Clinical significance of weight difference between donor and recipient in heart transplantation

Impact of predicted heart mass-based size matching on survival after heart transplantation in Korea: Analysis of the Korean Organ Transplant Registry

BACKGROUND

Previous studies regarding donor-recipient size and sex matching in heart transplantation (HTx) mainly included Caucasians with only a small portion of Asians. Even predicted heart mass (PHM) has not yet been elucidated in Asians. We evaluated the association between donor-recipient sex and size matching, including mismatching by PHM, and post-heart transplant survival in Korea.

METHODS

We enrolled 660 adult HTx recipients between January 2014 and December 2020 using the Korean Organ Transplant Registry data. Recipients were categorized based on donor-recipient PHM, body weight, and sex matching. The primary outcome was 1-year mortality and retransplantation after HTx and survival analyses were performed using Kaplan-Meier method and Cox proportional hazard models.

RESULTS

Among 660 patients, 74 (11.2%), 404 (61.2%), and 182 (27.6%) received undersized (<-15%), matched (-15% to 20%), and oversized (>20%) hearts by PHM, respectively. Size mismatching by PHM was present in a large number of sex-mismatched patients with 85.1% of male donor-female recipients being classified as oversized by PHM and 62.2% of female donor-male recipients being classified as undersized by PHM. Recipients of undersized or oversized hearts by PHM showed an increased 1-year mortality compared with recipients of matched-size hearts (14.8% versus 9.7%; log-rank p = 0.038). The increased mortality persisted after adjusting for other factors affecting mortality (hazard ratio = 1.60, 95% confidence interval: 1.01-2.56). These associations were not shown in obese recipients (body mass index ≥25 kg/m²). Heart size mismatching by body weight (log-rank p = 0.332) or sex mismatching (all, log-rank p > 0.05) did not predict 1-year mortality after HTx.

CONCLUSION

Heart size matching by PHM, not by body weight or sex, was associated with increased 1-year mortality after HTx in Korea.

Impact of donor-to-recipient weight ratio on the hospital outcomes of pediatric heart transplantation

Background

Identifying the factors that can influence the prognosis and final outcomes of pediatric heart transplantation is important and makes it possible to prevent complications and improve outcomes. Coordination of donor characteristics with the recipient in terms of sex, weight, body mass index (BMI), and body surface area (BSA) is an important factor that can influence the outcome of the transplantation. There is still no consensus regarding the role of discrepancy in anthropometrics between donors and recipients. The aim of this study was to investigate the relationship between donor and recipient weight mismatch on the early outcomes of pediatric heart transplantation. In this historical cohort study, 80 children who had underwent heart transplantation for the first time between 2014 and 2019 in Shahid Rajaie Cardiovascular Medical and Research Center in Tehran, Iran, were enrolled and divided into three groups according to donor-to-recipient weight ratio (0.8 < D/RW ≤ 1.5, 1.5 < D/RW ≤ 2.5, and 2.5 < D/RW). The early outcomes of transplantation, during the first post-transplant month, including right heart failure, renal failure, graft rejection, inotrope dependency, duration of intubation, length of ICU stay, death and requiring extracorporeal membrane oxygenation, were recorded through reviewing patient records.

Results

Median donor-to-recipient BSA ratio was directly associated with higher vasoactive–inotropic score (P = 0.038), while no significant association was found between donor-to-recipient weight ratio and vasoactive–inotropic score (P = 0.07). No significant relationship was found between other outcomes and donor-to-recipient weight ratio or donor-to-recipient BSA ratio.

Conclusions

Patients who require heart transplantation may also benefit from mismatch donors, especially in those with significant cardiomegaly.

Impact of various sizing metrics on female donor to male recipient heart transplant outcomes

BACKGROUND

This study evaluated the impact of various sizing metrics on outcomes of female donor to male recipient orthotopic heart transplantation (OHT).

