Has Propranolol Eradicated the Need for Surgery in the Management of Infantile Hemangioma?

BACKGROUND

To assess the impact of propranolol as the first-line treatment of infantile hemangioma (IH) on the need for surgery in the management of IH.

METHODS

Retrospective study of 420 patients, with IH, referred to our multidisciplinary center between January 2005 and August 2014. Clinical data including sex, age at first consultation and at treatment initiation, location, size, number, aspect, and complication of IH, as well as the type of treatment were collected. Statistical analyses were conducted considering each patient and each tumor independently.

RESULTS

A total of 625 IH(420 patients (P))were reviewed, 113 patients had more than one IH (26.91%). Median age at first consultation was 7 months old. Overall, 243 patients were treated (57.86%) using either surgery (n=128 P/141 IH), propranolol (n=79 P/89 IH), corticosteroids (n=51 P/56 IH), and/or laser (n=34 P /36 IH). Propranolol was effective in all but 2 infants with IH. Seven patients (n=7/79 P; 8.86%) initially treated with propranolol, still required surgery, in contrast to 18 patients (n=18/51 P; 35.29%) initially treated with corticosteroids, and 103 patients (n=103/290 P; 35.51%) with no medical treatment. Since the availability of propranolol, patients were less likely to undergo surgery (48 P versus 80 P; P-Value < 0.001). This demonstrated that the use of propranolol reduced the need for surgery (P-Value < 0.001 with an OR of 0.177: CI 95% 0.079-0.396).

CONCLUSION

Propranolol has dramatically reduced the need for surgery, regarding indications and number of patients. Surgical correction remains important for sequelae management, non-responders or strawberry-like IH.

Usefulness of serum neurofilament light in the assessment of neurologic outcome in the pediatric population: a systematic literature review

Children undergoing general anesthesia and surgery in the early years of life are exposed to the possible neurotoxicity of anesthetic agents. Prospective studies have shown deficits in behavior, executive function, social communication, and motor function in children undergoing anesthesia and surgery. Different biomarkers of neuronal injury have been evaluated neuronal injury in the pediatric population, among which neurofilaments represent a significant advantage as they are proteins exclusively expressed in neuronal tissue. Our aim was to evaluate the utility of serum neurofilament light (NfL) as a prognostic biomarker of neuronal injury in the pediatric population. A literature search was performed on PubMed, Embase, and Cochrane Databases in November 2022 for studies concerning serum NfL in the pediatric population in addition to a neurological assessment. Inclusion criteria were as follows: (1) prospective or retrospective studies, (2) studies including pediatric population until the age of 18 years, (3) serum NfL sampling, and (4) evaluation of neurological outcome. Data collection regarding study design, pediatric age, serum NfL levels, and results for neurological assessment were extracted from each study. Four manuscripts met the inclusion criteria and evaluated the prognostic utility of serum NfL in neonatal encephalopathy in correlation with the neurodevelopmental outcome that was assessed by the Bayley Scales of Infant Development until the age of 2 years. Children with neonatal encephalopathy showed significantly higher serum NfL vs. healthy controls and high serum NfL levels predicted an adverse neurological outcome. The decrease of serum NfL to a nadir point between 10 and 15 years old reflects the brain growth in healthy controls. No studies were available in the perioperative period.  Conclusions: Serum NfL is a valuable biomarker in evaluating neuronal injury in the pediatric population. Further studies with perioperative serial sampling of serum NfL combined with standardized neurodevelopmental tests should be conducted to evaluate the neurotoxicity of anesthetic agents and monitor the effectiveness of specific neuroprotective strategies in pediatric patients undergoing anesthesia and surgery. What is Known: • Preclinical animal data have shown neurotoxicity of the anesthetic agents in the developing brain. • Data regarding anesthetic neurotoxicity in humans show limitations and no objective tools are available. What is New: • This systematic review showed that serum NfL is a valuable biomarker of neuronal injury in the pediatric population. • Perioperative use of serum NfL may be considered in future trials evaluating anesthetic neurotoxicity in the pediatric population and in monitoring neuroprotective strategies.

The burden and surveillance of RSV disease in young children in Belgium-expert opinion

Infections with respiratory syncytial virus (RSV) can cause severe disease. In young children, RSV is the most common cause of lower respiratory tract illness and life-threatening infections most commonly occur in the first years of life. In adults, elderly and immunocompromised people are most vulnerable. Recently there has been an acceleration in the development of candidate RSV vaccines, monoclonal antibodies and therapeutics which are expected to become available in Europe within the next 2-10 years. Understanding the true burden of childhood RSV disease will become very important to support public health authorities and policy makers in the assessment of new therapeutic opportunities against RSV disease. A systematic literature search was performed to map local data on the burden of RSV disease and to evaluate available RSV surveillance systems. A group of 9 paediatric infectious diseases specialists participated in an expert panel. The purpose of this meeting was to evaluate and map the burden associated with RSV infection in children, including patient pathways and the epidemiological patterns of virus circulation in Belgium. Sources of information on the burden of RSV disease in Belgium are very limited. For the outpatient setting, it is estimated that 5-10% of young patients seen in primary care are referred to the hospital. Around 3500 children between 0 and 12 months of age are hospitalized for RSV-bronchiolitis every year and represent the majority of all hospitalizations. The current Belgian RSV surveillance system was evaluated and found to be insufficient. Knowledge gaps are highlighted and future perspectives and priorities offered.

CONCLUSION

The Belgian population-based RSV surveillance should be improved, and a hospital-led reporting system should be put in place to enable the evaluation of the true burden of RSV disease in Belgium and to improve disease management in the future.

WHAT IS KNOWN

• RSV bronchiolitis is a very important cause of infant hospitalization. • The burden of disease in the community is poorly studied and underestimated.

WHAT IS NEW

• This expert opinion summarizes knowledge gaps and offers insights that allow improvement of local surveillance systems in order to establish a future-proof RSV surveillance system.

Atrial fibrillation in a pediatric patient caused by an unusual malignant etiology: A case report

This case report describes a 15-year-old patient with a known congenital malformation syndrome and immune deficiency, presenting with new-onset atrial fibrillation (AF) after a recent diagnosis of an intrathoracic mass. Transthoracic echocardiography showed a structurally and functionally normal heart and workup confirmed a primary diffuse large B-cell lymphoma, with pericardial and left atrial involvement on cardiac magnetic resonance imaging. Electrical cardioversion was successfully performed to convert the AF and chemotherapy was promptly started. Antiarrhythmic treatment was continued for 6 weeks, without recurrent AF. We discuss the pathogenesis of AF in the setting of malignancies as well as the management strategies of AF, mainly based on adult guidelines.

