children. It has a 5-year mortality or heart transplant rate of 40%. Diagnosis often is delayed because initial symptoms are similar to common pediatric illnesses. Disease progression is tracked by symptoms, echocardiogram, and biomarkers. Treatment is extrapolated from mostly adult heart failure (HF) literature. Recent studies demonstrate differences between pediatric and adult HF pathophysiology. Increased collaboration among PHF programs is advancing the management of PHF. Unfortunately, there are patients who ultimately require heart transplantation, with increasing numbers supported by a ventricular assist device as a bridge to transplantation.

Beta-blockers for congestive heart failure in children

BACKGROUND

Beta-blockers are an essential part of standard therapy in adult congestive heart failure and therefore, are expected to be beneficial in children. However, congestive heart failure in children differs from that in adults in terms of characteristics, aetiology, and drug clearance. Therefore, paediatric needs must be specifically investigated. This is an update of a Cochrane review previously published in 2009.

OBJECTIVES

To assess the effect of beta-adrenoceptor-blockers (beta-blockers) in children with congestive heart failure.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and LILACS up to November 2015. Bibliographies of identified studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised, controlled, clinical trials investigating the effect of beta-blocker therapy on paediatric congestive heart failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and assessed data from the included trials.

MAIN RESULTS

We identified four new studies for the review update; the review now includes seven studies with 420 participants. Four small studies with 20 to 30 children each, and two larger studies of 80 children each, showed an improvement of congestive heart failure with beta-blocker therapy. A larger study with 161 participants showed no evidence of benefit over placebo in a composite measure of heart failure outcomes. The included studies showed no significant difference in mortality or heart transplantation rates between the beta-blocker and control groups. No significant adverse events were reported with beta-blockers, apart from one episode of complete heart block. A meta-analysis of left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) data showed a very small improvement with beta-blockers. However, there were vast differences in the age, age range, and health of the participants (aetiology and severity of heart failure; heterogeneity of diagnoses and co-morbidities); there was a range of treatments across studies (choice of beta-blocker, dosing, duration of treatment); and a lack of standardised methods and outcome measures. Therefore, the primary outcomes could not be pooled in meta-analyses.

AUTHORS' CONCLUSIONS

There is not enough evidence to support or discourage the use of beta-blockers in children with congestive heart failure, or to propose a paediatric dosing scheme. However, the sparse data available suggested that children with congestive heart failure might benefit from beta-blocker treatment. Further investigations in clearly defined populations with standardised methodology are required to establish guidelines for therapy. Pharmacokinetic investigations of beta-blockers in children are also required to provide effective dosing in future trials.

Growth differentiation factor 15 as a useful biomarker of heart failure in young patients with unrepaired congenital heart disease of left to right shunt

BACKGROUND

Growth differentiation factor 15 (GDF 15) is a member of the transforming growth factor-beta superfamily and is considered to be a useful biomarker for severity of heart failure (HF) in repaired congenital heart disease (CHD). The aim of this study was to determine the clinical implication of GDF 15 in children with unrepaired CHD.

METHODS

Subjects included 69 patients (≤14 years old) who had unrepaired CHD with left to right shunt and underwent cardiac catheterization. Demographic and hemodynamic data, including oxygen demand-supply relationship, were collected from medical records. Severity of HF was evaluated using modified Ross score. Serum GDF 15 levels were determined using enzyme-linked immunosorbent assay and correlated with patients' demographics, hemodynamic data, and blood chemistry data.

RESULTS

Subjects had median age of 71 (range 1-173) months and simple acyanotic CHDs with mean pulmonary to systemic flow ratio of 2.0 (1.0-5.6), median N-terminal pro type Brain natriuretic peptide (NT-pro-BNP) of 162.8 (17.1-8789) pg/mL, and median GDF 15 of 242.1 (13.6-1116.7) pg/mL. GDF 15 significantly positively correlated with the modified Ross score, mean pulmonary artery pressure, oxygen extraction rate (OER), and Ln NT-pro-BNP, but negatively correlated with age, oxygen delivery and its components, and estimated glomerular filtration rate (eGFR). Multiple linear regression analysis revealed significant correlation of GDF 15 levels with the modified Ross score, OER, and eGFR.

