Usha Krishnan

Outcomes of congenital diaphragmatic hernia in the modern era of management.

OBJECTIVEnTo identify clinical factors associated with pulmonary hypertension (PH) and mortality in patients with congenital diaphragmatic hernia (CDH).nnnSTUDY DESIGNnA prospective cohort of neonates with a diaphragm defect identified at 1 of 7 collaborating medical centers was studied. Echocardiograms were performed at 1 month and 3 months of age and analyzed at a central core by 2 cardiologists independently. Degree of PH and survival were tested for association with clinical variables using Fischer exact test, χ(2), and regression analysis.nnnRESULTSnTwo hundred twenty patients met inclusion criteria. Worse PH measured at 1 month of life was associated with higher mortality. Other factors associated with mortality were need for extracorporeal membrane oxygenation, patients inborn at the treating center, and patients with a prenatal diagnosis of CDH. Interestingly, patients with right sided CDH did not have worse outcomes.nnnCONCLUSIONSnSeverity of PH is associated with mortality in CDH. Other factors associated with mortality were birth weight, gestational age at birth, inborn status, and need for extracorporeal membrane oxygenation.

Implications of the U.S. Food and Drug Administration Warning against the Use of Sildenafil for the Treatment of Pediatric Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) contributes to disability and death in children with diverse cardiac, pulmonary, or systemic diseases, and therapeutic options are currently limited. Data from adult studies provide the basis for most PAH-specific therapies; however, many of these medications are commonly used in children on an off-label basis due to the life-threatening nature of PAH. Although currently approved for use in adult PAH, sildenafil is used extensively off-label for the treatment of neonates, infants, and children with PAH. Past studies have generally suggested favorable effects and outcomes in infants and young children with PAH, but these reports are generally uncontrolled observations, except for one single-center trial for persistent pulmonary hypertension of the newborn. Despite extensive clinical experience with sildenafil therapy in children and approval by the European Medicines Agency for its pediatric use in Europe, the U.S. Food and Drug Administration recently issued a warning against the use of sildenafil for pediatric PAH between 1 and 17 years of age due to an apparent increase in mortality during long-term therapy. Although these data are extremely limited, this U.S. Food and Drug Administration review challenges the pediatric PAH community to further assess the efficacy and safety of sildenafil, especially with chronic treatment. Although low doses of sildenafil are likely safe in pediatric PAH, further studies should carefully examine its role in the long-term therapy of children, especially with diverse causes of PAH. Pediatric patients with PAH require close surveillance and frequent monitoring, and persistent sildenafil monotherapy is likely insufficient with disease progression.

Survival Differences in Pediatric Pulmonary Arterial Hypertension : Clues to a Better Understanding of Outcome and Optimal Treatment Strategies

OBJECTIVESnIn order to describe survival and treatment strategies in pediatric pulmonary arterial hypertension (PAH) in the current era of PAH-targeted drugs and to identify predictors of outcome, we studied uniformly defined contemporary patient cohorts at 3 major referral centers for pediatric PAH (New York [NY], Denver, and the Netherlands [NL]).nnnBACKGROUNDnIn pediatric PAH, discrepancies exist in reported survival rates between North American and European patient cohorts, and robust data for long-term treatment effects are lacking.nnnMETHODSnAccording to uniform inclusion criteria, 275 recently diagnosed consecutive pediatric PAH patients who visited the 3 referral centers between 2000 and 2010 were included.nnnRESULTSnUnadjusted survival rates differed between the center cohorts (1-, 3-, and 5-year transplantation-free survival rates: 100%, 96%, and 90% for NY; 95%, 87%, and 78% for Denver; and 84%, 71%, and 62% for NL, respectively; p < 0.001). Based on World Health Organization (WHO) functional class and hemodynamic parameters, disease severity at diagnosis differed between the center cohorts. Adjustment for diagnosis, WHO functional class, indexed pulmonary vascular resistance, and pulmonary-to-systemic arterial pressure ratio resolved the observed survival differences. Treatment with PAH-targeted dual and triple therapy during the study period was associated with better survival than treatment with PAH-targeted monotherapy.nnnCONCLUSIONSnSurvival rates of pediatric PAH patients differed between 3 major referral centers. This could be explained by differences between the center cohorts in patients diagnoses and measures of disease severity, which were identified as important predictors of outcome. In this study, treatment with PAH-targeted combination therapy during the study period was independently associated with improved survival.

