Temporal changes in left ventricular systolic function in heart donors: results of serial echocardiography

Donor Electrocardiogram Associations With Cardiac Dysfunction, Heart Transplant Use, and Survival: The Donor Heart Study

BACKGROUND

Potential organ donors often exhibit abnormalities on electrocardiograms (ECGs) after brain death, but the physiological and prognostic significance of such abnormalities is unknown.

OBJECTIVES

This study sought to characterize the prevalence of ECG abnormalities in a nationwide cohort of potential cardiac donors and their associations with cardiac dysfunction, use for heart transplantation (HT), and recipient outcomes.

METHODS

The Donor Heart Study enrolled 4,333 potential cardiac organ donors at 8 organ procurement organizations across the United States from 2015 to 2020. A blinded expert reviewer interpreted all ECGs, which were obtained once hemodynamic stability was achieved after brain death and were repeated 24 ± 6 hours later. ECG findings were summarized, and their associations with other cardiac diagnostic findings, use for HT, and graft survival were assessed using univariable and multivariable regression.

RESULTS

Initial ECGs were interpretable for 4,136 potential donors. Overall, 64% of ECGs were deemed clinically abnormal, most commonly as a result of a nonspecific St-T-wave abnormality (39%), T-wave inversion (19%), and/or QTc interval >500 ms (17%). Conduction abnormalities, ectopy, pathologic Q waves, and ST-segment elevations were less common (each present in ≤5% of donors) and resolved on repeat ECGs in most cases. Only pathological Q waves were significant predictors of donor heart nonuse (adjusted OR: 0.39; 95% CI: 0.29-0.53), and none were associated with graft survival at 1 year post-HT.

CONCLUSIONS

ECG abnormalities are common in potential heart donors but often resolve on serial testing. Pathologic Q waves are associated with a lower likelihood of use for HT, but they do not portend worse graft survival.

Left Ventricular Dysfunction Associated With Brain Death: Results From the Donor Heart Study

BACKGROUND

Left ventricular dysfunction in potential donors meeting brain death criteria often results in nonuse of donor hearts for transplantation, yet little is known about its incidence or pathophysiology. Resolving these unknowns was a primary aim of the DHS (Donor Heart Study), a multisite prospective cohort study.

METHODS

The DHS enrolled potential donors by neurologic determination of death (n=4333) at 8 organ procurement organizations across the United States between February 2015 and May 2020. Data included medications administered, serial diagnostic tests, and transthoracic echocardiograms (TTEs) performed: (1) within 48 hours after brain death was formally diagnosed; and (2) 24±6 hours later if left ventricular (LV) dysfunction was initially present. LV dysfunction was defined as an LV ejection fraction <50% and was considered reversible if LV ejection fraction was >50% on the second TTE. TTEs were also examined for presence of LV regional wall motion abnormalities and their reversibility. We assessed associations between LV dysfunction, donor heart acceptance for transplantation, and recipient 1-year survival.

RESULTS

An initial TTE was interpreted for 3794 of the 4333 potential donors by neurologic determination of death. A total of 493 (13%) of these TTEs showed LV dysfunction. Among those donors with an initial TTE, LV dysfunction was associated with younger age, underweight, and higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) and troponin levels. A second TTE was performed within 24±6 hours for a subset of donors (n=224) with initial LV dysfunction; within this subset, 130 (58%) demonstrated reversibility. Sixty percent of donor hearts with normal LV function were accepted for transplant compared with 56% of hearts with reversible LV dysfunction and 24% of hearts with nonreversible LV dysfunction. Donor LV dysfunction, whether reversible or not, was not associated with recipient 1-year survival.

CONCLUSIONS

LV dysfunction associated with brain death occurs in many potential heart donors and is sometimes reversible. These findings can inform decisions made during donor evaluation and help guide donor heart acceptance for transplantation.

Impact of donor ventricular function on heart transplantation outcomes

BACKGROUND

Some heart transplant (HTx) centers have expanded their donor eligibility criteria in response to the organ shortage; one area of active interest involves utilizing hearts with ventricular dysfunction. Our study seeks to identify if a relationship exists between donor left ventricular ejection fraction (LVEF) and ischemic time or donor age on HTx outcomes.