METHODS

We queried the United Network of Organ Sharing database to analyze all isolated, primary adult OHTs from January 1, 2010 to January 20, 020. Patients were stratified by donor-recipient sex pairing. Logistic regression was used to investigate risk-adjusted effects of current size matching criteria (weight ratio, body mass index [BMI] ratio, predicted heart mass [pHM] ratio) on 1-year posttransplant mortality. Kaplan-Meier analysis was used to compare posttransplant survival among cohorts.

RESULTS

A total of 22,450 patients were analyzed, of which 3019 (13.4%) underwent female-to-male transplantation. Of sex-matched pairs, female-to-male donation had the lowest proportion of undersized hearts using weight and BMI ratio metrics (10.5% and 5.2%) but had the highest proportion of undersizing using pHM metrics (48.1%) (all p < 0.001). Female-to-male recipients had the lowest rate of unadjusted 1-year survival (90.0%, p = 0.0169), and increased hazards of mortality after risk adjustment (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.01-1.36, p = 0.034). Undersizing using pHM (donor-recipient ratio <0.85) was the only metric found to be associated in increased mortality after risk adjustment (OR: 1.32, 95% CI: 1.02-1.71, p = 0.035).

CONCLUSION

Female-to-male heart transplantation has the worst survival of all sex-matching combinations. Although female donors in this cohort are appropriately sized using traditional metrics, half are under-sized using pHM. This, combined with its strong association with mortality, underscores the importance of routine pHM assessment when evaluating female donors for male recipients.

Size matching in heart transplantation: Is predicted heart mass the optimal method in a United Kingdom cohort?

Predicted heart mass (PHM) equations have been proposed as an alternative method for size matching in heart transplantation. We assessed association between donor-recipient size mismatch, defined using PHM equations, and survival post-heart transplant in the United Kingdom. Data from all adult patients who received a heart transplant between 1995 and 2017 were obtained from the United Kingdom Transplant Registry. PHM was calculated using published equations. Primary outcome was 1-year survival post-heart transplantation. Recipients of undersized organs had reduced 1-year survival (HR 1.31, 95% CI 1.03-1.67, p = .03). Oversizing had no impact on survival (HR 0.99, 95% CI 0.78-1.26, p = .96). Gender mismatching had no impact on survival in the cohort matched by PHM (HR 1.12, 95% CI 0.86-1.47, p = .4). In recipients without pulmonary hypertension, undersizing by PHM had no impact on 1-year survival (HR 0.95, 95% CI 0.61-1.49, p = .83). In recipients with pulmonary hypertension, oversizing donor RV by using PHM RV equation (PHM_RV ) results in improved survival at 1 year (HR 0.65, 95% CI 0.5-0.83, p = .001). In conclusion, receiving an organ undersized by PHM was associated with decreased 1-year survival. Subgroup analyses demonstrated that undersizing only impacted survival in recipients with pulmonary hypertension and that these recipients had improved outcomes if they received an organ with an RV oversized by >10% by PHM_RV .

CARDIAC TRANSPLANT -A SINGLE CENTRE RETROSPECTIVE OBSERVATION

Background and Aim: Advances in pharmacological and nonpharmacological management of heart failure shifted the paradigm to transplantation of heart. Currently so many centers are doing heart transplant as the availability of donors and recipients are increasing day by day. The goal of this study is to share our experience in all our heart transplantation procedures. Ours is a tertiary care government multi super Speciality hospital. In our institute we have been doing cardiac surgeries for six years and heart transplants for past three years. In this discussion we share our experience about how we did all the procedures in our center . Method: After getting approval from institutional research committee we analyzed 8 transplants done in our center. The preoperative optimization, monitoring tools, anesthetic technique and post-operative complications and management are discussed . Apart from routine monitors we have used BIS, Cerebral oximetry and cardiac output monitors. Result: Of the eight cases, six are doing well including a (pediatric) 10-year-old recipient. Of the remaining two, one patient died on 3rd Post-Operative Day due to acute kidney injury and the other was death due to acute rejection. Conclusion: The key points we have learnt from our experience are careful selection and preparation of the donor, adequate preload with optimal inotropic support during weaning, minimizing increase in pulmonary vascular resistance and good pain relief are key aspects for successful outcome.

