Decreased Risk of Strokes in Children with Ventricular Assist Devices Within ACTION.

We sought to characterize strokes in children with ventricular assist devices. Of 407 patients in the ACTION registry (4/1/18-5/3/2021), 45 (11%) experienced 52 strokes (45 ischemic and 7 hemorrhagic). Median time to stroke was 23.5 days and 19/52 (37%) occurred ≤ 10 days. Stroke rate was 0.09 and 0.63 strokes per patient-year for implantable continuous and paracorporeal devices, respectively. Patients with stroke were younger, more likely to have congenital heart disease and have been on extracorporeal membrane oxygenation at time of VAD. Based on these data, ACTION is now focused on decreasing strokes in these higher-risk patients with particular attention to the peri-implant period.

Characteristics and Outcomes of Pediatric Patients With a Ventricular Assist Device Presenting to the Emergency Department.

OBJECTIVES: A growing number of children receive support from left ventricular assist devices (LVADs) in the outpatient setting. Unexpected complications of LVAD support occur that require emergent management, and no studies examine how pediatric LVAD patients present to the emergency department (ED). The goals of this study were (1) to describe frequency of visits, clinical characteristics, adverse events, and outcomes of LVAD-supported children treated in ED settings and (2) to evaluate for associations between specified patient outcomes and ED care location. METHODS: This was a retrospective cohort study of children in a single-center outpatient VAD program who presented to several EDs during a 10-year period. We defined adverse events according to the Advanced Cardiac Therapies Improving Outcomes Network registry guidelines. Secondary analysis evaluated for associations between specified patient outcomes (adverse events, hospitalizations, intensive care unit admissions) and ED care location (institutional vs other ED). RESULTS: Of 104 subjects with LVAD implantations during the study period, 30 (28.8%) transitioned to outpatient care. Among subjects in the outpatient VAD program, 24 (80%) of 30 had 54 visits to various EDs over 141.9 patient-months. The median age at time of ED visit was 13.5 years (range, 7.2-17.9 years). The median number of visits per subject was 1 (range, 0-6). The most common complaints on arrival to the ED were vomiting or abdominal pain (16.7%), fever (15.3%), and headache (13.9%). Seventeen adverse events occurred during 14 (25.9%) of 54 ED visits. The most common adverse events were major infection (33.3%) and right heart failure (16.7%). Hospital admission resulted from 41 (75.9%) of 54 ED visits, including 17 (41.5%) of 41 to a cardiovascular intensive care unit. Care at a nonspecialty ED was associated with a higher rate of hospitalization (93.8% vs 68.4%, P = 0.049). During the study period, 4 subjects (13.3%) died, including 1 patient on destination therapy, 1 with multisystem organ failure due to cardiogenic shock, and 2 with hemorrhagic stroke. No patient died while in the ED. CONCLUSIONS: Among subjects in a single outpatient pediatric VAD program presenting to the ED, the most common complaints were abdominal pain/vomiting, fever, and headache. The most common adverse events were major infection and right heart failure. Subjects had a high rate of ED utilization and hospital admission.

Impact of ventricular assist device implantation on the nutritional status of children awaiting heart transplantation.

BACKGROUND: Malnutrition is common in pediatric heart failure and is associated with mortality. The effect of VAD support on malnutrition in children is unknown. We sought to compare the prevalence and severity of malnutrition at HT in children on VAD support vs OMT to inform decisions regarding support strategies. METHODS: Retrospective chart review involving all patients <18 years who underwent HT at Stanford between 1/1/2011 and 3/1/2018. Malnutrition diagnosis and severity were defined by ASPEN guidelines using the lowest age-adjusted z-score for weight (WAZ), height (HAZ), and BMI (BMIZ) when the patient was euvolemic. Changes in z-scores from baseline to HT and across groups were analyzed. RESULTS: A total of 104 patients (52 in each group) were included. Among all patients, WAZ (-0.9 vs 0.3, P < 0.001) and BMIZ (0 vs 0.6, P < 0.001) improved while HAZ (-0.9 vs -0.9, P = 0.4) did not. Compared to children on OMT, children on VAD experienced greater increases in WAZ (0.8 vs 0.3, P < 0.001) and BMIZ (0.7 vs 0.2, P < 0.003) at HT. The prevalence of moderate-to-severe malnutrition decreased in VAD patients (40% to 19%, P < 0.001) and increased in OMT patients (37% to 46%, P < 0.001), leading to a lower prevalence of moderate-to-severe malnutrition at HT (19% vs 46%, P = 0.003). CONCLUSIONS: Malnutrition is common in pediatric HT candidates. Compared to children on OMT, children on VAD support had greater improvement in nutritional status while awaiting HT, and a lower prevalence of malnutrition at HT.

