Hypercholesterolemia is common after pediatric heart transplantation: initial experience with pravastatin

mTor-inhibition within the first days after pediatric heart transplantation is a potentially safe option to prevent cardiac allograft vasculopathy

BACKGROUND

Immunosuppression after heart transplantation (HTX) with mammalian target of rapamycin (mTOR) inhibitors serves as a prophylaxis against rejection and to treat coronary vascular injury. However, there is little data on the early, preventive use of everolimus after pediatric HTX.

METHODS

Retrospective study of 61 pediatric HTX patients (48 cardiomyopathy and 13 congenital heart disease), 28 females, median age 10.1 (range 0.1-17.9) years transplanted between 2008 and 2020. We analyzed survival, rejection, renal function, occurrence of lymphoproliferative disorder, and allograft vasculopathy together with adverse effects of early everolimus therapy combined with low-dose calcineurin inhibitors.

RESULTS

Everolimus therapy was started at a median 3.9 (1-14) days after HTX. Median follow-up was 4.3 (range 0.5-11.8) years, cumulative 184 patient years. The estimated 1- and 5-year survival probability was 89% (CI 82%:98%) and 87% (CI 78%:97%). Four patients developed rejection (6.6%) (maximum 2R ISHLT criteria). No patient suffered from chronic renal failure. Three patients (4.9%) developed post-transplant lymphoproliferative disorder. Five patients suffered relevant wound-healing disorders after transplantation, four of them carrying relevant risk factors before HTX (mechanical circulatory support (n = 3), delayed chest closure after HTX (n = 3)). No recipient developed cardiac allograft vasculopathy.

CONCLUSION

Initiating everolimus within the first 14 days after HTX seems to be well tolerated, enabling a low incidence of rejection, post-transplant lymphoproliferative disorders, renal failure, and reveals no evidence of cardiac allograft vasculopathy as well as good overall survival in pediatric heart transplant recipients.

Obesity and dyslipidemia predict cardiac allograft vasculopathy and graft loss in children and adolescents post-heart transplant: A PHTS multi-institutional analysis

BACKGROUND

Obesity and dyslipidemia afflict children of all ages. We explored the prevalence of obesity and dyslipidemia in pediatric heart transplant (HT) recipients and its effects on cardiac allograft vasculopathy (CAV) and survival.

METHODS

This study included primary HT recipients (≤18 years) transplanted between 01/1996 and 12/2018 included in the Pediatric Heart Transplant Society database. Obesity was categorized according to WHO/CDC guidelines and dyslipidemia according to the National Cholesterol Education Program. Kaplan-Meier analyses for CAV and graft loss stratified for BMI and lipid panels were generated and risk factors identified using multivariate analyses.

RESULTS

Among 6291 HT patients (median age [range] at HT = 4.3 [0.6-12.8] years; 45% Female; 68% White), 56% had a normal BMI at HT. Obese patients at HT had an increased risk for graft loss (HR 1.19, 95% CI 1.01-1.4, p = .04). Poor total cholesterol (TC), LDL-C, and TG were associated with the risk of both CAV (HR 1.79, p < .0001; HR 1.65, p = .0015; HR 1.53, p < .0001, respectively) and graft loss (HR 1.58, p = .0008; HR 1.22, p = .04; HR 1.43, p = .0007, respectively).

CONCLUSIONS

Pediatric patients who are obese at the time of HT and dyslipidemic at 1 year post-HT are at an increased risk for CAV and graft loss. Preventative interventions may reduce morbidity and mortality among this cohort.

Cardiac allograft vasculopathy: A review

BACKGROUND

Heart transplantation has become the standard of care for pediatric patients with end-stage heart disease, and outcomes have consistently improved over the last few decades. CAV, however, remains a leading cause of morbidity and mortality in heart transplantation and is the leading cause of death beyond 3 years post-transplantation. We sought out to provide an in-depth overview of CAV in the pediatric heart transplant population.

METHODS

Database searches were conducted in both Medline and Embase on the topic of cardiac vasculopathy in pediatric heart transplant recipients. The search used five broad concept terms: heart transplant; pediatric; CAV; diagnosis, prognosis, and risk factors; and guidelines and reviews. References were captured if there was at least one term in each of the concepts. The search was limited to articles in the English language.

RESULTS

A total of 148 articles were identified via the literature search with further articles identified via review of references. Pediatric data regarding the etiology and development of CAV remain limited although knowledge about the immune and non-immune factors playing a role are increasing. CAV continues to be difficult to detect with many invasive and non-invasive methods available, yet their effectiveness in the detection of CAV remains suboptimal. There remains no proven medical intervention to treat or reverse established CAV disease, and CAV is associated with high rates of graft loss once detected. However, several medications are used in hopes of preventing, slowing progression, or modifying the outcomes.

CONCLUSION

This review provides a comprehensive overview of CAV, discusses its clinical presentation, risk factors, diagnostic tools used to identify CAV in the pediatric population, and highlights the current therapeutic options and the need for ongoing research.

