Impact of prolonged ischemic time on pediatric heart transplantation outcomes: Improved outcomes in the most recent era.

BACKGROUND: Impacts of ischemic time (IT) on pediatric heart transplant outcomes are multifactorial. We aimed to analyze the effect of prolonged IT on graft loss after pediatric heart transplantation. We hypothesized that graft survival with prolonged IT has improved across eras. METHODS: Patients <18 years old in the Pediatric Heart Transplant Society database were included (N=6,765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, retransplant, or need for mechanical circulatory support in the first 7 days post-transplant. Descriptive statistical methods were used to compare differences between patient characteristics and IT. Kaplan-Meier survival analysis compared freedom from graft loss, rejection, and infection. Multivariable analysis was performed for graft loss and SGF (hazard and logistic regression modeling, respectively). RESULTS: Diagnoses were cardiomyopathy (N = 3,246) and congenital heart disease (CHD; N = 3,305). CHD were younger, more likely to have an IT ≥4.5 hours, and more likely to require extracorporeal membrane oxygenation or mechanical ventilation at transplant (all p < 0.001). Median IT was 3.6 hours (interquartile range 2.98-4.31; range 0-10.5). IT was associated with early graft loss (HR 1.012, 95% CI 1.005-1.019), but not when analyzed only in the most recent era. IT was associated with SGF (OR 1.016 95%CI 1.003-1.030). CONCLUSIONS: Donor IT was independently associated with an increased risk of graft loss, albeit with a small effect relative to other risk factors. Graft survival with prolonged IT has improved in the most recent era but the risk of SGF persists.

Three decades of collaboration through the Pediatric Heart Transplant Society Registry: A journey through registry data with a highlight on children with single ventricle anatomy.

BACKGROUND: The Pediatric Heart Transplant Society (PHTS) Registry was founded 30 years ago as a collaborative effort among like-minded providers of this novel life-saving technique for children with end-stage heart failure. In the intervening decades, the data from the Registry have provided invaluable knowledge to the field of pediatric heart transplantation. This report of the PHTS Registry provides a comprehensive look at the data, highlighting both the longevity of the registry and one unique aspect of the PHTS registry, allowing for exploration into children with single ventricle anatomy. METHODS: The PHTS database was queried from January 1, 1993 to December 31, 2019 to include pediatric (age < 18 years) patients listed for HT. For our analysis, we primarily analyzed patients by era. The early era was defined as children listed for HT from January 1, 1993 to December 31, 2004; middle era January 1, 2005 to December 31, 2009; and recent era January 1, 2010 to December 31, 2019. Outcomes after listing and transplant, including mortality and morbidities, are presented as unadjusted for risk, but compared across eras. RESULTS: Since 1993, 11 995 children were listed for heart transplant and entered into the PHTS Registry with 9755 listed during the study period. The majority of listings occurred within the most recent era. Waitlist survival improved over the decades as did posttransplant survival. Other notable changes over time include fewer patients experiencing allograft rejection or infection after transplant. Waitlist and posttransplant survival have changed dramatically in patients with single ventricle physiology and significantly differ by stage of single ventricle palliation. SUMMARY: Key points from this PHTS Registry summary and focus on patients with single ventricle congenital heart disease in particular, include the changing landscape of candidates and recipients awaiting heart transplant. There is clear improvement in waitlist and transplant outcomes for children with both cardiomyopathy and congenital heart disease alike.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database.

BACKGROUND: Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) on the basis of relative and absolute contraindications to transplantation. Multiple factors may lead to changes in the strategy of support after LVAD implantation. METHODS: Based on INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020 data, 11,262 patients survived to 3 months on continuous-flow LVADs with intent of BTT or DT. Preimplant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months. RESULTS: Among 3216 BTT patients at 3 months, later transplant delisting or death without transplant occurred in 536 (16.7%) and was more common with age, profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51; P = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure as defined by inotropic therapy, predicted delisting and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33; P = 0.0024). Of 8046 patients surviving to 3 months with the intent of destination therapy, 750 (9.3%) subsequently underwent listing or transplantation, often with initial histories of acute HF (HR 1.70, 95% CI 1.27-2.27; P = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63; P = 0.0099). Multiple gastrointestinal bleeding events (≥ 4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275; P = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9; P = 0.0011). CONCLUSIONS: Implant strategies change over time in relation to preimplant characteristics and adverse events post implant. Preimplant recognition of factors predicting later change in implant strategy will refine initial triage, whereas further reduction of post-LVAD complications will expand options, including eventual consideration of heart transplantation.

