A prospective multicenter feasibility study of a miniaturized implantable continuous flow ventricular assist device in smaller children with heart failure

BACKGROUND

There is no FDA-approved left ventricular assist device (LVAD) for smaller children permitting routine hospital discharge. Smaller children supported with LVADs typically remain hospitalized for months awaiting heart transplant-a major burden for families and a challenge for hospitals. We describe the initial outcomes of the Jarvik 2015, a miniaturized implantable continuous flow LVAD, in the NHLBI-funded Pumps for Kids, Infants, and Neonates (PumpKIN) study, for bridge-to-heart transplant.

METHODS

Children weighing 8 to 30 kg with severe systolic heart failure and failing optimal medical therapy were recruited at 7 centers in the United States. Patients with severe right heart failure and single-ventricle congenital heart disease were excluded. The primary feasibility endpoint was survival to 30 days without severe stroke or non-operational device failure.

RESULTS

Of 7 children implanted, the median age was 2.2 (range 0.7, 7.1) years, median weight 10 (8.2 to 20.7) kilograms; 86% had dilated cardiomyopathy; 29% were INTERMACS profile 1. The median duration of Jarvik 2015 support was 149 (range 5 to 188) days where all 7 children survived including 5 to heart transplant, 1 to recovery, and 1 to conversion to a paracorporeal device. One patient experienced an ischemic stroke on day 53 of device support in the setting of myocardial recovery. One patient required ECMO support for intractable ventricular arrhythmias and was eventually transplanted from paracorporeal biventricular VAD support. The median pump speed was 1600 RPM with power ranging from 1-4 Watts. The median plasma free hemoglobin was 19, 30, 19 and 30 mg/dL at 7, 30, 90 and 180 days or time of explant, respectively. All patients reached the primary feasibility endpoint. Patient-reported outcomes with the device were favorable with respect to participation in a full range of activities. Due to financial issues with the manufacturer, the study was suspended after consent of the eighth patient.

CONCLUSION

The Jarvik 2015 LVAD appears to hold important promise as an implantable continuous flow device for smaller children that may support hospital discharge. The FDA has approved the device to proceed to a 22-subject pivotal trial. Whether this device will survive to commercialization remains unclear because of the financial challenges faced by industry seeking to develop pediatric medical devices. (Supported by NIH/NHLBI HHS Contract N268201200001I, clinicaltrials.gov 02954497).

Successful implementation of telehealth visits in the paediatric heart failure and heart transplant population

The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) and Pediatric Heart Transplant Society (PHTS) convened a working group at the beginning of 2020 during the COVID-19 pandemic, with the aim of using telehealth as an alternative medium to provide quality care to a high-acuity paediatric population receiving advanced cardiac therapies. An algorithm was developed to determine appropriateness, educational handouts were developed for both patients and providers, and post-visit surveys were collected. Telehealth was found to be a viable modality for health care delivery in the paediatric heart failure and transplant population and has promising application in the continuity of follow-up, medication titration, and patient education/counselling domains.

Apixaban overdose in children: case report and proposed management. A brief communication from the Pediatric and Neonatal Thrombosis and Hemostasis SSC of ISTH

Background

Direct oral anticoagulants are commonly prescribed for adults and increasingly also for children requiring anticoagulation therapy. While household medications should not be accessible to children, accidental, and intentional overdoses occur.

Key Clinical Question

How should apixaban overdose in children be managed?.

Clinical Approach

We present a case of an accidental overdose with the factor Xa antagonist apixaban in a young child and propose an approach to the management of cases of apixaban overdose in children.

Conclusion

Given the increasing use of direct oral anticoagulants, it is important to have an approach to the management of overdose of these medications.

Nucleated Red Blood Cells Are Predictive of In-Hospital Mortality for Pediatric Patients

PURPOSE

We sought to establish whether nucleated red blood cells (NRBCs) are predictive of disposition, morbidity, and mortality for pediatric patients presenting to the emergency department (ED).

