Children presenting with acute pericarditis to the emergency department

Advancing multidisciplinary management of pediatric hyperinflammatory disorders

Pediatric hyperinflammatory diseases, including Still's disease, Kawasaki disease (KD), multisystem inflammatory syndrome in children (MIS-C), and recurrent pericarditis (RP), represent a spectrum of conditions characterized by immune dysregulation and systemic inflammation. Each disorder exhibits distinct pathophysiological mechanisms and clinical features, yet their overlapping presentations often pose diagnostic challenges. Early and accurate differentiation is critical to mitigate complications such as macrophage activation syndrome (MAS), coronary artery aneurysms, and myocardial dysfunction. This narrative review explores the pathophysiology, diagnostic criteria, and management of these conditions, emphasizing the utility of advanced biomarkers, imaging modalities, and genetic testing. For Still's disease, the review highlights the transformative role of biologic therapies targeting IL-1 and IL-6 in reducing systemic inflammation and improving outcomes. In KD, timely administration of intravenous immunoglobulin (IVIG) and combination with high-dose steroids in high-risk patients is pivotal for preventing coronary complications. MIS-C, associated with SARS-CoV-2 infection, requires tailored immunomodulatory approaches, including corticosteroids and biologics, to address severe hyperinflammation and multiorgan involvement. RP management prioritizes NSAIDs, colchicine, and IL-1 inhibitors to reduce recurrence and corticosteroid dependence. The review advocates for a multidisciplinary approach, integrating standardized diagnostic algorithms and disease-specific expertise to optimize patient care. Future research directions include the identification of predictive biomarkers, exploration of novel therapeutic targets, and development of evidence-based treatment protocols to enhance long-term outcomes in pediatric inflammatory diseases.

Recurrent pericarditis and interleukin (IL)-1 inhibitors

Recurrent pericarditis (RP) is defined by the European Society of Cardiology (ESC) as an instance of acute pericarditis (AP) that occurs at least 4-6 weeks after the resolution of a previous episode of the same ailment. To mitigate the risk of RP, it is advised to administer accurate and prolonged pharmacological treatment for both the initial AP and subsequent RP. ESC guidelines recommend commencing treatment for any single episode of AP, including those that contribute to RP, with non-steroidal anti-inflammatory drugs (NSAIDs) in conjunction with colchicine for several months, often followed by gradual tapering. If there is an inadequate response, corticosteroids (CS) may be introduced cautiously. However, in a minority of cases, even when NSAIDs, colchicine, and CS are administered together at the highest recommended dosages, they may prove ineffective. In such instances, treatment with immunosuppressive drugs or biologics is advised. Among biologics, interleukin (IL)-1 inhibitors have been extensively studied, although certain gaps remain. This narrative review delves into the rationale for employing IL-1 inhibitors and presents findings from existing studies regarding their efficacy, tolerability, and safety. Analysis of the literature indicates that there is currently insufficient data to ascertain the true therapeutic role of IL-1 inhibitors in managing and preventing RP. However, theoretically, drugs targeting both IL-1α and IL-1β may offer superior efficacy compared to those solely targeting IL-1β due to the significant involvement of both cytokines in inflammation. Further research is warranted to determine the comparative effectiveness of IL-1α and IL-1β inhibitors.

Management of acute pericarditis

PURPOSE OF REVIEW

Provide an update on current management and most recent evidence in the treatment of pediatric pericarditis.

RECENT FINDINGS

While treatment of acute pericarditis has not significantly changed over the last decade, management of recurrent acute pericarditis, with increased attention to autoinflammation as a causal mechanism, has evolved substantially. This includes clinical trial evidence that newer medications targeting interleukin-1 receptors are effective in recurrent forms of pericarditis. In addition, advanced imaging utilizing cardiac magnetic resonance has emerged as a particularly effective way to detect ongoing pericardial inflammation in support of more difficult-to-treat patients.

SUMMARY

Recent advances in acute and recurrent pericarditis management have allowed for a more tailored approach to the individual patient. Yet, unresolved questions require further research.

Pediatric Pericarditis: Update

PURPOSE OF REVIEW

While there have now been a variety of large reviews on adult pericarditis, this detailed review specifically focuses on the epidemiology, clinical presentation, diagnosis, and management of pediatric pericarditis. We have tried to highlight most pediatric studies conducted on this topic, with special inclusion of important adult studies that have shaped our understanding of and management for acute and recurrent pericarditis.