CONCLUSIONS

GDF 15 mainly reflects oxygen demand-supply relationship and can be used as a diagnostic marker of HF in unrepaired CHD with left to right shunt for a wide range of age and diagnoses.

The influence of heart failure on the pharmacokinetics of cardiovascular and non-cardiovascular drugs: a critical appraisal of the evidence

Prescribing in heart failure (HF), a common disease state that predominantly affects the older population, is often a challenging task because of the dynamic nature of the condition, requiring frequent monitoring and medication review, the presence of various comorbidities, and the frailty phenotype of many patients. The significant alterations in various organs and tissues occurring in HF, particularly the reduced cardiac output with peripheral hypoperfusion and the structural and functional changes of the gastrointestinal tract, liver and kidney, might affect the pharmacokinetics of several drugs. This review critically appraises the results of published studies investigating the pharmacokinetics of currently marketed cardiovascular and selected non-cardiovascular drugs in HF patients and control groups, identifies gaps in the current knowledge, and suggests avenues for future research in this complex patient population.

Pediatric Cardiomyopathies

Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534.

Perspective on precision medicine in paediatric heart failure

In 2015, President Obama launched the Precision Medicine Initiative (PMI), which introduced new funding to a method of research with the potential to study rare and complex diseases. Paediatric heart failure, a heterogeneous syndrome affecting approximately 1 in 100000 children, is one such condition in which precision medicine techniques may be applied with great benefit. Current heart failure therapies target downstream effects of heart failure rather than the underlying cause of heart failure. As such, they are often ineffective in paediatric heart failure, which is typically of primary (e.g. genetic) rather than secondary (e.g. acquired) aetiology. It is, therefore, important to develop therapies that can target the causes of heart failure in children with greater specificity thereby decreasing morbidity, mortality and burden of illness on both patients and their families. The benefits of co-ordinated research in genomics, proteomics, metabolomics, transcriptomics and phenomics along with dietary, lifestyle and social factors have led to novel therapeutic and prognostic applications in other fields such as oncology. Applying such co-ordinated research efforts to heart failure constitutes an important step in advancing care and improving the lives of those affected.

Novel carvedilol paediatric nanomicelle formulation: in-vitro characterization and in-vivo evaluation

Objectives

Carvedilol (CAR) is a poorly water-soluble beta-blocker. Its encapsulation within nanomicelles (NMs) could improve drug solubility and its oral bioavailability, allowing the development of a paediatric liquid CAR formulation with commercially available copolymers: D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and poly(vinyl caprolactam)-poly(vinyl acetate)-poly(ethylene glycol) (Soluplus®).

Methods

Drug-loaded NMs were prepared by copolymer and CAR dispersion in distilled water. Micellar size and morphology were characterized by dynamic light scattering and transmission electron microscopy, respectively. In-vitro drug permeation studies were evaluated by conventional gut sac method. In-vivo CAR oral bioavailability from NMs dispersions and drug control solution was evaluated in Wistar rats.

Key findings

Carvedilol apparent aqueous solubility was increased (up to 60.4-folds) after its encapsulation within NMs. The micellar size was ranged between 10.9 and 81.9 nm with a monomodal size distribution. There was a significant enhancement of CAR relative oral bioavailability for both copolymers vs a micelle-free drug solution (P &lt; 0.05). This improvement was higher for TPGS-based micelles (4.95-fold) in accordance with the in-vitro CAR permeation results.

Conclusions

The present investigation demonstrates the development of highly concentrated CAR liquid micellar formulation. The improvement on drug oral bioavailability contributes to the potential of this NMs formulation to enhance CAR paediatric treatment.