Seventh Annual Society of Thoracic Surgeons Pedimacs Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs), supported by The Society of Thoracic Surgeons, provides detailed information on pediatric patients supported with ventricular assist devices (VADs). METHODS: From September 19, 2012, to December 31, 2022, 1463 devices in 1219 patients aged <19 years were reported to the registry from 40 North American hospitals. RESULTS: Cardiomyopathy remains the most common underlying etiology (59%), followed by congenital heart disease (26%) and myocarditis (8%). Implantable continuous devices were most common (39%) type, followed by paracorporeal pulsatile (28%) and paracorporeal continuous (27%) devices. At 6 months after VAD implantation, a favorable outcome (transplant, recovery, or alive on device) was achieved in 85% of patients, which was greatest among those on implantable continuous VADs (92%) and least for paracorporeal continuous VADs (68%), although the patient population supported on these devices is different. CONCLUSIONS: This Seventh Pedimacs Report demonstrates the continued importance of VADs in the treatment of children. With the complexity of cardiac physiologies and sizes of patients, multiple types of devices are used, including paracorporeal continuous, paracorporeal pulsatile, and implantable continuous devices. The preoperative risk factors and differences in patient populations may account for some of the differences in survival observed among these devices. This report, along with other collaborative work, continues to advance the care of this challenging and vulnerable population.

Risk factors for 1-year allograft loss in pediatric heart transplant patients using machine learning: An analysis of the pediatric heart transplant society database.

BACKGROUND: Pediatric heart transplant patients are at greatest risk of allograft loss in the first year. We assessed whether machine learning could improve 1-year risk assessment using the Pediatric Heart Transplant Society database. METHODS: Patients transplanted from 2010 to 2019 were included. The primary outcome was 1-year graft loss free survival. We developed a prediction model using cross-validation, by comparing Cox regression, gradient boosting, and random forests. The modeling strategy with the best discrimination and calibration was applied to fit a final prediction model. We used Shapley additive explanation (SHAP) values to perform variable selection and to estimate effect sizes and importance of individual variables when interpreting the final prediction model. RESULTS: Cumulative incidence of graft loss or mortality was 7.6%. Random forests had favorable discrimination and calibration compared to Cox proportional hazards with a C-statistic (95% confidence interval [CI]) of 0.74 (0.72, 0.76) versus 0.71 (0.69, 0.73), and closer alignment between predicted and observed risk. SHAP values computed using the final prediction model indicated that the diagnosis of congenital heart disease (CHD) increased 1 year predicted risk of graft loss by 1.7 (i.e., from 7.6% to 9.3%), need for mechanical circulatory support increased predicted risk by 2, and single ventricle CHD increased predicted risk by 1.9. These three predictors, respectively, were also estimated to be the most important among the 15 predictors in the final model. CONCLUSIONS: Risk prediction models used to facilitate patient selection for pediatric heart transplant can be improved without loss of interpretability using machine learning.

Survival in Pediatric Patients With Ventricular Assist Devices: A Special Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) provides detailed understanding on pediatric patients supported with ventricular assist devices (VADs). We sought to identify important variables affecting mortality in pediatric VADs. METHODS: Patients aged <19 years, from 2012 to 2021, were included. Survival analyses were performed using Kaplan-Meier. Parametric hazard modeling was used to identify risk factors for death. RESULTS: Of the 1109 patients, the most common devices were implantable continuous (IC, 448 [40%]), followed by paracorporeal pulsatile (PP, 306 [28%]), paracorporeal continuous (PC, 293 [26%]), and percutaneous (58 [5%]). Patients with percutaneous device, infants, congenital heart disease, biventricular support, and Interagency Registry for Mechanically Assisted Circulatory Support profile 1 had worse overall survival at 6 months. Positive outcome was 83% at 6 months. Consistent with their cohort composition, device type positive outcomes at 6 months were IC, 92%; PP, 84%; and PC, 69%. Parametric hazard modeling for overall survival showed an early hazard for death with biventricular support, congenital heart disease (CHD), intubation before implantation, PC device, and renal impairment, whereas a constant hazard was associated with ascites. For patients <10 kg, parametric modeling showed an early hazard for CHD, intubation, and renal impairment. Modeling in CHD patients showed an early hazard for biventricular support, renal impairment, and use of PC/PP devices. CONCLUSIONS: This multivariable analysis of the complete Pedimacs database demonstrates that illness at VAD implantation, diagnosis, and strategy of support affect survival and differ by device type. We hope this is the first step in creating a predictive tool to help providers and families have informed expectations.

