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

Donor-recipient age- or sex-mismatched osteochondral allografts do not adversely affect cumulative graft survival rates after transplantation in the knee

BACKGROUND

Osteochondral allograft transplantation (OCAT) can be performed without the need for blood-type matching or anti-rejection medications. However, other donor-recipient mismatch variables could influence outcomes. Therefore, it is critical to examine the impacts of sex and age mismatching on functional OCA survival.

METHODS

Prospectively collected data for patients undergoing primary knee OCAT enrolled in a lifelong outcomes registry were analyzed for functional OCA survival based on sex- and age-matched and -mismatched cohorts. Treatment failure was defined as the need for OCAT revision surgery or knee arthroplasty.

RESULTS

162 donor-recipient pairs were analyzed; 57 (35.2%) were sex-mismatched and 89 (54.9%) were age-mismatched. Sex-mismatched OCATs were not associated with a significantly different cumulative graft survival rate when compared to sex-matched OCATs (78.9% vs 75.2% p = 0.324). Age-mismatched OCATs were not associated with a significantly different cumulative graft survival rate when compared to age-matched OCATs (71.6% vs 81.5% p = 0.398). When adjusting for sex, BMI, concomitant procedures, and surgery type, age-mismatched and sex-mismatched OCATs were not significantly associated with higher likelihood for treatment failure.

CONCLUSION

By analyzing functional graft survival rates for donor-recipient sex- or age-mismatched OCAs following primary OCAT, the results of the present study support current donor-recipient matching protocols for OCA transplantation in the knee. Based on current evidence, donor-recipient blood-type, sex-, and age-matching are not required for safe and effective primary OCAT in the knee. However, further studies are imperative for defining modifiable variables that further optimize safety and outcomes while maximizing donor tissue quality, availability, access, and use.

Donor age and ischemic time in heart transplantation - implications for organ preservation

BACKGROUND

The Organ Care System and Non-ischemic Heart Preservation methods have emerged as significant advancements in heart transplantation, designed to mitigate ischemic injury and extend preservation times. However, their high costs and logistical complexities necessitate strategic utilization.

METHODS

We evaluated data from 83,761 heart transplants registered in the International Society for Heart and Lung Transplantation registry from 1988 to 2018. Utilizing a Cox proportional hazards model, we explored the influence of donor age and ischemic time on transplant survival. A key innovation of our study is the development of a nomogram to predict post-transplant survival, incorporating both traditional and advanced statistical methods.

RESULTS

The median age of recipients was 52 years (22% female) and 33 years (31% female) for donors. Analysis revealed a median ischemic time of 3 hours and median survival of 11.5 years across the cohort. The nomogram showed a decline in survival probabilities with increasing donor age, notably from age 40 and more significantly with ischemic times >4 hours. Ischemic times ≥4 hours versus <2 hours were associated with hazard ratio (HR) of 1.2 (95% CI, 1.1-1.3) for donors aged 40-59, a disparity that escalated for donors aged ≥60 (HR: 2.0; 95% CI, 1.5-2.7).

CONCLUSIONS

This study highlights the importance of careful donor selection and indicates that certain groups, particularly older donors with prolonged ischemic times, might benefit from ex-vivo preservation techniques. The developed nomogram offers a practical tool for clinicians, enhancing decision-making by providing detailed insights into the relationship between donor age, ischemic time, and post-transplant mortality.

Donor and Recipient Age Influence Outcomes Following Orthotopic Heart Transplantation in the 2018 US Heart Allocation System

BACKGROUND

This study evaluates the interaction of donor and recipient age with outcomes following heart transplantation under the 2018 heart allocation system.

METHODS

The United Network for Organ Sharing registry was queried to analyze adult primary isolated orthotopic heart transplant recipients and associated donors from August 18, 2018, to June 30, 2021. Both recipient and donor cohorts were grouped according to age: <65 and ≥65 y for recipients and <50 and ≥50 y for donors. The primary outcome was survival. Subanalyses were performed to evaluate the impact of donor age.

