Palliation + VAD insertion in 15 Neonates and Infants with Functionally Univentricular Circulation

Single Ventricular Assist Device Care and Outcomes for Failed Stage I Palliation: A Single-Center Decade of Experience

Single ventricular assist device (SVAD) use before and after stage I palliation (S1P) is increasing with limited data on outcomes. To address this knowledge gap, we conducted a single-center retrospective review to assess pre- and post-SVAD clinical status, complications, and outcomes. We leveraged a granular, longitudinal, local database that captures end-organ support, procedural interventions, hematologic events, laboratory data, and antithrombotic strategy. We identified 25 patients between 2013 and 2023 implanted at median age of 53 days (interquartile range [IQR] = 16-130); 80% had systemic right ventricles and underwent S1P. Median SVAD days were 54 (IQR = 29-86), and 40% were implanted directly from ECMO. Compared to preimplant, there was a significant reduction in inotrope use ( p = 0.013) and improved weight gain ( p = 0.008) post-SVAD. Complications were frequent including bleeding (80%), stroke (40%), acute kidney injury (AKI) (40%), infection (36%), and unanticipated catheterization (56%). Patients with in-hospital mortality had significantly more bleeding complications ( p = 0.02) and were more likely to have had Blalock-Thomas-Taussig shunts pre-SVAD ( p = 0.028). Survival to 1 year postexplant was 40% and included three recovered and explanted patients. At 1 year posttransplant, all survivors have technology dependence or neurologic injury. This study highlights the clinical outcomes and ongoing support required for successful SVAD use in failed single-ventricle physiology before or after S1P.

Current Status of Cardiac Xenotransplantation: Report of a Workshop of the German Heart Transplant Centers, Martinsried, March 3, 2023

This report comprises the contents of the presentations and following discussions of a workshop of the German Heart Transplant Centers in Martinsried, Germany on cardiac xenotransplantation. The production and current availability of genetically modified donor pigs, preservation techniques during organ harvesting, and immunosuppressive regimens in the recipient are described. Selection criteria for suitable patients and possible solutions to the problem of overgrowth of the xenotransplant are discussed. Obviously microbiological safety for the recipient and close contacts is essential, and ethical considerations to gain public acceptance for clinical applications are addressed. The first clinical trial will be regulated and supervised by the Paul-Ehrlich-Institute as the National Competent Authority for Germany, and the German Heart Transplant Centers agreed to cooperatively select the first patients for cardiac xenotransplantation.

Impact of ventricular assist device use on pediatric heart transplant waitlist mortality: Analysis of the scientific registry of transplant recipients database

BACKGROUND

Children awaiting heart transplant (Tx) have a high risk of death due to donor organ scarcity. Historically, ventricular assist devices (VADs) reduced waitlist mortality, prompting increased VAD use. We sought to determine whether the VAD survival benefit persists in the current era.

METHODS

Using the Scientific Registry of Transplant Recipients, we identified patients listed for Tx between 3/22/2016 and 9/1/2020. We compared characteristics of VAD and non-VAD groups at Tx listing. Cox proportional hazards models were used to identify risk factors for 1-year waitlist mortality.

RESULTS

Among 5054 patients, 764 (15%) had a VAD at Tx listing. The VAD group was older with more mechanical ventilation and renal impairment. Unadjusted waitlist mortality was similar between groups; the curves crossed ~90 days after listing (p = .55). In multivariable analysis, infant age (HR 2.77, 95%CI 2.13-3.60), Black race (HR 1.57, 95%CI 1.31-1.88), congenital heart disease (HR 1.23, 95%CI 1.04-1.46), renal impairment (HR 2.67, 95%CI 2.19-3.26), inotropes (HR 1.28, 95%CI 1.09-1.52), and mechanical ventilation (HR 2.23, 95%CI 1.84-2.70) were associated with 1-year waitlist mortality. VADs were not associated with mortality in the first 90 waitlist days but were protective for those waiting ≥90 days (HR 0.43, 95%CI 0.26-0.71).

CONCLUSIONS

In the current era, VADs reduce waitlist mortality, but only for those waitlisted ≥90 days. The differential effect by race, size, and VAD type is less clear. These findings suggest that Tx listing without VAD may be reasonable if a short waitlist time is anticipated, but VADs may benefit those expected to wait >90 days.

An Analysis of 186 Transplants for Pediatric or Congenital Heart Disease: Impact of Pretransplant VAD

BACKGROUND

We reviewed our management strategy and outcome data for all 181 patients with pediatric or congenital heart disease who received 186 heart transplants from January 1, 2011, to March 1, 2022, and evaluated the impact of pretransplant ventricular assist device (VAD).