Cardiovascular health in pediatric heart transplant patients

BACKGROUND

Ideal "cardiovascular health" (CVH)-optimal diet, exercise, nonsmoking, BMI, BP, lipids, and glucose-is associated with healthy longevity in adults. Pediatric heart transplant (HT) patients may be at risk for suboptimal CVH.

METHODS

Single-center retrospective study of HT patients 2003-2014 who survived 1 year post-transplant. Five CVH metrics were collected at listing, 1, 3 and 5 years post-transplant (diet and exercise were unavailable). CVH was scored by summing individual metrics: ideal = 2, intermediate = 1, and poor = 0 points; total scores of 8-10 points were considered high (favorable). CVH was compared between HT patients and the US pediatric population (GP) utilizing NHANES 2007-2016. Logistic regression was performed to examine the association of CVH 1 year post-transplant with a composite adverse outcome (death, re-listing, coronary vasculopathy, or chronic kidney disease) 3 years post-transplant.

RESULTS

We included 110 HT patients (median age at HT: 6 years [range 0.1-21]) and 19,081 NHANES participants. CVH scores among HT patients were generally high at listing (75%), 1 (74%), 3 (87%) and 5 (76%) years post-transplant and similar to GP, but some metrics (e.g., glucose) were worse among HT patients. Among HT patients, CVH was poorer with older age and non-Caucasian race/ethnicity. Per 1-point higher CVH score, the demographic-adjusted OR for adverse outcomes was 0.95 (95% CI, 0.7-1.4).

CONCLUSIONS

HT patients had generally favorable CVH, but some metrics were unfavorable and CVH varied by age and race/ethnicity. No significant association was detected between CVH and adverse outcomes in this small sample, but study in a larger sample is warranted.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients: A Scientific Statement From the American Heart Association

This scientific statement presents considerations for clinical management regarding the assessment and risk reduction of select pediatric populations at high risk for premature cardiovascular disease, including acquired arteriosclerosis or atherosclerosis. For each topic, the evidence for accelerated acquired coronary artery disease and stroke in childhood and adolescence and the evidence for benefit of interventions in youth will be reviewed. Children and adolescents may be at higher risk for cardiovascular disease because of significant atherosclerotic or arteriosclerotic risk factors, high-risk conditions that promote atherosclerosis, or coronary artery or other cardiac or vascular abnormalities that make the individual more vulnerable to the adverse effects of traditional cardiovascular risk factors. Existing scientific statements and guidelines will be referenced when applicable, and suggestions for risk identification and reduction specific to each setting will be described. This statement is directed toward pediatric cardiologists, primary care providers, and subspecialists who provide clinical care for these young patients. The focus will be on management and justification for management, minimizing information on pathophysiology and epidemiology.

Statin Safety and Associated Adverse Events: A Scientific Statement From the American Heart Association

One in 4 Americans >40 years of age takes a statin to reduce the risk of myocardial infarction, ischemic stroke, and other complications of atherosclerotic disease. The most effective statins produce a mean reduction in low-density lipoprotein cholesterol of 55% to 60% at the maximum dosage, and 6 of the 7 marketed statins are available in generic form, which makes them affordable for most patients. Primarily using data from randomized controlled trials, supplemented with observational data where necessary, this scientific statement provides a comprehensive review of statin safety and tolerability. The review covers the general patient population, as well as demographic subgroups, including the elderly, children, pregnant women, East Asians, and patients with specific conditions such as chronic disease of the kidney and liver, human immunodeficiency viral infection, and organ transplants. The risk of statin-induced serious muscle injury, including rhabdomyolysis, is <0.1%, and the risk of serious hepatotoxicity is ≈0.001%. The risk of statin-induced newly diagnosed diabetes mellitus is ≈0.2% per year of treatment, depending on the underlying risk of diabetes mellitus in the population studied. In patients with cerebrovascular disease, statins possibly increase the risk of hemorrhagic stroke; however, they clearly produce a greater reduction in the risk of atherothrombotic stroke and thus total stroke, as well as other cardiovascular events. There is no convincing evidence for a causal relationship between statins and cancer, cataracts, cognitive dysfunction, peripheral neuropathy, erectile dysfunction, or tendonitis. In US clinical practices, roughly 10% of patients stop taking a statin because of subjective complaints, most commonly muscle symptoms without raised creatine kinase. In contrast, in randomized clinical trials, the difference in the incidence of muscle symptoms without significantly raised creatinine kinase in statin-treated compared with placebo-treated participants is <1%, and it is even smaller (0.1%) for patients who discontinued treatment because of such muscle symptoms. This suggests that muscle symptoms are usually not caused by pharmacological effects of the statin. Restarting statin therapy in these patients can be challenging, but it is important, especially in patients at high risk of cardiovascular events, for whom prevention of these events is a priority. Overall, in patients for whom statin treatment is recommended by current guidelines, the benefits greatly outweigh the risks.