METHODS

A single-center retrospective cohort study examining all ED encounters from patients aged younger than 19 years between January 2016 and March 2020, during which a complete blood count was obtained. Univariate analysis and multivariable logistic regression were used to test the presence of NRBCs as an independent predictor of patient-related outcomes.

RESULTS

The prevalence of NRBCs was 8.9% (4195/46,991 patient encounters). Patient with NRBCs were younger (median age 4.58 vs 8.23 years; P < 0.001). Those with NRBCs had higher rates of in-hospital mortality (30/2465 [1.22%] vs 65/21,741 [0.30%]; P < 0.001), sepsis (19% vs 12%; P < 0.001), shock (7% vs 4%; P < 0.001), and cardiopulmonary resuscitation (CPR) (0.62% vs 0.09%; P < 0.001). They were more likely to be admitted (59% vs 51%; P < 0.001), have longer median hospital length of stay {1.3 (interquartile range [IQR], 0.22-4.14) vs 0.8 days (IQR, 0.23-2.64); P < 0.001}, and median intensive care unit (ICU) length of stay (3.9 [IQR, 1.87-8.72] vs 2.6 days [IQR, 1.27-5.83]; P < 0.001). Multivariable regression revealed presence of NRBCs as an independent predictor for in-hospital mortality (adjusted odds ratio [aOR], 2.21; 95% confidence interval [CI], 1.38-3.53; P < 0.001), ICU admission (aOR, 1.30; 95% CI, 1.11-1.51; P < 0.001), CPR (aOR, 3.83; 95% CI, 2.33-6.30; P < 0.001), and 30-day return to the ED (aOR, 1.15; 95% CI, 1.15-1.26; P < 0.001).

CONCLUSIONS

The presence of NRBCs is an independent predictor for mortality, including in-hospital mortality, ICU admission, CPR, and readmission within 30 days for children presenting to the ED.

Initial multicenter experience with ventricular assist devices in children and young adults with muscular dystrophy: An ACTION registry analysis

PURPOSE

Cardiac disease results in significant morbidity and mortality in patients with muscular dystrophy (MD). Single centers have reported their ventricular assist device (VAD) experience in specific MDs and in limited numbers. This study sought to describe the outcomes associated with VAD therapy in an unselected population across multiple centers.

METHODS

We examined outcomes of patients with MD and dilated cardiomyopathy implanted with a VAD at Advanced Cardiac Therapies Improving Outcomes Network (ACTION) centers from 9/2012 to 9/2020.

RESULTS

A total of 19 VADs were implanted in 18 patients across 12 sites. The majority of patients had dystrophinopathy (66%) and the median age at implant was 17.2 years (range 11.7-29.5). Eleven patients were non-ambulatory (61%) and 6 (33%) were on respiratory support pre-VAD. Five (28%) patients were implanted as a bridge to transplant, 4 of whom survived to transplant. Of 13 patients implanted as bridge to decision or destination therapy, 77% were alive at 1 year and 69% at 2 years. The overall frequencies of positive outcome (transplanted or alive on device) at 1 year and 2 years were 84% and 78%, respectively. Two patients suffered a stroke, 2 developed sepsis, 1 required tracheostomy, and 1 experienced severe right heart failure requiring right-sided VAD.

CONCLUSIONS

This study demonstrates the potential utility of VAD therapies in patients with muscular dystrophy. Further research is needed to further improve outcomes and better determine which patients may benefit most from VAD therapy in terms of survival and quality of life.

Untargeted metabolomics as an unbiased approach to the diagnosis of inborn errors of metabolism of the non-oxidative branch of the pentose phosphate pathway