Predicting Stereoselective Disposition of Carvedilol in Adult and Pediatric Chronic Heart Failure Patients by Incorporating Pathophysiological Changes in Organ Blood Flows-A Physiologically Based Pharmacokinetic Approach

Chronic heart failure (CHF) is a systemic low perfusion syndrome resulting from impairment in the pumping function of the heart. The decrease in blood supply to body organs can potentially affect the pharmacokinetics (PK) of the drugs being administered. Carvedilol is administered as a racemic mixture and undergoes extensive stereoselective first pass metabolism. For such a drug, the pathophysiological changes occurring in CHF can have a profound impact on PK, and thus the resulting pharmacodynamic response, of both enantiomers. The aim of the current work was to predict stereoselective disposition of carvedilol after incorporating the pathophysiological changes in CHF into a whole-body physiologically based PK model using Simcyp, and to scale that model to pediatric CHF patients on a physiologic basis to investigate whether the same changes in the adult model can also be adopted for children. The developed model has successfully described PK of carvedilol enantiomers in healthy adults and in patients after the incorporation of reduced organ blood flows, as seen by the visual predictive checks and the calculated observed/predicted ratios for all PK parameters of interest. In contrast to adults, pediatric patients up to 12 years of age were better described without the reductions in organ blood flow, whereas older pediatric patients were better described after incorporating organ blood flow reductions. These findings indicate that the incorporated blood flow reductions in the adult model cannot be directly adopted in pediatrics, at least for the young ones; however, to draw definite conclusions, more data are still needed.

A physiologically based pharmacokinetic drug-disease model to predict carvedilol exposure in adult and paediatric heart failure patients by incorporating pathophysiological changes in hepatic and renal blood flows

Background and Objective

Chronic diseases are associated with pathophysiological changes that could have profound impacts on drug pharmacokinetic behaviour, with a potential need to modify the administered drug therapy. It is important to acknowledge that most patients with chronic illnesses do not have a single, predominant condition but suffer from multiple comorbidities. The rapid advancement in physiologically based pharmacokinetic (PBPK) modelling, as well as the increasing quantitative knowledge of disease-related pathophysiological changes, facilitate building of drug–disease models. However, there are only a few published examples of PBPK models incorporating the pathophysiological changes that occur with chronic diseases. The objective of this study was to develop PBPK models that incorporate the haemodynamic changes in hepatic and renal blood flows occurring in chronic heart failure (CHF) and to evaluate these changes in adults and children, using carvedilol as a model drug.

Methods

After a comprehensive literature search to select the model input parameters, two PBPK models were developed. Model 1 was based on human liver and intestinal microsome clearances, and model 2 was based on clearance by specific cytochrome P450 enzymes. After evaluation of both models in healthy adults, the reduced hepatic and renal blood flows were incorporated into the developed models to predict carvedilol exposure in the adult CHF population. The adult carvedilol models were scaled down to children by using Simcyp^® (Simcyp Ltd, Sheffield, UK). In order to show the impact of reduced organ blood flows on carvedilol disposition, the predictions in the CHF population were made with and without reductions in organ blood flows.

Results

The predictions made by both models in healthy adults were comparable and within the 2-fold error range. In adults with CHF, the mean observed/predicted ratio [ratio_(Obs/Pred)] for oral clearance (CL/F) without reductions in organ blood flows was outside the 2-fold error range, i.e. 0.34 (95 % confidence interval [CI] 0.31–0.37), with use of both models. The mean CL/F ratio_(Obs/Pred) values after incorporation of reduced organ blood flows were 1.0 (95 % CI 0.92–1.08) and 0.95 (95 % CI 0.88–1.03) with use of models 1 and 2, respectively. The mean ratio_(Obs/Pred) values for the pharmacokinetic parameters were not improved after incorporation of reduced blood flows in paediatric patients, except in those above 17 years of age, who were categorized according to the New York Heart Association classification of CHF, where the CL/F ratio_(Obs/Pred) values in two patients were closer to unity.

Conclusion

There was a strong connection between a decrease in hepatic clearance of carvedilol and an increase in the severity of CHF, especially in adults and in paediatric patients above 17 years of age. The incorporated reductions in hepatic and renal blood flows occurring in moderate and severe CHF patients resulted in improved predictions of carvedilol exposure. The developed models can be extended to predict exposures of drugs with high hepatic extraction in the CHF population.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-015-0253-7) contains supplementary material, which is available to authorized users.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Chronic Heart Failure

OBJECTIVE

Heart failure is a serious complication that can occur in patients with a variety of congenital and acquired disorders including congenital heart disease, cardiomyopathy, and myocarditis. Furthermore, heart failure patients comprise an increasing number of ICU admissions. Thus, it is important for those caring for patients with critical cardiovascular disease to have a thorough understanding of the medications used for the treatment of heart failure. The aim of this review is to provide an overview, rationale, indications, and adverse effects of medications used in the treatment of chronic heart failure.