End-of-life and palliative care provision to adults with congenital heart disease: mortality follow-back study using administrative data

Background

Although many adults with congenital heart disease (CHD) still die prematurely, end-of-life care for these patients receives limited attention. There are indications that current care provision at the end of life is burdensome, expensive, and not in line with patients' needs and preferences. We sought to analyse end-of-life care in adult CHD patients to determine whether health services need to be optimized.

Purpose

This study aimed to describe patterns of healthcare consumption of adults with CHD who died in the last year of life.

Methods

This retrospective mortality follow-back study used data of the BELgian COngenital heart disease Database combining Administrative and Clinical data (BELCODAC), including individually linked healthcare claims, death certificates and clinical data from adults with CHD in Flanders (Belgium). For this study, adults with CHD who died between 2007 and 2016 from any cause except sudden death, accident or violence, were selected for inclusion. Accidental, violent, and sudden deaths were identified based on causes of death and healthcare use in the last 3 months of life. Healthcare consumption was based on nomenclature codes derived from healthcare claims data.

Results

A total of 327 eligible patients (median age: 58 y; 54% women; 43% mild CHD; 45% moderate CHD; 11% complex CHD; 49% cardiovascular cause of death) were identified. During the last year of life, healthcare use increased substantially (Fig. 1). During the last month of life, 54% of patients were hospitalised, 55% visited the emergency department, and 15% were admitted to an intensive care unit at least once (Fig. 2). A total of 8% and 5% of patients underwent heart surgery or catherization in the last month of life, respectively. Furthermore, 70% of patients had at least one encounter with a general practitioner and 11% with a CHD specialist in the last month of life. Specialist palliative care was provided to 13% of patients in the last month of life.

When looking at the subgroup of patients with CHD that died due to a cardiovascular cause, proportions of patients that were hospitalised or had visits at the emergency department or intensive care unit in the last month of life were similar (Fig. 2). However, these patients underwent more heart surgeries (11%) and catherizations (8%), had more encounters with CHD specialists (15%), and received remarkably less specialized palliative care (4%) in the last month of life.

Conclusion

Resource utilization increased substantially during the last year of life, resulting in high acute healthcare consumption in the last month of life. It is remarkable that only a minority of patients received palliative care, especially when looking at patients who died due to a cardiovascular cause. Our findings motivate the need to assess if and how end-of-life is planned for adults with CHD. Future studies using qualitative analyses and survey methodology are needed to optimize the management of end-of-life care.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Research Foundation Flanders, European Society of Cardiology, Koning Boudewijnstichting, National Foundation on Research in Pediatric Cardiology, Swedish Research Council for Health, Working Life and Welfare-FORTE

Last year of life of adults with congenital heart diseases: causes of death and patterns of care

AIMS

Although life expectancy in adults with congenital heart diseases (CHD) has increased dramatically over the past five decades, still a substantial number of patients dies prematurely. To gain understanding in the trajectories of dying in adults with CHD, the last year of life warrants further investigation. Therefore, our study aimed to (i) define the causes of death and (ii) describe the patterns of healthcare utilization in the last year of life of adults with CHD.

METHODS AND RESULTS

This retrospective mortality follow-back study used healthcare claims and clinical data from BELCODAC, which includes patients with CHD from Belgium. Healthcare utilization comprises cardiovascular procedures, CHD physician contacts, general practitioner visits, hospitalizations, emergency department (ED) visits, intensive care unit (ICU) admissions, and specialist palliative care, and was identified using nomenclature codes. Of the 390 included patients, almost half of the study population (45%) died from a cardiovascular cause. In the last year of life, 87% of patients were hospitalized, 78% of patients had an ED visit, and 19% of patients had an ICU admission. Specialist palliative care was provided to 17% of patients, and to only 4% when looking at the patients with cardiovascular causes of death.

CONCLUSIONS

There is a high use of intensive and potentially avoidable care at the end of life. This may imply that end-of-life care provision can be improved. Future studies should further examine end-of-life care provision in the light of patient's needs and preferences, and how the healthcare system can adequately respond.

Healthcare use at the end of life of patients with congenital heart disease: does heart failure matter?

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Research Foundation Flanders (to PM, EG, and LVB)

European Society of Cardiology (Nursing Training Grant to LVB)

Background

Heart failure (HF) is a common cause of morbidity and mortality in patients with congenital heart disease (CHD). Although limited in scope, previous studies suggest that patients with heart failure follow a specific end-of-life trajectory with episodes of serious complications, which may impact the patterns of care as death approaches.

Aims

The study aims to identify differences in characteristics and patterns of care in the last year of life in deceased CHD patients with and without HF.

Methods

This retrospective study used data of deceased adult patients included in the BELgian COngenital heart disease Database combining Administrative and Clinical data (BELCODAC). To describe patterns of care in the last year of life, we captured information about hospitalisations, emergency department visits, and visits to the general practitioner using nomenclature codes. Heart failure was identified as having HF as cause of death and/or at least one prescription of a loop diuretic in the last year of life. Sensitivity analyses with a stricter definition for HF (HF as cause of death or ≥ 1 prescription of a loop diuretic combined with a prescription of digoxin, dopamine, dobutamine, other non-glycoside stimulants, metoprolol, bisoprolol, carvedilol, aldosterone antagonists, ACE inhibitors or ARBs) were performed as well.

Results

During the period 2007–2016, 390 adults with CHD died, of which 170 patients with HF (44%). Patients with HF were older, died more often due to a cardiovascular cause of death, and had more complex heart lesions, compared to patients without HF (Table 1). While the number of emergency department visits and hospitalisations in the last year was similar, patients with HF had almost twice as much monthly visits at the general practitioner in their last year of life (Table 1). As shown in Figure 1, the mean number of hospitalisations and emergency department visits increased in a similar fashion throughout the last year of life, but the pattern of general practitioner visits was substantially different for patients with and without HF. The sensitivity analyses, in which a stricter definition for HF was used, yield very similar results. In these analyses, the difference in mean monthly hospitalisations was also significant between the two groups.

Conclusions

This study shows clinically important differences in characteristics and patterns of care of deceased patients with CHD with and without heart failure. Patients with HFhave different needs and should receive a tailored approach at the end of life. Future research is needed to understand these differences and investigate these patients' end-of-life care needs in more detail.

Funding acknowledgments: This work was supported by Research Foundation Flanders; European Society of Cardiology; the King Baudouin Foundation; the National Foundation on Research in Pediatric Cardiology; and the Swedish Research Council for Health, Working Life and Welfare-FORTE.