Inborn errors of metabolism (IEM) involving the non-oxidative pentose phosphate pathway (PPP) include the two relatively rare conditions, transketolase deficiency and transaldolase deficiency, both of which can be difficult to diagnosis given their non-specific clinical presentations. Current biochemical testing approaches require an index of suspicion to consider targeted urine polyol testing. To determine whether a broad-spectrum biochemical test could accurately identify a specific metabolic pattern defining IEMs of the non-oxidative PPP, we employed the use of clinical metabolomic profiling as an unbiased novel approach to diagnosis. Subjects with molecularly confirmed IEMs of the PPP were included in this study. Targeted quantitative analysis of polyols in urine and plasma samples was accomplished with chromatography and mass spectrometry. Semi-quantitative unbiased metabolomic analysis of urine and plasma samples was achieved by assessing small molecules via liquid chromatography and high-resolution mass spectrometry. Results from untargeted and targeted analyses were then compared and analyzed for diagnostic acuity. Two siblings with transketolase (TKT) deficiency and three unrelated individuals with transaldolase (TALDO) deficiency were identified for inclusion in the study. For both IEMs, targeted polyol testing and untargeted metabolomic testing on urine and/or plasma samples identified typical perturbations of the respective disorder. Additionally, untargeted metabolomic testing revealed elevations in other PPP metabolites not typically measured with targeted polyol testing, including ribonate, ribose, and erythronate for TKT deficiency and ribonate, erythronate, and sedoheptulose 7-phosphate in TALDO deficiency. Non-PPP alternations were also noted involving tryptophan, purine, and pyrimidine metabolism for both TKT and TALDO deficient patients. Targeted polyol testing and untargeted metabolomic testing methods were both able to identify specific biochemical patterns indicative of TKT and TALDO deficiency in both plasma and urine samples. In addition, untargeted metabolomics was able to identify novel biomarkers, thereby expanding the current knowledge of both conditions and providing further insight into potential underlying pathophysiological mechanisms. Furthermore, untargeted metabolomic testing offers the advantage of having a single effective biochemical screening test for identification of rare IEMs, like TKT and TALDO deficiencies, that may otherwise go undiagnosed due to their generally non-specific clinical presentations.

Safety and Efficacy of Warfarin Therapy in Kawasaki Disease

OBJECTIVE

To describe the safety and efficacy of warfarin for patients with Kawasaki disease and giant coronary artery aneurysms (CAAs, ≥8 mm). Giant aneurysms are managed with combined anticoagulation and antiplatelet therapies, heightening risk of bleeding complications.

STUDY DESIGN

We reviewed the time in therapeutic range; percentage of international normalization ratios (INRs) in range (%); bleeding events, clotting events; INRs ≥6; INRs ≥5 and <6; and INRs <1.5.

RESULTS

In 9 patients (5 male), median age 14.4 years (range 7.1-22.8 years), INR testing was prescribed weekly to monthly and was done by home monitor (n = 5) or laboratory (n = 3) or combined (1). Median length of warfarin therapy was 7.2 years (2.3-13.3 years). Goal INR was 2.0-3.0 (n = 6) or 2.5-3.5 (n = 3), based on CAA size and history of CAA thrombosis. All patients were treated with aspirin; 1 was on dual antiplatelet therapy and warfarin. The median time in therapeutic range was 59% (37%-85%), and median percentage of INRs in range was 68% (52%-87%). INR >6 occurred in 3 patients (4 events); INRs ≥5 <6 in 7 patients (12 events); and INR <1.5 in 5 patients (28 events). The incidence of major bleeding events and clinically relevant nonmajor bleeding events were each 4.3 per 100 patient-years (95% CI 0.9-12.6). New asymptomatic coronary thrombosis was detected by imaging in 2 patients.

CONCLUSIONS

Bleeding and clotting complications are common in patients with Kawasaki disease on warfarin and aspirin, with INRs in range only two-thirds of the time. Future studies should evaluate the use of direct oral anticoagulants in children as an alternative to warfarin.

Outpatient management of intra-corporeal left ventricular assist device system in children: a multi-center experience