Predicted heart mass-based size matching among recipients with moderate pulmonary hypertension: Outcomes and sex effect

BACKGROUND

There is a lack of evidence to guide appropriate donor sizing in recipients with moderate pulmonary hypertension (pHTN) awaiting heart transplantation (HTx). It is common practice to oversize donor hearts for such recipients to prevent post-operative right ventricular failure. Therefore, our objective was to determine if oversizing in pre-transplant moderate pHTN provides a survival advantage.

METHODS

The United Network for Organ Sharing database was analyzed to include HTx recipients from 1994 to 2016. Recipients were considered as having moderate pHTN if the pulmonary vascular resistance (PVR) was 2.5 to 5 Wood units (WU) or transpulmonary gradient (TPG) was 10 to 18 mm Hg. Heart size mismatch was determined using the predicted heart mass equations. A size mismatch of ≥15% in either direction was considered undersized or oversized, respectively. Ninety-day and 1-year survival were analyzed based on size matching via univariate and Cox regression analysis. Propensity matching was performed to specifically evaluate the effect of donor sex among male transplant recipients.

RESULTS

Among 29,441 HTx recipients, 10,666 had moderate pHTN by PVR criteria and 12,624 HTx patients had moderate pHTN according to TPG criteria. Among patients with a PVR of 2.5 to 5 WU, oversizing was not associated with lower mortality compared with matched hearts at 90 days (7.6% vs 7.4%; p = 0.75) and 1 year (12.1% vs 11.3%; p = 0.26). Conversely, undersizing the donor was associated with a higher 90-day (10.6% vs 7.6% vs 7.4%; p < 0.01) and 1-year (15.3% vs 12.1% vs 11.3%; p < 0.01) mortality than recipients receiving oversized or matched hearts, respectively. On Cox regression analysis, there was no benefit with oversizing at 90 days (hazard ratio [HR] 0.88; p = 0.23) and 1 year (HR 0.99; p = 0.90), whereas undersizing was associated with higher 90-day (HR 1.32; p = 0.02) and 1-year mortality (HR 1.23; p = 0.03) compared to size-matched controls. Among patients with moderate pHTN based on TPG of 10 to 18 mm Hg, neither undersizing nor oversizing was predictive of mortality at 90 days and 1 year according to Cox regression analysis. Propensity matching revealed that female-to-male transplantation had similar 1-year mortality to male-to-male transplantation, and there was no advantage to oversizing female donors for male recipients.

CONCLUSIONS

In this registry-based analysis, there was no benefit to oversizing donors for cardiac transplant recipients with moderate pHTN. Elimination of this restriction could increase the donor pool and reduce wait times for such recipients.

Validation of Cardiovascular Magnetic Resonance-Derived Equation for Predicted Left Ventricular Mass Using the UK Biobank Imaging Cohort: Tool for Donor-Recipient Size Matching

BACKGROUND

Current guidance from International Society for Heart and Lung Transplantation recommends using body weight for donor-recipient size matching for heart transplantation. However, recent studies have shown that predicted heart mass, using body weight, height, age, and sex, may represent a better method of size matching. We aim to validate a cardiovascular magnetic resonance (CMR)-derived equation for predicted left ventricular mass (LVM) in a cohort of normal individuals in the United Kingdom.

METHODS

This observational study was conducted in 5065 middle-aged (44-77 years old) UK Biobank participants who underwent CMR imaging in 2014 to 2015. Individuals with cancer diagnosis in the previous 12 months or history of cardiovascular disease were excluded. Predicted LVM was calculated based on participants' sex, height, and weight recorded at the time of imaging. Correlation analyses were performed between the predicted LVM and the LVM obtained from manual contouring of CMR cine images. The analysis included 3398 participants (age 61.5±7.5 years, 47.8% males).

RESULTS

Predicted LVM was considerably higher than CMR-derived LVM (mean±SD of 138.8±28.9 g versus 86.3±20.9 g). However, there was a strong correlation between the 2 measurements (Spearman correlation coefficient 0.802, P<0.0001).