Torsade de pointe due to QT prolongation following erythromycin administration in a preterm infant

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality in preterm infants. Chorioamnionitis is an important risk factor for the development of sepsis, therefore neonates born to mothers developing signs of amnionitis need to be treated with antibiotics immediately after birth. Ureaplasma spp can be a causative agent of vaginal or intra amniotic infection needing antibiotic treatment. Macrolides are frequently used to treat maternal intrauterine infection, but antibiotic treatment of the neonate should be consciously chosen with consideration of potential side effects. Indeed, macrolides are great purveyors of heart rhythm disorders.

CASE PRESENTATION

We describe the case of a 29 weeks preterm infant born to a mother with Ureaplasma spp infection. The baby was treated with erythromycin immediately after birth. During the second day of life, the baby presented some episodes of tachyarrhythmia with premature ventricular beats (PVBs) that were followed by a non-sustained ventricular tachycardia as high as 270 bpm leading to a cardiac arrest. After resuscitation, tachycardia resolved but the rhythm was characterised by numerous PVBs and an electrocardiogram (ECG) diagnosed a Long QT Syndrome (LQTS). Erythromycin was discontinued, and the rhythm normalised a few days after withdrawal.

CONCLUSIONS

Erythromycin should be administered in neonates only if no other choice is available, as although generally well tolerated, its administration can be associated with QTc interval prolongation. When no other option is available, paediatricians should be aware to perform cardiac monitoring or at least serial ECGs before and during erythromycin administration.

Different levels of care for follow-up of adults with congenital heart disease: a cost analysis scrutinizing the impact on medical costs, hospitalizations, and emergency department visits

AIM

To scrutinize the economic impact of different care levels, such as shared care, in the follow-up of adult congenital heart disease (ACHD) patients.

METHODS

The BELgian COngenital heart disease Database combining Administrative and Clinical data (BELCODAC) was analyzed. Patients (N = 6579) were categorized into five care levels based on their cardiac follow-up pattern between 2006 and 2010. Medical costs, hospitalizations, and emergency department visits were measured between 2011 and 2015.

RESULTS

In patients with moderate lesions, highly specialized cardiac care (HSC; exclusive follow-up by ACHD specialists) and shared care with predominantly specialized cardiac care (SC+) were associated with significantly lower medical costs and resource use compared to shared care with predominantly general cardiac care (SC-) and general cardiac care (GCC). In the patient population with mild lesions, HSC was associated with better economic outcomes than SC- and GCC, but SC+ was not. HSC was associated with fewer hospitalizations (- 33%) and less pharmaceutical costs (- 46.3%) compared to SC+. Patients with mild and moderate lesions in the no cardiac care (NCC) group had better economic outcomes than those in the GCC and SC- groups, but post-hoc analysis revealed that they had a different patient profile than patients under cardiac care.

CONCLUSION

More specialized care levels are associated with better economic outcomes in patients with mild or moderate lesions in cardiac follow-up. Shared care with strong involvement of ACHD specialists might be a management option to consider. Characteristics of patients without cardiac follow-up but good medium-term economic prospects should be further scrutinized.

Provision of palliative care to adults with congenital heart disease at the end of life

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by Research Foundation Flanders [grant numbers G097516N to PM, 12E9816N to EG and 1154719N to LVB]; the King Baudouin Foundation (Fund Joseph Oscar Waldmann-Berteau & Fund Walckiers Van Dessel); the National Foundation on Research in Pediatric Cardiology; and the Swedish Research Council for Health, Working Life and Welfare -FORTE (grant number STYA-2018/0004).

OnBehalf

BELCODAC consortium

Background

Although recent position papers have discussed and advocated for the integration of palliative care in the treatment course of adults with congenital heart defects (CHD), empirical studies reporting to what extent palliative care is currently provided, are still lacking.

Purpose

(1) To explore the current provision of palliative care to adults with CHD in the last 6 months of their life; and (2) to describe the profile of patients who received palliative care.

Methods

In this retrospective study, data of deceased adult patients included in the BELgian COngenital heart disease Database combining Administrative and Clinical data (BELCODAC) were analysed. Palliative care provision (i.e., admission to palliative care ward, or palliative care at home) was identified using nomenclature codes. The level of anatomical complexity was based on the Bethesda classification. Descriptive analyses were performed.

Results

During the period 2006-2016, 480 adults with CHD died (mean age: 54.4y; 45% simple CHD, 43% moderate CHD, 12% complex CHD). We identified that 75 patients (16%) had at least one nomenclature code linked to palliative care in the last 6 months of their life. More specifically, 16 patients were admitted to an inpatient palliative care service and 67 patients received palliative care at home. Of the patients who received palliative care at home, 40 patients were cared for by a multidisciplinary team specialized in palliative care provision and 59 patients received care from nurses and/or general practitioners while being recognized as a palliative patient. A total of 8 patients received palliative care both at the inpatient palliative care service and at home.

Of the 75 patients receiving palliative care, 44 (59%) had a neoplasm as the primary cause of death and a cardiac cause of death was reported for 10 patients (13%) (see Figure 1). The mean age of patients receiving palliative care was 57.9 years. Most patients receiving palliative care had a simple CHD (n = 40; 53%), 29 patients (39%) had a moderate lesion, and 6 patients (8%) had a complex lesion. That means that, respectively, 19%, 14%, and 11% of all deceased patients with a simple, moderate, and complex heart lesion received palliative care.

Conclusions

This is the first exploratory study on palliative care in adults with CHD. About one in six patients who died received palliative care. Of those who received palliative care, the cause of death was in most cases of a non-cardiac nature. Further research is needed to investigate the care trajectories and care needs of adults with CHD in the last months of life.

Figure 1. Causes of death of adults with CHD who received palliative care in the last 6 months of life (n = 75).

Results of Coarctation Repair by Thoracotomy in Pediatric Patients: A Single Institution Experience

BACKGROUND

Aortic coarctation is among the most common cardiovascular congenital abnormalities requiring repair after birth. Besides mortality, morbidity remains an important aspect. Accordingly, we reviewed our 20-year experience of aortic coarctation repair by thoracotomy, with emphasis on both short- and long-term outcomes.

METHODS

From 1995 through 2014, 214 patients underwent coarctation repair via left thoracotomy. Associated arch lesions were distal arch hypoplasia (n = 117) or type A interrupted aortic arch (n = 6). Eighty-four patients had isolated coarctation (group 1), 66 associated ventricular septal defect (group 2), and 64 associated complex cardiac lesions (group 3). Median follow-up was 8.4 years.