A Rotavirus-Induced Mouse Model to Study Biliary Atresia and Neonatal Cholestasis

Biliary atresia is a devastating neonatal cholangiopathy that affects both extra- and intrahepatic bile ducts progressing to fibrosis and end-stage liver disease by 2 years of age. Despite re-establishment of biliary drainage following a Kasai portoenterostomy (surgical procedure), many infants develop fibrosis requiring liver transplant. In the murine model of biliary atresia, rhesus rotavirus infection of newborn pups results in a cholangiopathy paralleling human biliary atresia and is used to study mechanistic aspects of the disease. The infected mice displayed histopathological signs similar to human biliary atresia, with bile duct obstruction, bile duct proliferation, and liver inflammation with fibrosis.

Using the Theory of Planned Behavior to Explore Pediatric Heart Transplant Recipients’ Dietary Behavior

Abstract. Heart transplantation is the treatment of choice for children with end-stage heart disease. Coronary artery vasculopathy is, however, a significant morbidity and leading cause of late graft loss, and hyperlipidemia a risk factor for its development. Improving diet in this population could have important benefits for patients. We wanted to understand what influences decisions about food intake in this patient group. Dietary intentions and behavior were examined using a questionnaire based on the Theory of Planned Behavior (TPB) with 67 children who had undergone heart transplantation at least 12 months previously. The TPB model was significant for both healthy and unhealthy dietary behaviors, explaining 55% and 38% of the variance, respectively. Ten percent of children reported not eating any fruit and/or vegetables in the previous week and only 29% reported eating fruit and/or vegetables every day. The Theory of Planned Behavior provides a framework for explaining some specific dietary behaviors related to individual food groups in children who have undergone heart transplantation. These preliminary data support using this approach to inform the development of interventions to improve fruit and vegetable consumption but the approach may be less useful for explaining and developing interventions to reduce the consumption of unhealthy foods.

Recent advances in the pathogenesis and management of biliary atresia

PURPOSE OF REVIEW

The purpose of this study is to review advances in both the pathogenesis and clinical management of biliary atresia.

RECENT FINDINGS

Immunologic studies have further characterized roles of helper T-cells, B-cells, and natural killer cells in the immune dysregulation following viral replication within and damage of biliary epithelium. Prominin-1-expressing portal fibroblasts may play an integral role in the biliary fibrosis associated with biliary atresia. A number of genetic polymorphisms have been characterized as leading to susceptibility for biliary atresia. Postoperative corticosteroid therapy is not associated with greater transplant-free survival. Newborn screening may improve outcomes of infants with biliary atresia and may also provide a long-term cost benefit.

SUMMARY

Although recent advances have enhanced our understanding of pathogenesis and clinical management, biliary atresia remains a significant challenge requiring further investigation.

Pediatric transplantation: opportunities for pharmacogenomics and genomics

Heterogeneity is the rule among pediatric heart transplant recipients. Patients vary in age, size, organ maturity, immune system maturity and underlying disease etiology, which can all influence post-transplant outcomes. Overall, the survival of pediatric transplant recipients continues to improve and the goal remains long-term survival of the primary graft and mitigation of long-term complications and adverse events. The evolving fields of pharmacogenomics and genomics have the potential to revolutionize and personalize the care of pediatric transplant recipients, and although clinical validation in a pediatric cohort is lacking, many of these technologies are becoming more readily available. We discuss genotype-guided dosing of immunosuppressant medications and other commonly used medications after transplantation, the influence of donor and recipient genotype on risk of post-transplant complications, genotype-guided selection of therapies to treat complications, and the use of next-generation sequencing for noninvasive detection of graft rejection.

Indications, tolerance and complications of a sirolimus and calcineurin inhibitor immunosuppression regimen: intermediate experience in pediatric heart transplantation recipients

Although SRL has been used in adults, few studies are reported in pediatric Htx recipients. Retrospective chart review of all Htx patients on SRL. We evaluated Cr at Htx and years 1, 3, 5, 7, 9, 11, 13, and 15 post-Htx. GFR was calculated (Schwartz). BMI, Hgb, lipid profiles, and complications were compared to 59 controls, and a matched case-control group used to compare GFR to SRL cohort. Twenty-one patients were converted to SRL 1-2 mg/day (target 4-8 ng/mL) and analyzed. Reasons for conversion: re-transplantation/TCAD (8), renal (7), rejection (5), other (1). Cr was higher (p = 0.004) and GFR lower (p = 0.025) in SRL group than controls at Htx. Patients began SRL a median of 3.6 yr (0.1-16.2) post-Htx at 15.2 yr of age (4.4-24.4), with follow-up 0.5-4.6 yr. SRL was well tolerated with no increase in hyperlipidemia, rejection or mortality. None required SRL discontinuation. SRL was well tolerated in pediatric Htx patients. Kidney function remained stable; subjects had no increase in mortality, rejection or PTLD. Multicenter studies using renal sparing protocols are needed to determine whether SRL should be used routinely in children.