RECENT FINDINGS

We find that the etiology of pediatric pericarditis differs from adult patients with pericarditis and has evolved over the years. Also, with the current COVID-19 pandemic, it is important for pediatric clinicians to be aware of pericardial involvement both due to the infection and from vaccination. Oftentimes, pericarditis maybe the only cardiac involvement in children with COVID-19, and so caregivers should maintain a high index of suspicion when they encounter children with pericarditis.  Large-scale contemporary epidemiological data regarding incidence and prevalence of both acute and recurrent pericarditis is lacking in pediatrics, and future studies should focus on highlighting this important research gap. Most of the current management strategies for pediatric pericarditis are from experiences gathered from adult data. Pediatric multicenter trials are warranted to understand the best management strategy for those with acute and recurrent pericarditis.

CASE VIGNETTE

A 6-year-old child with a past history of pericarditis almost 2 months ago comes in with a 2-day history of chest pain and fever. Per mother, he stopped his steroids about 2 weeks ago, and for the last 2 days has had a temperature of 102F and has been complaining of sharp mid-sternal chest pain that gets worse when he lies down and is relieved when he sits up and leans forward. On examination, he is tachycardic (heart rate 160 bpm), with normal blood pressure for age. He appears to be in pain (5/10), and on auscultation has a pericardial friction rub. His lab studies are notable for elevated white blood cell count and inflammatory markers (CRP and ESR). His electrocardiogram reveals sinus tachycardia and diffuse ST-elevation in all precordial leads. His echocardiogram demonstrates normal biventricular function and a trace pericardial effusion. His cardiac MRI confirms recurrent pericarditis. He is started on indomethacin and colchicine. He has complete resolution of his symptoms by day 3 of admission and is discharged with close follow-up.

The Epidemiology and Outcome of Pericardial Effusion in Hospitalized Children: A National Database Analysis

OBJECTIVES

To describe the epidemiology of pericardial effusion in hospitalized children and evaluate risk factors associated with the drainage of pericardial effusion and hospital mortality.

STUDY DESIGN

A retrospective study of a national pediatric discharge database.

RESULTS

We analyzed hospitalized pediatric patients from the neonatal age through 20 years in the Kids' Inpatient Database 2016, extracting the cases of pericardial effusion. Of the 6 266 285 discharged patients recorded, 6417 (0.1%) were diagnosed with pericardial effusion, with the highest prevalence of 2153 patients in teens (13-20 years of age). Pericardial effusion was drained in 792 (12.3%), and the adjusted risk of pericardial drainage was statistically low with rheumatologic diagnosis (OR, 0.485; 95% CI, 0.358-0.657, P < .001). The overall mortality in children with pericardial effusion was 6.8% and 10.9% of those who required pericardial effusion drainage (P < .001). The adjusted risk of mortality was statistically high with solid organ tumor (OR, 1.538; 95% CI, 1.056-2.239, P = .025) and pericardial drainage (OR, 1.430; 95% CI, 1.067-1.915, P = .017) and low in all other age groups compared with neonates, those with cardiac structural diagnosis (OR, 0.322; 95% CI, 0.212-0.489, P < .001), and those with rheumatologic diagnosis (OR, 0.531; 95% CI, 0.334-0.846, P = .008).

CONCLUSION

The risk of mortality in hospitalized children with pericardial effusion was higher in younger children with solid organ tumors and those who required pericardial effusion drainage. In contrast, it was lower in older children with cardiac or rheumatologic diagnoses.

Pericardial effusion among children: Retrospective analysis of the etiology and short-term outcome in a referral center in the south of Iran

Background and Aims

We reinvestigated the causes, symptoms, and management of childhood pericardial effusion (PE) and its gradual changes during recent years in a referral pediatric cardiology center in the south of Iran.

Methods

We retrospectively analyzed the profile of PE patients who were under 18 years old from 2015 to 2020. The patient's demographic, clinical, and paraclinical information was extracted and analyzed using SPSS software.