CONCLUSIONS

Predicted LVM calculated using a CMR-derived equation that incorporates height, weight, and sex has a strong correlation with CMR LVM in large cohort of normal individuals in the United Kingdom. Our findings suggest that predicted heart mass equations may be a valid tool for donor-recipient size matching for heart transplantation in the United Kingdom.

Alternative methods for virtual heart transplant-Size matching for pediatric heart transplantation with and without donor medical images available

BACKGROUND

Listed pediatric heart transplant patients have the highest solid-organ waitlist mortality rate. The donor-recipient body weight (DRBW) ratio is the clinical standard for allograft size matching but may unnecessarily limit a patient's donor pool. To overcome DRBW ratio limitations, two methods of performing virtual heart transplant fit assessments were developed that account for patient-specific nuances. Method 1 uses an allograft total cardiac volume (TCV) prediction model informed by patient data wherein a matched allograft 3-D reconstruction is selected from a virtual library for assessment. Method 2 uses donor images for a direct virtual transplant assessment.

METHODS

Assessments were performed in medical image reconstruction software. The allograft model was developed using allometric/isometric scaling assumptions and cross-validation.

RESULTS

The final predictive model included gender, height, and weight. The 25th-, 50th-, and 75th-percentiles for TCV percentage errors were -13% (over-prediction), -1%, and 8% (under-prediction), respectively. Two examples illustrating the potential of virtual assessments are presented.

CONCLUSION

Transplant centers can apply these methods to perform their virtual assessments using existing technology. These techniques have potential to improve organ allocation. With additional experience and refinement, virtual transplants may become standard of care for determining suitability of donor organ size for an identified recipient.

Predicted heart mass is the optimal metric for size match in heart transplantation

BACKGROUND

Donor-recipient size match is traditionally assessed by body weight. We assessed the ability of 5 size match metrics-predicted heart mass (PHM), weight, height, body mass index (BMI) and body surface area (BSA)-to predict 1-year mortality after heart transplant and to assess the effect of size match on donor heart turn down for size.

METHODS

The study cohort comprised 19,168 adult heart transplant recipients in the United Network for Organ Sharing registry between 2007 and 2016. Each size match metric was divided into 7 equally sized groups using the donor-recipient ratio for each metric. Single and multivariable Cox proportional hazard models for mortality 1 year after transplant were constructed.

RESULTS

Recipients in the severely (donor-recipient PHM ratio 0.54-0.86) undersized group for PHM experienced increased mortality, with a hazard ratio of 1.34 (95% confidence interval, 1.13-1.59; p < 0.001). There was no increased risk of death at 1 year if donors were undersized for weight, height, BMI, or BSA. We found that 32% of heart offers turned down for donor size would be acceptable using a PHM threshold of 0.86 or greater and that 14% of offers accepted (most of which are female donor to male recipient) were below this threshold.

CONCLUSIONS

PHM is the optimal donor-recipient size match metric for prediction of mortality after heart transplant. Many offers turned down for donor size were above the threshold for adequacy of size match by PHM identified, and thus, the use of PHM could improve donor heart utilization and post-transplant survival.

Post-heart transplant complications

Managing patients after heart transplantation is challenging, since these patients have unique clinical complications (associated with the immunosuppressive therapy and cardiac allograft rejection) together with atypical clinical presentations for infection and systemic inflammatory response syndrome. Survival rates have improved substantially with the use of new immunosuppressive drugs. High vigilance, early diagnosis, and appropriate intervention for allograft-related and non-allograft-related syndromes with significant morbidity and mortality are the keys to long-term survival of patients after transplantation.

Impact of low donor to recipient weight ratios on cardiac transplantation

BACKGROUND

International Society of Heart and Lung Transplantation guidelines for adult heart transplantation (HT) suggest a donor to recipient body weight ratio (WR) of greater than 0.8. For female to male transplants, a WR of greater than 0.9 is recommended.

