Antonio G. Cabrera

Outcomes of pediatric patients supported by the HeartMate II left ventricular assist device in the United States

OBJECTIVE The HeartMate II (HMII; Thoratec, Pleasanton, CA) continuous-flow left ventricular assist device (LVAD) is an established treatment modality for advanced heart failure in adults. The objective of this study was to evaluate outcomes of pediatric patients supported by the HMII LVAD. METHODS This was a retrospective review of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) of patients supported with a HMII from April 2008 to September 2011. The primary cohort comprised pediatric patients aged 11 to 18 years. Outcomes were compared with a group of young adults aged 19 to 39 years who underwent HMII implant during the same period. Ischemic etiologies for heart failure were excluded. RESULTS There were 28 pediatric patients, of whom 19 (68%) were males, 14 (46%) were African American, and 7 (25%) underwent device placement in a pediatric hospital. Competing outcomes analysis showed that at 6 months of follow-up, the composite of survival to transplantation, ongoing support, or recovery was 96% for the pediatric group, which was not significantly different from the young adult group (96%, p = 0.330). The 2 groups had similar INTERMACS profiles but differed in diagnosis, weight, and morbidities. Bleeding complications requiring surgical intervention were more common in the pediatric group. CONCLUSIONS Pediatric outcomes with a HMII LVAD are comparable to that of young adults. As we continue to monitor this growing group, more sophisticated characterization and comparisons will be possible. Also, as technology progress and second- and third-generation devices are introduced, the number of children who will benefit from mechanical support will continue to grow.

Effect of verapamil in infants with paroxysmal supraventricular tachycardia.

Twenty-nine consecutive spontaneous attacks of paroxysmal supraventricular tachycardia (PSVT) in 14 infants (mean age 4.4 months) were treated with verapamil. No infant had associated heart disease. Verapamil 1-2 mg i.v. was administered over 30 seconds. The dosage varied according to the weight of the infant. Within 60 seconds sinus rhythm was obtained in 28 instances (96.5%). No significant complications were observed. The high effectiveness, rapid action lack of undesirable side effects observed in this series suggest that verapamil is the drug of choice in the treatment of PSVT in infants without underlying heart diseas.

Prevalence and outcomes of pediatric in-hospital cardiopulmonary resuscitation in the United States: an analysis of the Kids' Inpatient Database*.

Objective:Population-based data on pediatric in-hospital cardiopulmonary resuscitation in the United States are scarce. Single-center studies and voluntary registries may skew the estimated prevalence and outcomes. This study aimed to determine the prevalence and outcomes of pediatric cardiopulmonary resuscitation on a national scale. Design:A retrospective analysis of the Healthcare Cost and Utilization Project 2006 Kids’ Inpatient Database was performed. Sample weighting was employed to produce national estimates. Setting:Three thousand seven hundred thirty-nine hospitals in 38 states participating with the Kids’ Inpatient Database. Patients:All patients <20 yrs of age hospitalized in participating institutions in 2006. Measurements and Main Results:Cardiopulmonary resuscitation was performed in 5,807 (95% confidence interval 5259–6355) children with prevalence of 0.77 per 1,000 admissions. Most patients (68%) were <1 yr old, and 44% were female. On multivariable analysis, cardiopulmonary resuscitation was associated with respiratory failure (odds ratio 41.5, 95% confidence interval 35.4–48.8), myocarditis (odds ratio 36.6, 95% confidence interval 21.9–61.0), acute renal failure (odds ratio 21.6, 95% confidence interval 17.5–26.7), heart failure (odds ratio 3.8, 95% confidence interval 3.0–4.8), and cardiomyopathy (odds ratio 3.8, 95% confidence interval 3.2–4.7). Overall mortality was 51.8% and greater among patients ≥1 yr (68%) vs. <1 yr (44%) (odds ratio 2.7, 95% confidence interval 2.3–3.2). Factors associated with mortality among patients receiving cardiopulmonary resuscitation on multivariable analysis included acute renal failure (odds ratio 1.5, 95% confidence interval 1.1–1.9), hepatic insufficiency (odds ratio 1.5, 95% confidence interval 1.01–2.4), sepsis (odds ratio 1.2, 95% confidence interval 1.01–1.4), and congenital heart disease (odds ratio 1.2, 95% confidence interval 1.01–1.5). Conclusions:Cardiopulmonary resuscitation is performed in approximately one in 1,300 pediatric hospitalizations. Approximately half of patients receiving cardiopulmonary resuscitation do not survive to discharge. Independent risk factors for mortality after receiving cardiopulmonary resuscitation included congenital heart disease, age ≥1 yr, acute renal failure, hepatic insufficiency, and sepsis.

