Can we safely expand the donation after circulatory death donor heart pool by extending the donor age limit?

OBJECTIVE: This study evaluates the impact of donor age on outcomes following donation after circulatory death heart transplantation. METHODS: The United Network for Organ Sharing registry was queried to analyze adult recipients who underwent isolated donation after circulatory heart transplantation from January 1, 2019, to September 30, 2023. The cohort was stratified into 2 groups according to donor age, where advanced donor age was defined as 40 years or more. Outcomes were 90-day and 1-year post-transplant survival. Propensity score matching was performed. Subgroup analysis was performed to evaluate the effects of recipient age on 90-day survival among the recipients with advanced-age donors. RESULTS: A total of 994 recipients were included in the study period, and 161 patients (17.1%) received allografts from advanced-age donors. During the study period, the annual incidence of donation after circulatory heart transplantation with advanced-age donors substantially increased. The recipients with advanced-age donors had similar 90-day and 1-year post-transplant survivals compared with the recipients with younger donors. The comparable 90-day survival persisted in a propensity score-matched comparison. In the subgroup analysis among the recipients with advanced-age donors, the recipients aged 60 years or more had significantly reduced 90-day survival compared with the recipients aged less than 60 years. CONCLUSIONS: The use of appropriately selected donation after circulatory donors aged 40 years or more has similar survival compared with that of younger donors. With careful candidate risk stratification and selection, consideration of using donation after circulatory donors aged more than 40 years may further ameliorate ongoing organ shortage with comparable early post-transplant outcomes.

Concomitant use of extracorporeal membrane oxygenation and percutaneous microaxial assist device support for cardiogenic shock.

Objectives: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) with concomitant percutaneous microaxial left ventricular assist device support is an emerging treatment modality for cardiogenic shock (CS). Survival outcomes by CS etiology with this support strategy have not been well described. Methods: This study was a retrospective, single-center analysis of patients with CS due to acute myocardial infarction (AMI-CS) or decompensated heart failure (ADHF-CS) supported with VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support from December 2020 to January 2023. Results: A total of 44 patients were included (AMI-CS, n = 20, and ADHF-CS, n = 24). Patients with AMI-CS and ADHF-CS had similar survival at 90 days postdischarge (P = .267) with similar destinations after support (P = .220). Patients with AMI-CS initially supported with VA-ECMO were less likely to survive 90 days postdischarge (P = .038) when compared with other cohorts. Limb ischemia and acute kidney injury occurred more frequently in patients presenting with AMI-CS (P =.013; P = .030). Subanalysis of ADHF-CS patients into acute-on-chronic decompensated HF and de novo HF demonstrated no difference in survival or destination. Conclusions: VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support can be used to successfully manage patients with CS. There is no difference in survival or destination for AMI-CS and ADHF-CS with this support strategy. AMI-CS patients with initial VA-ECMO support have increased mortality in comparison to other cohorts. Future multicenter studies are required to fully analyze the differences between AMI-CS and ADHF-CS with this support strategy.

Improved waitlist and comparable post-transplant outcomes in simultaneous heart-kidney transplantation under the 2018 heart allocation system.