Compassionate deactivation of ventricular assist devices in children: A survey of pediatric ventricular assist device clinicians' perspectives and practices.

OBJECTIVES: This study's objective was to investigate compassionate ventricular assist device deactivation (VADdeact) in children from the perspective of the pediatric heart failure provider. BACKGROUND: Pediatric VAD use is a standard therapy for advanced heart failure. Serious adverse events may affect relative benefit of continued support, leading to consideration of VADdeact. Perspectives and practices regarding VADdeact have been studied in adults but not in children. METHODS: A web-based anonymous survey of clinicians for pediatric VAD patients (<18 years) was sent to list-serves for the ISHLT Pediatric Council, the International Consortium of Circulatory Assist Clinicians Pediatric Taskforce, and the Pediatric Cardiac Intensivist Society. RESULTS: A total of 106 respondents met inclusion criteria of caring for pediatric VAD patients. Annual VAD volume per clinician ranged from <4 (33%) to >9 (20%). Seventy percent of respondents had performed VADdeact of a child. Response varied to VADdeact requests by parent or patient and was influenced by professional degree and region of practice. Except for the scenario of intractable suffering, no consensus on VADdeact appropriateness was reported. Age of child thought capable of making informed requests for VADdeact varied by subspecialty. The majority of respondents (62%) do not feel fully informed of relevant legal issues; 84% reported that professional society supported guidelines for VADdeact in children had utility. CONCLUSION: There is limited consensus regarding indications for VADdeact in children reported by pediatric VAD provider survey respondents. Knowledge gaps related to legal issues are evident; therefore, professional guidelines and educational resources related to pediatric VADdeact are needed.

A Quality Bundle to Support High-Risk Pediatric Ventricular Assist Device Implantation.

Pediatric ventricular assist device (VAD) implantation outcomes are increasingly promising for children with dilated cardiomyopathy and advanced decompensated heart failure (ADHF). VAD placement in patients with clinical features such as complex congenital cardiac anatomy, small body size, or major comorbidities remains problematic. These comorbidities have been traditionally prohibitive for VAD consideration leaving these children as a treatment-orphaned population. Here we describe the quality bundle surrounding these patients with ADHF considered high risk for VAD implantation at our institution. Over a 7-year period, a quality bundle aimed at the peri-operative care for children with high-risk features undergoing VAD implantation was incrementally implemented at a tertiary children's hospital. Patients were considered high risk if they were neonates (< 30 days), had single-ventricle physiology, non-dilated cardiomyopathy, biventricular dysfunction, or significant comorbidities. The quality improvement bundle evolved to include (1) structured team-based peri-operative evaluation, (2) weekly VAD rounds addressing post-operative device performance, (3) standardized anticoagulation strategies, and (4) a multidisciplinary system for management challenges. These measures aimed to improve communication, standardize management, allow for ongoing process improvement, and incorporate principles of a high-reliability organization. Between January 2010 and December 2017, 98 patients underwent VAD implantation, 48 (49%) of which had high-risk comorbidities and a resultant cohort survival-to-transplant rate of 65%. We report on the evolution of a quality improvement program to expand the scope of VAD implantation to patients with high-risk clinical profiles. This quality bundle can serve as a template for future large-scale collaborations to improve outcomes in these treatment-orphaned subgroups.

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.

Utility of a dedicated pediatric cardiac anticoagulation program: the Boston Children's Hospital experience.