Calcineurin inhibitor sparing in paediatric solid organ transplantation : managing the efficacy/toxicity conundrum

Despite their efficacy, the calcineurin inhibitors (CNIs) ciclosporin and tacrolimus carry a risk of debilitating adverse effects, especially nephrotoxicity, that affect the long-term outcome and survival of children who are given organ transplants. Simple reduction in dosage of CNI has little or no long-term benefit on their adverse effects, and complete withdrawal without threatening graft outcome may only be possible after liver transplantation. Until the last decade, the only option was to increase corticosteroid and/or azathioprine doses, which imposed additional long-term hazards. Considered here are the emerging generation of new agents offering an opportunity for improving long-term graft survival, minimizing CNI-related adverse events and ensuring patient well-being.A holistic, multifaceted strategy may need to be considered - initial selection and optimized use and monitoring of immunosuppressant regimens, early recognition of indicators of patient and graft dysfunction, and, where applicable, early introduction of CNI-sparing regimens facilitating CNI withdrawal. The evidence reviewed here supports these approaches but remains far from definitive in paediatric solid organ transplantation. Because de novo immunosuppression uses CNI in more than 93% of patients, reduction of CNI-related adverse effects has focused on CNI sparing or withdrawal.A recurring theme where sirolimus and mycophenolate mofetil have been used for this purpose is the importance of their early introduction to limit CNI damage and provide long-term benefit: for example, long-term renal function critically reflects that at 1 year post-transplant. While mycophenolic acid shows advantages over sirolimus in preserving renal function because the latter is associated with proteinuria, sirolimus appears the more potent immunosuppressant but also impairs early wound healing. The use of CNI-free immunosuppressant regimens with depleting or non-depleting antibodies plus sirolimus and mycophenolic acid needs much wider investigation to achieve acceptable rejection rates and conserve renal function. The adverse effects of the alternative immunosuppressants, particularly the dyslipidaemia associated with sirolimus, needs to be minimized to avoid replacing one set of adverse effects (from CNIs) with another. While we can only conjecture that judicious combinations with the second generation of novel immunosuppressants currently in development will provide these solutions, a rationale of low-dose therapy with multiple immunosuppressants acting by complementary mechanisms seems to hold the promise for efficacy with minimal toxicity until the vision of tolerance achieves reality.

Preparation of heparin-immobilized PVA and its adsorption for low-density lipoprotein from hyperlipemia plasma

In this study, heparin was covalently coupled by glutaraldehyde to Poly(vinyl alcohol) [PVA] in solid-liquid two-phase reaction system by two-step synthesis method to prepare a LDL-selective adsorbent. The parameters (the material ratio, reaction time and dosage of catalyzer) were investigated to evaluate their effect upon the immobilized amount of heparin onto the surface of PVA, IR was used to verify the covalent immobilization result and the heparin-modified PVA was also undergone the evaluation of its adsorption capability for low-density lipoprotein from hyperlipemia plasma, and its hemocompatibility was preliminarily evaluated by platelet adhesion test. Results showed: (1) under optimized reaction conditions the highest immobilization amount of heparin onto PVA surface within the experiments of this study has been obtained; (2) the optimized reaction conditions were: (i) at the refluxing temperature 78 degrees C; (ii) the material ratio of "PVA(g): 50% glutaraldehyde (ml)" was about "1:3"; (iii) the reaction time was about 5 h; and (iv) the amount of catalyzer (concentrated HCL) was about 1% of the 50% glutaraldehyde; (3) within the experiments of this study the highest immobilization amount would be up to 25 microg heparin on the surface of per g PVA granules; (4) the heparin-modified PVA granules showed significant adsorption for LDL under faintly alkaline environment (pH=7.2-9.5) ; (5) The result of platelet adhesion test showed no platelet adhered to its surface. Therefore, immobilization of heparin onto the surface of a support is one approach to prepare a kind of LDL adsorbent for blood purification.

Subclinical atherosclerosis after heart and heart-lung transplantation in childhood

Children after heart transplantation are considered as at-risk patients for extracardiac atherosclerotic complications. Noninvasive ultrasound measurement of the common carotid artery (IMT) provides valid information about the endothelial structure of the vascular system. Twenty-two patients (17 male, mean age 12.4 +/- 4.5 yr) after heart and (5.7 +/- 4.5 yr) heart-lung transplantation were enrolled. The mean IMT was measured and compared with a control group (18 children, 10 male, mean age 11.8 +/- 1.8 yr) and to normative data. Transplanted children had a higher IMT than controls (0.453 +/- 0.003 vs. 0.424 +/- 0.002 mm, p < 0.001). IMT-SDS was increased as well (1.6 +/- 0.1 vs. 0.8 +/- 0, p < 0.001). Transplanted children had a higher LDL/HDL-ratio (2.2 +/- 0.2 vs. 1.2 +/- 0.1, p < 0.001). Time after transplantation, age at the time of transplantation, or medical therapy did not influence the findings. We found evidence for subclinical atherosclerosis in children after heart and heart-lung transplantation. Even if single atherosclerotic risk factors could not be identified, transplanted children seem to be at risk for atherosclerosis. Our findings support the recently published statement of the AHA-Expert panel: after heart transplantation atherosclerotic complications may occur with increased incidence. We propose the IMT-measurement in these patients as an easy method to assess the vascular status and to guide preventive measures.