Result

In general, 150 out of 63,736 admitted patients (0.23% of the total pediatric admissions) were diagnosed with PE (male/female 1:1.17). The median age was 3.25 years (range:\ 2 days to 18 years; interquartile range: 9.5), and 50% of them were under 3 years of age. 32.6% had moderate to severe PE. Most patients presented with acute symptoms (68%) and respiratory problems, as the most common symptoms (30.6%). Tamponade signs were presented in 2% (n = 3) of the patients, and 80.7% (n = 121) were in a stable hemodynamic condition. In total, renal failure (22%) and parapneumonic effusion were the leading etiologies. Viral (7%) and bacterial (5%) pericarditis were the seventh and eighth causes; however, in severe cases, renal failure (22%) and bacterial pericarditis (14%) were dominant. In total, 14.1% (n = 21) of the patients needed pericardiocentesis that increased to 78.3% (n = 18) in severe cases. Only 6% had persistent PE for more than 3 months.

Conclusion

Childhood PE is mostly a result of renal failure and noninfectious causes. True pericarditis cases are not common, except in severe cases. It is more common in less than 3-year-old patients, and chronicity is rare. Severe cases had a high chance of pericardiocentesis, but other cases were mainly managed by treatment of the underlying causes.

Clinical Burden and Unmet Need in Recurrent Pericarditis: A Systematic Literature Review

Inflammation of the pericardium (pericarditis) is characterized by excruciating chest pain. This systematic literature review summarizes clinical, humanistic, and economic burdens in acute, especially recurrent, pericarditis, with a secondary aim of understanding United States treatment patterns and outcomes. Short-term clinical burden is well characterized, but long-term data are limited. Some studies report healthcare resource utilization and economic impact; none measure health-related quality-of-life. Pericarditis is associated with infrequent but potentially life-threatening complications, including cardiac tamponade (weighted average: 12.7% across 10 studies), constrictive pericarditis (1.84%; 9 studies), and pericardial effusion (54.7%; 16 studies). There are no approved pericarditis treatments; treatment guidelines, when available, are inconsistent on treatment course or duration. Most recommend first-line use of conventional treatments, for example, nonsteroidal antiinflammatory drugs with or without colchicine; however, 15-30% of patients experience recurrence. Second-line therapy may involve conventional therapies plus long-term utilization of corticosteroids, despite safety issues and the difficulty of tapering or discontinuation. Other exploratory therapies (eg, azathioprine, immunoglobulin, methotrexate, anakinra) present steroid-sparing options, but none are supported by robust clinical evidence, and some present tolerability challenges that may impact adherence. Pericardiectomy is occasionally pursued in treatment-refractory patients, although data are limited. This lack of an evidence-based treatment pathway for patients with recurrent disease is reflected in readmission rates, for example, 12.2% at 30 days in 1 US study. Patients with continued recurrence and inadequate treatment response need approved, safe, accessible treatments to resolve pericarditis symptoms and reduce recurrence risk without excessive treatment burden.

Current pharmacotherapy management of children and adults with pericarditis: Prospectus for improved outcomes

Pericarditis is the most common inflammatory pericardial disease in both children and adults. Since the 2015 European Society of Cardiology Guidelines for the diagnosis and management of pericardial disease were published, there have been significant updates to management. Pharmacotherapy has been historically reserved for idiopathic pericarditis (IP). However, there has been increasing use of pharmacotherapies, such as anti-inflammatory therapies, colchicine, and immunotherapies for other causes of pericarditis, such as post-cardiac injury syndromes (PCIS). Nevertheless, the quality of data varies depending on PCIS or idiopathic etiologies, as well as the adult and pediatric population. High-dose anti-inflammatory therapies should be used to manage symptoms associated with either etiology of pericarditis in both adults and children, but do not ameliorate the inflammatory disease process. Choice of anti-inflammatory should be guided by drug-drug/disease interactions, cost, tolerability, patient age, and should be tapered accordingly over several weeks to months. Colchicine should be added as adjuvant therapy to anti-inflammatory therapies in adults and children with IP, as it has been shown to lower the risk of recurrence, reduce pericarditis symptoms, and improve morbidity. Colchicine is also reasonable to add to adults and children with pericarditis secondary to PCIS. Systemic glucocorticoids increase risk of recurrence in adults and children with IP and are reserved for second-line treatment in acute and recurrent IP; they are generally avoided in PCIS. Immunotherapies are regarded as third-line for recurrent IP in adults and children. Limited evidence exists to support their use in patients with pericarditis from PCIS. Pharmacovigilance strategies, such as C-reactive protein and adverse drug event monitoring, are also important toward balancing efficacy and safety of the various strategies used to manage pericarditis in adults and children.

