State-Level Variation in Waitlist Mortality and Transplant Outcomes Among Patients Listed for Heart Transplantation in the US From 2011 to 2016

Risk and Reward: Nationwide Analysis of Cardiac Transplant Center Variation in Organ Travel Distance and the Effects on Outcomes

BACKGROUND

The 2018 UNOS allocation policy change deprioritized geographic boundaries to organ distribution, and the effects of this change have been widespread. The aim of this investigation was to analyze changes in donor transplant center distance for organ travel and corresponding outcomes before and after the allocation policy change.

METHODS

The UNOS database was utilized to identify all adult patients waitlisted for heart transplants from 2016 to 2021. Transplant centers were grouped by average donor heart travel distance based on whether they received more or less than 50% of organs from >250 miles away. Descriptive statistics were provided for waitlisted and transplanted patients. Regression analyses modeled waitlist mortality, incidence of transplant, overall survival, and graft survival.

RESULTS

Centers with a longer average travel distance had a higher mean annual transplant volume with a reduction in total days on a waitlist (86.6 vs. 149.2 days), an increased cold ischemic time (3.6 vs. 3.2 h), with no significant difference in post-transplant overall survival or graft survival.

CONCLUSIONS

The benefits of reducing waitlist time while preserving post-transplant outcomes extend broadly. The trends observed in this investigation will be useful as we revise organ transplant policy in the era of new organ procurement and preservation techniques.

Association of Heart Transplant Volume with Presence of Lung Transplant Programs and Heart Transplant's SRTR One-year Survival Rating

BACKGROUND

 Several factors affect heart transplant (HTx) and lung transplant (LTx) program outcomes. Variabilities in institutional and community characteristics have been shown to influence survival. At present, half of HTx centers in the United States do not possess a concomitant LTx program. This study sought to better understand the characteristics of HTx with and without LTx programs.

METHODS

 Nationwide transplant data were collected from the Scientific Registry of Transplant Recipients (SRTR) in August 2020. SRTR star rating ranges from tier 1 (lowest) to tier 5 (highest). HTx volumes and SRTR star ratings for survival were compared between the centers with heart-only (H0) programs and the centers with heart-lung (HL) programs.

RESULTS

 SRTR star ratings were available for 117 transplant centers with one or more HTx reported. The median number of HTx performed over 1 year was 16 (interquartile range [IQR]: 2-29). The number of HL centers (n = 67, 57.3%) were comparable to H0 centers (n = 50, 42.7%; p = 0.14). The HTx volume at the HL centers (28 [IQR: 17-41]) exceeded the HTx volume at the H0 centers (13 [IQR: 9-23]; p < 0.01), but were comparable to the LTx volume at the HL centers (31 [IQR: 16-46]; p = 0.25). The median HTx one-year survival rating was 3 (IQR: 2-4) at both the H0 and HL centers (p = 0.85). The HTx and LTx volumes were positively associated with the respective 1-year survivals (p < 0.01).

CONCLUSION

 While the presence of an LTx program is not directly associated with HTx survival, it has a positive association with the HTx volume. The HTx and LTx volumes are positively associated with the 1-year survival.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Development and Validation of a Risk Score Predicting Death Without Transplant in Adult Heart Transplant Candidates

Importance

The US heart allocation system prioritizes medically urgent candidates with a high risk of dying without transplant. The current therapy-based 6-status system is susceptible to manipulation and has limited rank ordering ability.

Objective

To develop and validate a candidate risk score that incorporates current clinical, laboratory, and hemodynamic data.

Design, Setting, and Participants

A registry-based observational study of adult heart transplant candidates (aged ≥18 years) from the US heart allocation system listed between January 1, 2019, and December 31, 2022, split by center into training (70%) and test (30%) datasets. Adult candidates were listed between January 1, 2019, and December 31, 2022.

Main Outcomes and Measures

A US candidate risk score (US-CRS) model was developed by adding a predefined set of predictors to the current French Candidate Risk Score (French-CRS) model. Sensitivity analyses were performed, which included intra-aortic balloon pumps (IABP) and percutaneous ventricular assist devices (VAD) in the definition of short-term mechanical circulatory support (MCS) for the US-CRS. Performance of the US-CRS model, French-CRS model, and 6-status model in the test dataset was evaluated by time-dependent area under the receiver operating characteristic curve (AUC) for death without transplant within 6 weeks and overall survival concordance (c-index) with integrated AUC.

