Marginal Donor Hearts Research Articles

Machine perfusion of marginal donor hearts: a valuable tool, but where and for whom?

Machine perfusion of marginal donor hearts: a valuable tool, but where and for whom?

ADONHERS (Aged DONor HEart Rescue by Stress Echo) National Protocol: Recipient's Survival after 10-Year Follow-Up.

Background: The gold-standard treatment for end-stage heart failure is heart transplantation, but the lack of organ donors remains an important limitation in this field. An accurate selection of marginal hearts is fundamental to increase organ availability. Purpose: In our study we analyzed if recipients receiving marginal donor (MD) hearts, selected by dipyridamole stress echocardiography according to the ADOHERS national protocol, had different outcomes compared to recipients with acceptable donor (AD) hearts. Methods: Data were collected and retrospectively analyzed from patients who received an orthotopic heart transplant at our institution between 2006 and 2014. Dipyridamole stress echo was performed on identified marginal donors and selected hearts were eventually transplanted. Clinical, laboratory and instrumental features of the recipients were evaluated and patients with homogenous baseline characteristics were selected. Results: Eleven recipients transplanted with a selected marginal heart and eleven recipients transplanted with an acceptable heart were included. Mean donor age was 41 ± 23. The median follow-up was 113 months (IQR 86-146 months). Age, cardiovascular risk and morpho-functional characteristics of the left ventricle were comparable between the two populations (p > 0.05). Left atrial size was significantly higher in patients with marginal hearts (acceptable atrial volume: 23 ± 5 mL; marginal atrial volume: 38 ± 5 mL; p = 0.003). Acceptable donor recipients showed a higher impact of Cardiac Allograph Vasculopathy (p = 0.019). No rejection differences were found between the two groups. Four patients deceased, three were standard donor recipients and one was from the marginal donor group. Conclusions: Our study shows how cardiac transplant (Htx) from selected marginal donor hearts through a non-invasive bedside technique can alleviate the shortage of organs without a difference in survival compared to acceptable donor hearts.

The 2-year postoperative left heart function in marginal donor heart recipients assessing by speckle tracking echocardiography.

This study analyzed the differences and explored the donor/recipient factors between marginal and standard donor heart recipients after heart transplantation (HT) by speckle tracking echocardiography (STE). Seventy-two HT patients were enrolled: 25 standard and 47 marginal donor heart recipients. Thirty HT patients completed 2-year continuous follow-up (1, 6, 12, 24months). Thirty healthy volunteers were controls. STE was used to track the strain characteristics of the left ventricle and atrium for detecting early changes in marginal donor heart recipients, including left ventricular global longitudinal, circumferential and radial strain (LVGLS, LVGCS, LVGRS) and left atrial strain in systole (LAS-S) and late diastole (LAS-A). The perioperative parameters were similar between the standard and marginal groups. No significant differences were found in left heart size, systolic and diastolic function parameters. Left ventricular systolic strain (LVGLS, LVGCS, LVGRS) and systolic and late diastolic left atrial strain (LAS-S, LAS-A) were lower in the HT recipients than the control group (P < 0.05), but there was no difference between the marginal and standard groups (P > 0.05). LVGLS, LVGCS, and LAS-S were low in the marginal group 1month after surgery but recovered gradually at 6months. The patients with donor/recipient body weight ratio < 0.8 group had lower LVGLS and LAS-S. STE showed no significant difference between marginal and standard donor recipients. The LVGLS and LAS-S were lower in those with a smaller donor/recipient body weight ratio. The cardiac function of HT patients was lower in the early postoperative period but gradually recovered over time.

The Clinical Outcomes of Marginal Donor Hearts: A Single Center Experience.

