Jennifer Conway

A multicenter study of the HeartWare ventricular assist device in small children

A multicenter study of the HeartWare ventricular assist device in small children Oliver Miera, MD, Richard Kirk, MD, Holger Buchholz, MD, Katharina R.L. Schmitt, MD, Christina VanderPluym, MD, Ivan M. Rebeyka, MD, Neil Wrightson, MD, Felix Berger, MD, Massimo Griselli, MD, and Jennifer Conway, MD From the Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany; Department of Pediatric Cardiology, Freeman Hospital, Newcastle Upon Tyne, UK; Stollery Children’s Hospital, University of Alberta, Edmonton, Alberta, Canada; and the Department of Cardiology, Boston Children’s Hospital, Boston, Massachusetts, USA

Now how do we get them home? Outpatient care of pediatric patients on mechanical circulatory support.

The last five yr have been monumental for the pediatric heart failure community. In the US, the most notable has been the FDA approval of the first pediatric specific device (Berlin Heart EXCOR®; Berlin Heart, Inc., Berlin, Germany). Subsequently, the field of heart failure has gained a great deal of knowledge regarding the nuances of MCS in children. Despite FDA approval in the US, the Berlin EXCOR® is only currently indicated for in‐hospital use. Due to the limitations with discharge and the positive in‐ hospital experiences with the Berlin EXCOR®, there has been an increased interest in the implantation of adult durable devices into children. While many institutions have focused their intial efforts on the first phase of care within the hospital, they are now ready to tackle the challenge of how to safely transition children to the community setting.

Risk factors for specific causes of death following pediatric heart transplant: An analysis of the registry of the International Society of Heart and Lung Transplantation

We sought to determine temporal changes in COD and identify COD‐specific risk factors in pediatric primary HTx recipients. Using the ISHLT registry, time‐dependent hazard of death after pediatric HTx, stratified by COD, was analyzed by multiphasic parametric hazard modeling with multivariable regression models for risk factor analysis. The proportion of pediatric HTx deaths from each of cardiovascular cause, allograft vasculopathy, and malignancy increased over time, while all other COD decreased post‐HTx. Pre‐HTx ECMO was associated with increased risk of death from graft failure (HR 2.43; p < 0.001), infection (HR 2.85; p < 0.001), and MOF (HR 2.22; p = 0.001), while post‐HTx ECMO was associated with death from cerebrovascular events/bleed (HR 2.55; p = 0.001). CHD was associated with deaths due to pulmonary causes (HR 1.78; p = 0.007) or infection (HR 1.72; p < 0.001). Non‐adherence was a significant risk factor for all cardiac COD, notably graft failure (HR 1.66; p = 0.001) and rejection (HR 1.89; p < 0.001). Risk factors related to specific COD are varied across different temporal phases post‐HTx. Increased understanding of these factors will assist in risk stratification, guide anticipatory clinical decisions, and potentially improve patient survival.

Mechanical Circulatory Support in Univentricular Hearts: Current Management

Failing single-ventricle patients have now come into focus as the next cohort where improvement in outcomes for mechanical circulatory support can be realized. There is a paucity of published patient reports or management protocols in this patient population. Increased interest exists in finding answers of how to bridge these patients to transplant. We review the current literature and describe our approach to the patient with univentricular heart needing mechanical circulatory support.

High Risk of Graft Failure in Emerging Adult Heart Transplant Recipients

Emerging adulthood (17–24 years) is a period of high risk for graft failure in kidney transplant. Whether a similar association exists in heart transplant recipients is unknown. We sought to estimate the relative hazards of graft failure at different current ages, compared with patients between 20 and 24 years old. We evaluated 11 473 patients recorded in the Scientific Registry of Transplant Recipients who received a first transplant at <40 years old (1988–2013) and had at least 6 months of graft function. Time‐dependent Cox models were used to estimate the association between current age (time‐dependent) and failure risk, adjusted for time since transplant and other potential confounders. Failure was defined as death following graft failure or retransplant; observation was censored at death with graft function. There were 2567 failures. Crude age‐specific graft failure rates were highest in 21–24 year olds (4.2 per 100 person‐years). Compared to individuals with the same time since transplant, 21–24 year olds had significantly higher failure rates than all other age periods except 17–20 years (HR 0.92 [95%CI 0.77, 1.09]) and 25–29 years (0.86 [0.73, 1.03]). Among young first heart transplant recipients, graft failure risks are highest in the period from 17 to 29 years of age.

Heart transplantation in children.

In the last 40 years, orthotopic heart transplantation has been established as a realistic treatment strategy for infants and children with severe forms of congenital heart disease and cardiomyopathy. The evaluation, management, and outcomes of these patients have continued to improve. These achievements have advanced pediatric cardiac transplantation and allowed more attention to be focused on improving quality of life after transplantation and reducing the long-term complications.

High Risk of Liver Allograft Failure During Late Adolescence and Young Adulthood.