Effectiveness and Safety of Inhaled Treprostinil for the Treatment of Pulmonary Arterial Hypertension in Children

The introduction of prostanoid therapy has revolutionized the treatment of pulmonary arterial hypertension (PAH). However, continuous intravenous prostacyclin infusion poses significant risks and challenges, particularly in children. Inhaled treprostinil has been shown to be safe and efficacious in adults. This study describes the safety and efficacy of inhaled treprostinil in children with PAH. A retrospective analysis of 29 children treated with inhaled treprostinil for ≥6 weeks was performed. Effects of inhaled treprostinil on exercise capacity, functional class, and echocardiographic and hemodynamic data were evaluated. Adverse events were documented. Patients received 3 to 9 breaths (6 μg/breath) of inhaled treprostinil 4 times/day. All were receiving background PAH therapy; 12 had previously received parenteral prostanoid. Inhaled treprostinil was discontinued in 4 patients because of symptoms including cough and bronchospasm (n = 3) and progression of PAH (n = 1). Mild side effects including cough (n = 9) and sore throat (n = 6) did not require discontinuation of therapy. World Health Organization functional class improved in 19 and was unchanged in 10; exercise capacity significantly improved with the 6-minute walk distance, improving on follow-up from 455.7 ± 71.5 to 498 ± 70 m (p = 0.01) and peak oxygen consumption increasing from 25.5 ± 10.2 to 27.4 ± 10 (p = 0.04). In conclusion, inhaled treprostinil was associated with improvement in exercise capacity and World Health Organization functional class when added to background targeted PAH therapy in children and had an acceptable safety profile. Based on these early data, further study of inhaled treprostinil appears warranted in pediatric patients with PAH.

Balloon atrial septostomy in pulmonary arterial hypertension: Effect on survival and associated outcomes

BACKGROUNDnPulmonary arterial hypertension (PAH) is a progressive disease that, without early identification and treatment, may lead to right heart failure, multi-organ dysfunction and early death. In severe PAH, in addition to maximal medical therapy, balloon atrial septostomy (BAS) may be used for palliation and as a bridge to lung transplantation. We present our contemporary institutional experience utilizing BAS in adult and pediatric patients with severe PAH.nnnMETHODSnWe performed a retrospective analysis of 46 BASs performed in 32 patients with PAH from 2002 to 2013. Data obtained included vital status, functional class, medications, hemodynamic measurements from right heart catheterizations and biomarkers. Lung transplantation-free and repeat-BAS-free survival was analyzed.nnnRESULTSnMedian age at BAS was 23 (range 1 to 56) years. The most common indications were symptomatic right heart failure (21 of 46 patients) and pre-syncope/syncope (19 of 46 patients); 69% of patients were WHO Functional Class III or IV pre-BAS. There were no procedural complications or deaths. There were no significant differences in biomarkers or hemodynamic findings between pre-BAS and 1 year or latest follow-up. Seven patients were successfully bridged to lung transplantation. Lung transplantation-free and repeat-BAS-free survival at 30 days, 1 year and 5 years was 87%, 61% and 32%, respectively.nnnCONCLUSIONSnIn our experienced center, BAS was shown to be safe in patients with severe PAH on maximal medical management, with no procedural deaths or complications. BAS was safely used as a bridge to lung transplantation or to alleviate right heart failure symptoms and/or syncope. Other potential benefits for end-organ function and overall survival remain to be determined.

Safety of Cardiac Catheterization at a Center Specializing in the Care of Patients with Pulmonary Arterial Hypertension

Cardiac catheterization is important for the management of patients with pulmonary arterial hypertension (PAH). It is used for diagnosis, assessment, and monitoring of PAH patients, as well as to perform interventions such as balloon atrial septostomy and coil embolization of collateral vessels. Although reports on the risks of catheterization in PAH patients are scarce, many centers hesitate to perform these procedures in such fragile patients. We performed a retrospective chart review of all cardiac catheterizations performed in PAH patients over 10 years at our pulmonary hypertension center. Demographic, hemodynamic, and outcome data were collected. Complication rates were determined, and multivariate proportional hazards modeling was performed to identify predictors of catheterization-related complications. There were 1,637 catheterizations performed in 607 patients over 10 years. Pediatric patients accounted for 50% of these cases, 48% were performed in patients with idiopathic PAH, and 49% were performed under general anesthesia. While the overall complication rate was 5.7%, the rate of major complications was only 1.2% (n = 20). Although there were 8 deaths during the admission following catheterization, only 4 of these were related to the procedure, yielding a catheterization-related mortality of 0.2%. In conclusion, when performed at a pulmonary hypertension center with expertise in the care of PAH patients, cardiac catheterization is associated with low complication rates and mortality, and it should remain an important tool in the management of these patients.

Late Left Ventricular Function After Surgery for Children With Chronic Symptomatic Mitral Regurgitation

