Lessons learned from a pediatric clinical trial: the Pediatric Heart Network angiotensin-converting enzyme inhibition in mitral regurgitation study

Biology of mitral valve prolapse: from general mechanisms to advanced molecular patterns-a narrative review

Mitral valve prolapse (MVP) represents the most frequent cause of primary mitral regurgitation. For several years, biological mechanisms underlying this condition attracted the attention of investigators, trying to identify the pathways responsible for such a peculiar condition. In the last ten years, cardiovascular research has moved from general biological mechanisms to altered molecular pathways activation. Overexpression of TGF-β signaling, for instance, was shown to play a key role in MVP, while angiotensin-II receptor blockade was found to limit MVP progression by acting on the same signaling pathway. Concerning extracellular matrix organization, the increased valvular interstitial cells density and dysregulated production of catalytic enzymes (matrix metalloproteinases above all) altering the homeostasis between collagen, elastin and proteoglycan components, have been shown to possibly provide a mechanistic basis contributing to the myxomatous MVP phenotype. Moreover, it has been observed that high levels of osteoprotegerin may contribute to the pathogenesis of MVP by increasing collagen deposition in degenerated mitral leaflets. Although MVP is believed to represent the result of multiple genetic pathways alterations, it is important to distinguish between syndromic and non-syndromic conditions. In the first case, such as in Marfan syndrome, the role of specific genes has been clearly identified, while in the latter a progressively increasing number of genetic loci have been thoroughly investigated. Moreover, genomics is gaining more interest as potential disease-causing genes and loci possibly associated with MVP progression and severity have been identified. Animal models could be of help in better understanding the molecular basis of MVP, possibly providing sufficient information to tackle specific mechanisms aimed at slowing down MVP progression, therefore developing non-surgical therapies impacting on the natural history of this condition. Although continuous progress has been made in this field, further translational studies are advocated to improve our knowledge of biological mechanisms underlying MVP development and progression.

A systematic review of the evidence supporting post-operative medication use in congenital heart disease

BACKGROUND

Targeted drug development efforts in patients with CHD are needed to standardise care, improve outcomes, and limit adverse events in the post-operative period. To identify major gaps in knowledge that can be addressed by drug development efforts and provide a rationale for current clinical practice, this review evaluates the evidence behind the most common medication classes used in the post-operative care of children with CHD undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

We systematically searched PubMed and EMBASE from 2000 to 2019 using a controlled vocabulary and keywords related to diuretics, vasoactives, sedatives, analgesics, pulmonary vasodilators, coagulation system medications, antiarrhythmics, steroids, and other endocrine drugs. We included studies of drugs given post-operatively to children with CHD undergoing repair or palliation with cardiopulmonary bypass.

RESULTS

We identified a total of 127 studies with 51,573 total children across medication classes. Most studies were retrospective cohorts at single centres. There is significant age- and disease-related variability in drug disposition, efficacy, and safety.

CONCLUSION

In this study, we discovered major gaps in knowledge for each medication class and identified areas for future research. Advances in data collection through electronic health records, novel trial methods, and collaboration can aid drug development efforts in standardising care, improving outcomes, and limiting adverse events in the post-operative period.

Updated analysis of pediatric clinical studies registered in ClinicalTrials.gov, 2008-2019

Background

Since the national clinical trials registry (ClinicalTrials.gov) launched in February 2000, more than 360,000 research studies in the United States and over 200 countries have registered. As the characteristics of pediatric clinical studies keep changing over time and the results-reporting mechanism is under evolving, to know about the relevant updates of data elements and the effect of policies on the quality of reporting results is significant.

Methods

In this research, 53,060 clinical studies related to children registered from January 2008 to December 2019 were downloaded from ClinicalTrials.gov on August 1st, 2020. Different types of studies and critical categorical variables were identified, based on which, Cochran-Armitage test was performed to explore temporal trend of study characteristics and common pediatric clinical conditions in four time subsets. Further, to examine heterogeneity among subgroups (funding sources, funding sites, pediatric clinical conditions,etc), chi-squared test was applied.