Congenital heart disease is the leading cause of stroke in children. Warfarin therapy can be difficult to manage safely in this population because of its narrow therapeutic index, multiple drug and dietary interactions, small patient size, high-risk cardiac indications, and lack of data to support anticoagulation recommendations. We sought to describe our institution's effort to develop a dedicated cardiac anticoagulation service to address the special needs of this population and to review the literature. In 2009, in response to Joint Commission National Patient Safety Goals for Anticoagulation, Boston Children's Hospital created a dedicated pediatric Cardiac Anticoagulation Monitoring Program (CAMP). The primary purpose was to provide centralized management of outpatient anticoagulation to cardiac patients, to serve as a disease-specific resource to families and providers, and to devise strategies to evolve clinical care with rapidly emerging trends in anticoagulation care. Over 5 years the CAMP Service, staffed by a primary pediatric cardiology attending, a full-time nurse practitioner, and administrative assistant with dedicated support from pharmacy and nutrition, has enrolled over 240 patients ranging in age from 5 months to 55 years. The most common indications include a prosthetic valve (34 %), Fontan prophylaxis (20 %), atrial arrhythmias (11 %), cardiomyopathy (10 %), Kawasaki disease (7 %), and a ventricular assist device (2 %). A patient-centered multi-disciplinary cardiac anticoagulation clinic was created in 2012. Overall program international normalized ratio (INR) time in therapeutic range (TTR) is favorable at 67 % (81 % with a 0.2 margin) and has improved steadily over 5 years. Pediatric-specific guidelines for VKOR1 and CYP2C9 pharmacogenomics testing, procedural bridging with enoxaparin, novel anticoagulant use, and quality metrics have been developed. Program satisfaction is rated highly among families and providers. A dedicated pediatric cardiac anticoagulation program offers a safe and effective strategy to standardize anticoagulation care for pediatric cardiology patients, is associated with high patient and provider satisfaction, and is capable of evolving care strategies with emerging trends in anticoagulation.

Lessons Learned from Managing Antithrombotic Therapy in Children Supported with Pediatric Ventricular Assist Devices.

Stroke, thromboembolism, and bleeding are the most recognized complications associated with pediatric ventricular assist devices (VADs) and the leading cause of death and disability on VAD support. Recently, newer antithrombotic strategies like bivalirudin have emerged that appear to be associated with a reduction in the neurologic event rates, especially for smaller pediatric-specific VADs like the Berlin Heart and PediMag/CentriMag systems where the risk of stroke is the highest. While contemporary antithrombotic therapies have likely contributed to lowering adverse event rates, we speculate that clotting and bleeding adverse events may have dropped because of a variety of other seemingly small changes to antithrombotic management that are independent of the antithrombotic agents used. This view is supported by recent reports documenting low stroke rates with anticoagulants other than bivalirudin, a drug that may have a wider therapeutic window but is not available in all locations throughout the world. The primary purpose of this report is 1) to summarize contemporary antithrombotic regimens used for smaller pediatric VADs today associated with low event rates in the United States and abroad and () to review 10 practical lessons learned and pitfalls to avoid that we believe to be important to reducing bleeding and clotting events based on our collective experience managing pediatric VADs over the past 20 years irrespective of the antithrombotic agents used.

Adverse Events Associated with Cardiac Catheterization in Children Supported with Ventricular Assist Devices.

Children on ventricular assist device (VAD) support can present several unique challenges, including small patient size, univentricular or biventricular congenital heart disease (1V- or 2V-CHD) and need for biventricular VAD (BiVAD) support. While cardiac catheterization can provide valuable information, it is an invasive procedure with inherent risks. We sought to evaluate the safety of catheterization in pediatric patients on VAD support. We performed a retrospective review of patients on VAD support who underwent catheterization at Lucile Packard Children's Hospital between January 1, 2014 and September 1, 2019. Using definitions adapted from Pedimacs, adverse events (AEs) after catheterization were identified, including arrhythmia; major bleeding or acute kidney injury within 24 hours; respiratory failure persisting at 24 hours; and stroke, pericardial effusion, device malfunction, bacteremia or death within 7 days. AEs were categorized as related or unrelated to catheterization. Sixty procedures were performed on 39 patients. Underlying diagnoses were dilated cardiomyopathy (48%), 1V-CHD (35%), 2V-CHD (8%), and other (8%). Devices were implantable continuous flow (72%), paracorporeal pulsatile (18%) and paracorporeal continuous flow (10%). Catheterizations were performed on patients in the ICU (60%), on inotropic support (42%), with deteriorating clinical status (37%) and on BiVAD support (12%). There were 9 AEs possibly related to catheterization including 6 episodes of respiratory failure, 2 major bleeding events, and 1 procedural arrhythmia. AE occurrence was associated with ICU status ( P = 0.01), BiVAD support ( P = 0.04) and procedural indication to evaluate worsening clinical status ( P = 0.04). Despite high medical acuity, catheterization can be performed with an acceptable AE profile in children on VAD support.

Compassionate Deactivation of Pediatric Ventricular Assist Devices: A Review of 14 Cases.