Prospective examination of HLA sensitization after VAD implantation in children and adults.

BACKGROUND: Ventricular assist devices (VADs) have improved survival to heart transplantation (HTx). However, VADs have been associated with development of antibodies against human leukocyte antigen (HLA-Ab) which may limit the donor pool and decrease survival post-HTx. Since HLA-Ab development after VAD insertion is poorly understood, the purpose of this prospective single-center study was to quantify the incidence of and evaluate risk factors for HLA-Ab development across the age spectrum following VAD implantation. METHODS: Adult and pediatric patients undergoing VAD placement as bridge to transplant or transplant candidacy between 5/2016 and 7/2020 were enrolled. HLA-Ab were assessed pre-VAD and at 1-, 3-, and 12-months post-implant. Factors associated with HLA-Ab development post-VAD implant were explored using univariate and multivariate logistic regression. RESULTS: 15/41 (37%) adults and 7/17 (41%) children developed new HLA-Ab post-VAD. The majority of patients (19/22) developed HLA-Ab within two months of implant. New class I HLA-Ab were more common (87% adult, 86% pediatric). Prior pregnancy was strongly associated with HLA-Ab development in adults post-VAD (HR 16.7, 95% CI 1.8-158, p = 0.01). Of the patients who developed new HLA-Ab post-VAD, in 45% (10/22) the HLA-Ab resolved while in 55% (12/22) the HLA-Ab persisted. CONCLUSION: More than one-third of adult and pediatric VAD patients developed new HLA-Ab early after VAD implant with the majority having class I antibodies. Prior pregnancy was strongly associated with post-VAD HLA-Ab development. Further studies are needed to predict regression or persistence of HLA-Ab developed post-VAD, to understand modulation of individuals' immune responses to sensitizing events, and to determine whether transiently detected HLA-Ab post-VAD recur and have long-term clinical impact post-heart transplantation.

The impact of obesity and LVAD-bridging on heart transplant candidate outcomes: a linked STS INTERMACS - OPTN/UNOS data analysis.

BACKGROUND: Limited data integrating waitlist and postheart transplant (HT) mortality have evaluated outcomes of left ventricular assist device (LVAD)-bridged strategy vs no LVAD according to patient characteristics. We evaluated waitlist and post-HT mortality in LVAD-bridged vs nonbridged patients based on body mass index (BMI). METHODS: We included linked adults listed for HT in Organ Procurement and Transplant Network/United Network for Organ Sharing and patients receiving durable LVAD as bridge to HT or candidacy in Society of Thoracic Surgeons/Interagency Mechanical Circulatory Support databases (2010-2019). Using BMI at listing or LVAD implant, we categorized patients as underweight (<18.5 kg/m2), normal weight (18.5-24.99 kg/m2), overweight (25-29.99 kg/m2), and obese (≥30 kg/m2). Kaplan-Meier analysis and multivariable Cox proportional hazards models informed the effect of LVAD-bridged and nonbridged strategy by BMI on waitlist, post-HT, and overall mortality (including waitlist and post-HT mortality). RESULTS: Among 11,216 LVAD-bridged and 17,122 nonbridged candidates, bridged candidates were more frequently obese (37.3% vs 28.6%) (p < 0.001). Multivariable analysis indicated increased waitlist mortality in LVAD-bridged vs nonbridged with overweight (Hazard ratio (HR) 1.18, 95% confidence interval (CI) 1.02-1.36) or obesity (HR 1.35, 95%CI 1.17-1.56) in comparison to normal weight candidates (HR 1.02, 95%CI 0.88-1.19) (p-interaction < 0.001). Post-transplant mortality was not statistically different in LVAD-bridged vs nonbridged patients across BMI categories (p-interaction = 0.26). There was a nonsignificant graded increase in overall mortality in LVAD-bridged with overweight (HR 1.53, 95%CI 1.39-1.68) or obesity (HR 1.61, 95%CI 1.46-1.78) compared to nonbridged patients (p-interaction = 0.13). CONCLUSIONS: LVAD-bridged candidates with obesity had higher waitlist mortality compared to nonbridged candidates with obesity. Post-transplant mortality was similar in LVAD-bridged and nonbridged patients, but obesity remained associated with increased mortality in both groups. This study may aid clinicians and advanced heart failure patients with obesity in decision-making.