Corticosteroid-induced adverse events in adults: frequency, screening and prevention

Corticosteroids represent the most important and frequently used class of anti-inflammatory drugs and are the reference therapy for numerous neoplastic, immunological and allergic diseases. However, their substantial efficacy is often counter-balanced by multiple adverse events. These corticosteroid-induced adverse events represent a broad clinical and biological spectrum from mild irritability to severe and life-threatening adrenal insufficiency or cardiovascular events. The purpose of this article is to provide an overview of the available data regarding the frequency, screening and prevention of the adverse events observed in adults during systemic corticosteroid therapy (topically administered corticosteroids are outside the remit of this review). These include clinical (i.e. adipose tissue redistribution, hypertension, cardiovascular risk, osteoporosis, myopathy, peptic ulcer, adrenal insufficiency, infections, mood disorders, ophthalmological disorders, skin disorders, menstrual disorders, aseptic necrosis, pancreatitis) and biological (i.e. electrolytes homeostasis, diabetogenesis, dyslipidaemia) events. Lastly, data about the prescription of corticosteroids during pregnancy are provided. This review underscores the absence of data on many of these adverse events (e.g. lipodystrophy, dyslipidaemia). Our intent is to present to practitioners data that can be used in a practical way to both screen and prevent most of the adverse events observed during systemic corticosteroid therapy.

Rational approach to the treatment for heterozygous familial hypercholesterolemia in childhood and adolescence: a review

Atherosclerosis represents a disease that begins in childhood and in which LDL cholesterol plays a pivotal role for the development of the pathology. Children and adolescents with high cholesterol levels are more likely than their peers to present cholesterol elevation as adults. The identification of genetic dyslipidemias associated with premature cardiovascular disease is crucial during childhood to delay or prevent the atherosclerotic process. Guidelines for the diagnosis and treatment of hypercholesterolemia during pediatric age are available from the National Cholesterol Education Program. A heart-healthy diet should begin at the age of 2 yr and a large number of studies have demonstrated no adverse effects on nutritional status, growth, pubertal development, and psychological aspects in children and adolescents limiting total and saturated fat intake. Pharmacotherapy should be considered in children over 10 yr of age when LDL cholesterol concentrations remain very high despite severe dietary therapy, especially when multiple risk factors are present. The only lipid-lowering drugs recommended up to now for childhood and adolescence are resins reported to be effective and well tolerated, although compliance is very poor because of unpalatability. The use of statins is increasing and seems to be effective and safe in children, even if studies enrolled a small number of patients and evaluated efficacy and safety for short-term periods. Recently, an interesting drug represented by ezetimibe has been found that may provide cholesterol-lowering additive to that reached with statin treatment. This review provides an update on recent advances in the diagnosis, therapy, and follow-up of familial hypercholesterolemia during pediatric age and adolescence.

Low HDL-C predicts the onset of transplant vasculopathy in pediatric cardiac recipients on pravastatin therapy

The levels and protein/lipid compositions of major lipoprotein particles of 19 pediatric cardiac transplant recipients (4-18 yr of age) were studied in this prospective, open clinical follow-up study before and at one yr of pravastatin therapy (10 mg/day). The recipients were grouped into those with (n = 6; group A) and those without (n = 13; group B) angiographically detectable vasculopathy. Twenty-one pediatric non-transplant controls were studied at baseline. At baseline, the group A recipients had 29% lower HDL-C concentrations (p = 0.031) and 29% higher apoB-100/apoA-I ratios (p = 0.034) than the group B recipients. At one yr of pravastatin, the respective figures were 29% (p = 0.013) and 33% (p = 0.005). Compared with the healthy pediatric controls, the transplant recipients had significantly higher serum TG before pravastatin [median (range): 1.3 mmol/L (0.6-3.2) vs. 0.7 mmol/L (0.3-2.4), p = 0.0002] and at one yr [1.3 mmol/L (0.5-3.5) vs. 0.7 mmol/L (0.3-2.4), p = 0.0004]. The baseline apoB-100/apoA1 ratios of the recipients were 33% higher (p = 0.005). In conclusion, low HDL-C and high apoB-100/apoA-I ratio were associated with angiographically detectable vasculopathy. Even though pravastatin effectively lowered the TC and LDL-C and improved compositional properties of LDL and HDL(2) particles, it failed to normalize the elevated TG and, in some patients, to prevent the progression of transplant vasculopathy.