METHODS

Continuous variables are presented as mean (SD); median [interquartile range] (range). Categorical variables are presented as number (percentage). Univariable associations with long-term mortality were assessed with Cox proportional hazards models. Impact of pretransplant VAD on survival was estimated with multivariable models.

RESULTS

Pretransplant VAD was present in 53 of 186 transplants (28.5%). Patients with VAD were younger (years): 4.8 (5.6); 1 [0.5-8] (0.1-18) vs 12.1 (12.7); 10 [0.7-17] (0.1-58); P = .0001. Patients with VAD had a higher number of prior cardiac operations: 3.0 (2.3); 2 [1-4] (1-12) vs 1.8 (1.9); 2 [0-3] (0-8); P = .0003. Patients with VAD were also more likely to receive an ABO-incompatible transplant: 10 of 53 (18.9%) vs 9 of 133 (6.8%); P = .028. Univariable associations with long-term mortality included: In multivariable analysis, pretransplant VAD did not impact survival while controlling for each one of the factors shown in univariable analysis to be associated with long-term mortality. Kaplan-Meier 5-year survival (95% CI) was 85.8% (80.0%-92.1%) for all patients, 84.3% (77.2%-92.0%) without pretransplant VAD, and 91.1% (83.1%-99.9%) with pretransplant VAD.

CONCLUSIONS

Our single-institution analysis of 181 patients receiving 186 heart transplants for pediatric or congenital heart disease over 11.25 years reveals similar survival in patients with (n = 51) and without (n = 130) pretransplant VAD. The presence of a pretransplant VAD is not a risk factor for mortality after transplantation for pediatric or congenital heart disease.

A single-institutional experience with 36 children less than 5 kilograms supported with the Berlin Heart: Comparison of congenital versus acquired heart disease

OBJECTIVES

We reviewed outcomes in all 36 consecutive children <5 kg supported with the Berlin Heart pulsatile ventricular assist device at the University of Florida, comparing those with acquired heart disease (n = 8) to those with congenital heart disease (CHD) (n = 28).

METHODS

The primary outcome was mortality. The Kaplan-Meier method and log-rank tests were used to assess group differences in long-term survival after ventricular assist device insertion. T-tests using estimated survival proportions were used to compare groups at specific time points.

RESULTS

Of 82 patients supported with the Berlin Heart at our institution, 49 (49/82 = 59.76%) weighed <10 kg and 36 (36/82 = 43.90%) weighed <5 kg. Of 36 patients <5 kg, 26 (26/36 = 72.22%) were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 36 patients <5 kg was [days]: median = 109, range = 4-305.) Eight out of 36 patients <5 kg had acquired heart disease, and all eight [8/8 = 100%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 8 patients <5 kg with acquired heart disease was [days]: median = 50, range = 9-130.) Twenty-eight of 36 patients <5 kg had congenital heart disease. Eighteen of these 28 [64.3%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 28 patients <5 kg with congenital heart disease was [days]: median = 136, range = 4-305.) For all 36 patients who weighed <5 kg: 1-year survival estimate after ventricular assist device insertion = 62.7% (95% confidence interval = 48.5-81.2%) and 5-year survival estimate after ventricular assist device insertion = 58.5% (95% confidence interval = 43.8-78.3%). One-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 55.6% (95% confidence interval = 39.5-78.2%) in CHD, P = 0.036. Five-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 48.6% (95% confidence interval = 31.6-74.8%) in CHD, P = 0.014.

CONCLUSION

Pulsatile ventricular assist device facilitates bridge to transplantation in neonates and infants weighing <5 kg; however, survival after ventricular assist device insertion in these small patients is less in those with CHD in comparison to those with acquired heart disease.

Outcomes of Children Supported With Pulsatile Paracorporeal Ventricular Assist Device: Congenital Versus Acquired Heart Disease

BACKGROUND

We reviewed the outcomes of 82 consecutive pediatric patients (less than 18 years of age) supported with the Berlin Heart ventricular assist device (VAD), comparing those with congenital heart disease (CHD; n  =  44) with those with acquired heart disease (AHD; n  =  37).

METHODS

The primary outcome was mortality after VAD insertion. Kaplan-Meier methods and log-rank tests were used to assess group differences in long-term survival.