Impact of adverse events on health-related quality of life after left ventricular assist device implantation: An STS INTERMACS analysis.

BACKGROUND: We sought to quantify the impact of pre- and postoperative variables on health-related quality of life (HRQOL) after left ventricular assist device (LVAD) implantation. METHODS: Primary durable LVAD implants between 2012 and 2019 in the Interagency Registry for Mechanically Assisted Circulatory Support were identified. Multivariable modeling using general linear models assessed the impact of baseline characteristics and postimplant adverse events (AEs) on HRQOL as assessed by the EQ-5D visual analog scale (VAS) and the Kansas City Cardiomyopathy Questionnaire-12 (KCCQ) at 6 months and 3 years. RESULTS: Of 22,230 patients, 9,888 had VAS and 10,552 had KCCQ reported at 6 months, and 2,170 patients had VAS and 2,355 had KCCQ reported at 3 years postimplant. VAS improved from a mean of 38.2 ± 28.3 to 70.7 ± 22.9 at 6 months and from 40.1 ± 27.8 to 70.3 ± 23.1 at 3 years. KCCQ improved from 28.2 ± 23.9 to 64.3 ± 23.2 at 6 months and from 29.8 ± 23.7 to 63.0 ± 23.7 at 3 years. Preimplant variables, including baseline VAS, had small effect sizes on HRQOL while postimplant AEs had large negative effect sizes. Recent stroke, respiratory failure, and renal dysfunction had the largest negative effect on HRQOL at 6 months, while recent renal dysfunction, respiratory failure, and infection had the largest negative effect at 3 years. CONCLUSIONS: AEs following LVAD implantation have large negative effects on HRQOL in early and late follow-up. Understanding the impact of AEs on HRQOL may assist shared decision-making regarding LVAD eligibility. Continued efforts to reduce post-LVAD AEs are warranted to improve HRQOL in addition to survival.

Timing and Outcomes of Concurrent and Sequential Biventricular Assist Device Implantation: A Society of Thoracic Surgeons Intermacs Analysis.

BACKGROUND: Biventricular heart failure remains a clinically challenging condition to manage. Available literature describing the use of durable biventricular assist device (BiVAD) support has numerous limitations hindering the development of useful treatment algorithms. Analysis of BiVAD use within a large multicenter data set is needed to clarify outcomes associated with this therapy. METHODS: The Society of Thoracic Surgeons Intermacs database was queried to identify adults aged ≥18 years who received durable circulatory support from January 1, 2010, to December 31, 2220. The data set was divided into the following cohorts: (1) left ventricular assist device (LVAD) only (n = 27,325), (2) LVAD and concurrent right ventricular assist device (RVAD) (n = 1090), and (3) LVAD and sequential RVAD (n = 556). Propensity score matching was used to compare 1-year mortality and adverse events between concurrent (n = 565) and sequential BiVADs (n = 565). RESULTS: Overall survival within 1 year was significantly worse for the BiVAD cohort compared with the LVAD-only cohort (12-month survival: 50.8% vs 82.6%; log-rank P < .001). In a propensity-matched cohort, patients implanted with a BiVAD concurrently had an improved survival compared with those implanted an LVAD and an RVAD sequentially (12-month survival: 55.8% vs 41.8%; log-rank P < .001). Early (<3 months) adverse event rates were higher among patients receiving sequential BiVADs for bleeding, infection, neurologic dysfunction, and renal dysfunction (P < .01). CONCLUSIONS: After matching for patient and disease characteristics, patients with sequential BiVAD implantation have worse outcomes than patients with concurrent BiVAD implantation.

Impact of race and health coverage on listing and waitlist mortality in pediatric cardiac transplantation.