METHODS

We performed a retrospective analysis on adult patients who had a HTx between 1996 and 2021 (n = 46,936). Donor LVEF (dLVEF) values were categorized into three groups: <50%, 50%-70%, and >70%. Ischemic time and donor age were stratified into four groups: ≤2.0, 2.1-3.0, 3.1-4.0, >4.0 h, and ≤30, 31-40, 41-50, >50 years, respectively. The outcome of interest was long-term survival.

RESULTS

Multivariable survival analysis found a slight increase in overall mortality risk for patients with donor ejection fractions <50% (HR = 1.16, p = .013). However, subsequent subgroup investigation discovered that this elevated hazard was only applicable when ischemic time was prolonged to >3.0 h (3.1-4.0 h: HR = 1.23, p = .024; > 4.0 h: HR = 1.52, p < .001). There was no significant difference in survival between dLVEF groups when ischemic time was limited to ≤3.0 h or when stratified by donor age.

CONCLUSION

HTx patients with a low donor ejection fraction have comparable survival to recipients with a normal dLVEF when ischemic time is limited to ≤3.0 h. Reduced dLVEF does not appear to be sensitive to advanced donor age. The clinical implications of our study may encourage the recruitment of more donor hearts for transplantation.

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.

Marginal donors and organ shortness: concomitant surgical procedures during heart transplantation: a literature review

Heart transplantation represents the gold standard for end-stage heart failure. However, due to the increasing demand and the shortage of available organs, donor supply remains the main limitation. Marginal donor hearts in high-risk candidates who do not meet standard listing criteria are the only alternative when life expectancy is limited, but their use is still debated. Surgical correction of detected coronary lesions or valvular heart defects allows further enlargement of the number of available organs. In this article, we offer a literature review on this topic and report two marginal donor hearts with angiography evidence of coronary stenosis and preserved ventricular function, which underwent concomitant myocardial revascularization during heart implantation.

Heart transplantation from donors with left ventricular ejection fraction under forty percent

BACKGROUND

Heart transplantation (HTx) remains the treatment of choice for patients with end-stage advanced heart failure. In 2016, the Shumakov National Medical Research Center commenced performing HTx from donors with abnormal left ventricular systolic function (LVEF < 40%). The aim of this study was to evaluate early and late outcomes of recipients after HTx from donors with abnormal LV systolic function.

METHODS

Four hundred eighty seven patients underwent HTx in our institution from January 2016 to December 2018. 27 (5.5%) patients were transplanted using cardiac allografts from donors with LVEF <40%.

RESULTS

A total of 47 donors with LVEF <40% were evaluated for potential donation. Most heart donors revealed a left ventricular ejection fraction ranging between 30% and 40%. Twenty-five recipients required urgent HTx. Four recipients presented with early allograft dysfunction. All surviving recipients demonstrated early (85.2%) or delayed (14.8%) recovery of systolic function (LVEF > 60%).

CONCLUSION

The use of dysfunctional donor hearts with impaired LV systolic function may be a realistic approach for expanding the donor pool. However, organs from such donors should be used for recipient cohorts requiring an urgent HTx, particularly for those with pretransplant mechanical circulatory support allowing for hemodynamic support in cases of early graft dysfunction in the post-transplant period.

Impact of Reported Donor Ejection Fraction on Outcome after Heart Transplantation

OBJECTIVES

 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.

METHODS

 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).

RESULTS

 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).

CONCLUSIONS

 Impaired dLVEF is associated with prolonged posttransplant recovery and slightly increased morbidity but has no significant impact on survival up to 1 year posttransplant.

Valvular surgery in donor hearts before orthotopic heart transplantation

BACKGROUND

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.

AIMS

To analyse the results of aortic and mitral valvular surgery in marginal donor hearts with valvulopathy before orthotopic heart transplantation.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

The Year in Cardiothoracic Transplantation Anesthesia: Selected Highlights from 2019

The highlights in cardiothoracic transplantation focus on the recent research pertaining to heart and lung transplantation, including expansion of the donor pool, the optimization of donors and recipients, the use of mechanical support, the perioperative and long-term outcomes in these patient populations, and the use of transthoracic echocardiography to diagnose rejection.