RESULTS

Forty-four CHD patients were supported (age: median  =  65 days, range  =  4 days-13.3 years; weight [kg]: median  =  4, range  =  2.4-42.3). Ten biventricular CHD patients were supported with eight biventricular assist devices (BiVADs), one left ventricular assist device (LVAD) only, and one LVAD converted to BiVAD, while 34 univentricular CHD patients were supported with single ventricle-ventricular assist devices (sVADs). In CHD patients, duration of VAD support was [days]: median  =  134, range  =  4-554. Of 44 CHD patients, 28 underwent heart transplantation, 15 died on VAD, and one was still on VAD. Thirty-seven AHD patients were supported (age: median  =  1.9 years, range  =  27 days-17.7 years; weight [kg]: median  =  11, range  =  3.1-112), including 34 BiVAD and 3 LVAD. In AHD patients, duration of VAD support was [days]: median  =  97, range  =  4-315. Of 37 AHD patients, 28 underwent transplantation, three died on VAD, five weaned off VAD (one of whom underwent heart transplantation 334 days after weaning), and one was still on VAD. One-year survival after VAD insertion was 59.9% (95% CI  =  46.7%-76.7%) in CHD and 88.6% (95% CI  =  78.8%-99.8%) in AHD, P  =  .0004. Five-year survival after VAD insertion was 55.4% (95% CI  =  40.8%-75.2%) in CHD and 85.3% (95% CI  =  74.0%-98.2%) in AHD, P  =  .002.

CONCLUSIONS

Pulsatile VAD facilitates bridge-to-transplantation in neonates, infants, and children with CHD; however, survival after VAD insertion is worse in patients with CHD than in patients with AHD.

Heart Transplantation in Patients Less Than 18 Years of Age: Comparison of 2 Eras Over 36 Years and 323 Transplants at a Single Institution

BACKGROUND

We reviewed our management strategy and outcome data for all 311 patients less than 18 years of age who underwent 323 heart transplants at our institution (1986 to 2022) in order to assess changes in patterns of practice and outcomes over time and to compare two consecutive eras: era 1 (154 heart transplants [1986 to 2010]) and era 2 (169 heart transplants [2011 to 2022]).

STUDY DESIGN

Descriptive comparisons between the two eras were performed at the level of the heart transplant for all 323 transplants. Kaplan-Meier survival analyses were performed at the level of the patient for all 311 patients, and log-rank tests were used to compare groups.

RESULTS

Transplants in era 2 were younger (6.6 ± 6.5 years vs 8.7 ± 6.1 years, p = 0.003). More transplants in era 2 were in infants (37.9% vs 17.5%, p < 0.0001), had congenital heart disease (53.8% vs 39.0%, p < 0.010), had high panel reactive antibody (32.1% vs 11.9%, p < 0.0001), were ABO-incompatible (11.2% vs 0.6%, p < 0.0001), had prior sternotomy (69.2% vs 39.0%, p < 0.0001), had prior Norwood (17.8% vs 0%, p < 0.0001), had prior Fontan (13.6% vs 0%, p < 0.0001), and were in patients supported with a ventricular assist device at the time of heart transplant (33.7% vs 9.1%, p < 0.0001). Survival at 1, 3, 5, and 10 years after transplant was as follows: era 1 = 82.4% (76.5 to 88.8), 76.9% (70.4 to 84.0), 70.7% (63.7 to 78.5), and 58.8% (51.3 to 67.4), respectively; era 2 = 90.3% (85.7 to 95.1), 85.4% (79.7 to 91.5), 83.0% (76.7 to 89.8), and 66.0% (49.0 to 88.8), respectively. Overall Kaplan-Meier survival in era 2 was better (log-rank p = 0.03).

CONCLUSIONS

Patients undergoing cardiac transplantation in the most recent era are higher risk but have better survival.

A Single-Institutional Experience with 36 Children Smaller Than 5 Kilograms Supported with the Berlin Heart Ventricular Assist Device (VAD) over 12 Years: Comparison of Patients with Biventricular versus Functionally Univentricular Circulation

OBJECTIVES

We reviewed outcomes in all 36 consecutive children <5 kg supported with the Berlin Heart pulsatile ventricular assist device (VAD) at the University of Florida, comparing those with univentricular circulation (n  =  23) to those with biventricular circulation (n  =  13).

METHODS

The primary outcome was mortality. Kaplan-Meier methods and log-rank tests were used to assess group differences in long-term survival after VAD insertion. T-tests using estimated survival proportions and standard errors were used to compare groups at specific time points.