Although the shortage of donor is a common problem worldwide, a significant portion of unutilized hearts are classified as marginal donor (MD) hearts. However, research on the correlation between the MD and the prognosis of heart transplantation (HTx) is lacking. This study was conducted to investigate the clinical impact of MD in HTx. Consecutive 73 HTxs during 2014 and 2021 in a tertiary hospital were analyzed. MD was defined as follows; a donor age >55 years, left ventricular ejection fraction <50%, cold ischemic time >240 minutes, or significant cardiac structural problems. Preoperative characteristics and postoperative hemodynamic data, primary graft dysfunction (PGD), and the survival rate were analyzed. Risk stratification by Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score was performed to examine the outcomes according to the recipient state. Each group was sub-divided into 2 risk groups according to the IMPACT score (low <10 vs. high ≥10). A total of 32 (43.8%) patients received an organ from MDs. Extracorporeal membrane oxygenation was more frequent in the non-MD group (34.4% vs. 70.7, p=0.007) There was no significant difference in PGD, 30-day mortality and long-term survival between groups. In the subgroup analysis, early outcomes did not differ between low- and high-risk groups. However, the long-term survival was better in the low-risk group (p=0.01). The outcomes of MD group were not significantly different from non-MD group. Particularly, in low-risk recipient, the MD group showed excellent early and long-term outcomes. These results suggest the usability of selected MD hearts without increasing adverse events.

373 ADONHERS (AGED DONOR HEART RESCUE BY STRESS ECHO) PROTOCOL FOR HEART DONATION FROM MARGINAL DONOR HEARTS: MONOCENTRIC RETROSPECTIVE STUDY ON RECIPIENT'S SURVIVAL AFTER 10-YEAR FOLLOW-UP

Abstract Backgorund Amelioration of therapies and increased survival in heart failure (HF) is leading to a growing number of patients affected by advanced HF, with an overall 1-year prognosis ranging from 25 to 75%. The gold standard treatment for end stage HF is heart transplantation (Htx), but lack of organs donors remains an important limitation. Marginal hearts can potentially improve and be utilized after a re-evaluation by “aggressive” assessment of donor left ventricular function. Purpose In our study we analysed if recipients of marginal donor hearts, selected by dipyridamole stress echocardiography, had different outcome compared to recipients with acceptable donor hearts. Methods Data collected from 2006 and 2014 of patients who received orthotopic Htx from marginal heart donors (group 1) and were retrospectively analysed and compared with recipients of acceptable heart donors (group 2). Bedside standard echocardiography and dipyridamole stress echo was performed for the selection of marginal hearts &amp;gt; 55 years old or &amp;lt; 55 with comorbidities/mildly dysfunctional left ventricle. Clinical, laboratory and instrumental features of the two groups of recipients were evaluated and patients with homogenous baseline characteristics were selected to reduce biases among the two groups. Follow-up through routine heart transplant surveillance included visit, echocardiography, blood tests, serial endomyocardial biopsies and coronary angiography. Results Twenty-two recipients were included in the study. Mean donors age was 41 ± 23, 45 ± 29 years for group 1 vs 36 ± 12 for group 2. The average follow-up was 113 months. Age, cardiovascular risk and morpho-functional characteristics of the left ventricle were comparable between the two population (P&amp;gt; 0.05). Left atrial size was significantly higher in marginal hearts (Optimal: p=0.007; Marginal: p=0.003). Acceptable recipients showed a higher impact of CAV (p= 0.019) together with more elevated values of cholesterol and triglycerides (p = 0.048 and p = 0.012 respectively). No differences concerning cellular or humoral rejection were found between the two groups. Four patients deceased, 3 had received a standard donor heart and 1 was from the marginal donor group, with and overall median time to death of 124 months. Conclusions Our small pilot study shows how the evaluation of marginal donor hearts with echo stress result to no affect recipients survival compared with controls of acceptable hearts. A well-controlled selection of marginal hearts could therefore improve the shortage of organs, reducing the long line of patients waiting for a heart.

ADONHERS (Aged DONor HEart Rescue by Stress echo) protocol for heart donation from marginal donor hearts: monocentric retrospective study on recipients survival after 10-year follow-up