Results

A total of 36,136 clinical trials and 16,692 observational studies were identified during the study period. The pediatric clinical trials increased from 7,029 (January 2008–December 2010) to 11,738 (January 2017–December 2019). The number of missing data has declined, with the maximum extent decline from 3.7 to 0.0% (Z = − 15.90, p <  0.001). Drug trials decreased from 48.8 to 28.9% (Z = − 24.68, p <  0.001). Behavioral trials, on the other hand, increased from 12.6 to 20.4% (Z = 12.28, p <  0.001). Most pediatric clinical trials were small-scale (58.9% enrolling 1–100 participants), single-site (61.4%) and funded neither by industry nor by the NIH (59.2%). The proportion of reporting study results varied by study type (χ² = 1,256.8, p <  0.001), lead sponsor (χ² = 4,545.6, p <  0.001), enrollment (χ² = 29.4, p <  0.001) and trial phase (χ² = 218.8, p <  0.001).

Conclusion

Pediatric clinical studies registered in ClinicalTrials.gov were dominated by small-scale interventional trials, containing significant heterogeneity in funding sources, funding sites, pediatric clinical conditions and study characteristics. Although the results database has evolved in the past decade, efforts to strengthen the practice of systematic reporting must be continued.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02658-4.

Recruitment, retention, and adherence in a clinical trial: The Pediatric Heart Network's Marfan Trial experience

BACKGROUND/AIMS

The Pediatric Heart Network Marfan Trial was a randomized trial comparing atenolol versus losartan on aortic root dilation in 608 children and young adults with Marfan syndrome. Barriers to enrollment included a limited pool of eligible participants, restrictive entry criteria, and a diverse age range that required pediatric and adult expertise. Retention was complicated by a 3-year commitment to a complex study and medication regimen. The Network partnered with the Marfan Foundation, bridging the community with the research. The aims of this study are to report protocol and medication adherence and associated predictive factors, and to describe recruitment and retention strategies.

METHODS

Recruitment, retention, and adherence to protocol activities related to the primary outcome were measured. Retention was measured by percentage of enrolled participants with 3-year outcome data. Protocol adherence was calculated by completion rates of study visits, ambulatory electrocardiography (Holter monitoring), and quarterly calls. Medication adherence was assessed by the number of tablets or the amount of liquid in bottles returned. Centers were ranked according to adherence (high, medium, and low tertiles). Recruitment, retention, and adherence questionnaires were completed by sites. Descriptive statistics summarized recruitment, retention, and adherence, as well as questionnaire results. Regression modeling assessed predictors of adherence.

RESULTS

Completion rates for visits, Holter monitors, and quarterly calls were 99%, 94%, and 96%, respectively. Primary outcome data at 3 years were obtained for 88% of participants. The mean percentage of medication taken was estimated at 89%. Site and age were associated with all measures of adherence. Young adult and African American participants had lower levels of adherence. Higher adherence sites employed more strategies; had more staffing resources, less key staff turnover, and more collaboration with referring providers; utilized the Foundation's resources; and used a greater number of strategies to recruit, retain, and promote protocol and medication adherence.

CONCLUSION

Overall adherence was excellent for this trial conducted within a National Institutes of Health-funded clinical trial network. Strategies specifically targeted to young adults and African Americans may have been beneficial. Many strategies employed by higher adherence sites are ones that any site could easily use, such as greeting families at non-study hospital visits, asking for family feedback, providing calendars for tracking schedules, and recommending apps for medication reminders. Additional key learnings include adherence differences by age, race, and site, the value of collaborative learning, and the importance of partnerships with patient advocacy groups. These lessons could shape recruitment, retention, and adherence to improve the quality of future complex trials involving rare conditions.

Pharmacology of enalapril in children: a review

Enalapril is an angiotensin-converting enzyme (ACE) inhibitor that is used for the treatment of (paediatric) hypertension, heart failure and chronic kidney diseases. Because its disposition, efficacy and safety differs across the paediatric continuum, data from adults cannot be automatically extrapolated to children. This review highlights paediatric enalapril pharmacokinetic data and demonstrates that these are inadequate to support with certainty an age-related effect on enalapril/enalaprilat pharmacokinetics. In addition, our review shows that evidence to support effective and safe prescribing of enalapril in children is limited, especially in young children and heart failure patients; studies in these groups are either absent or show conflicting results. We provide explanations for observed differences between age groups and indications, and describe areas for future research.