RESULTS

A total of 7601 recipients and 7601 donors were analyzed. Of these, 1584 recipients (20.8%) were ≥65 y old and 560 donors (7.4%) were ≥50 y old. Compared with recipients <65, recipients ≥65 had decreased 1-y (88.8% versus 92.3%) and 2-y (85.1% versus 88.5%) survival rates (P < 0.001). The association of recipient age ≥65 with lower survival persisted after adjusting for potential cofounders (hazard ratio, 1.38; 95% confidence interval, 1.18-1.61; P < 0.001). Recipients <65 with donors ≥50 had comparable 1-y and 2-y survival rates to recipients <65 with donors <50 (P =0.997). Conversely, transplantation of older allografts was associated with lower 1-y (84.2% versus 89.4%) and 2-y (79.5% versus 85.8%) survival rates in recipients ≥65 (P = 0.025).

CONCLUSIONS

Recipient age ≥65 continues to be associated with worse survival following heart transplantation in the 2018 heart allocation system compared with younger recipients. Donors ≥50 may be acceptable among recipients <65 with comparable outcomes. However, careful donor age selection should be considered for recipients ≥65, as the use of younger donor allografts appears to improve posttransplantation survival.

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.

Metabolic Syndrome and Heart Transplantation: An Underestimated Risk Factor?

Metabolic Syndrome (MetS), a multifactorial condition that increases the risk of cardio-vascular events, is frequent in Heart-transplant (HTx) candidates and worsens with immunosuppressive therapy. The aim of the study was to analyze the impact of MetS on long-term outcome of HTx patients. Since 2007, 349 HTx patients were enrolled. MetS was diagnosed if patients met revised NCEP-ATP III criteria before HTx, at 1, 5 and 10 years of follow-up. MetS was present in 35% of patients pre-HTx and 47% at 1 year follow-up. Five-year survival in patients with both pre-HTx (65% vs. 78%, p < 0.01) and 1 year follow-up MetS (78% vs 89%, p < 0.01) was worst. At the univariate analysis, risk factors for mortality were pre-HTx MetS (HR 1.86, p < 0.01), hypertension (HR 2.46, p < 0.01), hypertriglyceridemia (HR 1.50, p=0.03), chronic renal failure (HR 2.95, p < 0.01), MetS and diabetes at 1 year follow-up (HR 2.00, p < 0.01; HR 2.02, p < 0.01, respectively). MetS at 1 year follow-up determined a higher risk to develop Coronary allograft vasculopathy at 5 and 10 year follow-up (25% vs 14% and 44% vs 25%, p < 0.01). MetS is an important risk factor for both mortality and morbidity post-HTx, suggesting the need for a strict monitoring of metabolic disorders with a careful nutritional follow-up in HTx patients.

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.

Contemporary contribution of cardiac surgery for the treatment of cardiomyopathies and pericardial diseases

Cardiomyopathy refers to a spectrum of heterogeneous myocardial disorders characterized by morphological and structural alterations leading eventually to heart failure, by affecting cardiac filling and/or the cardiac systolic function. Heart transplantation is currently the gold standard surgical treatment for patients with heart failure, with a median survival in adults of 12 years according to international registries. However, the limited available donor pool does not allow its extensive employment. For this reason, mechanical circulatory supports are increasingly used, and in the short term are becoming as possible alternatives to heart transplantation, owing to improved technologies and increased biocompatibility. However, long-term outcomes of mechanical assist devices are still burdened with a high rate of adverse events. Conventional surgical treatments could be still considered as alternatives to heart replacement treatment when tailored both on patient clinical conditions and etiology of cardiac diseases. In particular, among patients affected by ischemic cardiomyopathy, coronary artery bypass grafting has proven to improve survival when associated to optimal medical treatment, and surgical ventricular restoration might be considered as a valid treatment in particular cases. Correction of functional mitral valve regurgitation by mitral annuloplasty, which aims to restore left ventricular geometry, has not demonstrated unambiguous results, and outcomes of this procedure are still controversial. Pericardial pathology becomes of surgical interest when it is responsible for a reduced filling capacity of the heart chambers, which can develop acutely (cardiac tamponade) or chronically (as in the case of constrictive pericarditis). This review focuses on the different surgical approaches that could be adopted to treat patients with heart failure and pericardial diseases.