OBJECTIVE: This study aimed to investigate the clinical trends and the impact of the 2018 heart allocation policy change on both waitlist and post-transplant outcomes in simultaneous heart-kidney transplantation in the United States. METHODS: The United Network for Organ Sharing registry was queried to compare adult patients before and after the allocation policy change. This study included 2 separate analyses evaluating the waitlist and post-transplant outcomes. Multivariable analyses were performed to determine the 2018 allocation system's risk-adjusted hazards for 1-year waitlist and post-transplant mortality. RESULTS: The initial analysis investigating the waitlist outcomes included 1779 patients listed for simultaneous heart-kidney transplantation. Of these, 1075 patients (60.4%) were listed after the 2018 allocation policy change. After the policy change, the waitlist outcomes significantly improved with a shorter waitlist time, lower likelihood of de-listing, and higher likelihood of transplantation. In the subsequent analysis investigating the post-transplant outcomes, 1130 simultaneous heart-kidney transplant recipients were included, where 738 patients (65.3%) underwent simultaneous heart-kidney transplantation after the policy change. The 90-day, 6-month, and 1-year post-transplant survival and complication rates were comparable before and after the policy change. Multivariable analyses demonstrated that the 2018 allocation system positively impacted risk-adjusted 1-year waitlist mortality (sub-hazard ratio, 0.66, 95% CI, 0.51-0.85, P < .001), but it did not significantly impact risk-adjusted 1-year post-transplant mortality (hazard ratio, 1.03; 95% CI, 0.72-1.47, P = .876). CONCLUSIONS: This study demonstrates increased rates of simultaneous heart-kidney transplantation with a shorter waitlist time after the 2018 allocation policy change. Furthermore, there were improved waitlist outcomes and comparable early post-transplant survival after simultaneous heart-kidney transplantation under the 2018 allocation system.

Donation after circulatory death improves probability of heart transplantation in waitlisted candidates and results in post-transplant outcomes similar to those achieved with brain-dead donors.

OBJECTIVE: To quantitate the impact of heart donation after circulatory death (DCD) donor utilization on both waitlist and post-transplant outcomes in the United States. METHODS: The United Network for Organ Sharing database was queried to identify all adult waitlisted and transplanted candidates between October 18, 2018, and December 31, 2022. Waitlisted candidates were stratified according to whether they had been approved for donation after brain death (DBD) offers only or also approved for DCD offers. The cumulative incidence of transplantation was compared between the 2 cohorts. In a post-transplant analysis, 1-year post-transplant survival was compared between unmatched and propensity-score-matched cohorts of DBD and DCD recipients. RESULTS: A total of 14,803 candidates were waitlisted, including 12,287 approved for DBD donors only and 2516 approved for DCD donors. Overall, DCD approval was associated with an increased sub-hazard ratio (HR) for transplantation and a lower sub-HR for delisting owing to death/deterioration after risk adjustment. In a subgroup analysis, candidates with blood type B and status 4 designation received the greatest benefit from DCD approval. A total of 12,238 recipients underwent transplantation, 11,636 with DBD hearts and 602 with DCD hearts. Median waitlist times were significantly shorter for status 3 and status 4 recipients receiving DCD hearts. One-year post-transplant survival was comparable between unmatched and propensity score-matched cohorts of DBD and DCD recipients. CONCLUSIONS: The use of DCD hearts confers a higher probability of transplantation and a lower incidence of death/deterioration while on the waitlist, particularly among certain subpopulations such as status 4 candidates. Importantly, the use of DCD donors results in similar post-transplant survival as DBD donors.

Concomitant Use of VA-ECMO and Impella Support for Cardiogenic Shock.

Background: VA-ECMO with concomitant Impella support (ECpella) is an emerging treatment modality for cardiogenic shock (CS). Survival outcomes by CS etiology with ECpella support have not been well-described. Methods: This study was a retrospective, single-center analysis of patients with cardiogenic shock due to acute myocardial infarction (AMI-CS) or decompensated heart failure (ADHF-CS) supported with ECpella from December 2020 to January 2023. Primary outcomes included 90-day survival post-discharge and destination after support. Secondary outcomes included complications post-ECpella support. Results: A total of 44 patients were included (AMI-CS, n = 20, and ADHF-CS, n = 24). Patients with AMI-CS and ADHF-CS had similar survival 90 days post-discharge (p = .267) with similar destinations after ECpella support (p = .220). Limb ischemia and acute kidney injury occurred more frequently in patients presenting with AMI-CS (p=.013; p = .030). Patients with initial Impella support were more likely to survive ECpella support and be bridged to transplant (p=.033) and less likely to have a cerebrovascular accident (p=.016). Sub-analysis of ADHF-CS patients into acute-on-chronic decompensated heart failure and de novo heart failure demonstrated no difference in survival or destination. Conclusion: ECpella can be used to successfully manage patients with CS. There is no difference in survival or destination for AMI-CS and ADHF-CS in patients with ECpella support. Patients with initial Impella support are more likely to survive ECpella support and bridge to transplant. Future multicenter studies are required to fully analyze the differences between AMI-CS and ADHF-CS with ECpella support.