Background Graft failure risk is highest during emerging adulthood (17-24 years) in kidney and heart transplant. It is unknown whether a similar association exists in liver transplant recipients. Methods We sought to estimate the relative hazards of graft failure at different current ages, compared with those aged 21 to 24 years. We evaluated 17 181 patients recorded in the Scientific Registry of Transplant Recipients who received a first isolated liver transplant at 40 years or younger (1988-2013) and had 6 months or longer of graft function. We used time-dependent Cox models to estimate the association between current age and failure risk, defined as retransplant or death after graft failure; observation was censored at death with graft function. Results There were 2540 failures. Absolute graft failure rates were highest in ages 25 to 29 years (3.0/100 person-years). Compared with individuals with the same time since transplantation, those aged 21 to 24 years had significantly higher failure rates than those younger than 17 years and older than 34 years; hazards did not differ for those aged 25 to 29 years (1.03 [0.86, 1.24]) and were lower, but not significantly, for those aged 17 to 20 years (hazards ratio, 0.83; 95% confidence interval, 0.68-1.01) and ages 30 to 34 years (hazards ratio, 0.84; 95% confidence interval, 0.70-1.01). Conclusions Among young first isolated liver transplant recipients, graft failure risks are highest in the period from 21 to 29 years of age.

Supporting pediatric patients with short-term continuous-flow devices

BACKGROUND Short-term continuous-flow ventricular assist devices (STCF-VADs) are increasingly being used in the pediatric population. However, little is known about the outcomes in patients supported with these devices. METHODS All pediatric patients supported with a STCF-VAD, including the Thoratec PediMag or CentriMag, or the Maquet RotaFlow, between January 2005 and May 2014, were included in this retrospective single-center study. RESULTS Twenty-seven patients (15 girls [56%]) underwent 33 STCF-VAD runs in 28 separate hospital admissions. The STCF-VAD was implanted 1 time in 23 patients (85%), 2 times in 2 patients (7%), and 3 times in 2 patients (7%). Implantation occurred most commonly in the context of congenital heart disease in 14 runs (42.2%), cardiomyopathy in 11 (33%), and after transplant in 6 (18%). The median age at implantation was 1.7 (interquartile range [IQR] 0.1, 4.1) years, and median weight was 8.9 kg (IQR 3.7, 18 kg). Patients were supported for a median duration of 12 days (IQR 6, 23 days) per run; the longest duration was 75 days. Before implantation, 15 runs (45%) were supported by extracorporeal membrane oxygenation (ECMO). After implantation, an oxygenator was required in 20 runs (61%) and continuous renal replacement therapy in 21 (64%). Overall, 7 runs (21%) resulted in weaning for recovery, 14 (42%) converted to a long-term VAD, 4 (12%) resulted in direct transplantation, 3 (9%) were converted to ECMO, and 5 (15%) runs resulted in death on the device or within 1 month after decannulation. The most common complication was bleeding requiring reoperation in 24% of runs. In addition, 18% of runs were associated with neurologic events and 15% with a culture-positive infection. Hospital discharge occurred in 19 of 28 STCF-VAD admissions (67%). In follow-up, with a median duration of 9.2 months (IQR 2.3, 38.3 months), 17 patients (63%) survived. CONCLUSIONS STCF-VADs can successfully bridge most pediatric patients to recovery, long-term device, or transplant, with an acceptable complication profile. Although these devices are designed for short-term support, longer support is possible and may serve as an alternative approach to patients not suitable for the current long-term devices.

Berlin Heart EXCOR use in patients with congenital heart disease

BACKGROUND Management of mechanical circulatory support in children with congenital heart disease (CHD) is challenging due to physiologic variations and anatomic limitations to device placement. In this study we examine the use of Berlin Heart EXCOR in CHD patients. METHODS CHD patients were identified from the EXCOR Pediatric Study data set (2007 to 2010). Mortality and serious adverse events were compared between CHD and non-CHD cohorts, and predictors of poor outcomes in the CHD cohort were identified. RESULTS CHD was present in 29% (n = 59, 18 with 1-ventricle physiology) of all EXCOR patients (N = 204). Successful bridge (transplant or wean) was less likely in CHD patients compared with non-CHD patients (48% vs 80%; p < 0.01). Among CHD patients, no neonates, 25% of infants (30 days to 1 year) and 65% of children (>1 year) were successfully bridged. Pre-implant congenital heart surgery (CHS) and extracorporeal membrane oxygenation (ECMO) on the same admission occurred in 60% of children ≤1 year of age (83% of neonates, 50% of infants), with 8% survival. Regardless of age, patients who did not have CHS and ECMO had 61% survival. Smaller pump, pre-implant bilirubin >1.2 mg/dl and renal dysfunction were independently associated with mortality. CONCLUSIONS End-organ function at implant reliably predicts adverse outcomes and should be considered when making implant decisions. EXCOR use in neonates and infants with CHD should be approached cautiously. If patients have undergone pre-implant CHS and ECMO, EXCOR support may not provide any survival benefit. EXCOR support in non-infants with CHD is challenging but can be consistently successful with appropriate patient selection.

An ISHLT consensus document for prevention and management strategies for mechanical circulatory support infection

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