Incidence and treatment of chylothorax after cardiac surgery in children: analysis of a large multi-institution database.

OBJECTIVE There is limited information regarding the true incidence of and risk factors for chylothorax after pediatric cardiac surgery. The objective of this study was to determine, from a large multi-institution database, incidence, associated factors, and treatment strategy in patients undergoing pediatric cardiac surgery. METHODS All patients younger than 18 years in the Pediatric Health Information System (PHIS) database who underwent congenital heart surgery or heart transplant from 2004 to 2011 were included. Procedure complexity was assessed by Risk Adjustment for Congenital Heart Surgery-1. RESULTS In all, 77,777 patients (55% male) of median age 6.7 months were included. Overall incidence of chylothorax was 2.8% (n = 2205), significantly associated with increased procedure complexity, younger age, genetic syndromes, vein thrombosis, and higher annual hospital volume. Patients with multiple congenital procedures had the highest incidence. Incidence increased with time, from 2% in 2004 to 3.7% in 2011 (P < .0001). Chylothorax was associated with longer stay (P < .0001), increased adjusted risk for in-hospital mortality (odds ratio, 2.13; 95% confidence interval, 1.75-2.61), and higher cost (P < .0001), regardless of procedure complexity. Of all patients with chylothorax, 196 (8.9%) underwent thoracic duct ligation or pleurodesis a median of 18 days after surgery. Total parenteral nutrition, medium-chain fatty acid supplementation, and octreotide were used in 56%, 1.7%, and 16% of patients, respectively. CONCLUSIONS Chylothorax is a significant problem in pediatric cardiac surgery and is associated with increased mortality, cost, and length of stay. Strategies should be developed to improve prevention and treatment.

Interhospital transport of children requiring extracorporeal membrane oxygenation support for cardiac dysfunction.

OBJECTIVE Many centers are able to emergently deploy extracorporeal membrane oxygenation (ECMO) as support in children with refractory hemodynamic instability, but may be limited in their ability to provide prolonged circulatory support or cardiac transplantation. Such patients may require interhospital transport while on ECMO (cardiac mobile [CM]-ECMO) for additional hemodynamic support or therapy. There are only three centers in the United States that routinely perform CM-ECMO. Our center has a 20-year experience in carrying out such transports. The purpose of this study was twofold: (1) to review our experience with pediatric cardiac patients undergoing CM-ECMO and (2) identify risk factors for a composite outcome (defined as either cardiac transplantation or death) among children undergoing CM-ECMO. DESIGN Retrospective case series. SETTING Cardiovascular intensive care and pediatric transport system. PATIENTS Children (n = 37) from 0-18 years undergoing CM-ECMO transports (n = 38) between January 1990 and September 2005. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A total of 38 CM-ECMO transports were performed for congenital heart disease (n = 22), cardiomyopathy (n = 11), and sepsis with myocardial dysfunction (n = 4). There were 18 survivors to hospital discharge. Twenty-two patients were transported a distance of more than 300 miles from our institution. Ten patients were previously cannulated and on ECMO prior to transport. Thirty-five patients were transported by air and two by ground. Six patients underwent cardiac transplantation, all of whom survived to discharge. After adjusting for other covariates post-CM-ECMO renal support was the only variable associated with the composite outcome of death/need for cardiac transplant (odds ratio = 13.2; 95% confidence interval, 1.60--108.90; P = 0.003). There were two minor complications (equipment failure/dysfunction) and no major complications or deaths during transport. CONCLUSIONS Air and ground CM-ECMO transport of pediatric patients with refractory myocardial dysfunction is safe and effective. In our study cohort, the need for post-CM-ECMO renal support was associated with the composite outcome of death/need for cardiac transplant.