Enhancing efficiency and scientific impact of a clinical trials network: the Pediatric Heart Network Integrated CARdiac Data and Outcomes (iCARD) Collaborative

Recent years have seen an exponential increase in the variety of healthcare data captured across numerous sources. However, mechanisms to leverage these data sources to support scientific investigation have remained limited. In 2013 the Pediatric Heart Network (PHN), funded by the National Heart, Lung, and Blood Institute, developed the Integrated CARdiac Data and Outcomes (iCARD) Collaborative with the goals of leveraging available data sources to aid in efficiently planning and conducting PHN studies; supporting integration of PHN data with other sources to foster novel research otherwise not possible; and mentoring young investigators in these areas. This review describes lessons learned through the development of iCARD, initial efforts and scientific output, challenges, and future directions. This information can aid in the use and optimisation of data integration methodologies across other research networks and organisations.

Pharmacotherapy in paediatric heart failure: a Delphi process

BACKGROUND

Little evidence exists to support pharmacotherapeutic strategies for heart failure management in paediatrics. A recent Europe-wide survey suggests that this translates into substantial variability in clinical practice.

OBJECTIVE

To conduct a formal discussion among an expert group of paediatric cardiology physicians on controversial aspects regarding the pharmacotherapy of children heart failure, facilitate consensus, and highlight areas of agreement and disagreement.

METHODS

A two-round modified Delphi process was conducted between July and August 2015. Topics addressed were predominantly selected from the results of a previous Europe-wide survey. Fourteen statements were presented for discussion grouped under three categories; Angiotensin-converting-enzyme-inhibitors: Considerations for optimal dosage; Angiotensin-converting-enzyme-inhibitors for the management of CHDs; Neurohumoral antagonists for the management of dilated cardiomyopathy-related heart failure.

RESULTS

A total of 13 paediatricians dedicated to cardiology from across Europe and the United States of America completed the study; of them, 92% had a working experience in the field of more than 10 years and were working in a specific paediatric cardiology unit. Agreement on the acceptance/rejection of 11 statements was achieved. Results show agreement on the importance of a set of topics relevant to the standardisation of the therapy as well as consensus upon specific therapeutic attitudes.

CONCLUSIONS

We have found areas of common thinking and motivation, which can provide a means of triggering scientific collaboration. Our results might also contribute to disseminate available paediatric evidence and promote reducing unjustified variability in everyday practice. Until solid evidence is available, other research methods can contribute to advancing the goal of safe and effective paediatric heart failure pharmacotherapy.

Pharmacotherapeutic management of paediatric heart failure and ACE-I use patterns: a European survey

OBJECTIVE

To characterise heart failure (HF) maintenance pharmacotherapy for children across Europe and investigate how angiotensin-converting enzyme inhibitors (ACE-I) are used in this setting.

METHODS

A Europe-wide web-based survey was conducted between January and May 2015 among European paediatricians dedicated to cardiology.

RESULTS

Out of 200-eligible, 100 physicians representing 100 hospitals in 27 European countries participated. All participants reported prescribing ACE-I to treat dilated cardiomyopathy-related HF and 97% in the context of congenital heart defects; 87% for single ventricle physiology. Twenty-six per cent avoid ACE-I in newborns. Captopril was most frequently selected as first-choice for newborns (73%) and infants and toddlers (66%) and enalapril for children (56%) and adolescents (58%). Reported starting and maintenance doses varied widely. Up to 72% of participants follow formal creatinine increase limits for decision-making when up-titrating; however, heterogeneity in the cut-off points selected existed. ACE-I formulations prescribed by 47% of participants are obtained from more than a single source. Regarding symptomatic HF maintenance therapy, 25 different initial drug combinations were reported, although 79% select a regimen that includes ACE-I and diuretic (thiazide and/or loop), 61% ACE-I and aldosterone antagonist; 44% start with beta-blocker, 52% use beta-blockers as an add-on drug. Of the 89 participants that prescribe pharmacotherapy to asymptomatic patients, 40% do not use ACE-I monotherapy or ACE-I-beta-blocker two-drug only combination.