Results

A total of 16 905 adult heart transplant candidates were listed (mean [SD] age, 53 [13] years; 73% male; 58% White); 796 patients (4.7%) died without a transplant. The final US-CRS contained time-varying short-term MCS (ventricular assist-extracorporeal membrane oxygenation or temporary surgical VAD), the log of bilirubin, estimated glomerular filtration rate, the log of B-type natriuretic peptide, albumin, sodium, and durable left ventricular assist device. In the test dataset, the AUC for death within 6 weeks of listing for the US-CRS model was 0.79 (95% CI, 0.75-0.83), for the French-CRS model was 0.72 (95% CI, 0.67-0.76), and 6-status model was 0.68 (95% CI, 0.62-0.73). Overall c-index for the US-CRS model was 0.76 (95% CI, 0.73-0.80), for the French-CRS model was 0.69 (95% CI, 0.65-0.73), and 6-status model was 0.67 (95% CI, 0.63-0.71). Classifying IABP and percutaneous VAD as short-term MCS reduced the effect size by 54%.

Conclusions and Relevance

In this registry-based study of US heart transplant candidates, a continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation.

Heart Transplant Waitlist Outcomes and Wait Time by Center Volume in the Pre-2018 Allocation Change Era

Although the transplant outcomes of centers are heavily monitored and compared, with a particular link between posttransplant outcomes and center volume demonstrated, little data exist comparing waitlist outcomes. Here, we explored waitlist outcomes by transplant center volume. We performed a retrospective analysis of adults listed for primary heart transplantation (HTx) from 2008 to 2018 using the United Network for Organ Sharing database. Transplant centers were split into low (<10 HTx/year), medium (10-30 HTx/year), and high (>30 HTx/year) volume, and waitlist outcomes were compared. Of the 35,190 patients included in our study, 23,726 (67.4%) underwent HTx, 4,915 (14.0%) died or deteriorated before receiving HTx, 1,356 (3.9%) were delisted due to recovery, and 1,336 (3.8%) underwent left ventricular assist device (LVAD) implantation. High-volume centers had higher rates of survival to transplant (71.3% vs. 60.6% for low-volume centers and 64.9% for medium-volume centers), and low rates of death or deterioration (12.6% vs. 14.6% for low-volume centers and 15.1% for medium-volume centers). Listing at a low-volume center was independently associated with death or delisting before HTx (HR 1.18, p = 0.007), whereas listing at a high-volume center (HR 0.86; p < 0.001) and prelisting LVAD (HR 0.67, p < 0.001) were protective. Death or delisting before HTx was lowest for patients listed in higher volume centers.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Impact of donation after circulatory death heart transplantation on waitlist outcomes and transplantation activity

INTRODUCTION

Donation after circulatory death (DCD) heart transplantation has been shown to have comparable outcomes to transplantation using brain death donors (DBDs). This study evaluates the impact of this alternative source of allografts on waitlist mortality and transplant volume.

METHODS

We compared waitlist mortality and transplant rates in patients who were registered before (2019 period) and after we adopted DCD heart transplantation (2021 period).

RESULTS

We identified 111 patients who were on the waiting list in 2019 and 77 patients who were registered during 2021. Total number of donor organ offers received in 2019 was 385 (178 unique donors) versus 3450 (1145 unique donors) in 2021. More than 40% of all donors in 2021 were DCDs. Waitlist mortality was comparable for patients in 2019 and 2021 (18/100 person-years in 2019 vs. 26/100 person-years in 2021, p = .49). The transplant rate was 67/100 person-years in 2019 versus 207/100 person-years in 2021 (p < .001). After adjusting for acuity status, gender, blood type, and weight, patients listed in 2021 had 2.08 times greater chance of transplantation compared to patients listed in 2019 (HR 2.08, 95% confidence interval [CI] 1.26-3.45, p = .004).

CONCLUSIONS

Use of DCD donor hearts significantly increased heart transplant rate in our institution.

Prognostic implications of inactive status in highest urgency categories among heart transplantation recipients in the new donor heart allocation system

BACKGROUND

Patients on the waiting list for heart transplantation (HT) can become inactive or made status seven because of medical reasons, such adverse events, complications, or psychosocial circumstances. If the condition that caused the inactivation is resolved, patients are re- activated. Information about the prognostic implications of Status 7 in the new donor heart allocation system has not been described. To bridge this knowledge gap, we performed an analysis of the United Network of Organ Sharing (UNOS) registry.

METHODS

Data on adult patients who underwent HT between October 18th, 2018 and October 2021, were queried from the UNOS registry. The main outcomes were post- transplant all-cause mortality, 1-year all-cause mortality and treated acute rejection. Since re-transplantation is a competing event for all-cause mortality, we performed competing risk survival analysis and reported sub distribution hazard ratios (SHR) from the Fine and Gray model to examine the relationship between inactive status and all-cause mortality.

