Donor hypernatremia and smoking addiction contribute to primary graft failure in heart transplantation

Disparities in donor heart acceptance between the USA and Europe: clinical implications

BACKGROUND AND AIMS

Given limited evidence and lack of consensus on donor acceptance for heart transplant (HT), selection practices vary widely across HT centres in the USA. Similar variation likely exists on a broader scale-across countries and HT systems-but remains largely unexplored. This study characterized differences in heart donor populations and selection practices between the USA and Eurotransplant-a consortium of eight European countries-and their implications for system-wide outcomes.

METHODS

Characteristics of adult reported heart donors and their utilization (the percentage of reported donors accepted for HT) were compared between Eurotransplant (n = 8714) and the USA (n = 60 882) from 2010 to 2020. Predictors of donor acceptance were identified using multivariable logistic regression. Additional analyses estimated the impact of achieving Eurotransplant-level utilization in the USA amongst donors of matched quality, using probability of acceptance as a marker of quality.

RESULTS

Eurotransplant reported donors were older with more cardiovascular risk factors but with higher utilization than in the USA (70% vs. 44%). Donor age, smoking history, and diabetes mellitus predicted non-acceptance in the USA and, by a lesser magnitude, in Eurotransplant; donor obesity and hypertension predicted non-acceptance in the USA only. Achieving Eurotransplant-level utilization amongst the top 30%-50% of donors (by quality) would produce an additional 506-930 US HTs annually.

CONCLUSIONS

Eurotransplant countries exhibit more liberal donor heart acceptance practices than the USA. Adopting similar acceptance practices could help alleviate the scarcity of donor hearts and reduce waitlist morbidity in the USA.

Comment on Oehler et al. Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit. Life 2022, 12, 1053

Oehler et al. described an interesting finding, stating that length of stay (LOS) of the donors in the intensive care unit (ICU) did not have an impact on the outcomes and survival of recipients up to 5 years after heart transplantation (HTx) [...].

Donor substance abuse and heart transplantation outcomes

Heart failure continues to account for millions of cases and deaths worldwide. Heart transplant is the gold standard for treatment of advanced heart failure. Unfortunately, the supply of donor hearts continues to be limited with the increase in demand for heart transplantation. In this review, we aim to explore the safety and efficacy of using hearts from donors with history of substance use. Despite the theoretical effect of cocaine and alcohol on the cardiovascular system, several studies demonstrate no difference in outcomes (overall survival, graft rejection, graft vasculopathy) when using hearts from patients with history of cocaine and alcohol use. The opioid epidemic has expanded the potential donor pool where the current studies have not shown any adverse outcomes when considering donors with history of opioid use. The currently available evidence would support the use of donor hearts from patients with history of alcohol, cocaine, opioids, and marijuana use. Further studies are needed to evaluate the safety of using donor hearts from patients with history of nicotine use.

Donor Noradrenaline Support Is Not Associated with Decreased Survival in Heart Transplant Recipients

Objective: Although the application of higher doses of norepinephrine (NE) in potential organ donors is a frequent reason for heart decline, its associations with outcomes after heart transplantation (HTx) are discussed controversially. Therefore, we aimed to explore donor NE support’s potential impact on outcomes in our single-center heart transplant cohort. Methods: All patients who had undergone HTx in our center between September 2010 and April 2022 (n = 241) were screened for eligibility. From those, all patients with complete data on donor NE support (n = 238) were included. Recipients were divided into three groups according to their donor NE support: without support (n = 26), with low support of 0.01−0.2 µg/kg/min (n = 132), and with high support of > 0.2 µg/kg/min (n = 80). Receiver operating characteristics (ROC) and Kaplan Meier analysis was used to investigate the association of donor NE support and mortality after heart transplantation. Recipient and donor variables, including peri- and postoperative characteristics, were reviewed and compared. Results: NE support in donors ranged between 0 and 2.94 µg/kg/min (median 0.13 µg/kg/min, IQR 0.05−0.26 µg/kg/min). No association between donor NE support and mortality after HTx was observed (AUC for overall survival 0.494). Neither Kaplan-Meier analysis in survival up to 5 years after transplantation (Log Rank p = 0.284) nor group comparisons showed significant differences between the groups. With few exceptions, baseline characteristics in recipients and donors were comparable between the groups. Regarding peri- and postoperative parameters, increasing donor NE support was associated with a longer duration of mechanical ventilation (68 h and 95 h vs. 47 h), longer postoperative IMC/ICU stay (14 vs. 15 vs. 19 days), and a higher need for mechanical life support post-HTx (26% and 39% vs. 12%). Conclusion: In this retrospective analysis, NE support in donors prior to heart transplantation was unrelated to differing survival after heart transplantation. However, higher doses of donor NE were associated with prolonged ventilation, longer duration on IMC/ICU, and a higher need for extracorporeal life support in recipients post-HTx.