Predictive factors of recurrence after pediatric acute pericarditis

OBJECTIVE

The predisposing factors for pericarditis recurrence in the pediatric population have not yet been established. This study aimed to define the risk factors for the unfavorable prognosis of pediatric acute pericarditis.

METHODS

This was a retrospective study that included all patients with acute pericarditis treated from 2011 to 2019 at a tertiary referent pediatric center.

RESULTS

The study included 72 children. Recurrence was observed in 22.2% patients. Independent risk factors for recurrence were: erythrocyte sedimentation rate≥50mm/h (p=0.003, OR 186.3), absence of myocarditis (p=0.05, OR 15.2), C-reactive protein≥125mg/L (p=0.04, OR 1.5), and non-idiopathic etiology pericarditis (p=0.003, OR 1.3). Corticosteroid treatment in acute pericarditis was associated with a higher recurrence rate than treatment with non-steroid anti-inflammatory therapy (p=0.04). Furthermore, patients treated with colchicine in the primary recurrence had lower recurrence rate and median number of repeated infections than those treated without colchicine (p=0.04; p=0.007, respectively).

CONCLUSION

Independent risk factors for recurrence are absence of myocarditis, non-idiopathic etiology pericarditis, C-reactive protein≥125mg/L, and erythrocyte sedimentation rate≥50mm/h. Acute pericarditis should be treated with non-steroid anti-inflammatory therapy. A combination of colchicine and non-steroid anti-inflammatory drugs could be recommended as the treatment of choice in recurrent pericarditis.

Does Colchicine Substitute Corticosteroids in Treatment of Idiopathic and Viral Pediatric Pericarditis?

Background and Objectives: Recurrence of pericarditis (ROP) is an important complication of the acute pericarditis. The aim of this study was to analyse the influence of aetiology, clinical findings and treatment on the outcome of acute pericarditis. Methods: Data were retrospectively collected from medical records of patients treated from 2011 to 2019 at a tertiary referent heart paediatric center. Results: Our investigation included 56 children with idiopathic and viral pericarditis. Relapse was registered in 8/56 patients, 2/29 (7.41%) treated with nonsteroidal anti-inflammatory drugs (NSAID) and 6/27 (28.57%) treated with corticosteroids (CS) and NSAID. Independent risk factors for ROP were viral pericarditis (p = 0.01, OR 31.46), lack of myocardial affection (p = 0.03, OR 29.15), CS use (p = 0.02, OR 29.02) and ESR ≥ 50 mm/h (p = 0.03, OR 25.23). In 4/8 patients the first recurrence was treated with NSAID and colchicine, while treatment of 4/8 patients included CS. Children with ROP treated with CS had higher median number of recurrence (5, IQR: 2–15) than those treated with colchicine (0, IQR: 0–0.75). Conclusions: Independent risk factors for recurrence are CS treatment, viral aetiology, pericarditis only and ESR ≥ 50 mm/h. Acute pericarditis should be treated with NSAID. Colchicine and NSAID might be recommended in children with the first ROP.

Recurrent Pericarditis in Children and Adolescents

Recurrent pericarditis (RP) is a clinical syndrome characterized by recurrent attacks of acute pericardial inflammation. Prognosis quoad vitam is good, although morbidity might be significant, especially in children and adolescents. Multiple potential etiologies result in RP, in the vast majority of cases through autoimmune or autoinflammatory mechanisms. Idiopathic RP is one of the most frequent diagnoses, that requires the exclusion of all known etiologies. Therapeutic advances in the last decade have been significant with the recognition of the effectiveness of anti IL1 therapy, but a correct diagnostic and therapeutic algorithm is of key importance. Unfortunately, most of evidence comes from studies in adult patients. Here we review the etiopathogenesis, diagnosis and management of RP in pediatric patients.

