Temporal trends in heart transplantation from high-risk donors: Are there lessons to be learned? A multi-institutional analysis

Donor risk analysis and validation in heart transplants: a single-centre experience

OBJECTIVES

A heart transplant (Htx) remains the gold standard treatment for patients with advanced heart failure. Considering the limited availability of organs, donor risk scores might improve organ selection and allocation. The objective of the study was to compare United Network for Organ Sharing, RADIAL and Eurotransplant scoring models in calculating post-Htx outcomes in an Italian Htx population.

METHODS

Between January 2000 and December 2017, a total of 461 adult patients underwent Htxs. United Network for Organ Sharing, RADIAL and Eurotransplant scores were calculated. Clinical features and donor risk scores were tested to identify preoperative, intraoperative and postoperative risk variables and eventually validate the scores on our population.

RESULTS

Early graft failure was detected in 16.1% (74/461). Post-Htx extracorporeal life support was used in 11.1% (51/461). Of the donor-related factors, the use of noradrenaline (P = 0.015) negatively influenced early outcomes, whereas an ischaemic time >240 min (P = 0.037) influenced early graft failure occurrence. The Eurotransplant donor score did not impact outcomes; the RADIAL score significantly influenced both early and late mortality; and the United Network for Organ Sharing score influenced only late mortality. On the multivariable analysis, after adjustment of scores per cohort, noradrenaline infusion was the main independent predictor of in-hospital mortality for the donors, whereas age of the recipient [odds ratio (OR) 1.003, 1.003-1.081; P = 0.032] and use of preoperative extracorporeal membrane oxygenation (OR 3.320, 1.124-9.805; P = 0.030) were the main independent predictors for the recipients.

CONCLUSIONS

None of the validated donor scoring systems fully behave as reliable predictors of transplant outcomes. According to our 'local only' graft selection, specific donor and recipient risk variables should be monitored in order to predict early and late outcomes satisfactorily.

Improved long-term outcomes after heart transplantation utilizing donors with a traumatic mode of brain death

Background

The donor’s mode of brain death (BD), being associated with impairment of myocardial function and hemodynamic performance, impacts the prognosis of the heart transplantation (HTx) recipient.

Methods

All patients who underwent HTx between 1996 and 2017 were categorized according to donor’s BD mechanism: traumatic BD (TBD) versus non-traumatic BD (NTBD).

Results

The TBD group included 105 recipients, and the NTBD group, 85 recipients. Kaplan-Meier survival analysis showed that overall survival was significantly higher for recipients of TBD hearts (10-year survival 58.1 vs. 37.6%, p = 0.044). Consistently, multivariate analysis showed that TBD was independently associated with a significant 43% reduction in mortality [95% confidence interval (CI) 0.42–0.75, p = 0.033]. Rejection rate was lower in the TBD group (total rejection score 0.44 ± 0.32 vs. 0.51 ± 0.38, p = 0.04; any rejection score 0.38 ± 0.26 vs. 0.45 ± 0.31, p = 0.030), and freedom from cardiac allograft vasculopathy (CAV) was significantly higher in recipients of traumatic vs. non-traumatic donors (10 years: 82.9 vs. 62.4%, log-rank p-value = 0.024). Multivariate analysis showed a significant 42% reduction in CAV [hazard ratio (HR) = 0.58, 95% CI 0.51–0.85, p = 0.022).

Conclusion

Mode of brain death significantly impacts HTx outcomes, with TBD being associated with reduced mortality, rejections and CAV.

Readmission and resource utilization after orthotopic heart transplant versus ventricular assist device in the National Readmissions Database, 2010-2014

BACKGROUND

As the technology of ventricular assist devices continues to improve, the morbidity and mortality for patients with a ventricular assist device is expected to approach that of orthotopic heart transplantation. The present study was performed to compare perioperative outcomes, readmission, and resource utilization between ventricular assist device implantation and orthotopic heart transplantation, using a national cohort.

METHODS

Patients who underwent either orthotopic heart transplantation or ventricular assist device implantation from 2010 to 2014 in the National Readmission Database were selected.

RESULTS

Of the 12,111 patients identified during the study period, 5,440 (45%) received orthotopic heart transplantation, while 6,671 (55%) received ventricular assist devices. Readmissions occurred frequently after ventricular assist device implantation and orthotopic heart transplantation, with greater rates at 30 days (29% versus 24%, P=.005) and 6 months (62% versus 46%, P < .001) for the ventricular assist device cohort. Cost of readmission was greater among ventricular assist device patients at 30 days ($29,115 versus $21,586, P=.0002) and 6 months ($34,878 versus $20,144, P = .0106).

CONCLUSION

Readmission rates and costs for patients with a ventricular assist device remain greater than their orthotopic heart transplantation counterparts. Given the projected increases in ventricular assist device utilization and limited transplant donor pool, further emphasis on cost containment and decreased readmissions for patients undergoing a ventricular assist device is essential to the viability of such therapy in the era of value-based health care delivery.