CONTEXT: Compassionate deactivation (CD) of ventricular assist device (VAD) support is a recognized option for children when the burden of therapy outweighs the benefits. OBJECTIVES: To describe the prevalence, indications, and outcomes of CD of children supported by VADs at the end of life. METHODS: Review of cases of CD at our institution between 2011 and 2020. To distinguish CD from other situations where VAD support is discontinued, patients were excluded from the study if they died during resuscitation (including extracorporeal membrane oxygenation), experienced brain or circulatory death prior to deactivation, or experienced a non-survivable brain injury likely to result in imminent death regardless of VAD status. RESULTS: Of 24 deaths on VAD, 14 (58%) were CD. Median age was 5.7 (interquartile range (IQR) 0.6, 11.6) years; 6 (43%) had congenital heart disease; 4 (29%) were on a device that can be used outside of the hospital. CD occurred after 40 (IQR: 26, 75) days of support; none while active transplant candidates. CD discussions were initiated by the caregiver in 6 (43%) cases, with the remainder initiated by a medical provider. Reasons for CD were multifactorial, including end-organ injury, infection, and stroke. CD occurred with endotracheal extubation and/or discontinuation of inotropes in 12 (86%) cases, and death occurred within 10 (IQR: 4, 23) minutes of CD. CONCLUSION: CD is the mode of death in more than half of our VAD non-survivors and is pursued for reasons primarily related to noncardiac events. Caregivers and providers both initiate CD discussions. Ventilatory and inotropic support is often withdrawn at time of CD with ensuing death.

The Stanford acute heart failure symptom score for patients hospitalized with heart failure.

BACKGROUND: Currently, there are no simple tools to evaluate the acute heart failure (HF) symptom severity in children hospitalized with acute decompensated HF (ADHF). We sought to develop an inpatient HF score (HFS) that could be used as a clinical tool and for clinical trials. METHODS: Pediatric HF clinicians at Stanford reviewed the limitations of existing HFSs, which include lack of calibration to the inpatient setting, omission of gastrointestinal symptoms, need for multiple age-based tools, and scores that prioritize treatment intensity over patient symptoms. To address these, we developed an acute HFS corresponding to the 3 cardinal symptoms of HF: difficulty with breathing, feeding, and activity. The score was iteratively improved over a 3-year pilot phase until no further changes were made. The inter-rater reliability (IRR) across a range of providers was assessed using the final version. Peak HFSs were analyzed against mortality and length of stay (LOS) for all pediatric HF discharges between July and October 2019. RESULTS: The final HFS was a 4-point ordinal severity score for each of the 3 symptom domains (total score 0-12). Among clinicians who scored 12 inpatients with ADHF simultaneously, the intraclass correlation (ICC) was 0.94 (respiratory ICC = 0.89, feeding ICC = 0.85, and activity ICC = 0.80). Score trajectory reflected our clinical impression of patient response to HF therapies across a range of HF syndromes including 1- and 2-ventricle heart disease and reduced or preserved ejection fraction. Among the 28 patients hospitalized during a 3-months period (N = 28), quartiles of peak score were associated with LOS (p < 0.01) and in-hospital mortality (p < 0.01): HFS 0 to 3 (median LOS of 5 days and mortality of 0%), HFS 4 to 6 (median LOS of 18 days and mortality of 0%), HFS 5 to 9 (median LOS of 29 days and mortality of 23%), and HFS 10 to 12 (median LOS of 121 days and mortality of 50%). CONCLUSION: This simple acute HFS may be a useful tool to quantify and monitor day-to-day HF symptoms in children hospitalized with ADHF regardless of etiology or age group. The score has excellent IRR across provider levels and is associated with major hospital outcomes supporting its clinical validity. Validation in a multicenter cohort is warranted.

The Creation of a Pediatric Health Care Learning Network: The ACTION Quality Improvement Collaborative.

Improving the outcomes of pediatric patients with congenital heart disease with end-stage heart failure depends on the collaboration of all stakeholders; this includes providers, patients and families, and industry representatives. Because of the rarity of this condition and the heterogeneity of heart failure etiologies that occur at pediatric centers, learnings must be shared between institutions and all disciplines to move the field forward. To foster collaboration, excel discovery, and bring data to the bedside, a new, collaborative quality improvement science network-ACTION (Advanced Cardiac Therapies Improving Outcomes Network)-was developed to meet the needs of the field. Existing gaps in care and the methods of improvement that will be used are described, along with the mission and vision, utility of real-world data for regulatory purposes, and the organizational structure of ACTION is described.