CONCLUSIONS

Despite some reluctance to use them in newborns, ACE-I seem key in paediatric HF treatment strategies. Use in single ventricle patients seems frequent, in apparent contradiction with current paediatric evidence. Disparate dosage criteria and potential formulation-induced variability suggest significant differences may exist in the risk-benefit profile children are exposed to. No uniformity seems to exist in the drug regimens in use. The information collected provides relevant insight into real-life clinical practice and may facilitate research to identify the best therapeutic options for HF children.

Current State of Pediatric Heart Failure

Pediatric heart failure (HF) represents an important cause of morbidity and mortality in childhood. There is an overlapping relationship of HF, congenital heart disease, and cardiomyopathy. The goal of treatment of HF in children is to maintain stability, prevent progression, and provide a reasonable milieu to allow somatic growth and optimal development. Current management and therapy for HF in children are extrapolated from treatment approaches in adults. There are significant barriers in applying adult data to children because of developmental factors, age variation from birth to adolescence, and differences in the genetic expression profile and &beta;-adrenergic signaling. At the same time, there are significant challenges in performing well-designed drug trials in children with HF because of heterogeneity of diagnoses identifying a clinically relevant outcome with a high event rate, and a difficulty in achieving sufficient enrollment. A judicious balance between extrapolation from adult HF guidelines and the development of child-specific data on treatment represent a wise approach to optimize pediatric HF management. This approach is helpful as reflected by the increasing role of ventricular assist devices in the management of advanced HF in children. This review discusses the causes, epidemiology, pathophysiology, clinical manifestations, conventional medical treatment, clinical trials, and the role of device therapy in pediatric HF.

Moving toward a paradigm shift in the regulatory requirements for pediatric medicines

Over the past two decades, there has been growing concern over the lack of proper medication for children. This review attempts to evaluate the current progress of EU Pediatric Regulation made since 2007. The lack of properly evaluated pediatric medication has for long been a source of concern in the European Union. The drugs that were used in the past were often not properly evaluated, and dosage was arbitrarily calculated. Therefore, it was necessary to establish the Pediatric Regulation (EC no. 1901/2006) in the EU which would mandate research for pediatric drugs. Current legislations in place not only require mandatory research by pharma industry but also have guidelines to direct the quality of pediatric research performed. The main aim of this regulation was to advance high-quality research and development of pediatric drugs, thereby increasing the availability of safe and effective drugs for children. It also aimed to improve the information available on existing pediatric drugs. It has been 9 years since the pediatric regulation was framed. The pharma industry now sees pediatric research as an integral process of development. Drug companies which develop plans for a new drug, new form of drug, new indication, or new route of administration for adults are obliged to integrate in their development plan similar research for pediatric populations as well.

CONCLUSION

It is hoped that the implementation of the current legislation will be reflected better in the future by the marketing of better and safer drugs for the pediatric population. The upcoming assessment to the European Commission in 2017 will further inform us on the impact after 10 years implementation of the legislation. What is Known: • The lack of properly evaluated pediatric medication has for long been a source of concern in the European Union. • Therefore, it was necessary to establish the EU Pediatric Regulation which would mandate research for pediatric drugs. What is New: • It has been 9 years since the pediatric regulation was framed, and the teething problems are slowly being overcome and the regulation is being used with increasing confidence. • As the Regulation is due for revision in 2017, this paper gives a current perspective on the impact of the regulation on availability and access to medicine for children.

The pediatric heart network: meeting the challenges to multicenter studies in pediatric heart disease

PURPOSE OF REVIEW

Because of the relatively small numbers of pediatric patients with congenital heart disease cared for in any individual center, there is a significant need for multicenter clinical studies to validate new medical or surgical therapies. The Pediatric Heart Network (PHN), with 15 years of experience in multicenter clinical research, has tackled numerous challenges when conducting multicenter studies.

RECENT FINDINGS

This review describes the challenges encountered and the strategies employed to conduct high-quality, collaborative research in pediatric cardiovascular disease.

SUMMARY

Sharing lessons learned from the PHN can provide guidance to investigators interested in conducting pediatric multicenter studies.