Cardiovascular risk reduction in high-risk pediatric patients: a scientific statement from the American Heart Association Expert Panel on Population and Prevention Science; the Councils on Cardiovascular Disease in the Young, Epidemiology and Prevention, Nutrition, Physical Activity and Metabolism, High Blood Pressure Research, Cardiovascular Nursing, and the Kidney in Heart Disease; and the Interdisciplinary Working Group on Quality of Care and Outcomes Research

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Asymptomatic statin-induced rhabdomyolysis after long-term therapy with the hydrophilic drug pravastatin

CASE SUMMARY

A male patient aged 73 years, 165 cm in height, and weighing 78 kg presented to the emergency department with dsypnea. He had undergone heart transplantation 7 years earlier and been receiving daily pravastatin therapy for >3 years without complaining of any symptoms. A physical examination of the patient at admission was unremarkable, except for dyspnea. However, laboratory testing revealed that his serum creative kinase (CK) concentration was substantially above the reference range. Pravastatin was immediately discontinued, and the patient was admitted to the intensive care unit for treatment. CK values declined after 3 days, and they returned to within reference range after 3 weeks. The patient was diagnosed with acute rhabdomyolysis; a score of 6 on the Naranjo adverse drug reaction probability scale indicated that pravastatin was the probable cause.

DISCUSSION

The hydrophilic statin pravastatin is frequently recommended for patients who have undergone heart transplantation due to its favorable tolerability profile. Unlike lipophilic statins, hydrophilic statins such as pravastatin are not metabolized in the liver via the cytochrome P450 system and have little potential for adverse events through interaction with drugs metabolized via this pathway. Based on a search of relevant literature, this report appears to be the first to describe a case of asymptomatic rhabdomyolysis occurring in a patient receiving long-term daily therapy with pravastatin after undergoing heart transplantation and who had no muscular symptoms or history of intense physical exertion. The occurrence of acute statin-induced rhabdomyolysis in this case suggests that even hydrophilic statins may have the potential to damage myocytes.

CONCLUSIONS

The hydrophilic statin pravastatin appears to have caused asymptomatic rhabdomyolysis, in the absence of physical exertion, in a patient who had undergone heart transplantation and had been receiving the drug for >3 years. Statin therapy should be initiated at the lowest effective dose, especially in patients who have undergone heart transplantation, and should be followed by close monitoring.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Advances in pediatric heart transplantation

PURPOSE OF REVIEW

Heart transplantation has become a reasonable treatment option for pediatric patients with end-stage heart failure or complex congenital cardiac defects not amenable to conventional surgical intervention. This review will summarize the current state of pediatric cardiac transplantation and review recent advances leading to new therapies.

RECENT FINDINGS

Improvements in early mortality after cardiac transplantation have occurred consistently over time since the 1980s, short-term survival rates are high, and most patients enjoy an excellent quality of life with minimal restrictions. The reduction of late mortality is still a major challenge, however, largely as a result of transplant-related coronary artery disease causing chronic graft failure and arrhythmogenic sudden death. Additional causes of morbidity and mortality occurring late after transplantation include renal dysfunction related to chronic immunosuppressive therapy with calcineurin inhibitors (tacrolimus or cyclosporine) and posttransplant lymphoproliferative disorders related to chronic immunosuppression. Newer agents (sirolimus, everolimus) have shown promise in immunosuppressive regimens that may alter the development or progression of long-term complications.

SUMMARY

New immunosuppressive agents allow alterations in drug regimens to minimize renal complications, and may influence the incidence and progression of transplant vasculopathy. Recent studies on posttransplant lymphoproliferative disorders should result in earlier diagnosis and therapy.

Pediatric cardiac transplantation

Pediatric heart transplantation has undergone major changes over the past two decades, marked by a substantial improvement in survival, reduction in posttransplant complications, and enhancement in quality of life for transplant recipients. Actuarial survival has improved substantially in the last decade. Indications for pediatric heart transplant have changed as surgery for complex congenital heart lesions has evolved. There are now left and right ventricular assist devices that are suitable for use in infants as a bridge to transplantation. New immunosuppressive agents have reduced the risk of rejection while minimizing side effects and strategies to reduce the risk of graft coronary disease are beginning to show promise. Finally, true long-term survival for children after heart transplant has now been demonstrated and quality of life is excellent.

Ten- and 20-year survivors of pediatric orthotopic heart transplantation

BACKGROUND

Pediatric heart transplantation is entering its third decade, allowing for the first time an analysis of a large group of true long-term survivors, specifically children who have survived > or =10 years post-transplantation.

METHODS

Fifty-two patients < or =18 years, who had undergone heart transplantation at Stanford between August 1974 and June 1993 and survived > or =10 years, were retrospectively reviewed.