RESULTS

There was one (0.5%) procedure-related death. Nine (4.2%) patients died during index admission. In-hospital mortality was 0.7% in group 1 and 2 and 12.5% in group 3 (P < .001). No patient had paraplegia. Actuarial five-year survival was 97.5% in group 1, 94% group 2 and 66% in group 3. Recurrent coarctation developed in 29 patients, all but four (1.8%) successfully treated by balloon dilatation. Freedom from reintervention (dilatation or surgery) at five years was 86%. At hospital discharge, 28 (13.5%) patients were hypertensive. At follow-up, hypertension was present in 11 (5.3%) patients.

CONCLUSIONS

Long-term results of aortic coarctation repair by thoracotomy are excellent, with percutaneous angioplasty being the procedure of choice for recurrences. Patient prognosis is dependent on associated cardiac malformations. In this study, the prevalence of late arterial hypertension was lower than previously reported.

Influenza Vaccination in Patients With Congenital Heart Disease in the Pre-COVID-19 Era: Coverage Rate, Patient Characteristics, and Outcomes

BACKGROUND

Influenza vaccination is the most commonly recommended immune prevention strategy. However, data on influenza vaccination in patients with congenital heart disease (CHD) are scarce. In this study, our goals were to: (1) measure vaccination coverage rates (VCRs) for influenza in a large cohort of children, adolescents, and adults with CHD; (2) identity patient characteristics as predictors for vaccination; and (3) investigate the effect of influenza vaccination on hospitalization.

METHODS

A nationwide cohort study in Belgium included 16,778 patients, representing 134,782 vaccination years, from the Belgian Congenital Heart Disease Database Combining Administrative and Clinical Data (BELCODAC). Data over 9 vaccination years (2006-2015) were used, and patients were stratified into 5 age cohorts: 6 months to 4 years; 5-17 years; 18-49 years; 50-64 years; and 65 years and older.

RESULTS

In the respective age cohorts, the VCR was estimated to be 6.6%, 8.0%, 23.9%, 46.6%, and 72.8%. There was a steep increase in VCRs as of the age of 40 years. Multivariable logistic regression showed that higher anatomical complexity of CHD, older age, presence of genetic syndromes, and previous cardiac interventions were associated with significantly higher VCRs. Among adults, men had lower and pregnant women had higher VCRs. The association between influenza vaccination and all-cause hospitalization was not significant in this study.

CONCLUSIONS

The influenza VCR in people with CHD is low, especially in children and adolescents. Older patients, particularly those with complex CHD, are well covered. Our findings should inform vaccination promotion strategies in populations with CHD.

Amiodarone-induced thyroid dysfunction in children: insights from the THYRAMIO study

BACKGROUND

Amiodarone treatment is effective against various types of arrhythmias but is associated with adverse effects affecting, among other organs, thyroid function. Amiodarone-induced thyroid dysfunction was not thoroughly evaluated in children as it was in adults, yet this affection may lead to irreversible neurodevelopmental complications. Our study aimed to define the incidence and risk factors of amiodarone-induced thyroid dysfunction in children.

METHODS

The study was designed as an observational study with a retrospective clinical series of 152 children treated by amiodarone in the Pediatric Cardiology Unit of our center from 1990 to 2019. All patients were divided into three groups according to their thyroid status: euthyroid, AIH (amiodarone-induced hypothyroidism) or AIT (amiodarone-induced thyrotoxicosis). Patients from these three groups were compared in terms of key clinical and therapeutic features.

RESULTS

Amiodarone-induced thyroid dysfunction was present in 23% of patients. AIT (5.3%) was three times less common than AIH (17.7%), and its occurrence increased with older age (p < 0.05), treatment dosage (p < 0.05), treatment duration (p < 0.05) and the number of loading doses administered (p < 0.05). There were no distinctive clinical features between euthyroid and AIH groups. A multivariable prediction model of AIT was built, with a yield of 66.7% as positive predictive value and 96.7% as negative predictive value.

CONCLUSION

We observed that one in five children developed amiodarone-induced thyroid dysfunction. Special attention is required for older children with a high dosage and long-term therapy and who received a large number of loading doses, since these children are at risk to develop AIT, which is more delicate to manage than AIH.

Combined Algorithm-Based Adaptations of Insulin Dose and Carbohydrate Intake During Exercise in Children With Type 1 Diabetes: Results From the CAR2DIAB Study

OBJECTIVES

To evaluate the evolution of subcutaneous glucose during two sessions of monitored aerobic exercise in children or adolescents with type 1 diabetes after adaptation of insulin doses and carbohydrate intake according to a combined algorithm.

METHODS

Twelve patients with type 1 diabetes (15.1 ± 2 years; diabetes duration: 9.5 ± 3.1 years) performed two series of exercise sessions after cardiac evaluation. The first series (TE#1) consisted in a monitored exercise of moderate to vigorous intensity coupled with a bout of maximum effort. The second series of exercises (TE#2) was carried out in real life during exercises categorized and monitored by connected watches. TE#2 sessions were performed after adaptation of insulin doses and fast-acting carbohydrates according to decision algorithms.

RESULTS

Patients did not experience episodes of severe hypoglycemia, symptomatic hyperglycemia, or hyperglycemia associated with ketosis. Analysis of CGM data (15 h) during TE#2 sessions revealed an overall improvement in glycemic average [± standard deviation] (104 ± 14 mg/dl vs. 122 ± 17 mg/dl during TE#1; p < 0.001), associated with a decrease in proportion of hyperglycemia in periods ranging from 4 h to 15 h after performing the exercises. The proportion of hypoglycemia was not changed, except during the TE#2 +4-8 h period, where a significant increase in hypoglycemia <60 mg/dl was observed (25% vs. 6.2%; p = 0.04), yet without concurrent complications.

CONCLUSION

In our pediatric series, the application of algorithmic adaptations of insulin doses and carbohydrate intake has globally improved glycemic control during 15 h after real-time exercises performed by children and adolescents with type 1 diabetes.

Outcomes of algorithm-based modifications of insulinotherapy during exercise in MDI vs insulin pump-treated children with type 1 diabetes: Results from the TREAD-DIAB study

OBJECTIVES

To evaluate the evolution of subcutaneous glucose (SG) after a standardized aerobic exercise in children and adolescents treated with continuous subcutaneous insulin infusion (CSII) or multiple daily injection (MDI) regimen before and after adaptation of insulin doses.

