Is Time Scheduling Important? An Analysis of Donor Heart Cross-clamp Times During Heart Transplantation

Background. Outcomes in heart transplantation are affected by a variety of variables and patient factors. However, the impact of circadian rhythms, gene expression, and transcription remain underexplored. We thus evaluated the potential role of donor heart cross-clamp times on short-term and long-term outcomes after heart transplantation. Methods. A total of 31 713 heart transplants were identified from the United Network for Organ Sharing Database. Patients were first stratified on the basis of time of donor procurement: 12 am to 12 pm or 12 pm to 12 am. To evaluate a possible effect of circadian rhythms, donor time was further divided into 5 groups based on preclinical data: 4 am to 8 am; 8 am to 11 am; 11 am to 5 pm; 5 pm to 10 pm; 10 pm to 4 am. Groups were assessed with comparative statistics. Long-term survival was evaluated using Kaplan-Meier methods and a multivariate Cox proportional hazard model. Results. Patients who received hearts recovered between 12 am and 12 pm had significantly higher survival than those who received hearts recovered between 12 pm and 12 am. This survival difference was observed in both unadjusted (P = 0.002) and adjusted analyses (hazard ratio [HR]: 0.93; 95% confidence interval [CI], 0.89-0.97; P < 0.001). On unadjusted analysis, the survival difference among the 5 groups was insignificant (P = 0.07). Following adjustment, the periods of 11 am to 5 pm (HR: 1.09, 95% CI, 1.02-1.17; P = 0.012), 5 pm to 10 pm (HR: 1.11; 95% CI, 1.04-1.19; P = 0.002), and 10 pm to 4 am (HR: 1.07; 95% CI, 1.01-1.15; P = 0.034), were all independently associated with increased long-term mortality. Notably, the time of 8 am to 11 am was not associated with a change in survival (HR: 1.04; 95% CI, 0.96-1.14; P = 0.3). Conclusions. Given the independent association of donor timing and survival after adjustment in a large national cohort, further investigation into the role of donor circadian rhythm and donor procurement time is warranted in preclinical and clinical studies. Understanding the underlying mechanisms of this observation could potentially lead to the development of effective treatments and donor procurement processes that prepare the organs for transplantation in a better condition

Trends in survival after heart transplantation based on Social Vulnerability Index in the United States

Background: The association of social vulnerability (SV) and cardiac transplant survival remains poorly defined, particularly related to long-term outcomes. The purpose of this study was to define the impact of SV on survival among heart transplant recipients with at least 1 year of survival post-transplant. Methods: Heart transplant recipients were identified using the United Network for Organ Sharing database between June 1, 2006, and December 31, 2020. The Center for Disease Control’s Social Vulnerability Index (SVI) database was used to stratify patients based on SVI into 3 groups: low: <25; average: 26 to 74; high: 75+. The groups were analyzed with comparative statistics, and unadjusted survival was assessed using Kaplan-Meier methods. To determine the independent association between SVI and survival, a multivariable Cox proportional hazard model was created. Results: There were 27,740 recipients identified. High SVI patients more commonly identified as Black individuals and had a higher incidence of diabetes, pretransplant intensive care unit admission, and need for concomitant kidney transplant (p < 0.05 for all). Additionally, high SVI patients had the longest length of stay post-transplant (21.4 days) (p < 0.05). High and average SVI patients had inferior 3-year, 5-year, and 10-year survival vs low SVI patients (p < 0.05). After adjustment, average (hazard ratio [HR]: 1.12) and high (HR: 1.16) SVI were independently associated with an increased risk of mortality on multivariable analysis (both p < 0.001). Conclusion: High or average SVI is independently associated with increased mortality following heart transplantation in patients with 1-year conditional survival. These findings demonstrate that disparities persist among heart transplant recipients during long-term follow-up

Lung transplantation following prior cardiac surgical procedures

Background: As lung transplant candidates are older with increased comorbidities, we sought to examine the prevalence and outcomes of lung transplant recipients after prior cardiac surgery. Methods: Lung transplants were identified from the United Network for Organ Sharing/Organ Procurement and Transplantation Network Database. Patients were stratified based on prior cardiac surgery (no surgery [NS], prior coronary artery bypass grafting [CABG], prior valve [Valve]). Unadjusted comparisons were performed among all groups, and propensity matching was utilized for adjusted comparisons. Survival was examined with Kaplan-Meier methods. Results: A total of 28,710 patients were identified, 467 (1.6%) had prior CABG and 84 (0.3%) had prior valvular surgery. Before matching, the NS group was significantly younger, less commonly male, and had lower lung allocation scores. There were significantly fewer bilateral lung transplants in the CABG and Valve groups. Length of stay was shortest in the CABG group, but there were no significant differences in postoperative stroke, dialysis, or in-hospital mortality. There was an increased incidence of cardiac/cerebrovascular cause of death in CABG recipients (18.3%) and malignancy death in Valve recipients (23.3%). Following matching, CABG 5-year survival was lower than NS (p < 0.01), while there was no significant difference between NS and Valve groups (p = 0.4). Conclusions: CABG and Valve recipients had decreased survival, however not at levels prohibitive to transplantation. Due to potentially increased risk of cardiovascular mortality, providers should evaluate the burden of vascular disease in potential recipients with prior CABG to improve patient selection and maximize post-transplant survival