Lack of donor and recipient age interaction in cardiac transplantation

Donor Age More Than 20 Years Greater Than Recipient Age Is Associated With Worse 5-Year Survival in Young Adult Heart Transplantation

Prior studies indicate donor age-recipient age (DA-RA) difference may be of prognostic value in adolescents, although not adults. We aim to analyze the relationship between DA-RA difference and long-term survival of young adult heart transplantation (HTx) recipients. First-time, single-organ HTx recipients aged 18-30 who underwent HTx between 2010 and 2020 were analyzed from the United Network for Organ Sharing (UNOS) registry. Four cohorts were created based on DA-RA difference. The primary outcome was 5 year post-HTx survival. Secondary outcome was post-HTx complications. One thousand eight hundred three donor-recipient pairs were divided into four groups: DA-RA < 0, 0 ≤ DA-RA < 10, 10 ≤ DA-RA < 20, and DA-RA ≥ 20 with 682 (37.8%), 651 (36.1%), 356 (19.7%), 114 (6.3%) pairs in each cohort, respectively. The estimated 5 year survival of the DA-RA ≥ 20 cohort was 66.5% compared to the other three groups at ~75%. After adjustment, DA-RA ≥ 20 was independently associated with worse survival compared to DA-RA < 0 (adjusted hazard ratio [HR] = 1.55; 95% confidence interval [CI] = 1.06-2.27; log-rank p = 0.008). There was no significant difference in complication incidence across cohorts. Among young adults, accepting a donor heart more than 20 years older than the recipient was associated with worse 5 year survival. We did not detect a significant difference up to 20 years. This information may help guide appropriate donor selection in the young adult population.

Influence of donor age and donor-recipient age difference on intimal hyperplasia in pediatric patients with young and adult donors vs. adult patients after heart transplantation

AIM

Optimal selection and allocation of donor hearts is a relevant aspect in transplantation medicine. Donor age and cardiac allograft vasculopathy (CAV) affect post-transplant mortality. To what extent donor age impacts intimal hyperplasia (CAVIH) in pediatric and adult patients after heart transplantation (HTx) is understudied.

METHODS

In a cohort of 98 HTx patients, 58 pediatric (24.1% with adult donors) and 40 adult patients, we assessed the effect of donor age and donor-recipient age difference (D-R) on the continuous parameter of maximal intima thickness (mIT) in optical coherence tomography. We evaluated their predictive value regarding higher mIT and the prevalence of CAVIH, defined as mIT > 0.3 mm, and compared it to established CAV risk factors.

RESULTS

In the overall population, donor age correlated with mIT (p < 0.001), while in the pediatric subpopulation, both donor age and D-R correlated with mIT (p < 0.001 and p = 0.002, respectively). In the overall population, donor age was a main predictor of higher mIT and CAVIH (p = 0.001 and p = 0.01, respectively) in addition to post-transplant interval, arterial hypertension, and dyslipidemia. In the pediatric patients, dyslipidemia remained a main predictor of both higher mIT and CAVIH (p = 0.004 and p = 0.040, respectively), while donor age and D-R were not.

CONCLUSION

While there was an effect of the non-modifiable parameter of donor age regarding maximal intimal thickness, a stronger association was seen between the modifiable risk factor dyslipidemia and higher maximal intimal thickness and CAVIH in both the overall population and the pediatric subpopulation.

Impact of age mismatch between donor and recipient on heart transplant mortality

The effect of donor-to-recipient (D-R) age mismatch in adult heart transplant population is not clearly described, and we undertook this study to determine the impact of age mismatch on mortality. Heart transplant recipients from 2000 to 2017 were identified using the United Network of Organ Sharing database. The cohort was divided into three groups: donor age within 5 years of recipient age (Group 1), donors >5 years younger than recipient (group 2), and donors >5 years older than recipients (Group 3). We also evaluated if this finding changed by recipient age. Twenty eight thousand, four hundred and eleven patients met the inclusion criteria. Compared to group 1, the adjusted hazard ratio (aHR) for mortality for group 2 was 0.91 (0.83-0.99, p value <.039) and for group 3 was 1.36 (1.21-1.52, p value <.001); however, when looking at recipient age as continuous variable, receiving a younger heart was protective only for recipients younger than 45 years of age, and receiving a heart transplant from an older donor was detrimental only in recipients aged 25-35.