BACKGROUND: Social factors like race and insurance affect transplant outcomes. However, little is known in pediatric heart transplantation. We hypothesized that race and insurance coverage impact listing and waitlist outcomes across eras. METHODS: Data from the Pediatric Heart Transplant Society multi-center registry prospectively collected between January 1, 2000-December 31, 2019 were analyzed. Patients were divided by race as Black, White and other and by insurance coverage at listing (US governmental, US private and non-US single payer systems (UK, Canada). Clinical condition at listing and waitlist outcomes were compared across races and insurance coverages. Categorical variables were compared using a chi-square test and continuous variables using the Wilcoxon rank sum test. Risk factors for waitlist mortality were examined using multiphase parametric hazard modeling. A sensitivity analysis using parametric hazard explored the interaction between race and insurance. RESULTS: At listing, compared to Whites (n = 5391) and others (n = 1167), Black patients (n = 1428) were older, more likely on US governmental insurance and had cardiomyopathy as the predominant diagnosis (p < 0.0001). Black patients were more likely to be higher status at listing, in hospital, on inotropes or a ventricular assist device (p < 0.0001). Black patients had significantly shorter time on the waitlist compared to other races (p < 0.0001) but had higher waitlist mortality (p = 0.0091), driven by the earlier era (2000-2009) (p = 0.0005), most prominently within the US private insurance cohort (p = 0.015). Outcomes were not different in other insurance cohorts or in the recent era (2010-2019). CONCLUSION: Black children are older and sicker at the time of listing, deteriorate more often and face a higher wait list mortality, despite a shorter waitlist period and favorable clinical factors, with improvement in the recent era associated with the recent US healthcare reforms. The social construct of race appears to disadvantage Black children by limiting referral, consideration or access to pediatric cardiac transplantation.

The Fontan immunophenotype and post-transplant outcomes in children: A multi-institutional study.

BACKGROUND: Patients after Fontan palliation represent a growing pediatric population requiring heart transplant (HTx) and often have lymphopenia (L) and/or hypogammaglobinemia that may be exacerbated by protein-losing enteropathy (PLE, P). The post-HTx effects of this altered immune phenotype are not well studied. METHODS: In this study of the Pediatric Heart Transplant Society Registry, 106 Fontan patients who underwent HTx between 2005 and 2018 were analyzed. The impact of lymphopenia and PLE on graft survival, infection, rejection, and malignancy was analyzed at 1 and 5 years post-HTx. RESULTS: The following combinations of lymphopenia and PLE were noted: +L+P, n = 37; +L-P, n = 23; -L+P, n = 10; and -L-P, n = 36. Graft survival between the groups was similar within the first year after transplant (+L+P: 86%, +L-P: 86%, -L+P: 87%, -L-P: 89%, p = .9). Freedom from first infection post-HTx was greatest among -L-P patients compared to patients with either PLE, lymphopenia, or both; with a 22.1% infection incidence in the -L-P group and 41.4% in all others. These patients had a significantly lower infection rate in the first year after HTx (+L+P: 1.03, +L-P: 1, -L+P: 1.3, -L-P: 0.3 infections/year, p < .001) and were similar to a non-single ventricle CHD control group (0.4 infections/year). Neither freedom from rejection nor freedom from malignancy 1 and 5 years post-HTx, differed among the groups. CONCLUSIONS: Fontan patients with altered immunophenotype, with lymphopenia and/or PLE, are at increased risk of infection post-HTx, although have similar early survival and freedom from rejection and malignancy. These data may encourage alternative immunosuppression strategies and enhanced monitoring for this growing subset of patients.

Early aspirin use and the development of cardiac allograft vasculopathy in pediatric heart transplant recipients: A pediatric heart transplant society analysis.

BACKGROUND: Cardiac allograft vasculopathy (CAV) remains a leading cause of graft loss in pediatric heart transplant (HTx) recipients. Adult literature suggests that aspirin (ASA) use in the early post-HTx period may reduce the risk of CAV. This study aimed to determine the impact of early ASA use on the development of CAV in pediatric HTx recipients. METHODS: All subjects <17 years of age at time of primary HTx who survived ≥3 years without evidence of CAV were identified for inclusion from the Pediatric Heart Transplant Society database (1996-2019). Early ASA use was defined as ASA started within the first 3 years post-HTx and was classified as continuous or intermittent. Frequency of ASA use was described across centers. Kaplan-Meier method assessed freedom from CAV and overall graft survival. Multiphase parametric hazard analyses and propensity score matched analysis were used to identify independent risk factors. RESULTS: 3,011 patients were included with 387 (13%) receiving continuous ASA, 676 (22%) receiving intermittent ASA, and 1,948 (65%) receiving no ASA. ASA use was highly variable across centers (0%-100%). At baseline patients receiving continuous ASA therapy demonstrated inferior graft survival (p < 0.001) and worse freedom from CAV (p = 0.002), but with lower CAV grades (p = 0.05). In multiphase parametric hazard modeling continuous ASA use was not independently associated with CAV, but remained associated with inferior graft survival. Propensity-matched sub-analysis between continuous and no ASA groups demonstrated no difference in freedom from CAV or overall graft loss. CONCLUSIONS: ASA use varies widely across pediatric HTx centers. Early ASA use did not reduce the risk of CAV or graft loss in pediatric heart transplant recipients.