RESULTS

Forty (77%) patients are currently alive. Thirteen survived >15 years and 5 >20 years (the longest being 26 years). Actuarial survival was 79.4% at 14 years and 53.1% at 20 years. Cardiomyopathy was the reason for transplantation in 71% and congenital heart disease (CHD) in 29%. At last evaluation, 71% were on a cyclosporine-based regimen and 23% a tacrolimus-based regimen; 33% were steroid-free. Twenty-seven percent were totally free from treatable rejection, 44% developed serious infections, 69% were receiving anti-hypertensives, and 8% required renal transplantation. Neoplasms occurred in 23%, graft coronary artery disease (CAD) in 31%, and 15% required re-transplantation. Of the 12 deaths, CAD was the most common cause (n = 4), followed by non-specific late graft failure (n = 3), infection (n = 2), rejection (n = 1), non-lymphoid cancer (n = 1) and lymphoid cancer (n = 1). Physical rehabilitation and return to normal lifestyle has been nearly 100%.

CONCLUSIONS

Heart transplantation in pediatric patients is compatible with true long-term survival with a growing cohort of children approaching their second and third decades. The gradual constant-phase decrease in survival noted in earlier studies appears to be continuing. Rejection and infection are low but persistent risks after the first years. Graft CAD and non-specific late graft dysfunction are the leading causes of death after 10 years. Rehabilitation is excellent.

Lipid profiles in pediatric thoracic transplant recipients are determined by their immunosuppressive regimens

BACKGROUND

Controversy exists over the pattern of lipidemic effects from calcineurin inhibitors and prednisone. We report an extensive longitudinal study of lipid profiles in pediatric thoracic transplant recipients.

METHODS

Serial fasting lipids of subjects from a single pediatric center, along with their immunosuppressive regimens, were examined. Groups were analyzed according to cyclosporine- or tacrolimus-based immunosuppression in addition to whether prednisone was used as adjunctive therapy.

RESULTS

Of a total of 119 subjects, 85 were and remained on tacrolimus (TAC), 13 remained on cyclosporine (CSA), 4 switched from TAC to CSA, and 17 switched from CSA to TAC. The median age at transplant was 100 months, and the latest follow-up was 48 months. The CSA Group had higher lipid levels than the TAC Group, and levels changed minimally over time. At 1 year, TAC vs CSA total cholesterol was 153 vs 186 mg/dl (p = 0.002), low-density lipoprotein (LDL) cholesterol was 92 vs 117 (p = 0.09), and high-density lipoprotein (HDL) cholesterol was 42 vs 48 (p = NS), respectively. At the latest follow-up, the TAC vs CSA cholesterol was 143 vs 180 mg/dl (p = 0.001), LDL was 84 vs 115 (p = 0.001), and HDL was 42 vs 41 (p = NS). Profiles of subjects that switched agents reflected the agent used (e.g., higher total cholesterol, LDL, and HDL while on cyclosporine). Sub-group analysis showed prednisone augmented the hyperlipidemic effects.

CONCLUSION

Hyperlipidemia is common in pediatric thoracic transplant patients and persists over time. It is more pronounced in cyclosporine subjects and is further elevated with prednisone. These findings indicate the need for close monitoring, and consideration for intervention, especially in high-risk sub-groups.

Predictors of graft longevity in pediatric heart transplantation

Given the volume of pediatric orthotopic heart transplants (OHTs) at several centers, it is now possible to generate pediatric-specific, single-center OHT survival data. The transplant experience for 152 pediatric OHT patients at our institution was reviewed. The following were noted for each patient: graft survival; immunosuppressant therapy; initial diagnosis; cause of graft failure; clinical status at time of transplant; donor and recipient blood type, sex, weight, and age; ischemic time; previous cardiac surgery; race; and immune status. A series of Kaplan-Meier survival curves were constructed. Univariate comparisons of survival curves were performed with the Breslow test to determine equality of each pair of curves. Only immunosuppression with tacrolimus and an initial diagnosis of noncongenital heart disease positively influenced survival in pediatric OHT patients (p < or = 0.021 and p < or = 0.03, respectively). The more recently transplanted patients, managed with tacrolimus, had less mortality early after OHT (acute rejection) and less mortality during the period 2 or 3 years after OHT. No other factors, including prior cardiothoracic surgery, sex matching, and race matching, significantly influenced survival. Recently transplanted patients managed with tacrolimus-based immunosuppression and patients with noncongenital cardiomyopathy have significantly superior graft survival.