RESEARCH DESIGN AND METHODS

Eleven CSII- and 13 MDI-treated patients performed 2 30-minute sessions of moderate to vigorous (70% of age-based maximal heart rate) exercise on a treadmill under continuous glucose monitoring (CGM). First sessions were scheduled without insulin modification (TT#1) while patients performed second sessions (TT#2) after preemptive algorithm-based insulin dose modifications.

RESULTS

While insulin adaptations did not modify immediate postexercise drops in blood glucose during TT#2 in either group, CSII-treated patients had their glucose control improved during TT#2 (mean of 141 ± 56 mg/dL vs 144 ± 80 mg/dL in TT#1; P < .05) with up to 86% of SG levels within targets during 16 hours postexercise. Contrarily, SG levels did not normalize during TT#2 in MDI-treated patients who experienced higher rates of hyperglycemia during the afternoon snack. As compared with TT#1, CSII-treated patients had reduced rates of hypoglycemia during 4 hours post-TT#2 (from 19.5% to 2.1%; P < .01) and had shorter duration of nocturnal hypoglycemia (35.5 ± 12.8 vs 204.7 ± 165 minutes; P = .04) whereas in the MDI group no changes in percentages of hypoglycemia were observed during TT#2.

CONCLUSION

In our pediatric cohort, algorithmic adaptations of insulin doses were associated with better outcomes in terms of postexercise glucose control in patients with CSII therapy but not with MDI treatment.

Dnmt3a-mediated inhibition of Wnt in cardiac progenitor cells improves differentiation and remote remodeling after infarction

Adult cardiac progenitor cells (CPCs) display a low capacity to differentiate into cardiomyocytes in injured hearts, strongly limiting the regenerative capacity of the mammalian myocardium. To identify new mechanisms regulating CPC differentiation, we used primary and clonally expanded Sca-1+ CPCs from murine adult hearts in homotypic culture or coculture with cardiomyocytes. Expression kinetics analysis during homotypic culture differentiation showed downregulation of Wnt target genes concomitant with increased expression of the Wnt antagonist, Wnt inhibitory factor 1 (Wif1), which is necessary to stimulate CPC differentiation. We show that the expression of the Wif1 gene is repressed by DNA methylation and regulated by the de novo DNA methyltransferase Dnmt3a. In addition, miR-29a is upregulated early during CPC differentiation and downregulates Dnmt3a expression, thereby decreasing Wif1 gene methylation and increasing the efficiency of differentiation of Sca-1+ CPCs in vitro. Extending these findings in vivo, transient silencing of Dnmt3a in CPCs subsequently injected in the border zone of infarcted mouse hearts improved CPC differentiation in situ and remote cardiac remodeling. In conclusion, miR-29a and Dnmt3a epigenetically regulate CPC differentiation through Wnt inhibition. Remote effects on cardiac remodeling support paracrine signaling beyond the local injection site, with potential therapeutic interest for cardiac repair.

High field magnetic resonance imaging of rodents in cardiovascular research

Transgenic and gene knockout rodent models are primordial to study pathophysiological processes in cardiovascular research. Over time, cardiac MRI has become a gold standard for in vivo evaluation of such models. Technical advances have led to the development of magnets with increasingly high field strength, allowing specific investigation of cardiac anatomy, global and regional function, viability, perfusion or vascular parameters. The aim of this report is to provide a review of the various sequences and techniques available to image mice on 7-11.7 T magnets and relevant to the clinical setting in humans. Specific technical aspects due to the rise of the magnetic field are also discussed.

Does Postoperative Cardiac Troponin-I Have Any Prognostic Value in Predicting Midterm Mortality After Congenital Cardiac Surgery?

OBJECTIVES

This study evaluated the prognostic value of postoperative cardiac troponin-I (cTnI) in predicting all-cause mortality up to 3 months after normothermic congenital cardiac surgery.

DESIGN

Prospective observational study.

SETTING

University hospital.

PARTICIPANTS

All children ages 0 to 10 years.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

cTnI was measured after the induction of anesthesia but before the surgery, at the pediatric intensive care unit arrival, and at 4, 12, and 24 hours postoperatively. Follow-up was extended up to 6 months. Overall, 169 children were analyzed, of whom 165 were survivors and 4 were nonsurvivors. cTnI levels were significantly higher in nonsurvivors only at 24 hours (p = 0.047). Children undergoing surgery with cardiopulmonary bypass (CPB) had significantly higher cTnI concentrations compared with those without CPB (p<0.001). Logistic regression analysis was performed on the 146 children in the CPB group with the following predictive variables: CPB time, postoperative cTnI concentrations, the presence of a cyanotic malformation, and intramyocardial incision. None of the variables predicted mortality. Postoperative cTnI concentrations did not predict 6 months׳ mortality. Only cTnI at 24 hours predicted the length of stay in the pediatric intensive care unit.

CONCLUSIONS

This study did not find that postoperative cTnI concentration predicted midterm mortality after normothermic congenital heart surgery. (ClinicalTrials.gov identifier: NCT01616394).

Long-Term Results of Balloon Valvuloplasty as Primary Treatment for Congenital Aortic Valve Stenosis: a 20-Year Review

In the presence of new surgical techniques, the treatment of congenital valvular aortic stenosis is under debate. We reviewed the results and late outcomes of all 93 patients aged 1 day to 18 years, treated with balloon valvuloplasty (BAV) as first-line therapy for congenital aortic valve stenosis in our center from January 1991 to May 2012. Mean age at procedure time was 2.4 years; 37 patients underwent BAV at age ≤30 days (neonates), 29 patients at age ≥1 month and <1 year (infants), and 27 patients were older than 1 year (children). The invasive BAV peak-to-peak aortic valve gradient (mean 59 ± 22 mmHg) was immediately reduced (mean 24 ± 12 mmHg). The observed diminution of gradient was similar for each age group. Four patients had significant post-BAV AI. Mean follow-up after BAV was 11.4 ± 7 years. The last echo peak aortic gradient was 37 ± 18 mmHg and mean gradient was 23 ± 10 mmHg, and two patients had significant AI. Actuarial survival for the whole cohort was 88.2 and 72.9 % for the neonates. All infants, except one, and all children survived. Sixty-six percent of patients were free from surgery, and 58 % were free from any reintervention, with no difference according to age. Freedom from surgery after BAV at 5, 10, and 20 years, respectively, was 82, 72, and 66 %. Our study confirms that BAV as primary treatment for congenital AS is an efficient and low-risk procedure in infants and children. In neonates, the prognosis is more severe and clearly related to "borderline LV."