Abstract Purpose Amelioration of therapies and increased survival in heart failure (HF) is leading to a growing number of patients affected by advanced HF, with an overall 1-year prognosis ranging from 25 to 75%. The gold standard treatment for end stage HF is heart transplantation (Htx), but lack of organs donors remains an important limitation. Marginal hearts can potentially improve and be utilized after a re-evaluation by “aggressive” assessment of donor left ventricular dysfunction, with an important increase of utilization rates (from 38–59%) in the latest years. In our study we analysed if recipients of marginal donor hearts, selected by dipyridamole stress echocardiography, had different outcome compared to recipients with acceptable donor hearts. Methods Data collected from 2006 and 2014 of patients who received orthotopic Htx were retrospectively analysed. Clinical, laboratory and instrumental features were evaluated and patients with homogenous baseline characteristics were selected to reduce biases among the two groups. Dipyridamole stress echo was performed on donors &amp;gt;55 years old or &amp;lt;55 with comorbidities/mildly dysfunctional left ventricle. Results Twenty-two recipients were included (eleven patients with a marginal donor heart, group 1, and eleven with acceptable donor heart, group 2). Mean donors age was 41±23, 45±29 years for group 1 vs 36±12 for group 2. The average follow-up was 113 months. Age, cardiovascular risk and morpho-functional characteristics of the left ventricle were comparable between the two population (P&amp;gt;0.05) (see Table 1). Left atrial size was significantly higher in marginal hearts (Optimal: p=0.007; Marginal: p=0.003). Optimal donors showed a higher impact of CAV (p=0.019) together with more elevated values of cholesterol and triglycerides (p=0.048 and p=0.012 respectively). No rejection differences were found between the two groups. Four patients deceased, 3 had received a standard donor heart and 1 was from the marginal donor group, with and overall median time to death of 124 months. Conclusions No mortality difference was detected among the two heart donor groups with a lower incidence of CAD in the marginal heart donor population. Our study shows how Htx from selected marginal donor heart can implement shortage of organs without difference in survival with acceptable donor hearts. Funding Acknowledgement Type of funding sources: None.

The outcomes of marginal donor hearts compared with ideal donors: a single-center experience in Iran.

BackgroundHeart transplantation has been considered the gold-standard treatment for patients with end-stage heart failure. This study assessed the survival outcomes of marginal donor hearts compared with ideal donor hearts in Iran.MethodsThis retrospective study is based on the follow-up data of heart donors and recipients in the Sina Hospital Organ Procurement Unit. Among the 93 participants, 75 were categorized as ideal donors (group A) and 18 as marginal donors (group B). Group C included heart recipients who received a standard organ, and group D included heart recipients who received a marginal one. To analyze differences in patient characteristics among the groups, posttransplant heart survival was assessed in all groups. All data were obtained from the hospital records.ResultsThe mean age of the donors was 26.27±11.44 years (median age, 28 years). The marginal age showed a significant association with donor age. The age of recipients had a significant effect on survival days in the ideal group. Most patients survived for at least 1 year, with a median of 645 days in recipients from marginal donors and 689 days in recipients from ideal donors.ConclusionsConsidering the lack of organ availability in Iran, it may be possible to use marginal donors for marginal recipients, therefore reducing the number of people on the waitlist. We also recommend establishing a national marginal donor system specifically for Iranian patients to extend the donor pool.

The Clinical Outcomes of Marginal Donor Hearts: A Single Center Experience the ‘Margins’ Are Only in Our Mind?

<h3>Purpose</h3> The average donor heart utilization rate is known to be 31.4% in South Korea, although reported to improve to 42.9% in 2019, still very low compared with other countries. More than 60% of donor hearts are discarded for the reason of their age or medical condition. However, were the donors truly marginal, and doomed to have poor outcomes? Herein, we suggest an answer to the questions with reporting outcomes of single heart transplant (HTx) center, which actively utilizes the marginal donors. <h3>Methods</h3> Consecutive 73 HTx done from June 2014 to August 2021 in a single tertiary hospital were analyzed. The marginal donor (MD) was defined as follows; a donor age > 55yrs, left ventricular ejection fraction < 50% or significant structural heart disease, cold ischemic time >240min. Preoperative characteristics of recipients and donors and postoperative hemodynamic data, primary graft dysfunction (PGD), and the survival rate were analyzed. <h3>Results</h3> A total of 32 recipients out of 73 received an organ from MDs. A significant difference in preoperative ECMO status between MD and non-marginal donor (NMD) group (34.4% vs 70.7%) was noted. There was no statistically significant difference in any-PGD (25.0% vs 14.6%, p=0.414). The cardiac index recorded immediate postop, 6hr, 12hrs, 18hrs showed slightly lower in MD group, however, caught-up NMD group after 24hrs. Also, long-term results represented by 5yr survival showed no significant difference between the two groups (survival rates 90.2% vs 87.5%, p = 0.712, Figure). <h3>Conclusion</h3> Appropriately selected donor hearts declined as ‘marginal donor' hearts may increase organ utilization without an increase in post-transplant PGD and mortality.