METHODS

The United Network for Organ Sharing database was examined for adult HT from 1999 to 2011. Controls with a WR of 0.9 or greater (normal donor to recipient weight ratio) were compared with patients with a WR of 0.6 to 0.89 (WRL) and a WR of less than 0.59 (WRVL). The primary measured outcome was survival.

RESULTS

Of the 21,928 patients undergoing HT, 14,592 (66.6%) were performed with a normal donor to recipient weight ratio, 7212 (32.9%) were performed with WRL, and 124 (0.6%) were performed with WRVL. In male donor to male recipient, male donor to female recipient, and female donor to female recipient HT, the use of WRL did not influence median survival (P = .3621) and was not associated with increased mortality (P = .7273). In female donor to male recipient HT, WRL was associated with decreased median survival (435 days, P = .0241) and was associated with increased mortality (hazard ratio, 1.201; P = .0383).

CONCLUSIONS

HT can be safely performed using WRL donors between sex-matched and male to female transplants. However, in female to male transplants, WRL donors are associated with decreased survival. Although clinical circumstances will guide decision making, consensus criteria may be revisited to liberalize the pool of acceptable donors in an era of unprecedented donor shortage.

Mechanical circulatory support and heart transplantation: donor and recipient factors influencing graft survival

BACKGROUND

Mechanical circulatory support is an accepted strategy to bridge patients to heart transplantation (HTx). Among mechanical circulatory support patients who go on to HTx, factors associated with improved graft survival have not been fully elucidated.

METHODS

Using the Scientific Registry for Transplant Recipients, we identified adults who were treated with a left ventricular assist device (LVAD) or total artificial heart (TAH) before HTx. Kaplan-Meier and multivariate Cox regression models were used to identify patient, donor, and device characteristics associated with graft survival.

RESULTS

Between January 1997 and February 2012, 2,785 adults underwent HTx. Before HTx, 2,674 patients were treated with a LVAD (HeartMate XVE, 724; HeartMate II, 1,882; HeartWare, 68), and 111 were treated with a TAH. Follow-up averaged 25 ± 24 months. Gender mismatch occurred in 23%. Graft survival did not differ between LVAD groups (all p > 0.168), but TAH was associated with reduced graft survival compared with LVADs (p < 0.001). After controlling for device type (LVAD vs TAH), lower recipient pulmonary vascular resistance, shorter ischemic time, younger donor age, donor-to-recipient gender match, and higher donor-to-recipient body mass index ratio were independent predictors of longer graft survival (all p < 0.05).

CONCLUSIONS

TAH was associated with reduced graft survival after transplant, and survival did not differ between the LVAD device groups. Additional variables that were independently associated with graft survival were donor age, recipient peripheral vascular resistance, ischemic time, gender match, and donor-to-recipient body mass index ratio. Recognition of these factors may inform decisions regarding device support and donor suitability.

Influence of size disparity of transplanted hearts on cardiac growth in infants and children

OBJECTIVE

We aimed to evaluate the influence of size disparity of the transplanted heart on cardiac growth in infant and child recipients by comparing donor body surface area (BSA) and cardiac dimensions during transplantation to the corresponding parameters of the recipient over a period of time.

METHODS

A retrospective review of medical and echocardiographic records of 147 children (5.3 ± 4.0; median, 4.1; range, 1 month-15 years) who underwent orthotopic heart transplantation was done. The patients were divided into age groups as follows: less than 1 year (n = 23), 1 to 2 years (n = 26), more than 2 to 5 years (n = 18), more than 5 to 10 years (n = 27), and more than 10 to 15 years (n = 53). Donor/recipient BSA ratio was determined during transplantation. Cardiac dimensions were measured 30 days after transplantation and compared at 1 year, 2 to 5 years, and 5 to 10 years after transplantation.