Impact of Deceased Donor Management on Donor Heart Use and Recipient Graft Survival

BACKGROUND

Current risk-adjusted models used to predict donor heart use and cardiac graft survival from organ donors after brain death (DBDs) do not include bedside critical care data. We sought to identify novel independent predictors of heart use and graft survival to better understand the relationship between donor management and transplantation outcomes.

STUDY DESIGN

We conducted a prospective observational study of DBDs managed from 2008 to 2013 by 10 organ procurement organizations. Demographic data, critical care parameters, and treatments were recorded at 3 standardized time points during donor management. The primary outcomes measures were donor heart use and cardiac graft survival.

RESULTS

From 3,433 DBDs, 1,134 hearts (33%) were transplanted and 969 cardiac grafts (85%) survived after 684 ± 392 days of follow-up. After multivariable analysis, independent positive predictors of heart use included standard criteria donor status (odds ratio [OR] 3.93), male sex (OR 1.68), ejection fraction > 50% (OR 1.64), and partial pressure of oxygen to fraction of inspired oxygen ratio > 300 (OR 1.31). Independent negative predictors of heart use included donor age (OR 0.94), BMI > 30 kg/m² (OR 0.78), serum creatinine (OR 0.83), and use of thyroid hormone (OR 0.78). As for graft survival, after controlling for known recipient risk factors, thyroid hormone dose was the only independent predictor (OR 1.04 per μg/h).

CONCLUSIONS

Modifiable critical care parameters and treatments predict donor heart use and cardiac graft survival. The discordant relationship between thyroid hormone and donor heart use (negative predictor) vs cardiac graft survival (positive predictor) warrants additional investigation.

Great variability in donor heart acceptance practices across the United States

Disparities in organ acceptance practices exacerbate donor heart nonuse and lead to increased waiting times and mortality for heart transplant candidates. We studied disparities in donor heart acceptance among US transplant centers and their relations to posttransplant outcomes. Candidate, potential transplant recipient match run, and deceased donor data were obtained from the United Network for Organ Sharing. We analyzed donor, candidate, and transplant center characteristics with respect to organ acceptance, offer acceptance, number of offers before acceptance (organ sequence number), and association with posttransplant mortality. A total of 693 420 donor heart offers made between April 2007 and December 2015 were included. We identified great variability in donor heart acceptance practices among US heart transplant centers. We identified donor and recipient characteristics that were strongly associated with heart organ and offer acceptance, and organ sequence number, and identified inconsistencies among centers with respect to how these characteristics influenced acceptance decisions. Finally, we identified characteristics that were highly predictive of donor heart nonuse and were not associated with increased recipient mortality, which may guide future efforts aimed at increasing use of available hearts for transplantation.

Cardiac Transplantation Using Hearts With Transient Dysfunction: Role of Takotsubo-Like Phenotype

BACKGROUND

The impact of different types of regional wall motion abnormalities (RWMAs), including the Takotsubo syndrome-like (TTS-like) phenotype, on posttransplant outcomes when using donor hearts with transient left ventricular systolic dysfunction (LVSD) is unknown. We evaluated the prevalence, clinical characteristics, and prognostic association of different RWMAs including TTS-like hypokinesis and posttransplant outcomes when using donor hearts with transient LVSD.

METHODS

From all adult (≥18 years) heart transplants in United Network of Organ Sharing between January 2007 and September 2015, we identified 472 donor hearts with improving or transient LVSD, defined as left ventricular ejection fraction ≤ 40% on initial transthoracic echocardiogram (TTE) that improved to ≥50% on follow-up TTE during donor evaluation. These improved LVSD donors were then subdivided into 3 groups based on RWMAs on the initial TTE, TTS-like (49, 10.38%), non-TTS RWMAs (74, 15.68%), and diffuse global hypokinesis (349, 73.94%), and compared for baseline characteristics and posttransplant outcomes with follow up until June 2018.