RESULTS

Of all 82 patients ever supported with Berlin Heart at our institution, 49 (49/82  =  59.76%) weighed <10 kg and 36 (36/82  =  43.90%) weighed <5 kg. Of these 36 patients who weighed <5 kg, 26 (26/36  =  72.22%) were successfully bridged to transplantation. Of these 36 patients who weighed <5 kg, 13 (13/36  =  36.1%) had biventricular circulation and were supported with 12 biventricular assist devices (BiVADs) and 1 left ventricular assist device (LVAD) (Age [days]: median  =  67, range  =  17-212; Weight [kilograms]: median  =  4.1, range  =  3.1-4.9), while 23 (23/36  =  63.9%) had univentricular circulation and were supported with 23 single ventricle-ventricular assist devices (sVADs) (Age [days]: median  =  25, range  =  4-215; Weight [kilograms]: median  =  3.4, range  =  2.4-4.9). Of 13 biventricular patients who weighed <5 kg, 12 (12/23  =  92.3%) were successfully bridged to cardiac transplantation. Of 23 functionally univentricular patients who weighed <5 kg, 14 (14/23  =  60.87%) were successfully bridged to cardiac transplantation. For all 36 patients who weighed <5 kg: 1-year survival estimate after VAD insertion  =  62.7% (95% confidence interval [CI]  =  48.5%-81.2%) and 5-year survival estimate after VAD insertion  =  58.5% (95% CI  =  43.8%-78.3%). One-year survival after VAD insertion: 84.6% (95% CI  =  67.1%-99.9%) in biventricular patients and 49.7% (95% CI  =  32.3%-76.4%) in univentricular patients, P  =  0.018. Three-year survival after VAD insertion: 84.6% (95% CI  =  67.1%-99.9%) in biventricular patients and 41.4% (95% CI  =  23.6%-72.5%) in univentricular patients, P  =  0.005.

CONCLUSION

Pulsatile VAD facilitates bridge to transplantation in neonates and infants weighing <5 kg; however, survival after VAD insertion in these small patients is less in those with univentricular circulation in comparison to those with biventricular circulation.

Support with Single Ventricle-Ventricular Assist Device (sVAD) in Patients with Functionally Univentricular Circulation Prior to Fontan Operation

Some patients with functionally univentricular circulation develop cardiac failure refractory to maximal management and are supported with a ventricular assist device (VAD). The purpose of this manuscript is to summarize our previous publications related to single ventricle-ventricular assist device (sVAD) support in patients with functionally univentricular circulation and to describe our current institutional approach at University of Florida to sVAD support in neonates, infants, and children prior to Fontan. Our programmatic philosophy at University of Florida is to strive to identify the minority of neonates with functionally univentricular circulation who are extremely high-risk prior to initiating staged palliation and to stabilize these neonates with primary preemptive sVAD in preparation for cardiac transplantation; our rationale for this approach is related to the challenges associated with failed staged palliation and subsequent bail-out sVAD support and transplantation. A subset of extremely high-risk neonates and infants with functionally univentricular ductal-dependent circulation undergo primary preemptive sVAD insertion and subsequent cardiac transplantation. Support with VAD clearly facilitates survival on the waiting list during prolonged wait times and optimizes outcomes after Norwood (Stage 1) by providing an alternative pathway for extremely high-risk patients. Therefore, the selective utilization of sVAD in extremely high-risk neonates facilitates improved outcomes for all patients with functionally univentricular ductal-dependent circulation. At University of Florida, our programmatic approach to utilizing sVAD support as a bridge to transplantation in the minority of neonates with functionally univentricular circulation who are extremely high-risk for staged palliation is associated with Operative Mortality after Norwood (Stage 1) Operation of 2.9% (2/68) and a one-year survival of 91.1% (82/90) for all neonates presenting with hypoplastic left heart syndrome (HLHS) or HLHS-related malformation with functionally univentricular ductal-dependent systemic circulation. Meanwhile, at University of Florida, for all 82 consecutive neonates, infants, and children supported with pulsatile paracorporeal VAD: Kaplan-Meier survival estimated one year after VAD insertion = 73.3% (95% confidence interval [CI] = 64.1-83.8%), and Kaplan-Meier survival estimated five years after VAD insertion = 68.3% (95% CI = 58.4-79.8%). For all 48 consecutive neonates, infants, and children at University of Florida with biventricular circulation supported with pulsatile paracorporeal VAD: Kaplan-Meier survival estimated one year after VAD insertion = 82.7% (95% CI = 72.4-94.4%), and Kaplan-Meier survival estimated five years after VAD insertion = 79.7% (95% CI = 68.6-92.6%). For all 34 consecutive neonates, infants, and children at University of Florida with functionally univentricular circulation supported with pulsatile paracorporeal sVAD: Kaplan-Meier survival estimated one year after VAD insertion = 59.7% (95% CI = 44.9-79.5%), and Kaplan-Meier survival estimated five years after VAD insertion = 50.5% (95% CI = 35.0-73.0%). These Kaplan-Meier survival estimates for patients supported with pulsatile paracorporeal VAD are better in patients with biventricular circulation in comparison to patients with functionally univentricular circulation both one year after VAD insertion (P=0.026) and five years after VAD insertion (P=0.010). Although outcomes after VAD support in functionally univentricular patients are worse than in patients with biventricular circulation, sVAD provides a reasonable chance for survival. Ongoing research is necessary to improve the outcomes of these challenging patients, with the goal of developing strategies where outcomes after sVAD support in functionally univentricular patients are equivalent to the outcomes achieved after VAD support in patients with biventricular circulation.