Donor hypernatremia is associated with increased mortality after heart transplantation: A retrospective study

BACKGROUND AND AIMS

Donor hypernatremia has been associated with primary graft dysfunction in heart transplantation (HTx) and is correlated with impaired outcome following liver and renal transplantation. However, controversial data exist regarding the impact of sodium dysregulation on survival. This study aims to investigate the impact of donor sodium levels on early morbidity and short- and midterm survival following HTx.

METHODS

Between September 2010 and June 2021, a total of n = 218 patients underwent HTx in our center. From those, 214 could be included retrospectively in our study. For each donor, sodium levels were collected and different cut-off levels from 145 to 159 mmol/L were investigated by Kaplan-Meier-analysis. Then, recipients were divided in three groups regarding donor sodium: Normonatremia (133-145 mmol/L, n = 73), mild hypernatremia (146-156 mmol/L, n = 105) and severe hypernatremia (>156 mmol/L, n = 35). Recipient and donor variables were reviewed and compared, including peri- and postoperative characteristics and recipient survival after up to 5 years after transplantation.

RESULTS

All patients were comparable regarding baseline characteristics and perioperative parameters. Regarding early mortality, 90-day survival was significantly reduced only in patients with severe donor hypernatremia in comparison to normonatremia (90% vs. 71%, p = .02), but not in mild hypernatremia (89%, p = .89). One-year survival was comparable in all groups (p > .28).

CONCLUSION

Severe donor hypernatremia was associated with reduced short-term survival, while the correlation weakens > 1 year after HTx. As our study is limited due to the nature of its retrospective, single-center approach, future prospective studies are needed to evaluate the importance of donor management with regard to hypernatremia.

Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th-75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3-8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan-Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients' peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

Impact of donor smoking history on post heart transplant outcomes: A propensity-matched analysis of ISHLT registry

PURPOSE

Smoking is a major public health issue, and its effect on cardiovascular outcomes is well established. This study evaluates the impact of donor smoking on heart transplant (HT) outcomes.

METHODS

HT recipients between January 1, 2005, and December 31, 2016, with known donor smoking status were queried from the International Society of Heart and Lung Transplantation (ISHLT) registry. The primary outcome was all-cause mortality, and secondary endpoints were graft failure, acute rejection, and cardiac allograft vasculopathy. We utilized propensity-score matching to identify cohorts of recipients with and without a history of donor smoking. Hazard ratios for post-transplant outcomes for the matched sample were estimated from separate Cox proportional hazard models.

RESULTS

Of 26 390 patients in the cohort, 18.9% had history of donor smoking. Donors with history of smoking were older, predominantly male and had higher incidence of diabetes, hypertension, cocaine use, and "high-risk" status. In propensity-matched analysis, recipients with a history of donor smoking had increased risk of death (HR 1.11, 95% CI 1.03-1.20) and higher risk of graft failure (HR 1.11, 95% CI 1.03-1.20).

CONCLUSION

Donor smoking was associated with increased mortality and higher incidence of graft failure following HT. Consideration of donor smoking history is warranted while evaluating donor hearts.