Author + information
- Received November 13, 2017
- Revision received April 20, 2018
- Accepted April 23, 2018
- Published online July 16, 2018.
- Anne I. Dipchand, MDa,∗ (, )@sickkids@UofT,
- Richard Kirk, MDb,
- David C. Naftel, PhDc,
- Elizabeth Pruitt, MSPHc,
- Elizabeth D. Blume, MDd,
- Robert Morrow, MDe,
- David Rosenthal, MDf,
- Scott Auerbach, MDg,
- Marc E. Richmond, MD, MSh,
- James K. Kirklin, MDi,
- for the Pediatric Heart Transplant Study Investigators
- aDepartment of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- bDepartment of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
- cDepartment of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
- dDepartment of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts
- eDepartment of Pediatrics, Children’s Health System of Texas, Dallas, Texas
- fDepartment of Pediatrics, Stanford University, Palo Alto, California
- gDivision of Cardiology, Department of Pediatrics, University of Colorado Anschutz Medical Campus and Children’s Hospital Colorado, Aurora, Colorado
- hDepartment of Pediatrics, Morgan Stanley Children’s Hospital–Columbia University Medical Center, New York, New York
- iDepartment of Cardiothoracic Surgery, University of Alabama at Birmingham, Birmingham, Alabama
- ↵∗Address for correspondence:
Dr. Anne I. Dipchand, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
Background Pediatric ventricular assist device (VAD) use has evolved dramatically over the last 2 decades.
Objectives This study sought to describe the evolution of VAD support to heart transplantation (HTx) in children in a large international multicenter cohort.
Methods Using data from the Pediatric Heart Transplant Study, comparisons were made between children (<18 years) supported to HTx (January 1, 1993 to December 31, 2015) with VAD or extracorporeal membrane oxygenation (ECMO) to VAD support.
Results Of 7,135 listed patients, 5,145 underwent HTx; 995 (19.3%) were supported by a VAD (113 with congenital heart disease [CHD]). Patients with a VAD as their first device (n = 821) were older, larger, and more likely to have cardiomyopathy (80%) than patients transitioned from ECMO to VAD (n = 164). In the VAD-only cohort, 79% underwent HTx and 14% died, compared with 69% and 24% in the ECMO-to-VAD cohort, respectively. Patients with cardiomyopathy achieved HTx 84% of the time, with a 9% waitlist mortality rate compared with 55% and 36%, respectively, for CHD. Among VAD-treated patients, 79% were age >10 years in the earliest era, a percentage decreasing to 34% more recently, though neonates still represent <1%. Overall, survival at 2 and 20 years showed no difference between VAD and no support (2 years: 75% vs. 80%; 20 years: 55% vs. 54%). Post-HTx outcomes were better for durable versus temporary VADs (p < 0.01) and for continuous versus pulsatile VADs (p < 0.01) from 2005 onward; timing of VAD had no impact on post-HTx survival (p = 0.65).
Conclusions For one-quarter of a century, major advances have occurred in mechanical support technology for children, thereby expanding the capability to bridge to HTx without compromising post-HTx outcomes. Significant challenges remain, especially for neonates and patients with CHD, but ongoing innovation portends improved methods of support during the next decade.
The clinical course and management of pediatric patients with advanced heart failure have become increasingly complex. The evolution of mechanical support options has opened a myriad of potential paths including temporary versus durable support and bridge to decision, recovery, or transplantation. Complex clinical trajectories allow for crossover among these options and make assessment of overall outcomes even more challenging.
Ventricular assist devices (VADs) as a means of mechanical circulatory support in pediatric patients became available in the 1990s (1) but it was not until the Berlin Heart Excor (Berlin Heart, Berlin, Germany) became more widely available in 2005 that VAD support became common, particularly among infants and small children (2,3). Blume et al. (4) reported the early pediatric VAD experience in North America in 99 patients who were supported for a mean of 57 days, with 77% undergoing transplantation. This percentage increased to 86% in the latter era of the study. Investigators in the United Kingdom analyzed 102 patients receiving support with the Excor and reported an 84% survival to transplantation or explantation rate (5).
The use of VAD as a bridge to transplantation in pediatric patients has continued to increase, with approximately one-third of pediatric patients currently undergoing heart transplantation from VAD support (6). Given the significant morbidity, mortality, resource implications, and gap between donor organ availability and demand, documentation of the spectrum of the use, impact, and relevant outcomes of VADs has become even more crucial. Single-center reports are small in numbers and limited in experience (7–11). The Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS) has been enrolling patients since 2012 and promises to be an important source of data moving forward, but it remains limited to pre-transplantation outcomes in durable VADs (12).