DATA SOURCES

PubMed, Medline, Cochrane Database of Systemic Reviews.

STUDY SELECTION

Studies were selected on their relevance for pediatric heart failure. When limited data on pediatric heart failure were available, studies in adult patients were selected.

DATA EXTRACTION

Relevant findings from studies were selected by the authors.

DATA SYNTHESIS

The rationale for the efficacy of most heart failure medications used in pediatric patients is extrapolated from studies in adult heart failure. Commonly used medications for chronic heart failure include β-receptor antagonists (e.g., carvedilol and metoprolol), and medications aimed at blocking the renin-angiotensin-aldosterone system (e.g., angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, aldosterone receptor antagonists). In addition, diuretics are useful for symptoms of fluid overload. For patients with impaired perfusion, inotropic agents are useful acutely, but may be associated with worse outcomes when used chronically. Newer medications that have been recently approved in adults (e.g., serelaxin, ivabradine, and neprilysin inhibitor [angiotensin receptor blocker]) may prove to be important in pediatric heart failure.

CONCLUSIONS

Heart failure patients are in an important population of critically ill children. The pharmacologic approach to these patients is aimed at treating symptoms of congestion and/or poor perfusion and improving long-term outcomes.

Beta-blockers for congestive heart failure in children

BACKGROUND

Beta-blockers are an essential part of standard therapy in adult congestive heart failure and therefore, are expected to be beneficial in children. However, congestive heart failure in children differs from that in adults in terms of characteristics, aetiology, and drug clearance. Therefore, paediatric needs must be specifically investigated. This is an update of a Cochrane review previously published in 2009.

OBJECTIVES

To assess the effect of beta-adrenoceptor-blockers (beta-blockers) in children with congestive heart failure.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and LILACS up to November 2015. Bibliographies of identified studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised, controlled, clinical trials investigating the effect of beta-blocker therapy on paediatric congestive heart failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and assessed data from the included trials.

MAIN RESULTS

We identified four new studies for the review update; the review now includes seven studies with 420 participants. Four small studies with 20 to 30 children each, and two larger studies of 80 children each, showed an improvement of congestive heart failure with beta-blocker therapy. A larger study with 161 participants showed no evidence of benefit over placebo in a composite measure of heart failure outcomes. The included studies showed no significant difference in mortality or heart transplantation rates between the beta-blocker and control groups. No significant adverse events were reported with beta-blockers, apart from one episode of complete heart block. A meta-analysis of left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) data showed a very small improvement with beta-blockers.However, there were vast differences in the age, age range, and health of the participants (aetiology and severity of heart failure; heterogeneity of diagnoses and co-morbidities); there was a range of treatments across studies (choice of beta-blocker, dosing, duration of treatment); and a lack of standardised methods and outcome measures. Therefore, the primary outcomes could not be pooled in meta-analyses.

AUTHORS' CONCLUSIONS

There is not enough evidence to support or discourage the use of beta-blockers in children with congestive heart failure, or to propose a paediatric dosing scheme. However, the sparse data available suggested that children with congestive heart failure might benefit from beta-blocker treatment. Further investigations in clearly defined populations with standardised methodology are required to establish guidelines for therapy. Pharmacokinetic investigations of beta-blockers in children are also required to provide effective dosing in future trials.

Diagnostic Accuracy of NT-ProBNP for Heart Failure with Sepsis in Patients Younger than 18 Years

This clinical study investigated plasma NT-proBNP levels as a potential predictor of heart failure in pediatric patients with sepsis. Plasma NT-ProBNP levels of 211 pediatric patients with sepsis and 126 healthy children were measured. Patients were stratified as with heart failure (HF) or without heart failure (non-HF). Patients were graded as having sepsis, severe sepsis, or septic shock. The optimal cut-off values of plasma NT-ProBNP for heart failure were determined by analyzing the receiver operating characteristic (ROC). In the HF, non-HF and control groups, the median plasma NT-proBNP levels were 3640, 656, and 226 ng/L, respectively. For all patients with sepsis, the optimal diagnostic cut-off value was 1268 ng/L for differentiating heart failure. In the severe sepsis patients and septic shock patients, the optimal diagnostic cut-off values were 1368 ng/L and 1525 ng/L, respectively. This report is the first one to reveal that NT-proBNP may predict heart failure in children with sepsis. It provides an important clinical reference for the diagnosis of heart failure in pediatric patients with sepsis, and enables monitoring septic children for cardiac involvement.