Donor-recipient age interaction and the impact on clinical results after heart transplantation

To evaluate the impact of donor-recipient age matching on clinical outcomes after heart transplantation, a total of 509 patients (January 1990-December 2018, mean follow-up 111 ± 80 months) were stratified into 4 groups (young-R/young-D, young-R/old-D, old-R/young-D, old-R/old-D) according to the recipient (young-R < 60, old-R ≥ 60 years) and the donor (young-D < 50, old-D ≥ 50 years) age. No difference was found among 30-day mortality (P = .11) and postoperative complications between groups. Both unadjusted and adjusted survival was significantly higher for group young-R/young-D than that of other groups, in which survival was similar [adjusted HR for mortality of 2.0(1.2-3.4), 2.1(1.4-3.8) and 2.5(1.6-4.1) for groups old-R/young-D, young-R/old-D, old-R/old-D, respectively]. Compared to other groups, the incidence of grade ≥ 2 CAV was significantly lower in old-R/young-D group [adjusted HR 0.4(0.2-0.7)]. Among young recipients, the rate of acute grade ≥ 2 rejection episodes was higher in those receiving an old donor graft (P = .04). Old recipient groups were more affected by neoplasms and severe renal failure than young recipient groups (P < .01). Employment of hearts from donors ≥50 years of age adversely affects survival in recipients <60 years of age but does not influence outcomes in older recipients. Also, donor and recipient ages seem to have opposite effects on incidence of rejections and CAV of high grade.

Review of the impact of donor characteristics on pediatric heart transplant outcomes

Heart transplantation (HTx) is a treatment option for end-stage heart failure in children. HTx is limited by the availability and acceptability of donor hearts. Refusal of donor hearts has been reported to be common with reasons for refusal including preexisting donor characteristics. This review will focus on the impact of donor characteristics and comorbidities on outcomes following pediatric HTx. A literature review was performed to identify articles on donor characteristics and comorbidities and pediatric HTx outcomes. There are many donor characteristics to consider when accepting a donor heart. Weight-based matching is the most common form of matching in pediatric HTx with a donor-recipient weight ratio between 0.7 and 3 having limited impact on outcomes. From an age perspective, donors <50 years can be carefully considered, but the impact of ischemic time needs to be understood. To increase the donor pool, with minimal impact on outcomes, ABO-incompatible donors should be considered in patients that are eligible. Other factors to be considered when accepting an organ is donor comorbidities. Little is known about donor comorbidities in pediatric HTx, with most of the data available focusing on infections. Being aware of the potential infections in the donor, understanding the testing available and risks of transmission, and treatment options for the recipient is essential. There are a number of donor characteristics that potentially impact outcomes following pediatric HTx, but these need to be taken into consideration along with their interactions with recipient factors when interpreting the outcomes following HTx.

Donor and recipient age matching in heart transplantation: analysis of the UNOS Registry

The association of donor and recipient age with survival following adult heart transplantation has not been well characterized. The purpose of this study was to examine the impact of the relationship between donor and recipient age on post-transplant survival. We retrospectively reviewed the 2005-2018 UNOS heart transplant database for all adult recipients undergoing first-time isolated heart transplantation. The impact of donor and recipient age on survival was analyzed with Cox proportional hazards modeling using restricted cubic splines. A total of 25 480 heart transplant donor and recipient pairs met inclusion criteria. Unadjusted and adjusted Cox proportional hazards modeling demonstrated a near-linear association between increasing donor age and decreased survival; in addition, older and younger recipient age was associated with decreased survival. After adjustment, there was no significant interaction between donor and recipient age. Older donors decreased survival similarly in both older and younger recipients. Increasing donor age and both younger and older recipient age are independently associated with worsened post-heart transplant survival. The relationship between donor and recipient age does not significantly affect survival following heart transplant.

Patient activation with respect to advanced heart failure therapy in patients over age 65 years

BACKGROUND

Clinical and ethical issues persist in determining candidacy for advanced heart failure (HF) therapies in elderly patients. Selection takes many factors into account, including "activation" (engagement and ability to self-manage).

OBJECTIVE

To investigate effects of age, activation, and depression/anxiety on selection and 6-month survival of participants considered for therapy.

METHODS

Consecutive people referred for advanced HF therapy completed the Patient Activation Measure and Hospital Anxiety and Depression Scale. We analyzed data from participants by age (≥65 vs. <65 years), stratified by approval for therapy.

RESULTS

Among 168 referred, 109 were approved, with no difference in activation between age groups (88% highly activated). Similarly, activation was not associated with age among those not approved. Activation was related to anxiety in older, approved participants, but not to depression.

CONCLUSIONS

Concerns regarding reduced self-management in the elderly may not be valid. Age alone should not disqualify a candidate for advanced HF therapy.

Heart Transplantation and Risk of Cardiac Vasculopathy Development: What Factors Are Important?

