Racial disparities in post-transplant stroke and mortality following stroke in adult cardiac transplant recipients in the United States

Black heart transplant recipients have a higher mortality rate than white recipients 6-12 months after transplant. Whether there are racial disparities in post-transplant stroke incidence and all-cause mortality following post-transplant stroke among cardiac transplant recipients is unknown. Using a nationwide transplant registry, we assessed the association between race and incident post-transplant stroke using logistic regression and the association between race and mortality among adults who survived a post-transplant stroke using Cox proportional hazards regression. We found no evidence of an association between race and the odds of post-transplant stroke (OR = 1.00, 95% CI: 0.83-1.20). The median survival time of those with a post-transplant stroke in this cohort was 4.1 years (95% CI: 3.0, 5.4). There were 726 deaths among the 1139 patients with post-transplant stroke, including 127 deaths among 203 Black patients and 599 deaths among 936 white patients. Among post-transplant stroke survivors, Black transplant recipients experienced a 23% higher rate of mortality compared to white recipients (HR = 1.23, 95% CI: 1.00-1.52). This disparity is strongest in the period beyond the first 6 months and appears to be mediated by differences in the post-transplant setting of care between Black and white patients. The racial disparity in mortality outcomes was not evident in the past decade. The improved survival of Black patients in the recent decade may reflect overall protocol improvements for heart transplant recipients irrespective of race, such as advancements in surgical techniques and immediate postoperative care as well as increased awareness about reducing racial disparities.

Post-transplant mortality and graft failure after induction immunosuppression among Black heart transplant recipients in the United States

Black heart transplant recipients are more likely to receive induction immunosuppression compared to other races because of higher rates of acute rejection, graft failure, and mortality. However, it is not known whether contemporary induction immunosuppression improves their post-transplant outcomes. To evaluate whether Black patients who were prescribed induction immunosuppression therapy have lower all-cause mortality or graft-failure rates compared to those who were not, we studied Black U.S. adult heart transplant recipients in the Scientific Registry of Transplant Recipients database (2008-2018). We used multivariable Cox proportional hazards regression analysis to compare the hazards of all-cause mortality or graft failure as a composite, for patients who were prescribed induction immunosuppression and those who were not. Among 5160 recipients, 2787 (54.0%) were prescribed induction immunosuppression and 2373 (46.0%) were not. There was no evidence of survival differences according to induction immunosuppression for the composite of all-cause mortality or graft failure (aHR = 1.13, 95% CI 0.96-1.32), mortality (aHR = 1.14, 95% CI 0.97-1.34), graft failure (aHR = 1.05, 95% CI 0.82-1.34) and acute rejection (aHR = 1.00, 95% CI 0.89-1.12). Given the side effects of treatment, future guidelines should reconsider the recommendation for induction immunosuppression among Black patients.

Racial and Ethnic Disparities in Incidence and Prognosis of Perioperative Stroke Among Pediatric Cardiac Transplant Recipients

Background

In the general population, Black children have a higher incidence of stroke and all‐cause mortality after stroke than White children. Beginning 6 months following cardiac transplantation, Black children have higher mortality than White children. However, whether there are racial and ethnic disparities in incidence and all‐cause mortality following perioperative stroke among pediatric cardiac transplant recipients is unknown.

Methods and Results

Using the Scientific Registry of Transplant Recipients, we studied children who underwent their first heart transplant in the United States between January 1994 and September 2019. Using multivariable logistic regression, we assessed the association between race and ethnicity and perioperative stroke. We used multivariable piecewise Cox regression to examine the association between race and ethnicity and mortality among survivors of perioperative stroke. Among 8224 children who had a first cardiac transplant, 255 (3%) had a perioperative stroke. Black children had 32% lower odds of perioperative stroke compared with White children (adjusted odds ratio, 0.68 [95% CI, 0.46–0.996]). Following perioperative stroke, mortality rates were similar for Black and White children in the first 6 months (adjusted hazard ratio [HR], 0.99 [95% CI, 0.44–2.26]). However, Black children had a higher mortality rate than White children beyond 6 months (adjusted HR, 3.36 [95% CI, 1.22–9.22]).