RESULTS

A total of 5267 adult patients underwent HT and were previously listed as Status 1 or Status 2 in the new allocation system. We identified 946 HT recipients temporarily inactivated while on HT list (18%). The number of temporarily inactive patients remained stable since the implementation of the new donor allocation system (p = .37). Approximately, two-thirds of temporarily inactive patients (65.9%) were inactivated for being too sick, whereas other frequent justifications for inactivity included left ventricular assist device implantation (7.8%) and insurance related issues (4.8%). Temporarily inactive HT recipients were more likely to be African Americans, males, have a higher body mass index (BMI) and significantly longer waiting time (391.6 ± 600 vs. 72.3 ± 223 days, p < .001) compared with never inactivated patients. In the unadjusted analyses 30-day mortality did not differ between groups, but both 1-year and overall all-cause mortality was significantly higher in temporarily inactive patients (1-year: SHR: 1.3; 95% confidence intervals [CI]: 1.03, 1.64; p = .028, overall mortality SHR: 1.31; 95% CI: 1.06, 1.64; p = .014). After adjustment for donor and recipient characteristics, a trend towards higher 1-year and overall mortality remained (1-year: SHR 1.32; 95% CI .99, 1.76, p = .006, overall mortality SHR: 1.29; 95% CI: .98-1.68, p = .065). No differences in treated acute allograft rejection at 1 year were found between groups.

CONCLUSIONS

Temporary inactive status while waiting for HT occurs in approximately one in five HT recipients listed in higher urgency categories after the implementation of the new allocation system. A signal of adverse long-term outcomes was found, and this could be explained by differences in recipient characteristics. Further research is required to elucidate pathways involved and possible implications for clinical practice.

Transition to heart transplantation in post-myocardial infarction ventricular septal rupture: a systematic review

Post-myocardial infarction ventricular septal rupture (MI-VSR) remains a dreadful complication with dismal prognosis. Surgical repair is the primary treatment strategy, whereas the role of heart transplantation (HT) as a primary option in MI-VSR is limited to case reports (CRs). We performed a systematic review of CRs to describe in-hospital mortality, and survival at 6 and 12 months in adult patients with MI-VSR treated with HT as a primary or bailout strategy. We performed a comprehensive search of Web of Science, PubMed, and Ovid Medline. The last search was completed on March 10, 2020. An aggregated score based on the CARE case report guideline was used to assess the quality of the CRs. We included CRs that described adult patients with MI-VSR treated with HT as a primary or bailout strategy. A total of 14 CRs between 1994 and 2015 were included, retrieving and analyzing the characteristics of 17 patients. A total of 12 patients underwent HT, with HT being the primary strategy in 8 patients and a bailout strategy for 4 patients following initial surgical repair, while 5 patients died awaiting HT under mechanical circulatory support (MCS), accounting for the total in-hospital mortality of this series (29%). Regarding long-term outcomes, 6 patients were reported to be alive at 6 months and 1 year after HT, while information was missing in the remaining 6 patients. In conclusion, HT supported by the use of temporary and durable MCS as a bridge to HT could be a feasible primary or bailout strategy to reduce the high in-hospital mortality of patients with MI-VSR.

Disparities in heart transplantation

PURPOSE OF REVIEW

Heart transplantation remains the gold standard therapy for end stage heart failure, but barriers remain, preventing equitable access to and affecting outcomes following transplantation. The objective of this review is to summarize current and historical literature on the disparities that persist, and to highlight the gaps in evidence for further investigation.

RECENT FINDINGS

Although progress has been made to increase the rates of advanced heart failure therapies to racial/ethnic minority populations and those with lower socioeconomic status, differential access and outcomes remain. The disparities that persist are categorized by patient demographics, social influences, geopolitical factors, and provider bias.

SUMMARY

Disparities in heart transplantation exist, which span a wide spectrum. Healthcare professionals need to be cognizant of these disparities that patients face in terms of access to and outcomes for heart transplantation. Further research and system changes are needed to make heart transplantation a fairer option for patients of varying backgrounds with end stage heart failure.

Pediatric heart transplantation: The past, the present, and the future

Heart transplantation (HTx) has a storied past, with origins dating back to the early twentieth century and the first pediatric orthotopic heart transplant performed in 1967 on a neonate with Ebstein abnormality. Today, approximately 500 pediatric HTx are performed annually, with survival times now measured in decades rather than days or weeks. In large part, advances in immunosuppression, critical care, dedicated transplant teams and mechanical circulatory support have paved the way for improvements in waitlist mortality and post-transplant survival, with future directions including the development of intracorporeal ventricular assist devices (VADs) for small children, expanding/standardizing donor criteria, and xenotransplantation.

Center variations in patient selection for simultaneous heart-kidney transplantation

There are no established regulations governing patient selection for simultaneous heart-kidney (SHK) transplantation, creating the potential for significant center-level variations in clinical practice.

METHODS

Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) file, we examined practice trends and variations in patient selection for SHK at the center level between January 1, 2004 and March 31, 2019.