The Utilization of Marginal Donors for Cardiac Re-Transplantation

<h3>Purpose</h3> The global shortage of available donor organs and the poor clinical outcomes of re-transplant patients raise the ethical and economic concerns. In this study, we examined the difference in post-transplant survival of re-transplant (re-HTx) patients with and without the use of marginal donor hearts. <h3>Methods</h3> The United Network of Organ Sharing database was retrospectively queried from January 2000 to March 2020 to identify adult (17 > years) patients underwent re-HTx. Recipients were divided into early (≦6 months after previous transplant)and late (>6 months after previous transplant) groups based on the timing of re-transplantation. Demographic data and outcomes were compared with and without the use of marginal donors in each group. Marginal donors were those who met at least one of the following characteristics: age greater than 55 years, cocaine or other intravenous drug use, hepatitis C positive, ejection fraction less than 0.45, and donor: recipient weight less than 0.8. <h3>Results</h3> There were 111 early and 1133 late re-transplantation.10-year mortality was significantly higher in the early transplantation compared with the late transplantation (Early 61.0% vs. Late 44.9%, log-rank P<0.001). There was no difference in preoperative patient background between the Marginal and non-Marginal groups in the early transplant group, while the Marginal group had a higher BMI (p<0.001), higher PRA (p=0.005), and longer total waiting time (0.018) than non-marginal group in the late transplant group. There was no significant difference in 10-year mortality between the marginal and non-marginal groups in either the early or late transplant groups. (Early: non-MD 58.5% vs. MD 62.0%, log-rank P=0.827; Late: non-MD 43.2% vs. MD 46.6%, log-rank P=0.699). <h3>Conclusion</h3> Utilization of marginal donor in patients undergoing re-HTx is not associated with worse outcomes both for early and late graft failure.

Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts.

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1–12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.

The clinical outcomes of marginal donor hearts: a single center experience

The clinical outcomes of marginal donor hearts: a single center experience

Donor-transmitted Anterior Myocardial Ischaemia in a Teenager: How to Proceed?

Background: Heart transplantation remains the treatment of choice for end-stage heart failure patients, owing to the associated dual improvements in quality of life, and prognosis. The discrepancy between higher demand and supply of donor organs is the limiting factor, and is established universally. Increasing consideration of donor populations up to 65 years of age and marginal donor hearts has helped to facilitate the availability of potential grafts. However, grafts from older donors carry the mid-term increased risk of coronary allograft vasculopathy, including donor-transmitted coronary disease. Case report: A 15-year-old female underwent orthotopic heart transplantation for non-ischaemic cardiomyopathy, the donor was a 44-year-old male. The recipient developed anterior wall ischaemia within a year requiring coronary angioplasty and stent implantation to treat the severe obstruction in the left anterior descending coronary artery. However, two months later, the patient was readmitted with in-stent restenosis. Therefore, to optimally revascularise the left anterior descending coronary artery, and minimise risks associated with re-sternotomy, a minimally invasive direct coronary artery by pass grafting of the left internal mammary artery to the left anterior descending artery was performed. Conclusion: Surgical revascularisation in generalised coronary allograft vasculopathy is an inadequate option; repeat heart transplantation is the treatment of choice, albeit given its morbidity, should be reserved for a highly selected patient population. In localised coronary lesions, conventional coronary bypass surgery may be a feasible choice in selected patients with left anterior descending artery lesions. Minimal invasive techniques, such as minimally invasive direct coronary artery bypass grafting rather than robotic techniques, would be preferable for ease of approach and to limit the surgical re-do trauma.

Impact of Reported Donor Ejection Fraction on Outcome after Heart Transplantation.

The global shortage of donor organs has urged transplanting units to extend donor selection criteria, for example, impaired left ventricular function (LVF), leading to the use of marginal donor hearts. We retrospectively analyzed our patients after orthotopic heart transplantation (oHTX) with a focus on the clinical outcome depending on donor LVF. Donor reports, intraoperative, echocardiographic, and clinical follow-up data of patients undergoing oHTX at a single-center between September 2010 and June 2020 were retrospectively analyzed. Recipients were divided into two groups based on donor left ventricular ejection fraction (dLVEF): impaired dLVEF (group I; dLVEF ≤ 50%; n = 23) and normal dLVEF group (group N; dLVEF > 50%; n = 137). There was no difference in 30-day, 90-day, and 1-year survival. However, the duration of in-hospital stay was statistically longer in group I than in group N (N: 40.9 ± 28.3 days vs. I: 55.9 ± 39.4 days, p < 0.05). Furthermore, postoperative infection events were significantly more frequent in group I (p = 0.03), which was also supported by multivariate analysis (p = 0.03; odds ratio: 2.96; confidence interval: 1.12-7.83). Upon correlation analysis, dLVEF and recipient LVEF prove as statistically independent (r = 0.12, p = 0.17). Impaired dLVEF is associated with prolonged posttransplant recovery and slightly increased morbidity but has no significant impact on survival up to 1 year posttransplant.