We sought to describe the changing spectrum of VAD use in pediatric heart transplantation candidates, the resultant complex clinical trajectories of patients with end-stage heart failure, and a comparison of post-transplantation outcomes among patients managed pre-transplantation with and without VAD therapy in the largest international multicenter cohort reported to date.
Patient group and data collection
This study used data from the PHTS (Pediatric Heart Transplant Study) database, an event-driven, multicenter, prospective registry of children <18 years of age who were listed for primary heart transplantation from 48 pediatric heart transplantation centers in North America, the United Kingdom, and Brazil (Online Table 1). PHTS data collection and management have been described previously; because it is an event-driven database, forms are submitted at the time of listing and then transplantation, death, or removal from the waitlist. If none of these events occur, an annual post-listing follow-up form is submitted (13). Institutional Review Board approval was obtained at the transplantation centers and the data analysis and coordinating center. The study group included all patients who were listed for heart transplantation between January 1, 1993, and December 31, 2015. The first recorded VAD implantation in the registry was on March 28, 1993 (Bio-Medicus BiVAD, Medtronic Bio-Medicus, Inc., Eden Prairie, Minnesota). VADs were classified into 2 types, temporary or durable, as listed in Table 1. Comparisons were made with all patients in the registry who did not have VAD support at any time while listed. Data were analyzed in 3 eras: 1993 to 2004, 2005 to 2009, and 2010 to 2015. Data collected included demographics, United Network for Organ Sharing (UNOS) status at listing, support at listing (intravenous inotropes, ventilator, prostaglandin, extracorporeal membrane oxygenation [ECMO], VAD), timing of ECMO support or VAD placement post-listing, death while waiting, delisting, indications for removal from wait list, transplantation, UNOS status at transplantation, support at time of transplantation (e.g., ECMO, VAD), date of most recent follow-up, death post-transplantation, and cause of death.
Patients who received VAD support at some point while waiting were compared with patients who did not require mechanical support between listing and transplantation. Means and standard deviations were calculated for continuous variables and compared by analysis of variance. Categorical variables were compared using chi-square tests. Alpha was set at 0.05 for significance. For time-related analyses, time 0 was set time of listing for patients who did not receive mechanical circulatory support and at time of first mechanical support for patients receiving ECMO or VAD support. All patients started with time 0 in the listed patients group and were censored at initiation of ECMO or VAD support. Competing-outcomes methods were used to analyze outcome after listing. Standard Kaplan-Meier depictions were generated for survival after transplantation with the log-rank test to compare overall survival between groups.
Overall patient group
Patient demographics and clinical characteristics at listing and transplantation by mechanical circulatory support device (MCSD) are summarized in Table 2. Of the 7,135 patients listed over this 22-year study, 5,145 (72%) underwent transplantation, and 995 (14%) patients were supported by a VAD at some point while waiting. A total of 821 (11.5%) patients received VAD support as their first device while they were listed (Figure 1A), and these patients make up the group in the Table 2 “Listing” column. Their mean age was 8 ± 6 years, and they were older, larger, and more likely to have cardiomyopathy than patients not requiring mechanical support during listing. For comparison purposes, the cohort of patients who received ECMO as the first device while listed (n = 752) (Figure 1B) were younger, smaller, and more likely to be ventilated and receiving inotropes. Only 20% of patients with VAD support during listing had a diagnosis of congenital heart disease compared with 51% undergoing ECMO during listing and 58% not requiring mechanical support while listed (p < 0.0001).
Of the 5,145 patients who underwent heart transplantation, 669 (13%) had VAD support at the time of transplantation. An additional 81 patients had a VAD as their final mode of support closest to transplantation, although it had been explanted before the transplantation procedure. These patients were analyzed together (n = 749; 14.6%) for the purposes of the analysis to reflect outcomes of patients who were bridged to transplantation with VAD support, and these patients make up the group reflected in the Table 2 “Transplant” column. Their mean age was 8.4 ± 6 years, and they were older, larger, more likely to have cardiomyopathy, and less likely to require inotropic support than patients not requiring mechanical support as a bridge to transplantation. The VAD support cohort had a mean waitlist duration of 3.38 months, no different from the 3.24 months for patients not requiring mechanical support but significantly longer than the 1 month for patients who underwent transplantation from ECMO support (p < 0.0001). A total of 92 (11.2%) patients with a diagnosis of congenital heart disease who had VAD support as their first device while listed made it to transplantation, with a total of 113 (15%) patients with congenital heart disease supported to transplantation with a VAD at any time while waiting (21 of these patients transitioned from ECMO support).