Clinical Characteristics and Treatment of Cardiomyopathies in Children

Cardiomyopathies are diseases of the heart muscle, a term introduced in 1957 to identify a group of myocardial diseases not attributable to coronary artery disease. The definition has since been modified to refer to structural and or functional abnormalities of the myocardium where other known causes of myocardial dysfunction, such as systemic hypertension, valvular disease and ischemic heart disease, have been excluded. In this review, we discuss the pathophysiology, clinical assessment and therapeutic strategies for hypertrophic, dilated and hypertrophic cardiomyopathies, with a particular focus on aspects unique to children.

Passive movement and active exercise for very young infants with congenital heart disease: a study protocol for a randomized controlled trial

Background

Delayed motor development is reported in patients with congenital heart disease (CHD). Exercise is widely used to facilitate motor development and improve motor ability. Exercise for adolescents and adults with CHD has been extensively studied. However, the evidence of exercise for infants with CHD is sparse. This study aims to identify the effect of passive movement and active exercise on motor development within very young CHD infants with cardiac catheterization.

Methods/Design

A prospective and randomized controlled trial will be conducted in very young CHD infants with cardiac catheterization. A total of 147 infants with CHD will be randomized by a 1:1:1 allocation ratio by computer to an exercise intervention group, a home-based intervention group and a control group. The exercise intervention group will receive passive movement and active exercise from experienced physiotherapists in pediatrics three times a week for 12 weeks. The home-based intervention group will receive passive movement and active exercise from their parents or caregivers at home three times a week for 12 weeks. The control group will receive follow up only. The follow-up duration is 20 months. The primary outcome measures are the motor quotient measured by the Peabody Developmental Motor Scales-II. The secondary outcome measures are the Ross score, ventricular function, bone quality, body length, weight, head circumference, upper arm circumference, and adverse events.

Discussion

This study has several important features, including the randomization process, the long follow-up duration, the control group, and the large sample size. The aim of this study is to determine whether 12-week passive movement and active exercise promotes motor development and produces other beneficial effects for very young CHD infants with cardiac catheterization. Therefore, this study will contribute new knowledge regarding the rehabilitation program in very young CHD infants with cardiac catheterization.

Trial registration

Current Controlled Trials ChiCTR-IOR-15005909 (January 31, 2015).

Presentation, diagnosis, and medical management of heart failure in children: Canadian Cardiovascular Society guidelines

Pediatric heart failure (HF) is an important cause of morbidity and mortality in childhood. This article presents guidelines for the recognition, diagnosis, and early medical management of HF in infancy, childhood, and adolescence. The guidelines are intended to assist practitioners in office-based or emergency room practice, who encounter children with undiagnosed heart disease and symptoms of possible HF, rather than those who have already received surgical palliation. The guidelines have been developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, and are accompanied by practical Recommendations for their application in the clinical setting, supplemented by online material. This work does not include Recommendations for advanced management involving ventricular assist devices, or other device therapies.

Role of the NT-proBNP level in the diagnosis of pediatric heart failure and investigation of novel combined diagnostic criteria