Effect of preoperative extracorporeal membrane oxygenation therapy on postventricular assist device outcomes: an analysis of the STS Pedimacs database.

OBJECTIVES: Extracorporeal membrane oxygenation (ECMO) support prior to ventricular assist device (VAD) therapy is frequently used for stabilizing INTERMACS 1 and 2 paediatric patients. Data regarding outcomes with this strategy is limited. METHODS: Patient characteristics and outcomes post-VAD therapy with and without preop ECMO support were compared. Survival and risk factor analysis was performed for all patients and INTERMACS profile 1 subgroup. RESULTS: Of 541 INTERMACS 1 and 2 patients enrolled in Paediatric Interagency Registry for Mechanical Circulatory Support registry, 391 received primary VAD implantation and ECMO prior to VAD therapy was utilized in 150 patients. Younger age (P < 0.0001) and shock (P < 0.0001) were more common in group 2, with lower survival at 1, 6 and 12 months compared to group 1 (P < 0.0001). Freedom from infection (P = 0.03) was higher in group 1. Freedom from stroke (P = 0.7) was similar. Paracorporeal continuous flow devices led to poor survival in both groups 1 and 2 (P = 0.4). Implantable continuous flow (P < 0.0001) and paracorporeal pulsatile devices (P = 0.007) had better survival in primary VAD group. INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure, paracorporeal continuous and percutaneous devices were associated with higher mortality. Preop ECMO therapy was not associated with higher mortality (P = 0.12). Survival of INTERMACS profile 1 patient was similar at 1, 6 and 12 months in both groups (P = 0.1). CONCLUSIONS: INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure and use of paracorporeal continuous flow or percutaneous assist devices are associated with a higher postoperative mortality. Preop ECMO therapy however is not independently associated with higher postop mortality.

Right Heart Failure Following Left Ventricular Device Implantation: Natural History, Risk Factors, and Outcomes: An Analysis of the STS INTERMACS Database.

BACKGROUND: Our current understanding of right heart failure (RHF) post-left ventricular assist device (LVAD) is lacking. Recently, a new Interagency Registry for Mechanically Assisted Circulatory Support definition of RHF was introduced. Based on this definition, we investigated natural history, risk factors, and outcomes of post-LVAD RHF. METHODS: Patients implanted with continuous flow LVAD between June 2, 2014, and June 30, 2016 and registered in the Interagency Registry for Mechanically Assisted Circulatory Support/Society of Thoracic Surgeons Database were included. RHF incidence and predictors, and survival after RHF were assessed. The manifestations of RHF which were separately analyzed were elevated central venous pressure, peripheral edema, ascites, and use of inotropes. RESULTS: Among 5537 LVAD recipients (mean 57±13 years, 49% destination therapy, support 18.9 months) prevalence of 1-month RHF was 24%. Of these, RHF persisted at 12 months in 5.3%. In contrast, de novo RHF, first identified at 3 months, occurred in 5.1% and persisted at 12 months in 17% of these, and at 6 months occurred in 4.8% and persisted at 12 months in 25%. Higher preimplant blood urea nitrogen (ORs,1.03-1.09 per 5 mg/dL increase; P<0.0001), previous tricuspid valve repair/replacement (ORs, 2.01-10.09; P<0.001), severely depressed right ventricular systolic function (ORs,1.17-2.20; P=0.004); and centrifugal versus axial LVAD (ORs,1.15-1.78; P=0.001) represented risk factors for RHC incidence at 3 months. Patients with persistent RHF at 3 months had the lowest 2-year survival (57%) while patients with de novo RHF or RHF which resolved by 3 months had more favorable survival outcomes (75% and 78% at 2 years, respectively; P<0.001). CONCLUSIONS: RHF at 1 or 3 months post-LVAD was a common and frequently transient condition, which, if resolved, was associated with relatively favorable prognosis. Conversely, de novo, late RHF post-LVAD (>6 months) was more frequently a persistent disorder and associated with increased mortality. The 1-, 3-, and 6-month time points may be used for RHF assessment and risk stratification in LVAD recipients.