Characteristics of Non-postoperative Pediatric Pericardial Effusion: A Multicenter Retrospective Cohort Study from the Pediatric Health Information System (PHIS)

Little is known about the causes and risks of non-postoperative pericardial effusion (PCE) in pediatric patients. We sought to assess the diagnoses most frequently associated with admissions for PCE, and to determine if certain conditions were associated with higher in-hospital mortality and rates of readmission. Nationally distributed data from 44 pediatric hospitals in the 2004-2015 Pediatric Health Information System database were used to identify patients with hospital admissions for International Classification of Disease, Ninth Revision (ICD-9) codes for PCE and/or cardiac tamponade. Children with congenital heart disease were excluded. ICD-9 codes for conditions associated with PCE were grouped into eight categories: neoplastic, renal, autoimmune/inflammatory, pneumonia, viral, bacterial, hypothyroidism, and idiopathic. Multivariable models were used to evaluate odds of in-hospital mortality and readmission within 30 and 90 days. There were 9902 patients who met inclusion criteria. Total in-hospital mortality was 8.2% (n = 813); of those without a neoplastic diagnosis, mortality was 6.5% (n = 493/7543). Idiopathic PCE accounted for the most admissions (36%), followed by neoplasms (24%), pneumonia (20%), and autoimmune/inflammatory disease (19%). In multivariable models, odds of death were highest for neoplasms (adjusted odds ratio 3.83, p < 0.001) and renal disease (adjusted odds ratio 2.86, p < 0.001). Children with a neoplasm, renal disease, and those undergoing pericardiocentesis had the highest rates of readmission at 30 and 90 days. Children admitted with non-postoperative PCE have multiple associated conditions. Neoplasm and renal disease in the setting of PCE are associated with the highest odds of in-hospital mortality among concomitant conditions; children with a neoplasm, renal disease, and those undergoing pericardiocentesis have the highest odds of readmission.

Development of quality metrics for ambulatory pediatric cardiology: Chest pain

OBJECTIVE

As part of the American College of Cardiology Adult Congenital and Pediatric Cardiology Section effort to develop quality metrics (QMs) for ambulatory pediatric practice, the chest pain subcommittee aimed to develop QMs for evaluation of chest pain.

DESIGN

A group of 8 pediatric cardiologists formulated candidate QMs in the areas of history, physical examination, and testing. Consensus candidate QMs were submitted to an expert panel for scoring by the RAND-UCLA modified Delphi process. Recommended QMs were then available for open comments from all members.

PATIENTS

These QMs are intended for use in patients 5-18 years old, referred for initial evaluation of chest pain in an ambulatory pediatric cardiology clinic, with no known history of pediatric or congenital heart disease.

RESULTS

A total of 10 candidate QMs were submitted; 2 were rejected by the expert panel, and 5 were removed after the open comment period. The 3 approved QMs included: (1) documentation of family history of cardiomyopathy, early coronary artery disease or sudden death, (2) performance of electrocardiogram in all patients, and (3) performance of an echocardiogram to evaluate coronary arteries in patients with exertional chest pain.

CONCLUSIONS

Despite practice variation and limited prospective data, 3 QMs were approved, with measurable data points which may be extracted from the medical record. However, further prospective studies are necessary to define practice guidelines and to develop appropriate use criteria in this population.

Recurrent pericarditis in children and adolescents: a multicentre cohort study

OBJECTIVE

Limited data are available about recurrent pericarditis in children. We sought to explore contemporary causes, characteristics, therapies and outcomes of recurrent pericarditis in paediatric patients.

METHODS

A multicentre (eight sites) cohort study of 110 consecutive cases of paediatric patients with at least two recurrences of pericarditis over an 11-year period (2000-2010) [median 13 years, interquartile range (IQR) 5, 69 boys].

RESULTS

Recurrences were idiopathic or viral in 89.1% of cases, followed by postpericardiotomy syndrome (9.1%) and familial Mediterranean fever (0.9%). Recurrent pericarditis was treated with nonsteroidal anti-inflammatory drugs (NSAIDs) in 80.9% of cases, corticosteroids in 64.8% and colchicine was added in 61.8%. Immunosuppressive therapies were administered in 15.5% of patients after subsequent recurrences. After a median follow-up of 60th months, 528 subsequent recurrences were recorded (median 3, range 2-25). Corticosteroid-treated patients experienced more recurrences (standardized risk of recurrence per 100 person-years was 93.2 for patients treated with corticosteroids and 45.2 for those without), side effects and disease-related hospitalizations (for all P < 0.05). Adjuvant therapy with colchicine was associated with a decrease in the risk of recurrence from 3.74 per year before initiation of colchicine to 1.37 per year after (P < 0.05). Anakinra therapy (n = 12) was associated with a drop in the number of recurrences from 4.29 per year before to 0.14 per year after (P < 0.05). Transient constrictive pericarditis developed in 2.7% of patients.