Off-pump revascularization in a 2-year-old girl after neonatal arterial switch

One drawback of the arterial switch operation for treating transposition of the great arteries is the occurrence of coronary lesions, found during follow-up in about 5% of (a)symptomatic children. The established corrective procedures include coronary artery proximal patch arterioplasty or coronary artery bypass grafting (CABG). To avoid aortic manipulations and extracorporeal circulation, off-pump coronary artery bypass (OPCAB) has become increasingly used in the adult population. We report a case of OPCAB revascularization in a symptomatic 2-year-old child.

Iron overload in children undergoing cancer treatments

BACKGROUND

Iron overload is responsible for severe morbidity and mortality in polytransfused patients. Although repeated blood transfusions are needed during the treatment of most cancers, pediatric patients are not routinely screened for subsequent iron overload.

PROCEDURE

Seventy-five patients were identified as candidates for cancer treatment and enrolled prospectively in a yearly protocol including a cardiac and liver magnetic resonance imaging coupled with ferritin level measurements. Patients were divided into four groups using the intensity of treatment rating (ITR-3).

RESULTS

Fifty-nine patients reached 1-year of follow-up and liver iron overload was found in up to 66% of them. Such overload correlated with the total volume of red blood cells transfused and persisted at least 2 years after the initiation of therapy. Moderate myocardial overload was also, but less frequently (14%), observed in these patients.

CONCLUSIONS

Our study demonstrated that severe liver iron overload as well as moderate myocardial iron overload can be found 1 year after cancer treatment and that this overload persists overtime. The patients with higher ITR and those who have received more than a liter of blood red cells per square meter, regardless of their diagnosis or ITR, are at risk of iron overload and should be screened carefully.

Cardiotoxicity of childhood cancer treatment: update and current knowledge on long-term follow-up

Therapeutic advances in paediatric oncology allowed increasing numbers of children to survive until adulthood. However, chemotherapy and radiotherapy are potentially cardiotoxic and contribute to a significant morbidity and mortality, cardiovascular events remaining the leading cause of death among survivors. This review summarizes the physiopathology of treatment-related cardiovascular diseases, their incidence, and the risk factors associated with each specific therapy. Few studies have investigated the cardiac outcomes of adult surviving from childhood cancers but all demonstrated a substantial risk for late cardiac effects. Cardiovascular monitoring, prevention, and early detection of cardiac dysfunction are, therefore, the keystones of an improved long-term outcome.

Cardiac and neurological assessment of normothermia/warm blood cardioplegia vs hypothermia/cold crystalloid cardioplegia in pediatric cardiac surgery: insight from a prospective randomized trial

OBJECTIVE

Although normothermia and warm blood cardioplegia are widely used in adults, cold crystalloids and hypothermia remain routinely used in pediatric cardiac surgery. The superiority of either technique in both brain and myocardial protection remains controversial. We designed a prospective randomized study to compare both approaches in terms of early myocardial protection and late neurodevelopmental status.

METHODS

From 2004 to 2005, 47 patients were randomly assigned to either mild hypothermia associated to cold crystalloid cardioplegia (CCC, 22 patients) or normothermia with intermittent warm blood cardioplegia (IWBC, 25 patients). Intramyocyte adenosine triphosphate (ATP) was measured before, during and after cardioplegic arrest and results between groups were compared. In addition to their cardiac status, early and late neurologic assessment was performed by psychometric evaluation tests.

RESULTS

Intracellular ATP levels were not significantly different between the two groups. However, intragroup comparison revealed different profiles according to myocardial protection: in the normothermia/warm blood cardioplegia group, ATP concentration increased during cardioplegic arrest and returned to initial values afterward (11 nmol mg(-1) vs 21 nmol mg(-1) vs 10 nmol mg(-1), p < 0.001), such changes did not occur in the cold protocol (17 nmol mg(-1) vs 19 nmol mg(-1) vs 14 nmol mg(-1), p = NS). Early neurological outcome was similar in both groups. At late follow-up (mean = 4 years), no significant difference was observed between the two groups.

CONCLUSIONS

This study demonstrates that normothermia/IWBC protocols are not deleterious when compared with more conventional approaches. A more physiologic ATP steady state, reflecting the absence of cellular ischemic insult was observed in the IWBC group. Importantly, no significant difference was found between IWBC and CCC groups in terms of early and late neurodevelopmental status.

Iron overload in polytransfused patients without heart failure is associated with subclinical alterations of systolic left ventricular function using cardiovascular magnetic resonance tagging

BACKGROUND

It remains incompletely understood whether patients with transfusion related cardiac iron overload without signs of heart failure exhibit already subclinical alterations of systolic left ventricular (LV) dysfunction. Therefore we performed a comprehensive evaluation of systolic and diastolic cardiac function in such patients using tagged and phase-contrast CMR.

METHODS

19 patients requiring regular blood transfusions for chronic anemia and 8 healthy volunteers were investigated using cine, tagged, and phase-contrast and T2* CMR. LV ejection fraction, peak filling rate, end-systolic global midventricular systolic Eulerian radial thickening and shortening strains as well as left ventricular rotation and twist, mitral E and A wave velocity, and tissue e' wave and E/e' wave velocity ratio, as well as isovolumic relaxation time and E wave deceleration time were computed and compared to cardiac T2*.

RESULTS

Patients without significant iron overload (T2* > 20 ms, n = 9) had similar parameters of systolic and diastolic function as normal controls, whereas patients with severe iron overload (T2* < 10 ms, n = 5), had significant reduction of LV ejection fraction (54 ± 2% vs. 62 ± 6% and 65 ± 6% respectively p < 0.05), of end-systolic radial thickening (+6 ± 4% vs. +11 ± 2 and +11 ± 4% respectively p < 0.05) and of rotational twist (1.6 ± 0.2 degrees vs. 3.0 ± 1.2 and 3.5 ± 0.7 degrees respectively, p < 0.05) than patients without iron overload (T2* > 20 ms) or normal controls. Patients with moderate iron overload (T2* 10-20 ms, n = 5), had preserved ejection fraction (59 ± 6%, p = NS vs. pts. with T2* > 20 ms and controls), but showed reduced maximal LV rotational twist (1.8 ± 0.4 degrees). The magnitude of reduction of LV twist (r = 0.64, p < 0.001), of LV ejection fraction (r = 0.44, p < 0.001), of peak radial thickening (r = 0.58, p < 0.001) and of systolic (r = 0.50, p < 0.05) and diastolic twist and untwist rate (r = -0.53, p < 0.001) in patients were directly correlated to the logarithm of cardiac T2*.