BACKGROUND The aim of this study was to find the main risk factors for development of cardiac allograft vasculopathy (CAV), especially factors identified before the surgical procedure and factors related to the recipient profile and the medical history of the donor. MATERIAL AND METHODS There were 147 patients who had heart transplantation (HT) included in this study: mean age was 45.8±15.3 years. All study patients had coronary angiography after HT. Analyzed risk factors were: non-immunologic recipient risk factors (age of transplantation, smoking, hypertension, lipids, diabetes, obesity and weight gain after HT), immunologic recipient risk factors (acute cellular rejection (ACR), acute humoral rejection (AMR), cytomegalovirus (CMV) episodes), and donor-related risk factors (age, sex, catecholamine usage, ischemic time, compatibility of sex and blood groups, cause of death, cardiac arrest). RESULTS CAV was recognized in 48 patients (CAV group); mean age 53.6±13.6 years. There were 99 patients without CAV (nonCAV group); mean age 48.3±15.5 years. A univariate Cox analysis of the development of coronary disease showed statistical significance (p<0.05) for baseline high-density lipid (HDL), ACR, AMR, CMV, and donor age. Multivariate Cox regression model confirmed that only baseline HDL, episodes of ACR, donor age, and CMV infection are significant for the frequency of CAV after HT. CONCLUSIONS Older donor age is highly associated with CAV development. Older donor age and low level of HDL in heart recipients with the strongest influence of immunologic risk factors (ACR, CMV infection) were linked with development of CAV.

Predictors of 1-year mortality in heart transplant recipients: a systematic review and meta-analysis

Objective

A systematic summary of the observational studies informing heart transplant guideline recommendations for selection of candidates and donors has thus far been unavailable. We performed a meta-analysis to better understand the impact of such known risk factors.

Methods

We systematically searched and meta-analysed the association between known pretransplant factor and 1-year mortality identified by multivariable regression models. Our review used the Grading of Recommendations, Assessment, Development and Evaluation for assessing the quality of assessment. We pooled risk estimates by using random effects models.

Results

Recipient variables including age (HR 1.16 per 10-year increase, 95% CI 1.10–1.22, high quality), congenital aetiology (HR 2.35, 95% CI 1.62 to 3.41, moderate quality), diabetes (HR 1.37, 95% CI 1.15 to 1.62, high quality), creatinine (HR 1.11 per 1 mg/dL increase, 95% CI 1.06 to 1.16, high quality), mechanical ventilation (HR 2.46, 95% CI 1.48 to 4.09, low quality) and short-term mechanical circulatory support (MCS) (HR 2.47, 95% CI 1.04 to 5.87, low quality) were significantly associated with 1-year mortality. Donor age (HR 1.20 per 10-year increase, 95% CI 1.14 to 1.26, high quality) and female donor to male recipient sex mismatch (HR 1.38, 95% CI 1.06 to 1.80, high quality) were significantly associated with 1-year mortality. None of the operative factors proved significant predictors.

Conclusion

High-quality and moderate-quality evidence demonstrates that recipient age, congenital aetiology, creatinine, pulsatile MCS, donor age and female donor to male recipient sex mismatch are associated with 1-year mortality post heart transplant. The results of this study should inform future guideline and predictive model development.

Immunological and Fibrotic Mechanisms in Cardiac Allograft Vasculopathy

Cardiac allograft vasculopathy (CAV) has a high prevalence among patients that have undergone heart transplantation. Cardiac allograft vasculopathy is a multifactorial process in which the immune system is the driving force. In this review, the data on the immunological and fibrotic processes that are involved in the development of CAV are summarized. Areas where a lack of knowledge exists and possible additional research can be completed are pinpointed. During the pathogenesis of CAV, cells from the innate and the adaptive immune system cooperate to reject the foreign heart. This inflammatory response results in dysfunction of the endothelium and migration and proliferation of smooth muscle cells (SMCs). Apoptosis and factors secreted by both the endothelium as well as the SMCs lead to fibrosis. The migration of SMCs together with fibrosis provoke concentric intimal thickening of the coronary arteries, which is the main characteristic of CAV.

Pediatric heart transplantation

Pediatric heart transplantation (pHTx) represents a small (14%) but very important and particular part in the field of cardiac transplantation. This treatment has lifelong impact on children. To achieve the best short and especially long-term survival with adequate quality of life, which is of crucial importance for this young patient population, one has to realize and understand the differences with adult HTx. Indication for transplantation, waitlist management including ABO incompatible (ABOi) transplantation and immunosuppression differ. Although young transplant recipients are ultimately likely to be considered for re-transplantation. One has to distinguish between myopathy and complex congenital heart disease (CHD). The differences in anatomy and physiology make the surgical procedure much more complex and create unique challenges. These recipients need a well-organized and educated team with pediatric cardiologists and intensivists, including a high skilled surgeon, which is dedicated to pHTx. Therefore, these types of transplants are best concentrated in specialized centers to achieve promising outcome.