BACKGROUNDnThe use of quantitative echocardiography has been emphasized in optimizing timing of surgery in adult patients with mitral regurgitation to avoid irreversible left ventricular dysfunction. In contrast, surgery for infants and children is often delayed until the appearance of severe symptoms because of the patients size and anticoagulation requirements and the possible need for early reoperation. The purpose of this study was to determine long-term ventricular function after mitral valve surgery in symptomatic children and to analyze risk factors for adverse outcome.nnnMETHODS AND RESULTSnThirty-three patients (0.5 to 19 years old) operated on for mitral regurgitation as a single hemodynamically significant lesion were studied. All but 3 had medically refractory symptoms. One patient died during surgery, and 32 were followed for 0.3 to 17.1 years (mean, 4.5 years). The mean preoperative left ventricular shortening fraction was 0.38+/-0.09. Successful mitral valvuloplasty or replacement was documented by long-term normalization of end-diastolic dimensions. Early postoperative shortening fraction was significantly reduced (0.28+/-0.1, P<.01), but it improved to 0.40+/-0.07 (P<.01) on late follow-up, at which time only 1 patient had ventricular dysfunction. Preoperative shortening fractions did not correlate well with early or late postoperative values (r=.18 and r=.31, respectively). Seven of 32 surviving patients had preoperative shortening fractions <0.33 (mean, 0.26+/-0.05) and 25 >0.33 (mean, 0.39+/-0.08). Analysis of these subgroups showed no significant differences between the groups in early or late postoperative function. Duration of mitral insufficiency appeared to be associated with the development of atrial arrhythmias.nnnCONCLUSIONSnLate left ventricular function normalizes in children after surgical correction of mitral insufficiency. In contrast to adults, delay of surgery in children with significant mitral regurgitation until the onset of severe symptoms does not increase the risk for long-term ventricular dysfunction, although late atrial arrhythmias are more likely to be encountered.

Subcutaneous Treprostinil for Pulmonary Hypertension in Chronic Lung Disease of Infancy

Pulmonary arterial hypertension (PAH) associated with chronic lung disease of infancy can be a life-threatening disease affecting an increasing number of former premature infants. There is a need for improved delivery of targeted PAH therapies for this subgroup of patients who have severe and persistent PAH despite standard respiratory care for chronic lung disease. Currently infants who have severe PAH despite oral or inhaled therapy receive continuous intravenous prostanoid therapy (mostly epoprostenol), which is complicated because of the need for central venous access and associated catheter-related complications. We present a series of 5 infants who were successfully treated with a continuous infusion of subcutaneous treprostinil, which is a longer-acting prostanoid with similar hemodynamic effects. There were improvements in echocardiographic assessment of right ventricular function and estimated pulmonary hypertension, and in respiratory support required within weeks of therapy. Unlike commonly in adults, these 5 infants had no instances of severe site erythema, bleeding, bruising, or infection. In our experience with 5 former extremely preterm infants who had PAH associated with chronic lung disease, subcutaneous treprostinil was safe, efficacious, and well tolerated. We believe that subcutaneous treprostinil can be beneficial in a select group of former premature infants who have chronic lung disease and severe pulmonary arterial hypertension who have not responded adequately to conservative therapies.

Management of aortopulmonary collaterals in children following cardiac transplantation for complex congenital heart disease

BACKGROUNDnHeart transplantation (HTx) is increasingly utilized as therapy for end-stage cyanotic congenital heart disease. This study investigates the presence and impact of aortopulmonary collaterals (APCs) associated with cyanotic heart disease on the early post-operative course of patients undergoing transplantation. High output cardiac failure due to residual aortopulmonary collaterals can affect outcome following heart transplantation.nnnMETHODSnSeven patients with hemodynamically significant APCs post-transplant were identified among 40 patients with cyanotic congenital heart disease undergoing HTx. The peri- and intra-operative courses of these patients were reviewed. All 7 patients required prolonged inotropic support despite normal ventricular function and no allograft rejection; 5 were ventilator-dependent due to significant pulmonary vascular congestion. Selective angiography demonstrated the presence of significant aortopulmonary collaterals at 7 to 19 days post-transplant. Coil embolization of aortopulmonary collaterals was performed in all patients; a mean of 6 (2 to 16) vessels/patient were embolized.nnnRESULTSnAfter embolization, pulmonary edema resolved and heart size normalized in all patients; inotropic support was weaned within 2 to 10 days in 5 patients. One patient developed transient renal failure secondary to excessive contrast load and another had enterococcal sepsis within 24 hours after the procedure. All patients were asymptomatic from 4 to 10 years of follow-up post-HTx.nnnCONCLUSIONSnAortopulmonary collaterals should be considered a cause of early donor heart failure in children following HTx for cyanotic congenital heart disease. Early detection and treatment of aortopulmonary collaterals by coil embolization is necessary to improve the post-transplant course in these complex patients.

Evaluation and Management of Pulmonary Hypertension in Children with Bronchopulmonary Dysplasia.

Usha Krishnan, MD*, Jeffrey A. Feinstein, MD*, Ian Adatia, MBChB, Eric D. Austin, MD, Mary P. Mullen, MD, PhD, Rachel K. Hopper, MD, Brian Hanna, MD, PhD, Lew Romer, MD, Roberta L. Keller, MD, Jeffrey Fineman, MD, Robin Steinhorn, MD, John P. Kinsella, MD, D. Dunbar Ivy, MD, Erika Berman Rosenzweig, MD, Usha Raj, MD, Tilman Humpl, MD, and Steven H. Abman, MD, for the Pediatric Pulmonary Hypertension Network (PPHNet)