Does donor‐recipient age difference matter in outcome of heart transplantation?

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.

Artificial intelligence-derived cardiac ageing is associated with cardiac events post-heart transplantation

Aims

An artificial intelligence algorithm detecting age from 12-lead electrocardiogram (ECG) has been suggested to reflect 'physiological age'. An increased physiological age has been associated with a higher risk of cardiac mortality in the non-transplant population. We aimed to investigate the utility of this algorithm in patients who underwent heart transplantation (HTx).

Methods and results

A total of 540 patients were studied. The average ECG ages within 1 year before and after HTx were used to represent pre- and post-HTx ECG ages. Major adverse cardiovascular event (MACE) was defined as any coronary revascularization, heart failure hospitalization, re-transplantation, and mortality. Recipient pre-transplant ECG age (mean 63 ± 11 years) correlated significantly with recipient chronological age (mean 49 ± 14 years, R = 0.63, P < 0.0001), while post-transplant ECG age (mean 54 ± 10 years) correlated with both the donor (mean 32 ± 13 years, R = 0.45, P < 0.0001) and the recipient ages (R = 0.38, P < 0.0001). During a median follow-up of 8.8 years, 307 patients experienced MACE. Patients with an increase in ECG age post-transplant showed an increased risk of MACE [hazard ratio (HR): 1.58, 95% confidence interval (CI): (1.24, 2.01), P = 0.0002], even after adjusting for potential confounders [HR: 1.58, 95% CI: (1.19, 2.10), P = 0.002].

Conclusion

Electrocardiogram age-derived cardiac ageing after transplantation is associated with a higher risk of MACE. This study suggests that physiological age change of the heart might be an important determinant of MACE risk post-HTx.

Heart Transplantation of the Elderly-Old Donors for Old Recipients: Can We Still Achieve Acceptable Results?

As society is ageing, an increasing prevalence of elderly heart failure patients will be expected. In order to increase the donor pool, acceptance of older donors might be a reasonable choice. All patients undergoing heart transplantation between 2010 and 2021 at a single department were retrospectively reviewed and divided into different study groups with regard to recipient (≤60 years (R^Y) or >60 years (R^O)) and donor age (≤50 years (D^Y) or >50 years (D^O). A total of n = 201 patients were included (D^Y/R^Y, n = 91; D^O/R^Y, n = 38; D^Y/R^O, n = 41; D^O/R^O, n = 31). Neither incidence of severe primary graft dysfunction (p = 0.64) nor adverse events, such as kidney failure (p = 0.27), neurological complications (p = 0.63), infections (p = 0.21) or acute graft rejection (p = 1.00), differed between the groups. However, one-year survival was impaired in the D^O/R^O group (56.0%) compared to the other groups (D^Y/R^Y: 86.1%, D^Y/R^O: 78.8%, D^O/R^Y: 74.2%, p = 0.02). Given the impaired one-year survival, acceptance of grafts from old donors for old recipients should be performed with caution and by experienced centres only. Nevertheless, because of the otherwise dismal prognosis of elderly heart failure patients, transplantation of patients may still improve the therapy outcome.

Evaluation of donor heart for transplantation

Cardiac transplantation is considered the gold-standard treatment option for patients suffering from end-stage heart failure refractory to maximum medical therapy. A major determinant of graft function and recipient survival is a comprehensive evaluation of the donor allograft. Challenges arise when designing and implementing an evidence-based donor evaluation protocol due to the number of influential donor-specific characteristics and the complex interactions that occur between them. Here, we present our systematic approach to donor evaluation by examining the impact that relevant donor variables have on graft function and recipient outcomes.

Incidence and impact of primary graft dysfunction in adult heart transplant recipients: A systematic review and meta-analysis

PURPOSE

Primary graft dysfunction (PGD) is a leading cause of early mortality after heart transplant (HTx). To identify PGD incidence and impact on mortality, and to elucidate risk factors for PGD, we systematically reviewed studies using the ISHLT 2014 Consensus Report definition and reporting the incidence of PGD in adult HTx recipients.

METHODS

We conducted a systematic search in January 2020 including studies reporting the incidence of PGD in adult HTx recipients. We used a random effects model to pool the incidence of PGD among HTx recipients and, for each PGD severity, the mortality rate among those who developed PGD. For prognostic factors evaluated in ≥2 studies, we used random effects meta-analyses to pool the adjusted odds ratios for development of PGD. The GRADE framework informed our certainty in the evidence.

RESULTS

Of 148 publications identified, 36 observational studies proved eligible. With moderate certainty, we observed pooled incidences of 3.5%, 6.6%, 7.7%, and 1.6% and 1-year mortality rates of 15%, 21%, 41%, and 35% for mild, moderate, severe and isolated right ventricular-PGD, respectively. Donor factors (female sex, and undersized), recipient factors (creatinine, and pre-HTx use of amiodarone, and temporary or durable mechanical support), and prolonged ischemic time proved associated with PGD post-HTx.

CONCLUSION

Our review suggests that the incidence of PGD may be low but its risk of mortality high, increasing with PGD severity. Prognostic factors, including undersized donor, recipient use of amiodarone pre-HTx and recipient creatinine may guide future studies in exploring donor and/or recipient selection and risk mitigation strategies.

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.

Relation of Length of Survival After Orthotopic Heart Transplantation to Age of the Donor

We aim to evaluate the impact of donor age on the outcomes in orthotropic heart transplantation recipients. The United Network for Organ Sharing database was queried for adult patients (age; ≥60) underwent first-time orthotropic heart transplantation between 1987 and 2019 (n = 18,447). We stratified the cohort by donor age; 1,702 patients (9.2%) received a heart from a donor age of <17 years; 11,307 patients (61.3%) from a donor age of 17 ≥, < 40; 3,525 patients (19.1%) from a donor age of 40 ≥, < 50); and 1,913 patients (10.4%) from a donor age of ≥50. There was a significant difference in the survival likelihood (p < 0.0001) based on donor's age-based categorized cohort, however, the median survival was 10.5 years in the cohort in whom the donor was <17, 10.3 years in whom the donor was 17 ≥, < 40, 9.4 years in whom the donor was 40 ≥, < 50, and 9.0 years in whom the donor was ≥ 50. Additionally, there was no significant difference in the episode of acute rejection (p = 0.19) nor primary graft failure (p = 0.24). In conclusion, this study demonstrated that patients receiving hearts from the donor age of ≥50 years old showed slight inferior survival likelihood, but appeared to be equivalent median survival.

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.