The complex clinical trajectories of the entire patient cohort on the basis of the first MCSD (VAD, ECMO, or other) while listed are summarized in Figure 1. A total of 821 pediatric patients received VAD support as their first type of mechanical support at some point while waiting (Figure 1A), and an additional 174 patients transitioned to VAD after ECMO (n = 164) (Figure 1B, Table 3) or another MCSD (n = 10) (Online Figure 1), thus making up the VAD cohort of 995 patients (14%). A total of 288 patients had the VAD in place on the date of listing. Those patients who transitioned to VAD while waiting did so at a median time of 0.43 months (range 0.13 to 1.23 months): 0.39 months (range 0.13 to 1.25 months) for durable devices and 0.71 months (range 0.13 to 1.41 months) for temporary devices.
Overall, 635 (77%) of patients who had VAD support as their first MCSD underwent transplantation and 119 (14%) died, but the pathways to these endpoints were not direct; 22% of patients initially underwent VAD explantation, with 30% of those requiring reinstitution of mechanical support (VAD or ECMO). Overall, 387 (51%) of patients undergoing ECMO support as their first MCSD underwent transplantation and 273 (36%) died, but again the pathways to these endpoints were not direct. This cohort included 164 (22%) patients who transitioned to VAD support while waiting; 113 (68.9%) of these patients underwent transplantation, again with variable interim courses to reach that endpoint.
For completeness, Online Figure 1 depicts the clinical trajectories for the small cohort (n = 33) of patients whose first MCSD was not VAD or ECMO; most of these MCSDs were intra-aortic balloon pumps (n = 29). Only the 9 patients who transitioned to VAD contribute further to this analysis.
VAD support by era and type
VAD use increased across all 3 eras (Figure 2). Overall, most of the VADs used in this large pediatric cohort were durable, both the first VAD while listing and the VAD at the time of transplantation, and this was evident across all 3 eras (Table 4). Clinical trajectories for temporary (n = 67) and durable (n = 501) left VADs (LVADs) as the first device are depicted in Online Figures 2 and 3. The clinical trajectories for VAD-treated patients by era are detailed by Online Figures 4 to 6. Of note, the complexity of patient care trajectories increased predominantly for the most recent era.
A total of 215 (26%) patients had biventricular VAD (BiVAD) support as their first mechanical support strategy while listed, 39 (18%) with a temporary LVAD and 176 (82%) with a durable LVAD. Overall, 167 BiVAD-treated patients (78%) underwent transplantation and 37 (17%) died. The clinical trajectories of patients who had BiVAD support are summarized in Online Figures 7 and 8. By era, 40% of the BiVADs were in era 1, 42% were in era 2, and the percentage decreased to 18% for the most recent era. A total of 17 patients had a right ventricular VAD (RVAD) alone as their first device; 65% of these patients underwent transplantation, and 29% died (Online Figure 9). Device use by brand and LVAD versus RVAD use are summarized in Online Table 2.
Looking at pulsatile versus continuous-flow devices from 2005 onward, survival rates at 2 years after listing were significantly lower for pulsatile compared with continuous devices (p < 0.01) (Figure 3).
VAD support by age and era
Table 5 summarizes the age distributions for VAD at any time while waiting by era. A total of 79% of all children who had VAD support while waiting in the earliest era were older than 10 years of age, and this percentage dropped to 34% in the most recent era because of increasing VAD support in the younger age groups, most notably the 1-month to 1-year age group (7.6% to 26%) and the 1- to 5-year age group (3.4% to 23%). Even in the most recent era the proportion of neonates <1 month of age supported by VAD at any time remained extremely low (1%).
Table 6 details the outcome of VAD support at any time while waiting (n = 995). The rate of death while waiting during VAD support was highest in the earliest era (24%) and dropped to 16% in the most recent era. One-third of all patients listed who had a temporary VAD died while waiting compared with 14% of those listed who had a durable device. Overall, 17% died, 76% underwent transplantation, and a further 8% of patients were still waiting at the time of analysis. Outcomes by VAD type and by era are also summarized in the Table 6.
Figure 4 shows the competing outcomes for patients with VAD support as their first device (Figure 1A) compared with patients with a VAD after ECMO (Figure 1B). A total of 58% of patients who had VAD as their first device while listed underwent transplantation by 6 months post-implantation compared with 53% of patients who had VAD support followed ECMO support (p = 0.03).