The aim of this study was to investigate the modified Ross criteria score and the diagnostic cut-off level for plasmatic amino-terminal pro-brain natriuretic peptide (NT-proBNP) in the diagnosis of pediatric heart failure, by analyzing the receiver operating characteristic (ROC) curve. The plasma NT-proBNP level was measured in 80 children diagnosed with heart failure according to the modified Ross criteria, 80 children with non-cardiogenic dyspnea and 80 healthy children. The NT-proBNP levels were then compared using an F-test. The cut-off score for heart failure in the modified Ross criteria and the diagnostic cut-off level for plasmatic NT-proBNP in pediatric heart failure were determined by ROC curve analysis. The results demonstrated that the NT-proBNP level was markedly increased in 76 of the 80 children with heart failure, and the correlation with the modified Ross criteria was 95%. Based on ROC curve analysis, the diagnosis of pediatric heart failure was most accurate when the modified Ross criteria score was ≥4 and the plasmatic NT-proBNP level was ≥598 ng/l. The NT-proBNP level was normal (0–300 ng/l) in the children with non-cardiogenic dyspnea and the healthy children. Significant differences were observed in the comparison of the three groups (P<0.01). In conclusion, a NT-proBNP level of ≥598 ng/l, combined with a modified Ross criteria score ≥4, is highly diagnostic of heart failure in children.

Clinical and echocardiographic outcome in patients receiving carvedilol for treatment of dilated cardiomyopathy

OBJECTIVE

To determine outcome of children receiving carvedilol in addition to other standard drug therapy for treatment of dilated cardiomyopathy.

METHODS

Children receiving carvedilol for treatment of dilated cardiomyopathy with moderate to severe ventricular dysfunction were included into the study. Data on history, clinical examination and investigations were obtained and detailed echocardiography findings were recorded for the initial and all subsequent visits.

RESULTS

Thirty-three children, mean age 26 ± 30 mo (range 7 mo to 138 mo) were enrolled. Carvedilol was initiated at a mean dose of 0.14 ± 0.03 mg/kg/d and the maintenance dose was 0.46 ± 0.14 mg/kg/d. At a follow up of 6-90 mo (mean of 28 ± 23 mo), functional class using Ross classification for pediatric heart failure improved from 2.7 to 1.3. The left ventricular ejection fraction rose from a basal value of 22 % ± 7 % (10-40 %) to 42 % ± 15 % (15-65 %) (p < 0.0001). Similarly, left ventricular fractional shortening increased significantly from 16 ± 6 % (8-34 %) to 21 ± 7 % (10-44 %) (p < 0.0001). One patient deteriorated and died of refractory heart failure. Carvedilol was discontinued in two more patients temporarily due to bronchospasm during respiratory infection.

CONCLUSIONS

The present study suggests that improvement in ventricular function and clinical symptoms is seen on oral carvedilol added to standard drug therapy in pediatric patients with dilated cardiomyopathy and moderate to severe ventricular dysfunction. The drug is well tolerated with minimal side effects but close monitoring is required as it may worsen heart failure and bronchospasm.

The effect of carvedilol treatment on chronic heart failure in pediatric patients with dilated cardiomyopathy: a prospective, randomized-controlled study

This study aimed to evaluate the clinical efficacy and safety of carvedilol for pediatric patients with chronic heart failure caused by dilated cardiomyopathy. Seven pediatric medical centers participated in this prospective study. Pediatric patients (n = 89) were randomly divided into an experimental group (carvedilol treatment) and a control group (conventional treatment). The analysis excluded 12 patients lost during the follow-up period. Carvedilol was added to the therapy of the experimental group after at least 1 month of basic treatment with digoxin, an angiotensin-converting-enzyme inhibitor, and diuretics. The control patients received the same basic treatment but did not receive carvedilol. The initial dose of carvedilol was 0.1 (mg/kg day), and the dose was doubled every 2 weeks until the maximum tolerated dose or 0.8 (mg/kg day) was achieved. The tolerated dose was maintained for 6 months. The Ross scales and echocardiographic parameters including left ventricular diastolic diameter, left ventricular systolic diameter, left ventricular ejection fraction, left ventricular fractional shortening, and serous brain natriuretic peptide (BNP) concentration, as well as clinical progress were compared between the two groups. The Ross scales decreased by 11.94% in the experimental group, which was more than in the control group (2.81%). In addition, changes to other echocardiographic parameters in the experimental group also were superior to those in the control group. The serous BNP concentration in the experimental group decreased by 30.1%, which also was more than the decrease (22.2%) observed in the control group. Clinical improvement was demonstrated by 40%, no change by 35%, and clinical deterioration by 25% of the patients in the experimental group, and by respectively 37.8, 27, and 35.2% of the patients in the control group. These differences were not statistically significant. Only one patient demonstrated a severe adverse event, severe pulmonary infection, and complete atrioventricular block. None of the other carvedilol-treated patients experienced drug-related side effects. Carvedilol can be safely used for treatment of chronic heart dysfunction in pediatric patients with dilated cardiomyopathy. The results in this study showed an apparent improvement in the cardiac function of these patients. Additional clinical studies are required to determine the most favorable dosing levels and regimens of carvedilol before its safety and efficacy for the pediatric population can be determined conclusively.