CONCLUSION

Multiple transfused patients with normal ejection fraction and without heart failure have subclinical alterations of systolic and diastolic LV function in direct relation to the severity of cardiac iron overload. Among all parameters, left ventricular twist is affected earliest, and has the highest correlation to log (T2*), suggesting that this parameter might be used to follow systolic left ventricular function in patients with iron overload.

Prenatal diagnosis of abnormal cardinal systemic venous return without other heart defects: a case series

OBJECTIVES

To describe fetal spectrum and echocardiographic characteristics of anomalous systemic venous return (ASVR, cardinal veins) without other structural heart defects (isolated ASVR), evaluate associated extracardiac and genetic anomalies and review neonatal outcome.

METHODS

From 2003 to 2009, 369 consecutive fetuses were diagnosed with cardiac malformation, including 27 cases with an isolated ASVR. The following variables were collected: type of ASVR, extracardiac anomalies, karyotype and short-term outcome.

RESULTS

The most common forms of ASVR were persistent left superior vena cava (SVC) (n = 15) and interrupted inferior vena cava (IVC) (n = 6). The other ASVR types were a persistent left SVC without a right SVC (n = 4), bilateral agenesis of the SVC with cephalic venous drainage toward the IVC through the azygos system (n = 1) and total ASVR to the coronary sinus (n = 1). Genetic disorders were confirmed in five cases, all with a persistent left SVC, with extracardiac anomalies present in four of them. Ten other patients had extracardiac anomalies detected prenatally or postnatally. When available, ASVR diagnosis was confirmed postnatally in all cases.

CONCLUSION

Isolated ASVRs can be accurately diagnosed prenatally and are frequently associated with extracardiac and genetic anomalies. A detailed morphological ultrasound and fetal karyotype should be suggested. Neonatal outcome was mainly related to the associated anomalies.

Lymphatic system anomalies in Crouzon syndrome

Crouzon syndrome is a rare genetic disorder characterised mainly by distinctive malformations of the skull and facial region and caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. No study reported on oedemas related to lymphatic system abnormalities in these patients. A case of Crouzon syndrome displaying classic facial anomalies but also with bilateral lower limb oedema is reported in whom lymphoscintigraphic investigation of the limbs clearly delineated the presence of lymphatic system anomalies.

Huge left ventricular aneurysm in a minimally symptomatic 11-year-old boy

An 11-year-old boy presented with mild shortness of breath and tachycardia and was diagnosed with a huge left ventricular aneurysm ruptured in a secondary pseudoaneurysm. This report highlights the complementary use of echocardiography and cardiac magnetic resonance imaging in the preoperative assessment of this anomaly.

Prenatal diagnosis of thoracic ectopia cordis by real-time fetal cardiac magnetic resonance imaging and by echocardiography

Ectopia cordis is a rare congenital defect commonly associated with intra- and extra-cardiac anomalies. This report highlights the complimentary use of echocardiography and cardiac magnetic resonance imaging for detailed prenatal characterization of the anomaly at 23-week gestation.

Sepsis is associated with an upregulation of functional beta3 adrenoceptors in the myocardium

OBJECTIVE

To analyze the implication of the beta3-adrenoceptor (beta3-AR) pathway in human septic myocardium and a murine model of sepsis, a condition associated with myocardial depression.

METHODS AND RESULTS

beta3-AR and eNOS protein abundance were increased (332+/-66.4% and 218+/-39.3; P<0.05) in hearts from septic patients. The effect of BRL37344, a beta3-AR-preferential agonist, was analyzed by videomicroscopy on the contractility of neonatal mouse ventricular myocytes (NMVM) incubated with conditioned medium from LPS-stimulated cultured macrophages (Mc-LPS+ medium). Stimulation of untreated NMVM with BRL37344 dose-dependently decreased the amplitude of contractile shortening (P<0.05). This response was abolished by L-NAME (NOS inhibitor). Incubation in Mc-LPS+ medium potentiated the depressing effect of BRL37344 (P<0.05) as well as of SR58611A (P<0.05) in wild-type myocytes. Importantly, the contractile depression was abrogated in cardiomyocytes from beta3-AR KO mice.

CONCLUSIONS

beta3-AR are upregulated during sepsis in the human myocardium and by cytokines in murine cardiomyocytes, where they mediate an increased negative inotropic response to beta3 agonists. Activation of the beta3-AR pathway by catecholamines may contribute to the myocardial dysfunction in sepsis.

Usefulness of magnetic resonance imaging evaluation of congenital left ventricular aneurysms

Congenital left ventricular (LV) aneurysm is a rare malformation of unknown cause that is often associated with a poor prognosis. This study was undertaken to evaluate the usefulness of cardiac magnetic resonance imaging in patients with congenital LV aneurysms and to determine the relation between clinical manifestations and the morphologic and functional characteristics of the aneurysms. Among the 26 consecutive patients with congenital LV aneurysms included, the anomalies involved the apex or free wall in 15 and the submitral myocardium in 11. Cardiac magnetic resonance provided detailed anatomic and functional assessment of the aneurysms in all patients. Compared with submitral aneurysms, apical or free-wall aneurysms were larger (24 +/- 29 vs 3 +/- 2 ml/m(2), p = 0.02), were more frequently associated with scar tissue by myocardial delayed enhancement imaging (71% vs 0%, p = 0.03), and tended to be more commonly associated with symptoms (53% vs 18%, p = 0.08). Aneurysm volume but not location correlated with LV size (r = 0.735, p <0.0001) and the ejection fraction (r = 0.774, p <0.0001). Apical or free-wall aneurysms were resected in 5 patients, with no mortality. There was 1 death after aortic valve replacement in a patient with type B Niemann-Pick disease, which was not clearly related to the LV aneurysm. The remaining 25 patients are alive at a median age of 13.5 years. In conclusion, the experience with this cohort illustrates that cardiac magnetic resonance is well suited for the morphologic and functional evaluation of congenital LV aneurysms.

Endothelial beta3-adrenoceptors mediate vasorelaxation of human coronary microarteries through nitric oxide and endothelium-dependent hyperpolarization

BACKGROUND

Coronary vessel tone is modulated in part by beta-adrenergic relaxation. However, the implication of specific beta-adrenoceptor subtypes and their downstream vasorelaxing mechanism(s) in human coronary resistance arteries is poorly defined. beta3-Adrenoceptors were recently shown to vasodilate animal vessels and are expressed in human hearts.