Redo orthotopic heart transplantation in the current era.

OBJECTIVE: This study aims to investigate the trends, outcomes, and risk factors for mortality after redo orthotopic heart transplantation. METHODS: The United Network for Organ Sharing registry was used to identify adult orthotopic heart transplantation recipients from 2000 to 2020 and stratify into primary and redo cohorts. Five-year post-transplant survival was compared between 2 propensity-matched cohorts. Multivariable modeling was performed to identify risk-adjusted predictors of redo post-transplant mortality, both conditional and nonconditional on shorter-term survival. RESULTS: A total of 40,711 recipients were analyzed, 39,657 (97.4%) primary and 1054 (2.6%) redo. Redo recipients had a lower median age and were more frequently bridged with intravenous inotropes, intra-aortic balloon pump, or extracorporeal membrane oxygenation (all P < .05). One- and 5-year survivals were lower after redo orthotopic heart transplantation (90.0% vs 83.4% and 77.6% vs 68.6%, respectively) and remained lower after comparing 2 propensity-matched cohorts. Multivariable modeling found factors such as increasing donor age and graft ischemic times, along with pretransplant mechanical ventilation and blood transfusion, to negatively affect 90-day survival. Contingent on 1-year survival, donor factors such as hypertension (hazard ratio, 1.51; 95% confidence interval, 1.15-2.00, P = .004) and left ventricular ejection fraction less than 50% (hazard ratio, 2.22, 95% confidence interval, 1.16-4.24, P = .016) negatively affected survival at 5 years. CONCLUSIONS: Although infrequently performed, redo orthotopic heart transplantation remains associated with worse post-transplant outcomes compared with primary orthotopic heart transplantation. Although several high-risk features were identified to affect post-retransplant outcomes in the acute perioperative period, donor characteristics such as hypertension and decreased ejection fraction continue to have lasting negative impacts in the longer term.

Effect of untreated carotid artery stenosis at the time of isolated coronary artery bypass grafting.

Background: Severe carotid artery stenosis (sCAS) is frequently discovered at the time of evaluation for coronary arterial revascularization. However, there has been controversy regarding the optimal management of sCAS. This study evaluated the potential effects of untreated sCAS at time of coronary artery bypass grafting (CABG) in contemporary practice. Methods: This was a retrospective study from a multihospital healthcare system including patients undergoing isolated CABG between 2011 and 2018. Patients were stratified by the presence of sCAS (≥80% stenosis) in at least 1 carotid artery. Perioperative and 5-year stroke were compared, and multivariable analysis was used to identify risk-adjusted predictors of stroke and mortality. Results: A total of 5475 patients were included, 459 (8.4%) with sCAS and 5016 (91.6%) without sCAS. Patients with sCAS experienced more frequent perioperative stroke (4.4% vs 1.2%; P < .001), with most attributable to ischemic or embolic etiologies. The median duration of follow-up was 4.6 years (interquartile range, 3.0-6.5 years). One-year and 5-year survival were both lower in patients with sCAS (P < .001). In multivariable analysis, sCAS was associated with increased risk-adjusted hazard for both mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.02-1.60; P = .030) and stroke (HR, 1.76; 95% CI, 1.20-2.59; P = .004). The strongest risk-adjusted predictor for stroke was a previous history of stroke (HR, 2.51; 95% CI, 1.77-3.55; P < .001). Conclusions: This contemporary analysis of CABG procedures reveals that concurrent sCAS continues to confer a significant stroke risk, especially in those with history of previous stroke. Although whether sCAS lesions are responsible for most strokes is unclear, they likely serve as a surrogate for other stroke risk factors.