Vasoplegia after pediatric cardiac transplantation in patients supported with a continuous flow ventricular assist device.

OBJECTIVE: To determine the association between continuous flow ventricular assist devices and the incidence of vasoplegia following orthotopic heart transplant in children. Moreover, to propose a novel clinical definition of vasoplegia for use in pediatric populations. METHODS: This is a single-center, retrospective cohort study set in the cardiovascular intensive care unit of a tertiary children's hospital. All patients aged 3 years and older who underwent orthotopic heart transplant at Stanford University between April 1, 2014, and July 31, 2017, were included. Vasoplegia was defined by the use of vasoconstrictive medication, diastolic hypotension, preserved systolic heart function, and absence of infection or right atrial pressure or central venous pressure <5 mm Hg. RESULTS: Of 44 eligible patients, 21 were supported using a continuous flow ventricular assist device. Following heart transplant, 14 patients (32%) developed vasoplegia by the study definition. Development of vasoplegia was associated with pretransplant use of a continuous flow ventricular assist device (52% vs 13%) with a relative risk of 4.02 (95% confidence interval, 1.30-12.45; P = .009). No other variables were predictive of vasoplegia in univariable analysis. Presence of vasoplegia was not associated with adverse outcomes, although there were trends towards higher incidence of acute kidney injury and increased length of hospital stays. CONCLUSIONS: Children receiving continuous flow ventricular assist device support are at increased risk for vasoplegia following orthotopic heart transplant, using a novel definition of vasoplegia. Anticipation of this complication will allow for prompt intervention, thereby minimizing hemodynamic instability and impact on patient outcomes.

Long-Term Pediatric Ventricular Assist Device Therapy: A Case Report of 2100+ Days of Support.

Ventricular assist devices (VADs) have been placed as destination therapy in adults for more than 20 years, but have only recently been considered an option in a subset of pediatric patients. A 2016 report from the Pediatric Interagency Registry for Mechanical Circulatory Support revealed only eight pediatric patients implanted with a VAD as destination therapy. Herein, we report the case of an adolescent male with Becker muscular dystrophy who underwent VAD placement in 2011 as bridge to candidacy. He subsequently decided to remain as destination therapy and so far has accrued more than 2100 days on VAD support, the longest duration of pediatric VAD support reported in the literature to date.

Rehospitalization Patterns in Pediatric Outpatients with Continuous-Flow VADs.

As continuous-flow ventricular assist devices (CF-VADs) are used increasingly in children and adolescents, more pediatric patients will be supported as outpatients. Herein we report the patterns of rehospitalization after CF-VAD implantation at a single center. We retrospectively reviewed the medical records of 19 consecutive patients who received CF-VADs between December 6, 2010 and November 5, 2016 and were discharged on device therapy. The frequency, duration, and indications for all hospitalizations between the time of implant hospitalization discharge and January 8, 2016 were analyzed. There were a total of 52 rehospitalization episodes in 16 (84%) patients over 5,101 (median 93, interquartile range [IQR] 38, 226) follow-up days. There were a median of two (IQR 1, 3) hospitalizations per patient. The median time to first hospitalization was 14 (IQR 7, 62) days. The most common admitting diagnoses were suspected infection 13 (28%) and suspected pump thrombosis in 8 (17%). Thirty-one (60%) hospitalizations included procedures, including seven (13%) requiring device-related surgery. Overall, 89% of postimplant discharge days were spent outside of the hospital. Children with CF-VADs can be discharged with acceptable readmission rates and significant time spent out of hospital. Most patients will be rehospitalized at least once between implant hospitalization and transplantation, often within 2 weeks of hospital discharge, with the most common indications for admission being suspected infection and suspected pump thrombosis. Device-related complications necessitating surgical intervention most frequently occur in destination therapy patients who are supported for longer periods of time.