METHODS AND RESULTS

We examined the expression and functional role of beta3-adrenoceptors in human coronary microarteries and their coupling to vasodilating nitric oxide (NO) and/or hyperpolarization mechanisms. The expression of beta3-adrenoceptor mRNA and protein was demonstrated in extracts of human coronary microarteries. Immunohistochemical analysis revealed their exclusive localization in the endothelium, with no staining of vascular smooth muscle. In contractility experiments in which videomicroscopy was used, the nonspecific beta-agonist isoproterenol and the beta3-preferential agonist BRL37344 evoked an approximately 50% relaxation of endothelin-1-preconstricted human coronary microarteries. Relaxations were blocked by the beta1/beta2/beta3-adrenoceptor antagonist bupranolol but were insensitive to the beta1/beta2-adrenoceptor antagonist nadolol, confirming a beta3-adrenoceptor-mediated pathway. Relaxation in response to BRL37344 was absent in human coronary microarteries devoid of functional endothelium. When human coronary microarteries were precontracted with KCl (thereby preventing vessel hyperpolarization), the relaxation to BRL37344 was reduced to 15.5% and totally abrogated by the NO synthase inhibitor L-omega-nitroarginine, confirming the participation of a NO synthase-mediated relaxation. The NO synthase-independent relaxation was completely inhibited by the Ca2+-activated K+ channel inhibitors apamin and charybdotoxin, consistent with an additional endothelium-derived hyperpolarizing factor-like response. Accordingly, membrane potential recordings demonstrated vessel hyperpolarization in response to beta3-adrenoceptor stimulation.

CONCLUSIONS

Beta3-adrenoceptors are expressed in the endothelium of human coronary resistance arteries and mediate adrenergic vasodilatation through both NO and vessel hyperpolarization.

Potential use of beta(3)-adrenoceptor antagonists in heart failure therapy

Recently, a functional, negatively inotropic, beta(3)-adrenoceptor was characterized in the human heart. Several studies now suggest that this receptor might play an important role in the pathophysiology of heart failure, by counterbalancing the effects of a beta(1)- and beta(2)-stimulation. Therefore, this review summarizes the rationale and effects of beta-adrenergic blockade in chronic heart failure and specifically addresses the question of the potential use of beta(3)-adrenoceptor antagonists in the treatment of heart failure and other pathophysiological conditions associated with a decreased cardiac contractility.

Polymicrogyria in chromosome 22q11 deletion syndrome

Central nervous system (CNS) dysfunction is a cardinal feature in 22q11 deletion. The underlying CNS abnormalities remain, however, unknown. We report unilateral hemispheric polymicrogyria in a child with 22q11 deletion presenting with hemiplegia and cognitive and behavioural disorders. This observation widens the spectrum of brain malformations associated with this genetic defect. It further suggests a relationship between the 22q11 deletion and disorders of cerebral gyration. It would therefore be interesting to look for neuronal migration disorders in patients with 22q11 deletion presenting neurological signs, and on the other hand to screen for 22q11 deletion in patients with isolated neuronal migration disorders.

Real-time RT-PCR for the detection of beta-adrenoceptor messenger RNAs in small human endomyocardial biopsies

Quantification of mRNAs from extremely small human samples remains a challenge. Requiring minimal amounts of tissue and no post-reaction manipulation, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) is an attractive method to quantitatively assess the expression of rare mRNAs. We evaluated the applicability of the technique on RNA extracted from human endomyocardial biopsies and isolated cardiomyocytes, and compared the technique to the RT-competitive PCR approach. Primers and probes were designed to amplify the three subtypes of human beta -adrenoceptors (beta1-, beta2- and beta3 AR), as well as reference genes such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Hypoxanthine-guanine phosphoribosyltransferase (HPRT), and the oncogene ABL by real-time RT-PCR. Specific primers and a deleted competitor were synthetized to compare the quantitation of the beta 3 AR mRNA expression by RT-competitive PCR. We validated the technique on human cardiomyocytes either freshly isolated or selectively excised from fixed sections of human myocardium by Laser Capture Microdissection. The standard curves obtained for the cDNA's analysed showed mean slopes comprised between -3.3 and -3.7. Inter- and intra-assay variability of gene quantitation was reflected by mean values of the variance coefficients of Ct of 4.84+/-1.13% and 2.73+/-0.39% or 3.32+/-1.03% and 2.21+/-0.24% (corresponding to percent variances of copy numbers of 83.07+/-12.72% and 34.45+/-9.03% or 47.40+/-8.59% and 23.83+/-3.16%) for human beta3 AR and GAPDH genes, respectively. The expression of GAPDH, HPRT and ABL mRNA was characterized by a very low dispersion of individual values across cardiac pathologies, suggesting that these genes may be used as reference genes in quantitative PCR studies. Finally, we applied the technique to detect rare mRNAs, such as beta -AR mRNAs, from small human endomyocardial biopsies and even isolated cardiomyocytes. Real-time RT-PCR is appropriate to quantitate rare messenger RNAs, including in extremely small human tissue samples. This method appears very promising for futures studies of gene expression in several pathophysiological conditions, including heart failure.

Hsp90 and caveolin are key targets for the proangiogenic nitric oxide-mediated effects of statins

3-Hydroxy-3-methylglutaryl (HMG)-coenzyme A reductase inhibitors or statins exert direct beneficial effects on the endothelium in part through an increase in nitric oxide (NO) production. Here, we examined whether posttranslational modifications of the endothelial NO synthase (eNOS) could account for the proangiogenic effects of statins. We used endothelial cells (ECs) isolated from cardiac microvasculature, aorta, and umbilical veins, as well as dissected microvessels and aortic rings, that were cultured on reconstituted basement membrane matrix (Matrigel). Tube or precapillary formation was evaluated after statin treatment, in parallel with immunoblotting and immunoprecipitation experiments. Atorvastatin stimulated NO-dependent angiogenesis from both isolated and outgrowing (vessel-derived) ECs, independently of changes in eNOS expression. We found that in macro- but not microvascular ECs, atorvastatin stabilized tube formation through a decrease in caveolin abundance and its inhibitory interaction with eNOS. We also identified the chaperone protein hsp90 as a key target for the proangiogenic effects of statins. Using geldanamycin, an inhibitor of hsp90 function, and overexpression of recombinant hsp90, we documented that the statin-induced phosphorylation of eNOS on Ser1177 was directly dependent on the ability of hsp90 to recruit Akt in the eNOS complex. Finally, we showed that statin promoted the tyrosine phosphorylation of hsp90 and the direct interaction of hsp90 with Akt, which further potentiated the NO-dependent angiogenic processes. Our study provides new mechanistic insights into the NO-mediated angiogenic effects of statins and underscores the potential of these drugs and other modulators of hsp90 and caveolin abundance to promote neovascularization in disease states associated or not with atherosclerosis.