RESULTS

There were no significant differences in the ventricular end-diastolic diameter, volumes, and mass among those with a donor/recipient BSA ratio of less than 0.80, 0.8 to 1.2, and more than 1.2 (P = .80, .44, and .48, respectively). In all the cardiac dimensions and volumes measured, donor-recipient mismatch did not influence the continuous growth of the heart, as indicated by the measured parameters, in accordance with the recipients' increase in BSA over time. All calculated Z-scores at 1 year, 2 to 5 years, and 6 to 10 years after transplantation were normal when indexed to BSA.

CONCLUSIONS

This study demonstrates that despite size disparity of a transplanted heart, it undergoes normal growth in diastolic dimensions, volumes, and myocardial mass over time as appropriate for body growth after cardiac transplantation in infants and children.

Interactions among donor characteristics influence post-transplant survival: a multi-institutional analysis

BACKGROUND

Quantification of donor-associated risk in a specific heart transplant recipient is often difficult. Our aim was to identify donor characteristics that affect survival in the contemporary era.

METHODS

Between 1990 and 2006, 7,322 patients from 32 centers in the Cardiac Transplant Research Database underwent heart transplantation. Multivariable logistic regression analysis was used to identify donor-associated risk predictors and important interactions between these donor characteristics. Recipient survival was examined using parametric regression analysis in the hazard function domain.

RESULTS

Donor characteristics associated with post-transplant death included donor age, donor requirement for vasoactive therapy, positive donor cytomegalovirus serology, longer graft ischemic time, and lower donor body weight. Several interactions between individual donor characteristics affected survival. In male donors, history of hypertension and diabetes mellitus were risk factors for death (p = 0.006, p = 0.04, respectively), but not in female donors (p = 0.5, p = 0.8, respectively). There was a significant interaction between donor age and recipient-donor weight difference. If the donor was of younger age, increasing recipient-donor weight difference did not result in increased death. With increasing donor age, weight difference did result in compromised survival (p < 0.0003). Donor and recipient gender further modified the degree of risk: risk was higher in female donors and when recipients were male (p < 0.0003).

CONCLUSIONS

This multi-institutional analysis identified important interactions between donor characteristics that affect post-transplant survival that explain some of the discrepancies in the results of previous studies. The results are likely to aid in efficient organ allocation.

Impact of donor-to-recipient weight ratio on survival after heart transplantation: analysis of the United Network for Organ Sharing Database

BACKGROUND

Generally accepted donor criteria for heart transplantation limit allografts from donors within approximately 20% to 30% of the recipient's weight. We analyzed the impact of donor-to-recipient weight ratio on survival after heart transplantation.

METHODS AND RESULTS

Adult heart transplant recipients reported to the United Network for Organ Sharing from 1999 to 2007 were divided into 3 groups based on donor-to-recipient weight ratio: <0.8, 0.8 to 1.2, and >1.2. Kaplan-Meier methodology was used to estimate survival. Propensity-adjusted Cox regression modeling was used to analyze predictors of mortality. A total of 15 284 heart transplant recipients were analyzed; 2078 had weight ratio of <0.8, 9684 had 0.8 to 1.2, and 3522 had >1.2. Kaplan-Meier survival was not statistically different between groups at 5 years (P=0.26). Among patients with weight ratio <0.8, 5-year survival was lower for recipients with high pulmonary vascular resistance (>4 Woods units; P=0.02). Among recipients with high pulmonary vascular resistance, 5-year survival was similar for those with weight ratio 0.8 to 1.2 and >1.2 (P=0.44). Furthermore, male recipients with elevated pulmonary vascular resistance who received hearts from female donors had a significantly worse survival than males who received hearts from male donors (P=0.01). Propensity-adjusted multivariable analysis demonstrated that weight ratio <0.8 did not predict mortality (hazard ratio, 1.09; 95% CI, 0.94 to 1.27; P=0.21). Five-year survival after propensity matching was not statistically different between those with weight ratio <0.8 versus >/=0.8 (P=0.37).

CONCLUSIONS

Weight ratio did not predict mortality after heart transplantation. However, recipients with elevated pulmonary vascular resistance who received undersized hearts had poor survival. Furthermore, in the setting of high pulmonary vascular resistance, male recipients who received hearts from female donors had worse survival than those who received hearts from male donors. Extending donor criteria to include undersized hearts in select recipients should be considered.