CONCLUSION

Recurrent pericarditis has an overall favourable prognosis in children, although it may require frequent readmissions and seriously affect the quality of life, especially in patients treated with corticosteroids. Colchicine or anakinra therapies were associated with significant decrease in the risk of recurrence.

An Interesting Case of Viral Pericarditis

A previously healthy 14-year-old girl presented to the emergency department with a 3-day history of upper respiratory symptoms and 2 syncopal episodes. She was initially febrile, tachycardic, and tachypneic; the initial electrocardiogram showed diffuse T-wave inversions and right atrial enlargement. There was no pericardial effusion on bedside and formal echocardiography; the latter, however, revealed a hyperechogenic pericardium. A viral swab was positive for influenza B. Treatment with intravenous rehydration and ibuprofen was started with good response. The patient went home 24 hours later with the diagnosis of mild pericarditis and syncope likely secondary to dehydration impaired diastolic filling.The incidence of acute pericarditis in previously healthy children is unknown. There are no known case reports of influenza B-associated pericarditis in the pediatric population. There is little high quality evidence to guide the diagnosis and management of pericarditis in children. However, limited data suggest that the typically described presentation of chest pain, pericardial rub, pericardial effusion, and electrocardiogram changes occurs in children. The pediatric population seems to respond well to nonsteroidal anti-inflammatory drugs.

Idiopathic pericarditis and pericardial effusion in children: contemporary epidemiology and management

Background

Multicenter studies on idiopathic or viral pericarditis and pericardial effusion (PPE) have not been reported in children. Colchicine use for PPE in adults is supported. We explored epidemiology and management for inpatient hospitalizations for PPE in US children and risk factors for readmission.

Methods and Results

We analyzed patients in the Pediatric Health Information System database for (1) a code for PPE; (2) absence of codes for underlying systemic disease (eg, neoplastic, cardiac, rheumatologic, renal); (3) age ≥30 days and <21 years; and (4) discharge between January 1, 2007, and December 31, 2012, from 38 hospitals contributing complete data for each year of the study period. Among 11 364 hospitalizations with PPE codes during the study period, 543 (4.8%) met entry criteria for idiopathic or viral PPE. Significantly more boys were noted, especially among adolescents. No temporal trends were noted. Median age was 14.5 years (interquartile range 7.3 to 16.6 years); 78 patients (14.4%) underwent pericardiocentesis, 13 (2.4%) underwent pericardiotomy, and 11 (2.0%) underwent pericardiectomy; 157 (28.9%) had an intensive care unit stay, including 2.0% with tamponade. Median hospitalization was 3 days (interquartile range 2 to 4 days). Medications used at initial admission were nonsteroidal anti‐inflammatory drugs (71.3%), corticosteroids (22.7%), aspirin (7.0%), and colchicine (3.9%). Readmissions within 1 year of initial admission occurred in 46 of 447 patients (10.3%), mostly in the first 3 months. No independent predictors of readmission were noted, but our statistical power was limited. Practice variation was noted in medical management and pericardiocentesis.

Conclusions

Our report provides the first large multicenter description of idiopathic or viral PPE in children. Idiopathic or viral PPE is most common in male adolescents and is treated infrequently with colchicine.

Intravenous immunoglobulin therapy for refractory recurrent pericarditis

Recurrent pericarditis is a troublesome complication of idiopathic acute pericarditis and occurs more frequently in pediatric patients after cardiac surgery (postpericardiotomy syndrome). Conventional treatment with nonsteroidal antiinflammatory drugs, corticosteroids, and colchicine is not always effective or may cause serious adverse effects. There is no consensus, however, on how to proceed in those patients whose disease is refractory to conventional therapy. In such cases, human intravenous immunoglobulin, immunosuppressive drugs, and biological agents have been used. In this report we describe 2 patients with refractory recurrent pericarditis after cardiac surgery who were successfully treated with 3 and 5 monthly high-dose (2 g/kg) intravenous immunoglobulin until resolution of the effusion. Our experience supports the effectiveness and safety of this therapy.