Conclusions

Among pediatric cardiac transplant recipients, Black children have a lower incidence of perioperative stroke than White children. Among survivors of perioperative stroke, mortality is initially similar by race and ethnicity, but beyond 6 months, Black children have over a 3‐fold higher mortality rate than White children. Identifying and intervening on potential differences in care is essential to addressing these disparities.

Abstract WP212: Racial Disparities In Perioperative Stroke And Mortality Following Stroke In Adult Cardiac Transplant Recipients

Introduction: In the general US population, Black adults have a higher stroke incidence and mortality rate after stroke compared to white adults. Among heart transplant recipients, Black adults also have a higher mortality rate beginning 6-12 months post-transplant. Whether there are racial disparities in perioperative stroke incidence and all-cause mortality following perioperative stroke among cardiac transplant recipients is unknown.

Methods: Using the Scientific Registry of Transplant Recipients, we examined all adults in the United States who received their first heart transplant between January 2008 - December 2018. We used multivariable conditional logistic regression to assess the association between race and perioperative stroke. We used multivariable Cox proportional hazard regression to examine the association between race and mortality among adults who survived a perioperative stroke. In both models, we included age, sex, hospitalization status, prior ventricular assist device (VAD) implantation, extracorporeal membrane oxygenation (ECMO), calendar year, etiology of heart disease, bilirubin, and functional status as covariates.

Results: Among 20,912 adults, 428 (2.7%) white recipients and 126 (2.4%) Black recipients had a perioperative stroke. In a multivariable model, there was 11% lower odds of perioperative stroke in Black recipients compared to white recipients (OR = 0.89, 95% CI: 0.71, 1.12). Among perioperative stroke survivors, mortality rates were similar between Black and white recipients within 6 months (HR = 1.02, 95% CI: 0.70, 1.49) and in long-term follow up (HR = 0.95, 95% CI: 0.52, 1.73). However, our regression results were imprecise. Further adjustment for health behaviors and socioeconomic position did not alter the results.

Conclusion: Black recipients experienced a lower incidence of perioperative stroke; however, mortality rates were similar between Black and white recipients following perioperative stroke. These unexpected findings warrant further research.

Impact of chronic thrombocytopenia on in-hospital outcomes and healthcare resource utilization after transcatheter aortic valve replacement

BACKGROUND

There is little data on the impact of chronic thrombocytopenia (CTP) on outcomes after transcatheter aortic valve repair (TAVR). Most studies are from single centers and mostly focused on postprocedure thrombocytopenia.

OBJECTIVES

This study sought to report on the impact of CTP (>1 year) on in-hospital outcomes and healthcare resource utilization after TAVR.

METHODS

From the National Inpatient Sample (NIS) between 2012 and 2015, we identified patients with CTP who underwent TAVR. A 1:1 propensity-matched cohort was created to examine in-hospital outcomes in patients with and without CTP. The primary outcome was in-hospital mortality. Secondary outcomes included postprocedure complications, length of stay, total cost, and discharge disposition.

RESULTS

A matched pair of 4,300 patients with and without CTP were identified. Patients with CTP had higher in-hospital mortality as compared to no CTP patients (6.0 vs. 3.3%, p-value .007), increased postprocedure hemorrhage, platelet and blood transfusion, vascular complications, postop sepsis, and acute kidney injury. With regards to resource utilization, CTP patients had a longer length of stay, higher total cost and were more likely to be discharged to a facility (34.1 vs. 27.6%) other than home (All, p-value <.001). Subanalysis, however, revealed this difference in resource utilization was seen when patients developed postprocedure complications.

CONCLUSION

This study demonstrated higher risk of in-hospital mortality, perioperative complications, and healthcare resource utilization in patients with baseline CTP undergoing TAVR. Further studies are required to investigate ways to improve the management of these patients.