Training young pediatricians as leaders for the 21st century.

Objective. To conduct a needs assessment with young pediatricians who participate in a leadership training program and to evaluate the effectiveness of that program. Methods. In concert with the Johnson & Johnson Pediatric Institute, LLC, the American Academy of Pediatrics developed a 1-year strategy to train pediatricians who are <40 years old or <5 years in practice in leadership skills. Participants were nominated by American Academy of Pediatrics chapters and/or sections and were required to complete a detailed needs assessment, attend a 3-day training program, and commit to 1 leadership-related behavior change to be implemented within 6 months. A preanalytic/postanalytic design strategy was used. Results. A total of 56 applicants representing 33 US states participated; 44.6% were male, and more than half (51.8%) were employed at a medical school/hospital. The needs assessment indicated that participants were confident in many of their leadership qualities but desired increased training, particularly in areas of time and priority management and leading “from the middle.” Postsurvey instruments (n = 54, 96% response rate) determined that participants positively evaluated the training program and improved in self-reported basic competencies; 87% also reported fully or partially achieving a leadership-related goal identified in a behavior change contract. Conclusions. Results demonstrate that young physicians are eager for leadership training and that continuing medical education in this area can be provided with positive results. Core competencies, curriculum, and evaluative tools need to be developed further and training opportunities need to be expanded to other subpopulations of pediatricians and pediatric health care providers.

Infectious Complications and Outcomes in Children Supported with Left Ventricular Assist Devices

BACKGROUND Infectious complications constitute a major cause of morbidity and death in adult patients supported with left ventricular assist devices (VADs). The incidence and patient outcomes related to infectious complications in pediatric patients on VAD support remain largely unknown. The aim of this study was to determine the incidence of infection among pediatric VAD recipients and to characterize the microbiology, associated risk factors, and clinical outcome. METHODS We conducted a retrospective record review of all patients undergoing VAD support for ≥2 weeks at Texas Childrens Hospital from June 1999 to December 2011. Infections were categorized as VAD-specific, VAD-related, or non-VAD-related using the International Society for Heart and Lung Transplantation (ISHLT) definitions for VAD infections. RESULTS Fifty-two VADs were implanted in 51 patients; of these, 35 patients (69%) had 92 infections while receiving VAD support. These included 10 VAD-specific infections, 23 VAD-related infections, and 59 non-VAD infections. The overall rate of VAD infections (specific + related) was 8/1,000 days of VAD support. The most common pathogens were Staphylococcus aureus, coagulase-negative staphylococci, Pseudomonas aeruginosa, and Candida spp. Of 8 deaths that occurred during VAD support, 3 (37.5%) were directly related to infections. Continuous-flow VAD (p = 0.0427) and prior cardiac transplantation with rejection (p = 0.0191) were significantly associated with development of VAD infections. CONCLUSIONS Infectious complications are common in pediatric patients undergoing VAD support. VAD infections do not prevent successful cardiac transplantation in children.

Is mechanically bridging patients with a failing cardiac graft to retransplantation an effective therapy? Analysis of the United Network of Organ Sharing database.