Extracorporeal Membrane Oxygenation for Primary Graft Failure Following Heart Transplantation

Purpose Extracorporeal membrane oxygenation (ECMO) is a life-saving therapy providing hemodynamic support to patients with advanced cardiorespiratory compromise. Following orthotopic heart transplantation (HTX), primary graft failure (PGF), especially wherein there is significant right ventricular dysfunction, can necessitate such intensive support to bridge to recovery or additional therapy. Marginal donors are used to increase the donor pool given the excess of candidates in most jurisdictions. Methods We conducted a single-center retrospective cohort study examining HTX from donation after brain death (DBD) donors that required post-operative ECMO for PGF from January 2008 - September 2020. Donor and recipient information were collected including demographics, renal function, echocardiographic measurements, biopsy data, and outcome measures. Marginal donor hearts were identified according to validated criteria including use of donor triiodothyronine (T3), donor left ventricular ejection fraction 60 years old, and donor ischemic time >6 hours or >4 hours if donor age >40 years old. Results Overall, 376 DBD HTX were performed, of which 126 involved marginal donor hearts (33.3%). ECMO was required in 81 (21.4%) of these patients, 42 (51.9%) of which involved marginal donor hearts. Thus, ECMO rates were 15.5% and 33.3% in non-marginal and marginal donor hearts, respectively. Overall, ECMO was successfully weaned in 75 (92.6%) and 62 (76.5%) survived their index HTX admission. Among patients who received non-marginal organs, 36 (92.3%) had ECMO weaned and 31 (79.5%) survived their index HTX admission versus 39 (92.9%) and 31 (73.8%) for these endpoints respectively among patients receiving marginal organs. Conclusion Our center's experience indicates that ECMO can provide satisfactory outcomes in HTX patients requiring advanced hemodynamic support post-operatively for PGF. Marginal donor hearts were more likely to require ECMO support post-operatively but had comparable and acceptable rates of index-admission survival compared to non-marginal cases. Further work is needed to evaluate outcome differences as efforts are made to expand the donor pool around the world.

Cardiac rehabilitation program improves exercise capacity in heart transplantation recipients regardless of marginal donor factors.

Cardiac rehabilitation (CR) is recommended to improve exercise capacity after heart transplantation (HTx); however, the effects of marginal donor factors are unclear. Forty-one recipients participated in a 3-month CR program early after HTx (mean age 39 ± 14years; 88% male). Patients were divided into marginal (≥ 2 marginal donor factors; n = 24) and control groups (< 2 marginal donor factors; n = 17). We examined donor and recipient factors related to change in peak oxygen uptake (peak VO2) during the CR program using multiple linear regression analysis. Baseline characteristics were similar between groups, although the mean age was higher in the marginal group (43 ± 13 vs. 34 ± 14years, p = 0.043). Peak VO2 and knee extensor muscular strength (KEMS) improved significantly in both groups (p < 0.05), but there were no observed inter-group differences. Multiple analysis revealed change in KEMS (β = 0.52, 95% CI = 0.023-1.01) as an independent predictor of change in peak VO2 after adjustment for recipients' age, sex, and CR attendance frequency (adjusted R2 = 0.25, p = 0.0084), whereas marginal donor factors were not a predictor (p = 0.76). The CR program improved exercise capacity in HTx recipients regardless of marginal donor factors, suggesting that recipients of marginal donor hearts should be referred to CR programs.