RESULTS

Overall, SHK is becoming more common with most centers performing heart transplants also performing SHK. Among patients who underwent heart transplant who were receiving dialysis, the rate of SHK varied from 22% to 86% at the center level. Among patients not on dialysis, the median estimated glomerular filtration rate (eGFR) of patients receiving SHK varied between 19 and 59 mL/min/1.73 m² . When adjusting for other factors, the odds of SHK varied 57-fold between the highest and lowest SHK performing centers.

CONCLUSION

Variation in SHK at the center level suggests the need for national guidelines around the selection of patients for SHK.

Center-Level Variation in Transplant Rates Following the Heart Allocation Policy Change

IMPORTANCE

Wide state-level variability in waiting list outcomes have been noted for patients listed for heart transplant in the US, but little is known regarding center-level transplant rates since the heart allocation policy change.

OBJECTIVE

To evaluate center-level transplant rates following the recent allocation policy change for heart transplant.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the United Network for Organ Sharing database from October 18, 2015, to March 1, 2020, for a nationwide analysis of transplant centers in the US. Transplant candidates were stratified into 2 time cohorts, with era 1 denoting the 3-year period before the policy change (October 18, 2018), and era 2 representing the 500-day period after the policy change but before the beginning of the COVID-19 pandemic. Data were analyzed from May to June 2021.

EXPOSURE

The heart allocation policy change enacted on October 18, 2018.

MAIN OUTCOMES AND MEASURES

Competing risk regression for waiting list outcomes was performed to calculate adjusted era 1 and era 2 center-level transplant rates. Rates were compared across regions and states, as well as within organ procurement organizations. Pearson correlation coefficient was used to assess center-level factors associated with era 2 transplant rates.

RESULTS

Of 15 940 transplant candidates included for analysis, 5063 (median [IQR] age, 56 [45-63] years; 1385 women [27.4%]) comprised the era 2 cohort. The proportion of patients with temporary mechanical circulatory support increased between era 1 and era 2 (extracorporeal membrane oxygenation, 2.00% vs 3.42%; percutaneous ventricular assist device, 0.66% vs 1.86%; intra-aortic balloon pump, 5.21% vs 13.10%). The adjusted mean center-level likelihood of transplant increased after the rule change (from 48.1% in era 1 to 78.0% in era 2). Significant variation in transplant rates was observed across regions and states even among centers with shared organ procurement organizations. The largest absolute difference in transplant rates was 27.1% for 2 centers belonging to the same organ procurement organization. Centers with higher transplant volumes in era 2 and with a greater proportion of candidates with intra-aortic balloon pump were observed to have higher transplant rates.

CONCLUSIONS AND RELEVANCE

Despite sharing organ supply and having a small geographical distance, these findings suggest that intercenter disparities in the likelihood of transplant have persisted following the heart allocation policy change. Further work is necessary to ensure equitable allocation of organs in heart transplant.

Destination left ventricular assist devices in island states: asking too much or the inevitable solution

Background

Destination left ventricular assist device placement is increasing as a result of donor shortages and changing patient attitudes. As organ shortages become critical, LVAD programs become fundamental even in more remote regions of the world including island states. Here, we provide a look into the current state and availability of LVAD programs in island states.

Main body

A narrative review was performed using the World Health Organization Global Index Medicus and PubMed/MEDLINE databases to identify articles describing the island states having reported LVAD placements and programs. Additionally, INTERMACS reports were used. Data were retrieved and a review is presented describing the current state of LVADs in island states. The Caribbean region as a whole has a heart failure (HF) prevalence of 814 per 100,000 and Oceania 667 per 100,000 people. We estimate that over 3000 people in these islands need either a heart transplant or an LVAD.

Short conclusion

For HF patients living in island regions, special attention should be paid to the inability of having access to specialized mainland medical care. The continuous quest for a solution to HF in island regions should include the establishing of high-quality LVAD programs in a transfer-network centralized/regionalized system to care for those patients not candidates for long-distance air-bridging.

Disparities in heart and lung transplantation

PURPOSE OF REVIEW

Cardiothoracic transplantation is the definitive therapy for end-stage heart and lung disease. In service to this population, disparities in access and care must be simultaneously understood and addressed.

RECENT FINDINGS

There are sex, race, geographic, age, and underlying disease disparities in both heart and lung transplantation. Women have reduced waitlist survival but improved posttransplant survival when compared with men for both heart and lung transplantation. Black patients have worse outcome compared with other races postheart transplant. Geographic disparities impact the likelihood of receiving heart or lung transplant and the growing number of patients with advanced age seeking transplant complicates discussions on survival benefit. Finally, underlying disease has affected outcomes for both heart and lung transplant and now are incorporated into the allocation system.

SUMMARY

Though heart and lung transplantation have several existing disparities, it remains to be seen how advancements in medical technology, changes in donor organ allocation policies, and growing experience in patient selection will impact these concerns.