A total of 33 of 288 (11%) patients with a VAD in place at the time of listing died while waiting compared with 85 of 533 (16%) who had a VAD placed after listing (without ECMO first). Overall 2-year survival after listing was superior for patients with VAD support as their first device during listing compared with those patients who transitioned from ECMO to VAD (Figure 5A) (p < 0.01), and it was similar to listed patients who did not require mechanical support (censored at the time of VAD implantation or heart transplantation). Survival with device support while listed on the basis of temporary versus durable VAD (as defined in Table 1) at listing (Figure 6A) was significantly better for patients with durable devices (p < 0.01).
Overall survival after transplantation was no different for patients who waited with or without VAD support, with 20-year survival rates of 55% and 54%, respectively (p = 0.4). Both groups had superior survival compared with patients who were undergoing ECMO support closest to the time of transplantation (Figure 5B) (p < 0.01). Timing of VAD, either at listing or after listing, also did not have an impact on post-transplantation survival (Online Figure 10) (p = 0.65). Temporary versus durable VAD type closest to transplantation had no impact on survival after transplantation (Figure 6B) (p = 0.66).
Outcomes by era
Post-listing survival for patients with a temporary VAD (as defined in Table 1) appeared to improve in the more recent era, although the numbers were small and the difference was not statistically significant (Figure 7A) (p = 0.09). There was a trend toward improvement in post-listing survival for patients with a durable VAD (as defined in Table 1) across eras (Figure 7B) (p = 0.06).
There was no significant era effect in post-transplantation survival for patients with a temporary VAD closest to transplantation (Figure 7C) (p = 0.47). However, although the numbers are small, there was a trend toward improvement in post-transplantation survival for patients who underwent transplantation from a durable VAD in the most recent era, with a 5-year survival >80% (Figure 7D) (p = 0.06).
Overall survival after listing and after transplantation divided into the pre- and post-2005 era (Berlin Heart Excor approval) is depicted in Online Figure 11. Of note, when looked at this way, post-listing survival was significantly improved post-2005 (p = 0.03) for both temporary and durable VADs (including Berlin Heart Excor); however, post-transplantation survival was significantly improved in the post-2005 era only for the durable device group (p = 0.01).
Outcomes by age
Post-implantation survival for VAD support as the first device while waiting for transplantation was significantly worse between age groups, with a 2-year post-implantation survival of 78% for age >10 years compared with 53% for age <1 year (p < 0.01). Among those patients who survived to transplantation, there was no significant difference in post-transplantation survival (Figure 8A) (p = 0.51).
Outcomes for patients with congenital heart disease
By the end of the study period, overall 84% of the patients with cardiomyopathy underwent transplantation, with a 9% waitlist mortality compared with 57% and 33% for patients with congenital heart disease, respectively.
A total of 206 patients with congenital heart disease had VAD support while waiting (141 with biventricular and 65 with single-ventricle physiology), with a 43% waitlist mortality rate and 35% undergoing transplantation by 6 months compared with 13% and 63%, respectively, for patients with cardiomyopathy (Central Illustration). The mean age at implantation was 5.7 years (11 days to 18.2 years). VAD type included 45 temporary (22%) and 156 durable (77%) devices. Among patients receiving a VAD, 113 (55%) underwent transplantation, with 1- and 5-year survival rates of 82% and 74%, respectively. A total of 75 (36%) of patients were delisted or died waiting, with a mean wait time duration of 10 months (0 to 187 months). The 2-year survival post-device placement was significantly worse for patients with a diagnosis of congenital heart disease (45%) compared with cardiomyopathy (80%; p < 0.01) (Central Illustration). Survival post-transplantation following VAD support continues to be significantly lower for patients with a diagnosis of congenital heart disease compared with cardiomyopathy (Figure 8B) (p < 0.01). Although the numbers are small, patients with single-ventricle physiology had no difference in outcome post-VAD implantation compared with patients with biventricular physiology (41% vs. 47% at 12 months; p = 0.46). (Online Figure 12).
This is the largest international multicenter report of pediatric patients with VAD support as a bridge to transplantation. The clinical trajectories were very complex, but for the first time the entire spectrum of mechanical support use before transplantation has been documented. This includes the different devices and details of implantation, explantation, reimplantation, and transition from 1 MCSD type to another. This unique snapshot reflects the complexity of the patient care delivered in the VAD era for pediatric patients with end-stage heart disease.