Little is known about the outcomes of children supported on intracorporeal left ventricular assist device (HVAD), and the feasibility of outpatient management. All centers with pediatric patients discharged from the hospital on the device were identified using company database. A total of 14 centers were contacted, with 9 centers, contributing data retrospectively. From 2011 to 2013, 12 pediatric patients (7 females), mean aged 11.9 ± 2.3 years (range 8-15), mean weight 43 ± 19 kg (range 18-81), mean body surface area 1.3 ± 0.3 m(2) (range 0.76-1.96) were identified. Diagnosis included: dilated cardiomyopathy (CMP) (n = 5), noncompaction CMP (n = 4), toxic CMP (n = 2) and viral CMP (n = 1). Indications for support were permanent support (n = 1), bridge to recovery (n = 1) and bridge to transplantation (n = 10). Prior to HVAD implantation, all patients received intravenous inotropes and two patients were on temporary mechanical support. Overall mortality was 0%. Mean duration of inpatient and outpatient support were 56 (range: 19-95 days) and 290 days (range: 42-790), respectively. Mean readmission rate was 0.02 per patient month (2.1 per patient). No adverse events involving emergency department occurred. Eight children resumed local schooling. Home discharge of children supported on HVAD is feasible and safe. School integration can be achieved. There is wide center variability to discharge practice for children.

Right ventricular dysfunction in children supported with pulsatile ventricular assist devices

OBJECTIVES

To describe the incidence and severity of right ventricular dysfunction (RVD) in pediatric ventricular assist device (VAD) recipients and to identify the preoperative characteristics associated with RVD and their effect on outcomes.

METHODS

Children bridged to transplantation from 2004 to 2011 were included. RVD was defined as the use of a left VAD (LVAD) with an elevated central venous pressure of >16 mm Hg with inotropic therapy and/or inhaled nitric oxide for >96 hours or biventricular assist (BiVAD).

RESULTS

A total of 57 children (median age, 2.97 years; range 35 days to 15.8 years) were supported. Of the 57, 43 (75%) had an LVAD, and of those, 10 developed RVD. The remaining 14 (25%) required BiVAD. Thus, RVD occurred in 24 of 57 patients (42%). Preoperative variables such as younger age (P = .01), use of extracorporeal mechanical support (P = .006), and elevated urea (P = .03), creatinine (P = .02), and bilirubin (P = .001) were associated with RVD. Multiple logistic regression analysis indicated that elevated urea and extracorporeal mechanical support (odds ratio, 26.4; 95% confidence interval, 2.3-307.3; and odds ratio, 27.8; 95% confidence interval, 2.5-312.3, respectively) were risk factors for BiVAD. The patients who developed RVD on LVAD had a complicated postoperative course but excellent survival (100%), comparable to those with preserved right ventricular function (91%). The survival for those requiring BiVAD was reduced (71%).

CONCLUSIONS

RVD occurred in approximately 40% of pediatric VAD recipients and affects their peri-implantation morbidity and bridging outcomes. Preoperative extracorporeal membrane oxygenation and elevated urea were risk factors for BiVAD. Additional studies of the management of RVD in children after VAD implantation are warranted.

Empiric acyclovir for neonatal herpes simplex virus infection

BACKGROUND

Because neonatal herpes simplex virus (NHSV) infection is difficult to diagnose, there has been a move towards using more empiric acyclovir (ACV).

OBJECTIVE

The purpose of this study was to review the use of ACV to optimize future management of NHSV.

METHODS

Charts were reviewed for infants started on intravenous ACV up to day 43 of life--January 2001 through February 2007--at five hospitals in Edmonton and Calgary.

RESULTS

ACV was started for possible (N = 115) or proven (N = 3) herpes simplex virus (HSV) infection. Six of the infants with possible HSV infection later had proven HSV infection. Seizures (34%), hemodynamic instability (29%) and skin lesions (24%) were the most common indications for ACV. Among the 118 infants, 106 (90%) had cerebrospinal fluid obtained and 82 (69%) had at least one surface swab for HSV but 4 (3%) had no specimens submitted for HSV detection. ACV was continued for 3.9 ± 3.5 days in the infants with no proven HSV disease. Possible nephrotoxicity from ACV was recorded in 3 of these 109 infants and in none of the infants with proven HSV disease.

CONCLUSIONS

Clinicians in Alberta primarily consider the diagnosis of NHSV infection when confronted with a neonate with seizures, hemodynamic instability or suspicious skin lesions, but need to consider the diagnosis more often if all cases are to be treated at first presentation. They often perform incomplete investigations to rule out NHSV infection. Adverse events from ACV appear to be uncommon when the drug is used for suspected NHSV disease.