Maximizing donor allocation: A review of UNOS region 9 donor heart turn-downs

This study was performed to determine if organ selection practices for heart utilization by Region 9 transplant programs were optimal, and to identify opportunities to increase local organ recovery. A retrospective review of de-identified region-wide donor data January 1, 2010 through December 31, 2013 was performed. Over the study period 537 heart donors were identified, of which 321 (60%) were transplanted. Two hundred-sixteen consented hearts were not used; 190 of these were not recovered, and 26 were recovered but not transplanted. Of these, 245/321 (76%) hearts were transplanted at one of 5 regional programs, 15 (5%) were transplanted out of region as primary offers, and 61 (19%) were turned down in region and exported. Of the 61 exported hearts, 43 were turned down in region for donor-related "quality" codes (UNOS 830, 833-837) by at least one program, the remaining 18 hearts were turned down for non-"quality" reasons, primarily histocompatibility and size. Only 5/43 exported were turned down for "quality" reasons by all regional programs offered the organ. A review of consented, not recovered donor offers suggested an additional 28 organs were possibly appropriate for transplant. Our review of regional turn-downs suggests transplant centers could potentially identify additional usable organs without compromising short-term outcomes.

Pediatric Heart Donor Assessment Tool (PH-DAT): A novel donor risk scoring system to predict 1-year mortality in pediatric heart transplantation

BACKGROUND

In this study we sought to quantify hazards associated with various donor factors into a cumulative risk scoring system (the Pediatric Heart Donor Assessment Tool, or PH-DAT) to predict 1-year mortality after pediatric heart transplantation (PHT).

METHODS

PHT data with complete donor information (5,732) were randomly divided into a derivation cohort and a validation cohort (3:1). From the derivation cohort, donor-specific variables associated with 1-year mortality (exploratory p-value < 0.2) were incorporated into a multivariate logistic regression model. Scores were assigned to independent predictors (p < 0.05) based on relative odds ratios (ORs).

RESULTS

The final model had an acceptable predictive value (c-statistic = 0.62). The significant 5 variables (ischemic time, stroke as the cause of death, donor-to-recipient height ratio, donor left ventricular ejection fraction, glomerular filtration rate) were used for the scoring system. The validation cohort demonstrated a strong correlation between the observed and expected rates of 1-year mortality (r = 0.87). The risk of 1-year mortality increases by 11% (OR 1.11 [1.08 to 1.14]; p < 0.001) in the derivation cohort and 9% (OR 1.09 [1.04 to 1.14]; p = 0.001) in the validation cohort with an increase of 1-point in score. Mortality risk increased 5 times from the lowest to the highest donor score in this cohort. Based on this model, a donor score range of 10 to 28 predicted 1-year recipient mortality of 11% to 31%.

CONCLUSION

This novel pediatric-specific, donor risk scoring system appears capable of predicting post-transplant mortality. Although the PH-DAT may benefit organ allocation and assessment of recipient risk while controlling for donor risk, prospective validation of this model is warranted.

Heart transplantation research in the next decade--a goal to achieving evidence-based outcomes: National Heart, Lung, And Blood Institute Working Group

The National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group (WG) on August 5 to 6, 2010 in Bethesda, Maryland to discuss future directions of research in heart transplantation (HT). The WG was composed of researchers with expertise in the basic science, clinical science, and epidemiological aspects of advanced heart failure and HT. These experts were asked to identify the highest priority research gaps in the field and make recommendations for future research strategies. The WG was also asked to include approaches that capitalize on current scientific opportunities and focus on areas that required unique NHLBI leadership. Finally, the WG was charged with developing recommendations that would have short- and long-term impact on the field of HT. The WG participants reviewed key areas in HT and identified the most urgent knowledge gaps. These gaps were then organized into the following 4 specific research directions: 1) enhanced phenotypic characterization of the pre-transplant population; 2) donor-recipient optimization strategies; 3) individualized immunosuppression therapy; and, 4) investigations of immune and non-immune factors affecting late cardiac allograft outcomes. Finally, because the HT population is relatively small compared with other patient groups, the WG strongly urged concerted efforts to enroll every transplant recipient into a clinical study and to increase collaborative networks to optimize research in this field.

Donor scoring system for heart transplantation and the impact on patient survival

BACKGROUND

The aim of this study was to design and validate a heart donor score that reflects experts' perceived risk of allograft failure.

METHODS

All heart donors reported to Eurotransplant between January 1, 2005 and December 31, 2008 (N = 4,110) were used to create a donor score. Based on observed discard rates and using multivariate regression, points were assigned for the following donor factors: age; cause of death; body mass index (BMI); diabetes mellitus (DM); duration of ICU stay; compromised history (drug, abuse, sepsis, meningitis, malignancy, HBsAg(+) or anti-HCV(+)); hypertension; cardiac arrest; echocardiography; coronary angiogram; serum sodium; and noradrenaline and dopamine/dobutamine doses. The donor score was obtained by adding all points. All heart donors reported to Eurotransplant in 2009 were included to validate the score (N = 885).

RESULTS

All donor factors, except BMI, DM and duration of ICU stay, significantly predicted discard. Based on the median value of the score, donors were classified into low-risk donors (LRDs: ≤16 points) and high-risk donors (HRDs: ≥17 points). In the validation set, discard rates were significantly different when comparing HRDs (35%) and LRDs (7%) (p < 0.0001). In addition, the heart donor score was significantly associated with 3-year survival: LRD 81.5% vs HRD 70.0% (p = 0.004).

CONCLUSIONS

The heart donor score accurately reflects the likelihood of organ acceptance and predicts long-term patient mortality. Application of this score at time of donor reporting may facilitate donor risk assessment and allow for more appropriate matching of extended criteria donor hearts.