Choice of mechanical circulatory support device and era
Overall, 10 different manufacturers providing 6 different temporary devices and 13 durable devices have been reported to the PHTS registry. The initial choice of device for any individual patient depends on a number of different factors including the patient’s size, type of support needed (LVAD vs. BiVAD vs. RVAD), anticipated duration, goal of support, device availability, and diagnosis. A similar range of support options has also been documented in the International Society for Heart and Lung Transplantation registry (14) and the UNOS cohort (15). Between 2010 and 2015, VAD use in pediatric patients more than doubled compared with the 5 previous years, consistent with the International Society for Heart and Lung Transplantation registry data (6). Crossover among the different support strategies has become more prevalent in the most recent era, as captured in this report.
There have been 2 analyses of the UNOS database exploring pediatric VAD patients’ characteristics from 2005 onward that were similar to those reported herein, including a similar breakdown between patients with cardiomyopathy and patients with congenital heart disease (15,16). This current study, however, has been able to define characteristics from an even earlier period and has therefore been able to compare 3 eras and document notable changes from 1993 onward.
VAD use in neonates (<1 month of age) was not reported until the 2010 to 2015 era, and although infants (1 to 12 months) were recorded as receiving VAD support, they comprised a small group in the earliest era (8%) and received VAD support in any numbers only in the second and third eras, coinciding with the availability of the Berlin Heart Excor. VAD support in neonates <1 month of age remains low (1%) because mechanical support options are extremely limited and outcomes are poor, especially for infants weighing <5 kg. A total of 64% of babies <5 kg died compared with 38% weighing <10 kg, and only 27% versus 55%, respectively, underwent transplantation (17). There is thus an urgent need to address MCSD development for these small children because they are not insignificant in number and need.
Type of VAD support
Durable VAD use predominated over temporary across all eras, although there is increasing experience with temporary VADs on the basis of the numbers reported here. Although post-listing survival was worse with temporary VADs, with a waitlist mortality rate of 29% compared with 12% for durable VADs, it appears to be better than the reported waitlist mortality rate during ECMO support of 36% described here, similar to what is reported in published findings (18).
One-fourth of patients had BiVAD support as their first support strategy while listed, a finding that is similar to that reported both in single-center and registry-based studies (15% to 30%) (10,12). A similar proportion of patients underwent transplantation (78%), but with a higher waitlist mortality rate (17%) compared with LVAD alone. BiVAD use decreased in the most recent era, possibly reflecting the learning curve for decision making regarding the need for right-sided heart support in the pediatric setting. RVAD as a first device strategy was rarely used, with 65% undergoing transplantation.
Pulsatile VADs still predominate over continuous-flow VADs in pediatric patients, as also reported by the Stanford group (82% vs. 18%) (10). There is increasing evidence in published reports of improved outcomes using continuous-flow devices in the pediatric age range (12,19,20). Mathew et al. (19) reported favorable waitlist and post-transplantation outcomes for pediatric patients supported with continuous-flow VADs reported to the UNOS database. Post-listing survival was significantly better for continuous-flow devices in the cohort reported here, possibly heralding an evolving transition from pulsatile to continuous-flow devices, although the impact on outcomes in a larger cohort and across the pediatric spectrum of age and diagnoses remains to be seen.
Impact of underlying diagnosis: Cardiomyopathy versus congenital heart disease
Cardiomyopathy is by far the most common diagnosis in any VAD cohort: 80% in the Berlin Heart Excor investigational device exemption study (21) and 85% in the current larger cohort. These patients have much better outcomes across the board compared with patients with congenital heart disease. These differences in outcomes are explained by the multiple challenges that exist related to anatomy causing technical issues, physiology (e.g., shunt-dependent circulations, single-ventricle circulations), and the pump design for biventricular circulations. Although there have been case reports and small series of successful VAD support in patients with single-ventricle physiology circulations, reported outcomes are worse, both in terms of waitlist mortality and survival to transplantation (5). In a cohort of patients with congenital heart disease who were supported with VAD, survival to transplantation was 42% for single-ventricle patients versus 73% for patients with biventricular circulations. Patients with single-ventricle physiology had a dismal outcome, with no survivors among patients with VAD support after stage I or in single-ventricle patients weighing <7 kg (22). Reported survival for patients with congenital heart disease and VAD support in other series ranged from 62% to 69% (5,10). An analysis of the Berlin Heart Excor pediatric study dataset (2007 to 2010) found that successful bridge to transplantation or explantation was less likely (48% vs. 80%) in patients with congenital heart disease (23). In contrast to other reports, these investigators found that single-ventricle versus 2-ventricle physiology had similar VAD support outcomes and noted that the main differences in outcomes related to age and, more particularly, whether VAD support was initiated as a rescue following surgery (e.g., on the same admission as cardiac surgery) or reflected a later decline late after surgery on a separate admission. The outcomes herein were similar overall, with a 36% waitlist mortality rate, only 55% undergoing transplantation in patients with congenital heart disease, and no significant difference between single and biventricular circulations in this multicenter cohort.