Preservation by cold storage vs ex vivo normothermic perfusion of marginal donor hearts: clinical, histopathologic, and ultrastructural features

The aim of this study was to match clinical outcomes of heart transplantation (HTx) against histopathologic and ultrastructural characteristics of marginal grafts preserved by cold storage (CS) or ex vivo normothermic perfusion. Since 2011, 100 patients had undergone HTx at our institution by using marginal donors (aged ≥55 years, expected ischemic time of >4 hours, left ventricular ejection fraction of ≤50%, interventricular septum thickness of ≥14 mm, drug abuse history, episodes of cardiac arrest, and presence of mild coronary artery disease). CS was utilized in 79 cases (Group 1, 79%), and ex vivo perfusion was utilized in 21 (Group 2, 21%). Pre-operative data, survival, and complications in the first 5 years after HTx were analyzed. Myocardial biopsies were collected at graft harvesting, just before implantation, and immediately after aortic declamping. Pre-operative demographics were similar in the 2 groups. Graft utilization rate with ex vivo perfusion was 81%. Ischemic, cardiopulmonary bypass, and surgical times were shorter in Group 2 patients, who showed a lower incidence of overall complications (33% vs 13%, p = 0.04) and better 5-year survival (log-rank, p = 0.04). Moreover, restoration of hypertrophy-related sarcomere changes and mitigation of reperfusion-dependent myocardium injuries were more frequently observed in Group 2 hearts. Ex vivo perfusion allows for continuous evaluation of marginal donor hearts, favoring exclusion of unsuitable grafts, reduction of complications, and optimal survival of up to 5 years. Such results, supported by consistent histopathologic and ultrastructural findings, suggest better myocardial preservation.

EXTERNAL VALIDATION OF CURRENT INTERNATIONAL SHORT- AND LONG-TERM PROGNOSTIC MODELS FOR SURVIVAL IN HEART TRANSPLANT RECIPIENTS USING MARGINAL DONOR HEARTS AT SINGLE JAPANESE CENTER

Introduction: Current prognostic models to predict survival in heart transplant (HTx) recipients, which are ‘Index for Mortality Prediction After Cardiac Transplantation (IMPACT) model’ using the recipient-factor and ‘International Heart Transplantation Survival Algorithm (IHTSA) model’ using both recipient- and donor-factors, have been verified the good adaptation on the global registry data in HTx recipients. In Japan, extremely serious donor shortages will necessitate a long waiting period, and using more marginal donor hearts. But several donor risk factors for HTx were not included enough in these prognostic models. It is unclear whether these prognostic models can be adapted with HTx using more marginal donor hearts. This study aimed to validate the usefulness of IMPACT and IHTSA models for the prediction of long-term mortality in recipients transplanted marginal hearts. Materials and Methods: Consecutive 126 adult HTx recipients who underwent HTx between May 1999 and February 2020 were included in this study. The risk score based on IMPACT model was calculated for each recipient. And we entered the clinical data of each recipient and donor into the web-based calculator of the IHTSA model and calculated predicted 5-year mortality rate based on the IHTSA model. The discrimination for survival in our subjects was evaluated using Harrell’s concordance index (C-index). Survival analysis was conducted to evaluate the actual mortality rate in our subjects. Results and Discussion: Over median follow-up of 4.9 years [interquartile range (IQR); 2.6-9.0 years] after HTx, 8 recipients (6.3%) died during follow-up. The IMPACT score was median of 6.0 (IQR; 3.0-8.0), and the estimated 5-year mortality rate based on IHTSA model was median of 0.25 (IQR; 0.21-0.29). The predicted versus actual 5-year survival rates were 73.7% versus 95.8%. The discrimination (C-index) for survival using IMPACT score and 5-year mortality rate based on the IHTSA model were 0.689 and 0.720, respectively. Conclusion: This study validated a usefulness of two current prognostic models, IMPACT and IHTSA, for survival in HTx recipients using marginal donor hearts. Our results suggest that these models might be useful even in HTx recipients using highly marginal donor hearts. Further validation is needed to adapt an appropriate prognostic model in such clinical situation as serious donor shortages.