Review of the International Society for Heart and Lung Transplantation Practice guidelines for management of heart failure in children

In 2004, practice guidelines for the management of heart failure in children by Rosenthal and colleagues were published in conjunction with the International Society for Heart and Lung Transplantation. These guidelines have not been updated or reviewed since that time. In general, there has been considerable controversy as to the utility and purpose of clinical practice guidelines, but there is general recognition that the relentless progress of medicine leads to the progressive irrelevance of clinical practice guidelines that do not undergo periodic review and updating. Paediatrics and paediatric cardiology, in particular, have had comparatively minimal participation in the clinical practice guidelines realm. As a result, most clinical practice guidelines either specifically exclude paediatrics from consideration, as has been the case for the guidelines related to cardiac failure in adults, or else involve clinical practice guidelines committees that include one or two paediatric cardiologists and produce guidelines that cannot reasonably be considered a consensus paediatric opinion. These circumstances raise a legitimate question as to whether the International Society for Heart and Lung Transplantation paediatric heart failure guidelines should be re-reviewed. The time, effort, and expense involved in producing clinical practice guidelines should be considered before recommending an update to the International Society for Heart and Lung Transplantation Paediatric Heart Failure guidelines. There are specific areas of rapid change in the evaluation and management of heart failure in children that are undoubtedly worthy of updating. These domains include areas such as use of serum and imaging biomarkers, wearable and implantable monitoring devices, and acute heart failure management and mechanical circulatory support. At the time the International Society for Heart and Lung Transplantation guidelines were published, echocardiographic tissue Doppler, 3 dimensional imaging, and strain and strain rate were either novel or non-existent and have now moved into the main stream. Cardiac magnetic resonance imaging (MRI) had very limited availability, and since that time imaging and assessment of myocardial iron content, delayed gadolinium enhancement, and extracellular volume have moved into the mainstream. The only devices discussed in the International Society for Heart and Lung Transplantation guidelines were extracorporeal membrane oxygenators, pacemakers, and defibrillators. Since that time, ventricular assist devices have become mainstream. Despite the relative lack of randomised controlled trials in paediatric heart failure, advances continue to occur. These advances warrant implementation of an update and review process, something that is best done under the auspices of the national and international cardiology societies. A joint activity that includes the International Society for Heart and Lung Transplantation, American College of Cardiology/American Heart Association, the Association for European Paediatric and Congenital Cardiology (AEPC), European Society of Cardiology, Canadian Cardiovascular Society, and others will have more credibility than independent efforts by any of these organisations.

Characterization and quantification of dynamic eccentric regurgitation of the left atrioventricular valve after atrioventricular septal defect correction with 4D Flow cardiovascular magnetic resonance and retrospective valve tracking

BACKGROUND

To characterize and directly quantify regurgitant jets of left atrioventricular valve (LAVV) in patients with corrected atrioventricular septal defect (AVSD) by four-dimensional (4D)Flow Cardiovascular Magnetic Resonance (CMR), streamline visualization and retrospective valve tracking.

METHODS

Medical ethical committee approval and informed consent from all patients or their parents were obtained. In 32 corrected AVSD patients (age 26 ± 12 years), echocardiography and whole-heart 4DFlow CMR were performed. Using streamline visualization on 2- and 4-chamber views, the angle between regurgitation and annulus was followed throughout systole. On through-plane velocity-encoded images reformatted perpendicular to the regurgitation jet the cross-sectional jet circularity index was assessed and regurgitant volume and fraction were calculated. Correlation and agreement between different techniques was performed with Pearson's r and Spearman's rho correlation and Bland-Altman analysis.

RESULTS

In 8 patients, multiple regurgitant jets over the LAVV were identified. Median variation in regurgitant jet angle within patients was 36°(IQR 18-64°) on the 2-chamber and 30°(IQR 20-40°) on the 4-chamber. Regurgitant jets had a circularity index of 0.61 ± 0.16. Quantification of the regurgitation volume was feasible with 4DFlow CMR with excellent correlation between LAVV effective forward flow and aortic flow (r = 0.97, p < 0.001) for internal validation and moderate correlation with planimetry derived regurgitant volume (r = 0.65, p < 0.001) and echocardiographic grading (rho = 0.51, p = 0.003).