Twelfth Interagency Registry for Mechanically Assisted Circulatory Support Report: Readmissions After Left Ventricular Assist Device.

The twelfth annual report from The Society of Thoracic Surgeons (STS) Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) highlights outcomes for 26 688 continuous-flow left ventricular assist device (LVAD) patients over the past decade (2011-2020). In 2020, we observed the largest drop in yearly LVAD implant volumes since the registry's inception, which reflects the effects of the COVID-19 pandemic on cardiac surgical volumes in the United States. The 2018 heart transplant allocation policy change in the United States continues to affect LVAD implantation volumes and device strategy, with 78.1% of patients now receiving LVAD implants as destination therapy. Despite an older and sicker patient cohort, survival in the recent era (2016-2020) at 1 and 2 years continues to improve at 82.8% and 74.1%. Patient adverse event profile has also improved in the recent era, with significant reductions in stroke, gastrointestinal bleeding, infection, and device malfunction/pump thrombosis. Finally, we review the burden of readmissions after LVAD implant and highlight an opportunity to improve patient outcomes by reducing this frequent and vexing problem.

HVAD to Heartmate 3 Device Exchange: A Society of Thoracic Surgeons Intermacs Analysis.

BACKGROUND: On June 3, 2021 Medtronic, Inc announced discontinuation of the HVAD left ventricular assist device. The purpose of this analysis was to provide summary data on surgical risks of HVAD to HeartMate 3 exchange and compare survival after HVAD to HeartMate 3 exchange to survival after primary HVAD implantation. METHODS: Three cohorts within The Society of Thoracic Surgeons Intermacs database were identified: primary HVAD implant cohort (January 2017 to March 2021, n = 3797), HVAD to HeartMate 3 exchange cohort (December 2017 to March 2021, n = 45), and HVAD to HVAD exchange cohort (January 2017 to March 2021, n = 234). Mortality after HVAD to HeartMate 3 exchange was modeled and compared with the constant hazard phase for risk of mortality while on continued HVAD support. As a secondary analysis outcomes and survival were compared between patients who underwent HVAD to HeartMate 3 and HVAD to HVAD exchange. RESULTS: HVAD to HeartMate 3 exchange was associated with significantly reduced survival compared with survival while remaining on HVAD support (6 months after exchange, 73.8% [70% confidence interval, 68.6-77.8] vs 79.0% [70% confidence interval, 78.3-79] for continued HVAD support). Compared with HVAD to HVAD exchange, survival was higher after replacement with HeartMate 3 (1 year: 85.9% [70% confidence interval, 79.5-90.5] vs 66.6% [70% confidence interval, 63.0-70.0], P = .009). CONCLUSIONS: Compared with continued support on HVAD, an exchange to HeartMate 3 was found to be associated with a significant increase in mortality. For patients who required pump exchange on HVAD support, exchange to HeartMate 3 demonstrated superior survival. Currently there is insufficient evidence to support elective exchange from an HVAD to HeartMate 3.

Generalizability of Trial Data to Real-World Practice: An Analysis of The Society of Thoracic Surgeons Intermacs Database.