The Ross classification for heart failure in children after 25 years: a review and an age-stratified revision

Accurate grading of the presence and severity of heart failure (HF) signs and symptoms in infants and children remains challenging. It has been 25 years since the Ross classification was first used for this purpose. Since then, several modifications of the system have been used and others proposed. New evidence has shown that in addition to signs and symptoms, data from echocardiography, exercise testing, and biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP) all are useful in stratifying outcomes for children with HF. It also is apparent that grading of signs and symptoms in children is dependent on age because infants manifest HF differently than toddlers and older children. This review culminates in a proposed new age-based Ross classification for HF in children that incorporates the most useful data from the last two decades. Testing of this new system will be important to determine whether an age-stratified scoring system can unify the way communication of HF severity and research on HF in children is performed in the future.

Individual oral therapy with immediate release and effervescent formulations delivered by the solid dosage pen

New devices enabling freely selectable dosing of solid oral medications are urgently needed for personalized medicine. One approach is the use of the recently published Solid Dosage Pen, allowing flexible dosing of tablet-like sustained release slices from drug loaded extruded strands. Slices were suitable for oral single dosed application. The aim of the present study was the development of immediate release dosage forms for applications of the device, especially for young children. Using two model drugs, two different concepts were investigated and evaluated. Effervescent formulations were manufactured by an organic wet-extrusion process and immediate release formulations by a melt-extrusion process. Dissolution experiments were performed for both formulations to ensure the immediate release behavior. Extruded strands were individually dosed by the Solid Dosage Pen. Various doses of the two formulations were analyzed regarding uniformity of mass and content according to pharmacopoeial specifications. Proof of concept was demonstrated in both approaches as results comply with the regulatory requirements. Furthermore, storing stress tests were performed and drug formulations were characterized after storing. The results show that suitable packaging material has been selected and storage stability is probable.

Use of carvedilol in hypertension: an update

β-blockers are effective antihypertensive agents and, together with diuretics, have been the cornerstone of pioneering studies showing their benefits on cardiovascular morbidity and mortality as a consequence of blood pressure reduction in patients with hypertension. However, evidence from recent meta-analyses have demonstrated no benefit afforded by atenolol compared with placebo in risk of mortality, myocardial infarction, or stroke, and a higher risk of mortality and stroke with atenolol/propranolol compared with other antihypertensive drug classes. Thus, the effect of these agents on cardiovascular morbidity and mortality in hypertensive patients, especially their use in uncomplicated hypertension, has remained largely controversial. However, it is recognized that the clinical studies used in these meta-analyses were mainly based on the older second-generation β-blockers, such as atenolol and metoprolol. Actually, considerable heterogeneity in, eg, pharmacokinetic, pharmacological, and physicochemical properties exists across the different classes of β-blockers, particularly between the second-generation and newer third-generation agents. Carvedilol is a vasodilating noncardioselective third-generation β-blocker, without the negative hemodynamic and metabolic effects of traditional β-blockers, which can be used as a cardioprotective agent. Compared with conventional β-blockers, carvedilol maintains cardiac output, has a reduced prolonged effect on heart rate, and reduces blood pressure by decreasing vascular resistance. Studies have also shown that carvedilol exhibits favorable effects on metabolic parameters, eg, glycemic control, insulin sensitivity, and lipid metabolism, suggesting that it could be considered in the treatment of patients with metabolic syndrome or diabetes. The present report provides an overview of the main clinical studies concerning carvedilol administered as either monotherapy or in combination with another antihypertensive or more frequently a diuretic agent, with particular focus on the additional benefits beyond blood pressure reduction.