CONCLUSIONS

4DFlow CMR with streamline visualization revealed multiple, dynamic and eccentric regurgitant jets with non-circular cross-sectional shape in patients after AVSD correction. 4DFlow with retrospective valve tracking allows direct and accurate quantification of the regurgitation of these complex jets.

Public health research in congenital heart disease

Public health research is an integral part of the study of congenital heart disease. While this type of research has become more popular, particularly over the past decade, it has a history that stretches back to almost the beginnings of pediatric cardiology as a field. This review aims to introduce the concepts and methodologies of public health and how they relate to congenital heart disease, describe some of the challenges of traditional research methods in congenital heart disease, describe the history of public health research, and demonstrate the relevance of public health research, particularly databases, to pediatric cardiology fellows.

Comparative effectiveness of digoxin and propranolol for supraventricular tachycardia in infants

OBJECTIVES

Supraventricular tachycardia is the most common arrhythmia in infants, and antiarrhythmic medications are frequently used for prophylaxis. The optimal prophylactic antiarrhythmic medication is unknown, and prior randomized trials have been underpowered. We used data from a large clinical registry to compare efficacy and safety of digoxin and propranolol for infant supraventricular tachycardia prophylaxis. We hypothesized that supraventricular tachycardia recurrence is less common on digoxin when compared with propranolol.

DESIGN

Retrospective cohort study.

SETTING

Pediatrix Medical Group neonatal ICUs.

PATIENTS

Infants discharged from 1998 to 2012 with supraventricular tachycardia who were treated with digoxin or propranolol. We excluded infants discharged before completing 2 days of therapy, those with Wolff-Parkinson-White syndrome, structural heart defects (except atrial/ventricular septal defects and patent ductus arteriosus), and those started on multidrug therapy.

MEASUREMENTS AND MAIN RESULTS

We used Cox proportional hazards to evaluate supraventricular tachycardia recurrence, defined as need for adenosine or electrical cardioversion while exposed to digoxin versus propranolol, controlling for infant characteristics, inotropic support, supplemental oxygen, and presence of a central line. We identified 342 infants exposed to digoxin and 142 infants exposed to propranolol. The incidence rate of treatment failure was 6.7/1,000 infant-days of exposure to digoxin and 15.4/1,000 infant-days of exposure to propranolol. On multivariable analysis, treatment failure was higher on propranolol when compared with that on digoxin (hazard ratio, 1.97; 95% CI, 1.05-3.71). Hypotension was more frequent during exposure to digoxin versus propranolol (39.4 vs 11.1/1,000 infant-days; p < 0.001). There was no difference in frequency of other clinical adverse events.

CONCLUSIONS

Digoxin was associated with fewer episodes of supraventricular tachycardia recurrence but more frequent hypotension in hospitalized infants relative to propranolol.

A process for Decision-making after Pilot and feasibility Trials (ADePT): development following a feasibility study of a complex intervention for pelvic organ prolapse

BACKGROUND

Current Medical Research Council (MRC) guidance on complex interventions advocates pilot trials and feasibility studies as part of a phased approach to the development, testing, and evaluation of healthcare interventions. In this paper we discuss the results of a recent feasibility study and pilot trial for a randomized controlled trial (RCT) of pelvic floor muscle training for prolapse (ClinicalTrials.gov: NCT01136889). The ways in which researchers decide to respond to the results of feasibility work may have significant repercussions for both the nature and degree of tension between internal and external validity in a definitive trial.

METHODS

We used methodological issues to classify and analyze the problems that arose in the feasibility study. Four centers participated with the aim of randomizing 50 women. Women were eligible if they had prolapse of any type, of stage I to IV, and had a pessary successfully fitted. Postal questionnaires were administered at baseline, 6 months, and 7 months post-randomization. After identifying problems arising within the pilot study we then sought to locate potential solutions that might minimize the trade-off between a subsequent explanatory versus pragmatic trial.