BACKGROUND: Although the current wide-scale adoption of the HeartMate 3 left ventricular assist device can be attributed to favorable clinical trial outcomes, restrictive clinical trial eligibility criteria may result in lack of generalizability to real-world populations. We assessed the generalizability of left ventricular assist device clinical trial outcomes and evaluated the prognostic value of specific inclusion and exclusion criteria. METHODS: The Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Therapy With HeartMate 3 (MOMENTUM 3) eligibility criteria were applied to patients identified in The Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) who underwent HeartMate 3 implantation (n = 4610) between August 2017 and March 2020. Patients were categorized as trial-eligible or trial-ineligible and by number of ineligibility criteria. The effect of trial eligibility on mortality was estimated using Cox models. RESULTS: Indications for HeartMate 3 implant included destination therapy (n = 2827, 61%), bridge to candidacy (n = 969, 21%), and bridge to transplant (n = 702, 15%). A total of 1941 recipients (42%) were trial-ineligible, with 1245 (27%) meeting one ineligibility criterion, 470 (10%) meeting two, and 226 (5%) meeting three or more. Estimated 1-year mortality for trial-ineligible recipients was higher than for trial-eligible recipients (17% ± 1% vs 10% ± 1%, P < .001). Compared with trial-eligible patients, 1-year mortality was incrementally higher for patients meeting one ineligibility criterion (15% ± 1%), two criteria (16% ± 2%), and three or more criteria (30% ± 3%). Thrombocytopenia and elevated creatinine, bilirubin, and international normalized ratio in trial-ineligible patients were independently associated with increased mortality. CONCLUSIONS: Despite differences in mortality, both trial-eligible and trial-ineligible HeartMate 3 recipients had excellent outcomes in real-world practice, suggesting future trial eligibility criteria could be expanded.

The Effect of Infectious Complications During Ventricular Assist Device Use on Outcomes of Pediatric Heart Transplantation.

To describe the impact of infectious adverse events (IAEs) during ventricular assist device (VAD) support on graft loss, infection, and rejection after pediatric heart transplant (HT). Pedimacs data were linked to Pediatric Heart Transplant Society (PHTS) data for patients receiving a VAD followed by HT between September 2012 and December 2016. Linked patients were categorized into IAE on VAD (group A) and no IAE on VAD (group B). Infectious adverse event locations included nondevice, device (external or internal), and sepsis. Post-HT outcomes for analysis were graft loss, infection, and rejection. Time-dependent analysis included Kaplan-Meier and multiphase parametric hazard function analysis. We linked 207 patients (age 9.4 ± 6.3 years). Post-HT follow-up was 19.4 patient-months (<8 days-4.1 years). Group A included 42 patients (20%) with 62 IAEs. Group B included 165 patients without an IAE. Group A patients were younger (7.4 ± 6.1 vs. 9.5 ± 6.3 years; p = 0.03), waited longer for HT (5.3 ± 4.1 vs. 2.9 ± 2.5 months; p = 0.0005), and were hospitalized longer post-HT (42 ± 59 vs. 23 ± 22 days; p = 0.05). VAD-related IAEs were rare (N = 11). Groups A and B had similar freedom from first post-HT infection, rejection, and graft loss (all p > 0.1). However, patients with VAD-related IAE were somewhat more likely to experience rejection (p = 0.03) and graft loss (p = 0.01). Children with an IAE on VAD who survive to HT are younger, wait longer for HT, and remain hospitalized longer than those without an IAE on VAD. Overall, IAE on VAD did not impact post-HT outcomes, but VAD-related IAE may be associated with graft loss and rejection.

STS INTERMACS Database: The Key to Conduct Single-Arm Trials in Advanced Heart Failure Patients.

BACKGROUND: Safe introduction of novel mechanical circulatory support (MCS) devices into clinical practice is a challenging process. Single-arm trials using a control arm from existing database is an effective alternative that could be applied for regulatory approval. This study analyzes the capability of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to establish objective performance criteria and select patient population that could be used for future single-arm MCS trials. METHODS: Patients with INTERMACS profiles IM1-2 and IM3-5, who underwent implantation of isolated left ventricular assist devices between 2014 and 2017, were included. Both cohorts were further stratified into shock and nonshock groups using surrogate markers of shock (extracorporeal membrane oxygenation, temporary ventricular assist device, vasopressor infusions). Survival, transplantation rates, adverse events, 6-minute walk test, and quality-of-life measures were obtained for all 4 groups at 6 and 12 months. RESULTS: Total of 7907 patients were divided into IM1-2 (n = 3909), IM3-5 (n = 3998), shock (n = 3469), and nonshock (n = 3040) groups. Recategorization occurred in 11% of patients from the IM3-5 group into the shock group. Overall, patients in the shock group had similar outcomes to the IM1-2 group (1-year survival: 86% vs 85%; P = .74). Patients in the nonshock group also had similar outcomes to the IM3-5 (1-year survival: 90% vs 90%; P = .43). CONCLUSIONS: The INTERMACS database can successfully establish objective performance criteria and concurrent control group for single-arm trials that could be used to support regulatory approval of new, less invasive MCS. INTERMACS data allow reliable comparisons of outcomes and adverse events.