[Predictive variables of early mortality after orthotopic heart transplant in adults]

OBJECTIVE

The purpose of the study was to analyze some variables of donors, recipients and surgical procedures in order to discover factors that could predict mortality during the early stage (< 30 days) of orthotopic heart transplants.

MATERIAL AND METHOD

125 consecutive orthotopic heart transplants in adults were analyzed. The average age was 51 +/- 11 (range: 12-67), 109 (87%) were men, 16 were women (13%). Two groups were compared: 15 patients who died within 30 days after heart transplant and 110 who survived during that period. Immunosuppressive protocol: preoperative: Cyclosporin + Azathioprine. Intraoperative: Methylprednisolone Postoperative: Methylprednisolone (first 24 h), antilymphocyte monoclonal antibodies (7-10 days after heart transplant) + Cyclosporin + Azathioprine + Corticoids. The following parameters of the recipient were analyzed: sex, age, weight, size, thoracic perimeter, pretransplant cardiopathy, previous thoracic operations, functional stage or need for catecholamines during the days prior to the transplant, pulmonary artery pressure and resistance, history of systemic arterial hypertension, elevation of creatinine, blood type, urgent transplant indication, receptor/donor weight relationship. The following parameters of donors and operation were analyzed: sex, age, weight, thoracic perimeter, period in intensive care unit, dose of dopamine and dobutamine, blood type, origin of the organ, cause of death, ischaemia time, cardiopulmonary by-pass time and cardioplegia type.

RESULTS

The rate of early mortality was 12%. The univariate analysis showed differences in: prior cardiovascular surgery, receptor blood type, need for urgent transplantation, pulmonary artery resistance > 2.5 Wood Units, cardiopulmonary by-pass time, weight relationship between receptor and donor. The death cause of the donor proved significant. On multivariate analysis, the following parameters independently predicted early mortality: history of operation with extracorporeal circulation, high pulmonary artery resistance, urgent transplant, receptor/donor weight relation and time of extracorporeal circulation.

CONCLUSIONS

We believe that the results of our experience can help to stratify the risk in the orthotopic heart transplant recipient and even to contraindicate the procedure in some cases showing an accumulation of poor prognostic factors in borderline recipients.

Successful use of undersized donors for orthotopic heart transplantation--with a caveat

Accepted clinical practice has been to require body weights to be within 20% as a criterion for matching donor to recipient for cardiac transplantation. From November 1989 through September 1993 we began accepting larger differences in body weight between donor and recipient with 80 orthotopic heart transplants performed. Twenty-eight of these transplants used undersized donors (donor-to-recipient body weight ratio [DRBW] of 0.6 to 0.8) with the remaining donors being either size matched (DRBW = 0.8 to 1.0) or oversized (DRBW > 1.0). Thirty-three of the 80 transplant recipients (41%) were classified preoperatively as United Network for Organ Sharing (UNOS) status I and the remaining patients were classified as UNOS status II. Hospital survival for status I recipients was 9 of 14 (64%) for undersized donors, 7 of 8 (87.5%) for sized-matched donors, and 11 of 11 (100%) for oversized donors (p < 0.05). Hospital survival for status II recipients was 12 of 14 (85.7%) for undersized donors, 24 of 24 (100%) for sized-matched donors, and 8 of 9 (88.8%) for oversized donors. Our data support the continued use of hearts from undersized donors in status II recipients. The use of hearts from undersized donors in status I recipients is associated with increased mortality compared with size-matched donors and must be undertaken with caution.

Donor/recipient aorta size mismatch in heart transplantation: a technical alternative

A technical alternative is proposed to enable transplantation in cases of considerable size mismatch between donor and recipient aorta: interposition of a Dacron graft of intermediate diameter. This procedure was performed in a 56-year-old patient weighing 75 kg in whom a heart from a 40-kg donor was implanted.