Temporary Circulatory Support in U.S. Children Awaiting Heart Transplantation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has long served as the standard of care for short-term mechanical circulatory support in pediatrics. It is unknown whether newer-generation temporary circulatory support (TCS) devices afford children a meaningful survival advantage over ECMO. OBJECTIVES: This study sought to determine whether bridge-to-heart transplant survival with a TCS device is superior to ECMO after adjusting for patient differences. METHODS: All children ≤21 years of age listed for heart transplant from 2011 to 2015 who received a TCS device or ECMO as a bridge to transplant were identified using Organ Procurement and Transplantation Network data. Children supported with a TCS device were compared with a propensity score (PS)-matched cohort of children supported with ECMO as a bridge to transplant. The primary endpoint was Kaplan-Meier survival to transplant. RESULTS: The number of TCS devices implanted in children increased from ≤3 per year before 2011 to 50 in 2015. Overall, 93 patients implanted with TCS devices were included for analysis (59% left ventricular assist devices, 23% right ventricular assist devices, 18% biventricular assist devices). The most commonly used device was the CentriMag-PediMag system (65%), followed by TandemHeart (18%), Rotaflow (6%), and Impella (5%). Among 164 PS-matched patients, support duration was longer for the TCS cohort (median 19 days vs. 6 days; p < 0.001), and was longest for the CentriMag-PediMag (24 days vs. 6 days; p < 0.001) with 27% supported for >60 days. Compared with the ECMO cohort, the PS-matched TCS cohort had longer survival to transplant (hazard ratio: 0.49; 95% confidence interval: 0.30 to 0.79) and longer overall survival (hazard ratio: 0.61; 95% confidence interval: 0.39 to 0.96), with 90-day mortality before transplant that was modestly reduced (from 45% with ECMO to 39% with TCS). CONCLUSIONS: The use of TCS devices in children as a bridge to transplant has risen rapidly in recent years, led by the growth of magnetically levitated centrifugal flow pumps. Compared with conventional ECMO, TCS durations are longer, and more importantly, patient survival is superior.

Impact of a modified anti-thrombotic guideline on stroke in children supported with a pediatric ventricular assist device.

BACKGROUND: Stroke is the most feared complication associated with the Berlin Heart EXCOR pediatric ventricular assist device (VAD), the most commonly used VAD in children, and affects 1 in 3 children. We sought to determine whether a modified anti-thrombotic guideline, involving more intense platelet inhibition and less reliance on platelet function testing, is associated with a lower incidence of stroke. METHODS: All children supported with the EXCOR at Stanford from 2009 to 2014 were divided into 2 cohorts based on the primary anti-thrombotic guideline used to prevent pump thrombosis: (1) the Edmonton Anti-thrombotic Guideline (EG) cohort, which included children implanted before September 2012 when dual anti-platelet therapy was used with doses titrated to Thromboelastrography/PlateletMapping (TEG/PM); and (2) the Stanford Modified Anti-thrombotic Guideline (SG) cohort, which included children implanted on or after September 2012 when triple anti-platelet therapy was used routinely and where doses were uptitrated to high, weight-based dosing targets, with low-dose steroids administered as needed for inflammation. RESULTS: At baseline, the EG (N = 16) and SG (N = 11) cohorts were similar. The incidence rate of stroke in the SG cohort was 84% lower than in the EG cohort (0.8 vs 4.9 events per 1,000 days of support, p = 0.031), and 86% lower than in the previous Investigational Device Exemption trial (p = 0.006). The bleeding rate was also lower in the SG cohort (p = 0.015). Target doses of aspirin, clopidogrel and dipyridamole were higher (all p < 0.003), with less dosing variability in the SG cohort than in the EG cohort. There was no difference in adenosine diphosphate inhibition by TEG/PM, but arachidonic acid inhibition was higher in the SG cohort (median 75% vs 39%, p = 0.008). CONCLUSIONS: Stroke was significantly less common in pediatric patients supported with the Berlin Heart EXCOR VAD using a triple anti-platelet regimen uptitrated to high, weight-based dosing targets as compared with the dual anti-platelet regimen titrated to PM, and without a higher risk of bleeding. Larger studies are needed to confirm these findings.

Obesity and Premature Loss of Mobility in Two Adolescents with Becker Muscular Dystrophy After HeartMate II Implantation.

Weight gain is common after implantation of continuous-flow ventricular assist devices. Obesity can have a significant negative impact on mobility. For adolescents with Becker muscular dystrophy (BMD), for whom the ability to ambulate often persists into the mid-3rd decade, preservation of functional ability is critical. We report two cases of Thoratec HeartMate II left ventricular assist device (LVAD) implantation in adolescents with BMD for whom postoperative weight gain contributed significantly to an accelerated loss of ambulation and, in one case, driveline fracture in the context of repeated falls. As LVADs become an increasingly common therapy for endstage heart failure in adolescents with BMD, care must be focused not only on maintenance of device functionality, but also on management of aggressive weight, and preservation of ambulation, and skeletal muscle strength.