RESULTS

The feasibility study pointed to significant potential problems in relation to participant recruitment, features of the intervention, acceptability of the intervention to participants, and outcome measurement. Finding minimal evidence to support our decision-making regarding the transition from feasibility work to a trial, we developed a systematic process (A process for Decision-making after Pilot and feasibility Trials (ADePT)) which we subsequently used as a guide. The process sought to: 1) encourage the systematic identification and appraisal of problems and potential solutions; 2) improve the transparency of decision-making processes; and 3) reveal the tensions that exist between pragmatic and explanatory choices.

CONCLUSIONS

We have developed a process that may aid researchers in their attempt to identify the most appropriate solutions to problems identified within future pilot and feasibility RCTs. The process includes three key steps: a decision about the type of problem, the identification of all solutions (whether addressed within the intervention, trial design or clinical context), and a systematic appraisal of these solutions.

Outcomes analysis and quality improvement for the treatment of patients with pediatric and congenital cardiac disease

Tremendous progress has been made in the science of assessing the outcomes of the treatments of patients with pediatric and congenital cardiac disease. Multi-institutional databases have been developed that span subspecialty, geographic, and temporal boundaries. Linking of different databases enables additional analyses not possible using the individual data sets alone and can facilitate quality improvement initiatives. Measures of quality can be developed, in the domains of structure, process, and outcome, which can facilitate quality improvement. Parents are an integral part of the health care team and are key partners with regard to quality improvement. The role of the parent in the process of health care delivery can be facilitated by enhancing the organizational culture and creating methods of transparency, empowering parents, and implementing effective strategies of communication. The professionals caring for patients with pediatric and congenital cardiac disease, in collaboration with the patients and their families, now have the opportunity to capitalize on the power of our databases and move beyond outcome assessment and benchmarking, to collaborative quality improvement.

The Study of Antiarrhythmic Medications in Infancy (SAMIS)

Background—

Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergent cardiac care in children, yet its management has never been subjected to a randomized controlled clinical trial. The purpose of this study was to compare the efficacy and safety of the 2 most commonly used medications for antiarrhythmic prophylaxis of SVT in infants: digoxin and propranolol.

Methods and Results—

This was a randomized, double-blind, multicenter study of infants <4 months with SVT (atrioventricular reciprocating tachycardia or atrioventricular nodal reentrant tachycardia), excluding Wolff-Parkinson-White, comparing digoxin with propranolol. The primary end point was recurrence of SVT requiring medical intervention. Time to recurrence and adverse events were secondary outcomes. Sixty-one patients completed the study, 27 randomized to digoxin and 34 to propranolol. SVT recurred in 19% of patients on digoxin and 31% of patients on propranolol ( P =0.25). No first recurrence occurred after 110 days of treatment. The 6-month recurrence-free status was 79% for patients on digoxin and 67% for patients on propranolol ( P =0.34), and there were no first recurrences in either group between 6 and 12 months. There were no deaths and no serious adverse events related to study medication.

Conclusions—

There was no difference in SVT recurrence in infants treated with digoxin versus propranolol. The current standard practice may be treating infants longer than required and indicates the need for a placebo-controlled trial.

Clinical Trial Registration Information—

http://clinicaltrials.gov ; NCT-00390546.

Pediatric cardiovascular drug trials, lessons learned

Few drugs have been labeled for pediatric cardiovascular indications, and many children with cardiac disease are prescribed drugs off-label. Recent initiatives have narrowed this gap, and as a result, there are an increasing number of cardiology trials in the pediatric population. Many studies, however, have either failed to show a dose response in children or have not shown efficacy in children when they have established efficacy in adults. Clinical trials are challenging in children; many factors such as lack of development of a liquid formulation, failure to fully incorporate pharmacokinetic information into trial design, poor dose selection, the lack of clinical equipoise, and the use of difficult surrogate and composite primary endpoints have led to the difficulties and failures observed in several pediatric cardiovascular trials. These lessons learned may help to inform future pediatric clinical trial development.

Opportunities and challenges in linking information across databases in pediatric cardiovascular medicine

Multicenter databases are increasingly utilized in pediatric cardiovascular research. In this review, we discuss the rational for using these types of data sources, provide several examples of how large datasets have been utilized in clinical research, and describe different mechanisms for linking databases to enable studies not possible with individual datasets alone.