Valvular surgery in donor hearts before orthotopic heart transplantation

Donor heart shortage has extended the waiting time and increased the mortality of patients on the transplant waiting list. Widening old standard donor criteria has successfully increased the number of heart transplantations, but for many years, a valve disease in a donor heart has been considered a primary contraindication for organ donation. To analyse the results of aortic and mitral valvular surgery in marginal donor hearts with valvulopathy before orthotopic heart transplantation. Between January 2012 and November 2015, we performed 53 heart transplantations in our department. In four donors, echocardiography performed at the time of organ procurement showed a valvular disease: three had moderate-to-severe mitral regurgitation; and one had moderately severe aortic valve stenosis. The mean bench mitral repair and aortic replacement time, aortic cross-clamp time and total ischaemic time were: 18 (range 7-25) minutes, 78.7 (range 57-98) minutes and 184 (range 89-255) minutes, respectively. Intraoperative transoesophageal echocardiography showed good mitral repair or aortic prosthetic valve function, and good right and left ventricular function. One patient died of infectious pneumonia after 1 month. The mean duration of follow-up for the patients discharged home was 75±13 months, and all have returned to an active unrestricted lifestyle. Our limited series demonstrates that conventional valvular procedures performed on otherwise healthy donor hearts with mitral and aortic valve pathology can efficaciously expand the donor pool for orthotopic cardiac transplantation and decrease the mortality rate on the waiting list.

Eight-Hour Ex Situ Perfusion with Functional Assessment of an Adult Heart after 12 Hours Hypothermic Preservation: A Case Study

Ex situ heart perfusion (ESHP) allows resuscitation and functional assessment of marginal donor hearts to expand the donor pool. The current clinically available ESHP platform does not enable contractile assessment. We sought to determine if a marginal donor heart could be resuscitated and assessed on our custom ESHP system following an extended period of cold storage. Organ procurement and preservation were performed according to our current clinical protocol, utilizing Celsior as the preservation solution. The ESHP system was primed with 750mL of Steen (XVIVO Perfusion) and 750mL of SOM-TRN-001 (Somahlution). Isolated O negative red blood cells were added to achieve a hematocrit of 15%. Dobutamine 5mcg/min, Insulin 5u/h, and Nitroglycerin 1mcg/kg/min were infused continuously through ESHP. The perfusate was continuously dialyzed through an arterial line shunt to the venous reservoir at a rate of 300 ml/min. Blood gas was measured every two hours. Heart was transitioned to working mode at 8 hours by loading the atria at 8mmHg and functional assessment was performed PV catheter. A 67-year-old male donor heart with mild proximal one vessel coronary artery disease was procured, harvested and transported in cold storage for 12 hours until the organ was reperfused in our ESHP system. Following reanimation, the heart was perfused for 8 hours. Electrolytes were maintained within physiological range throught the ESHP period under the regulation of hemodialysis. Continously lactate consumption (Table I) indicates the heart's metabolism is working. PRSW, maximum (Emax) and end-systolic (Ees) elastance show the cardiac function measured at the end of of ESHP. We describe a successful resuscitation and ex situ pefusion of a marginal donor heart with 12 hours cold ischemia time. The feasibility of this method hypothesis is a promising strategy which can preclude the need for cumbersome and resource intense transport platforms.

Heart rate reserve during dipyridamole stress test applied to potential heart donors in brain death

A blunted heart rate reserve (HRR) during dipyridamole stress echocardiography (DSE) is a prognostically unfavorable sign of cardiac autonomic dysfunction. Short-term adjustments of heart rate (HR) are thought to rise from changes in neural input to the heart. DSE is applied in potential heart donors to rule out underlying coronary artery disease and left ventricular dysfunction. The aim of this study is to assess HRR during DSE in brain death. We enrolled two groups: group 1 (N.=49, 22 men, 54.6±8.8 years) with patients in brain death enrolled in the nationwide marginal donor heart recruiting program; group 2 (N.=49, 18 men, 66.4±12.0 years) referred to DSE for suspected or known coronary artery disease. All underwent DSE (0.84 mg/kg in 6') by quality-controlled readers certified via web-based training (1487/CE Lazio-1). We assessed left ventricular contractile reserve (LVCR) as stress/rest ratio of force (systolic blood pressure/end-systolic volume). HRR was calculated as the peak/rest HR ratio from 12-lead EKG. The two study groups were similar for prevalence of inducible ischemia (4/49 vs. 9/49, P=NS). Group 1 showed higher resting HR (group 1: 88.1±15.5 bpm vs. group 2: 66.5±11.5 bpm, P<0.01) and similar peak HR (group 1: 94.7±15.3 bpm vs. group 2: 89.5±19.3 bpm, P=0.144), with blunted HRR (group 1: 1.08±0.10 bpm vs. group 2: 1.36±0.31 bpm, P<0.01). HRR was unrelated to LVCR. HRR is almost abolished and unrelated to LVCR in brain-dead patients during DSE. The modulation of neural input to the heart is essential to determine HRR, and plays no significant role in determining the inotropic response during DSE.