BACKGROUND The results of bridging patients with cardiac allograft failure to retransplantation (ReTx) with mechanical circulatory support (MCS) have not been well studied. The United Network of Organ Sharing (UNOS) database was used to analyze outcomes of patients successfully bridged with MCS to cardiac ReTx. METHODS Of 1,690 cardiac ReTx identified in the UNOS database from October 1987 to July 2011, 149 (8.8%) were bridged to ReTx with MCS. RESULTS Patients bridged to ReTx with MCS had a poorer survival than patients not bridged (p < 0.0001). ReTx after ventricular assist device (VAD) support had better survival than ReTx after extracorporeal membrane oxygenation (ECMO; half-life, 3.9 years vs 61 days, p = 0.026). For patients bridged to ReTx, graft survival was 40% for ReTx within 1 year of primary Tx vs 64% (p = 0.003). When ReTx was performed 1 year after cardiac Tx, survival was similar in patients bridged with a VAD and those not bridged (mean, 7.5 vs 8.7 years; p = 0.8). Survival for patients bridged to ReTx with ECMO was consistently worse (p ≤ 0.05) in all analyses. The 1-year survival of ReTx after VAD performed in 2003 to 2011 (67%) was better than in the earlier era of 1987 to 2002 (37%, p = 0.005). CONCLUSIONS Bridging patients to ReTx with ECMO at any time is not advisable. Bridging patients with MCS to ReTx within 1 year of primary cardiac Tx is not advisable. Survival after ReTx for patients bridged by VAD has improved considerably over time. Patients who survive the first year after cardiac Tx can be bridged by VAD to ReTx with an expectation that outcomes can be similar to ReTx patients who did not require MCS.

Characteristics and Outcomes of Heart Failure–Related Intensive Care Unit Admissions in Children With Cardiomyopathy

OBJECTIVE The purpose of this study was to describe patient characteristics and outcomes of heart failure (HF)-related intensive care unit (ICU) hospitalizations in children with cardiomyopathy (CM). METHODS AND RESULTS A query of the Pediatric Health Information System database, a large administrative and billing database of 43 tertiary childrens hospitals, was performed. A total of 17,309 HF-related ICU hospitalizations from 2005 to 2010 of 14,985 children ≤18 years old were analyzed. Of those, 2,058 (12%) hospitalizations for CM-HF in 1,599 (11%) children were identified. Classification into CM subtypes was not possible owing to database limitations. The number of yearly CM-HF hospitalizations significantly increased during the study period (P = .036). Overall mortality was 11%, and cardiac transplantation occurred in 20% of hospitalizations. Mechanical circulatory support (MCS) was used in 261 (13%) of hospitalizations. Renal failure, MCS, respiratory failure, sepsis, and vasoactive medications were associated with mortality on multivariable analysis. Significant comorbidities associated with these hospitalizations included arrhythmias in 42%, renal failure in 13%, cerebrovascular disease in 6%, and hepatic impairment in 5%. CONCLUSIONS HF-related ICU hospitalizations in children with cardiomyopathy are increasing. These children are at high risk for poor outcomes with an in-hospital mortality of 11%.

Anticoagulation therapy trends in children supported by ventricular assist devices: a multi-institutional study.

Ventricular assist device (VAD) use in children has increased dramatically. There are currently few data regarding trends in anticoagulation management for pediatric VADs. A retrospective cohort study was conducted for patients with an International Classification of Diseases, Ninth Revision (ICD-9) code for VAD implantation from 2000 to 2011 from the Pediatric Health Information System database. Patient demographics, use of extracorporeal membrane oxygenation, orthotopic heart transplantation (OHT), disease states, and medications pertinent to the management of VAD anticoagulation were queried. Patients were grouped into 3 year time periods to evaluate trends in medication use over time. Four hundred sixty-six patients were identified with a median length of VAD therapy of 21 days (range 1–362 days). In-hospital mortality was 31.9%, and 54.5% underwent OHT. Length of VAD therapy and patients undergoing OHT increased, while mortality decreased. Patients received a median of two anticoagulant medications (range 0–6), one (range 0–4) antiplatelet medications, three (range 0–5) procoagulant medications, and one (range 0–3) antifibrinolytics. Patients received greater mean numbers of anticoagulant, procoagulant, antifibrinolytic, and antiplatelet agents, and the use of oral medications increased more than twofold over time. There is wide variability for in-hospital pediatric VAD anticoagulation management, with a significant increase in the use of oral agents in more recent years.