Impact of VAD use on waitlist mortality and post-transplantation outcomes
An analysis of the UNOS database demonstrated that with more widespread use of VADs in the recent era, the waitlist mortality rate has decreased by 50%; however, the wait time has increased from a median of 36 to 45 days (24). Mean wait times in this cohort were similar for the VAD cohort and the no mechanical support cohort. Data from the PediMACS registry demonstrated that 58.3% of patients underwent transplantation by 6 months (12), very similar to our results.
As confirmed in this larger cohort, reports have demonstrated improved waitlist survival and similar post-transplantation outcomes for patients supported by VAD (3,7), with VAD versus no mechanical circulatory support having equivalent 20-year post-transplantation survival. Durable VAD post-transplantation survival has improved over time, and 5 year post-transplantation survival from durable VAD was >80% in the most recent era. Post-implantation survival was better for older children (>10 years) compared with infants (<1 year), but importantly, post-transplantation survival was the same. Hence VAD development for this key age group would make a tremendous impact on overall outcomes.
Outcomes of multiple device support
De Rita et al. (25) reported a single-center study of multimodality support in 21 children from 1998 to 2014. These investigators demonstrated good outcomes from ECMO to VAD (5 of 6 survived to transplant) but no survivors from VAD to ECMO. Wehman et al. (16) also analyzed a subgroup of patients who transitioned from ECMO to VAD and found no difference in post-transplantation survival but did not assess waitlist survival. This analysis similarly demonstrated a 78% survival rate in patients transitioning from ECMO to VAD, although this rate was significantly lower than in patients whose first device was a VAD, and it was a much poorer outcome than in patients transitioning from VAD to ECMO. In the group described by De Rita et al. (25), the survival to transplantation from single VAD support was comparable to that seen with multiple VAD support. In contrast, in this cohort, 12.6% who had VAD as a single support episode died compared with 27% who had more than 1 episode of support.
This report spans an era of almost one-quarter of a century and is reliant on accurate reporting of data from multiple centers over a prolonged period of time. It thus has all the inherent limitations of any registry. Details on why various MCSD strategies were used cannot be identified, nor did the registry capture MCSD morbidity data. Delisting for sustained recovery and death between listing and transplantation with VAD support could be underestimated depending on reporting within the database, although all efforts were made to verify and accurately reflect this small cohort of patients.
There have been major advances in MCSD technology for pediatric patients over the 22 years of this study. These advances have enabled effective support to be offered to younger patients and safer technology offered to older patients. As a consequence, bridging to transplantation has reduced waitlist mortality without compromising post-transplantation survival. This report has documented in detail the different VAD strategies currently in use and has highlighted that challenges remain in determining the best support strategy for individual patients as well as in device development for infants, especially neonates, and for those with single-ventricle physiology. Ongoing innovation portends improved methods of support in the youngest patients during the next decade.
COMPETENCY IN MEDICAL KNOWLEDGE: The number of children supported with VADs while awaiting heart transplantation has been increasing and is associated with improved survival.
TRANSLATIONAL OUTLOOK: Further studies are needed to define the optimum timing and types of mechanical support for pediatric patients with congenital heart disease.
Dr. Rosenthal has received research support from Berlin Heart; and has received educational meeting support from HeartWare. Dr. Kirklin has received a stipend as Chair of the data and safety monitoring board for the Xeltis pediatric extracardiac conduit trial; and has received institutional support as principal investigator of the INTERMACS National Mechanical Circulatory Support Registry. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Abbreviations and Acronyms
- biventricular VAD
- extracorporeal membrane oxygenation
- left ventricular assist device
- mechanical circulatory support device
- Pediatric Interagency Registry for Mechanical Circulatory Support
- right ventricular assist device
- United Network for Organ Sharing
- ventricular assist device
- Received November 13, 2017.
- Revision received April 20, 2018.
- Accepted April 23, 2018.
- 2018 American College of Cardiology Foundation
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