Effect of age on lipid profiles in pediatric heart transplant recipients

This study's objectives were to determine if pediatric orthotopic heart transplant (OHT) recipients over all ages develop hyperlipidemia and, secondarily, to identify the effects of immunosuppressive agents and statins on lipid profiles in these patients. Retrospective chart review was performed for pediatric patients transplanted between January 1987 and June 2002. Of the 100 OHTs performed, 50 patients satisfied the inclusion criteria and were grouped by age at OHT as follows: group 1 (n = 16): 0-4 yr; group 2 (n = 10): 5-9 yr; group 3 (n = 15): 10-14 yr; group 4 (n = 9): 15-18 yr. There were 2789 lipid levels recorded, and each patient had an average of 14 post-OHT lipoprotein panels measured. Post-OHT total cholesterol and low-density lipoprotein (LDL) levels were significantly greater than those of the general population for the entire follow-up period in all age groups, except for LDL levels in group 2. Cyclosporin level and prednisone dose were positively associated with total cholesterol and LDL levels (p < 0.03). Statins significantly decreased total cholesterol and LDL levels (p < 0.001). Hyperlipidemia affects OHT patients of all ages. Even the youngest patients may benefit from immunosuppression using an alternative to cyclosporin, such as tacrolimus, and steroid-free regimens, which may improve lipid profiles. Once safety and efficacy data are available, all age groups may benefit from statins.

Neointimal Inflammation and Adventitial Angiogenesis Correlate With Severity of Cardiac Allograft Vasculopathy in Pediatric Recipients

BACKGROUND

Chronic inflammation and angiogenesis have been implicated in the pathogenesis of both cardiac allograft vasculopathy (CAV) and age-related vasculopathy. Because concurrent atherosclerosis does not complicate assessment of CAV in children, we sought to characterize the spectrum of coronary lesions in this population and determine whether inflammatory infiltrates and angiogenesis correlate with severity of CAV.

METHODS

In 18 pediatric heart specimens CAV was graded 1 to 4 (none to severe). Each case was assigned to either: Group I, no inflammation; Group II, perivascular inflammation; or Group III, perivascular and neointimal inflammation. Inflammatory infiltrates were immunophenotyped using anti-CD3, anti-CD20 and HAM 56. Angiogenesis was assessed by determining microvascular density (MVD) in 5 high-power fields (HPFs) per section.

RESULTS

CAV was evident in 94% of cases, and inflammation in 61%. Cases with neointimal inflammation had significantly more severe CAV compared with cases without inflammation (2.7 +/- 0.16 vs 1.9 +/- 0.2, p = 0.002). MVD was significantly higher in both inflammation groups (Groups II and III) compared with Group I (4.1 +/- 0.5 per HPF and 5.9 +/- 0.5 vs 3.1 +/- 0.7, p = 0.018 and p = 0.002) and correlated with the degree of CAV (p = 0.007). The perivascular infiltrates (Group II, n = 5) contained lymphocytes, macrophages and plasma cells, and 67% of neointimal infiltrates (Group III, n = 6) also contained eosinophils.

CONCLUSIONS

CAV in children is more common than previously reported. Our data indicate that CAV is often associated with inflammation and that adventitial angiogenesis correlated with the severity of CAV.

Sirolimus immunosuppression in pediatric heart transplant recipients: A single-center experience

BACKGROUND

Sirolimus has been used in heart transplant recipients for treatment of rejection, alternative immunosuppression (IS) and promotion of regression and prevention of graft vasculopathy (coronary artery disease [CAD]). This study reports on our center's experience with 16 children who underwent heart transplantation.

METHODS

Data were obtained by retrospective review.

RESULTS

Median age at time of review was 12.3 years (n = 16, 5.1 to 18.0 years; 9 boys, 7 girls), and at time of transplant 7.5 years (6 months to 18.0 years). Median time of sirolimus introduction was 2.7 years (1 month to 8.2 years) post-transplant. Fifteen patients were on steroids, 10 on tacrolimus (FK) and mycophenolate mofetil (MMF), 5 on FK and 1 on MMF with no calcineurin inhibitors (CNIs). The average dose of sirolimus was 0.25 mg/kg or 7.0 mg/m(2) to maintain a target level of 5 to 15 mug/liter. Sirolimus was started for CAD in 6 patients (38%), rejection in 5 (31%), and in 5 with combinations of CNI intolerance, CAD, renal dysfunction and rejection. All 6 who received sirolimus for rejection (International Society for Heart and Lung Transplantation [ISHLT] Grade 3A) showed improvement on follow-up biopsies. Two of 3 who received sirolimus for renal dysfunction showed improvement (glomerular filtration rate [GFR] 43 to 67 and 32 to 106 ml/min per 1.73 m(2), respectively). Side effects included hyperlipidemia (38%), abdominal pain (31%), mouth ulcers (26%), anemia or neutropenia (12.5%), persistent pericardial effusion (6%) and interstitial lung disease (6%). Sirolimus therapy was discontinued in 3 patients due to side effects.

CONCLUSIONS

In this study sirolimus was found to be a valuable IS agent for the management of rejection, significant renal dysfunction and CNI side effects. These results support the need for prospective studies of the role of sirolimus in primary rejection prophylaxis, primary CAD prophylaxis and CAD regression. There also exists a need to establish an adverse event profile for this drug.