RESULTS

Donors with TTS-like LVSD were older and more likely to be female. The type of RWMA on initial TTE (including TTS-like) of transient LVSD donor hearts was not associated with 1-year or 5-year posttransplant mortality. Posttransplant functional status scores of recipients (at 1 year) and donor left ventricular ejection fraction (at median follow-up of 3.6 years) improved in all 3 subgroups. Rates of stroke or pacemaker predischarge were also similar.

CONCLUSIONS

In the largest analysis of transplanted donor hearts with transient LVSD, 1 in 4 had RWMAs on the initial TTE, but this was not associated with adverse posttransplant outcomes. Donor hearts with initial LVSD should be pursued irrespective of TTS-like hypokinesis or other RWMAs.

Assessment of potential heart donors: A statement from the French heart transplant community

Assessment of potential donors is an essential part of heart transplantation. Despite the shortage of donor hearts, donor heart procurement from brain-dead organ donors remains low in France, which may be explained by the increasing proportion of high-risk donors, as well as the mismatch between donor assessment and the transplant team's expectations. Improving donor and donor heart assessment is essential to improve the low utilization rate of available donor hearts without increasing post-transplant recipient mortality. This document provides information to practitioners involved in brain-dead donor management, evaluation and selection, concerning the place of medical history, electrocardiography, cardiac imaging, biomarkers and haemodynamic and arrhythmia assessment in the characterization of potential heart donors.

Organ donor management: Eight common recommendations and actions that deserve reflection

Despite major advances in our understanding of the physiopathology of brain death (BD), there are important controversies as to which protocol is the most appropriate for organ donor management. Many recent reviews on this subject offer recommendations that are sometimes contradictory and in some cases are not applied to other critically ill patients. This article offers a review of the publications (many of them recent) with an impact upon these controversial measures and which can help to confirm, refute or open new areas of research into the most appropriate measures for the management of organ donors in BD, and which should contribute to discard certain established recommendations based on preconceived ideas, that lead to actions lacking a physiopathological basis. Aspects such as catecholamine storm management, use of vasoactive drugs, hemodynamic objectives and monitoring, assessment of the heart for donation, and general care of the donor in BD are reviewed.

Treatment Goals during Care of Adult Donors That Can Influence Outcomes of Heart Transplantation

Myocardial dysfunction during care of adult donors can result from injury occurring before hospital admission or during the progression of brain death. Few evidence-based data correlate specific hemodynamic goals during donor care with outcomes of heart transplantation, although many recommendations exist. Spontaneous reversal of early heart damage or correction of poor cardiac performance can yield outcomes equivalent to outcomes in recipients who had ideal donors. Hemodynamic goals developed in the operating room can be applied in intensive care to improve outcomes of transplantation. These goals include maintenance of mean arterial pressure greater than 60 mm Hg, central venous pressure less than 12 mm Hg, cardiac output greater than 3.8 L/min, cardiac index greater than 2.1, and systemic vascular resistance between 800 and 1200 dyne · sec · cm−5. The ejection fraction and other echocardiographic data also provide helpful guidance when determining whether a heart is suitable for transplantation and during therapy. Titration of cardiovascular variables often requires invasive monitoring to ensure that cardiac preload, afterload, and contractility are optimal.

Cardiac dysfunction following brain death in children: prevalence, normalization, and transplantation

OBJECTIVES

Cardiac dysfunction has been reported to occur in as much as 42% of adults with brain death, and may limit cardiac donation after brain death. Knowledge of the prevalence and natural course of cardiac dysfunction after brain death may help to improve screening and transplant practices but adequately sized studies in pediatric brain death are lacking. The aims of our study are to describe the prevalence and course of cardiac dysfunction after pediatric brain death.

DESIGN

Cross-sectional study.

SETTING/SUBJECTS

We examined an organ procurement organization database (Life Center Northwest) of potential pediatric cardiac donors diagnosed with brain death between January 2011 and November 2013.

INTERVENTION

Transthoracic echocardiograms were reviewed for cardiac dysfunction (defined as ejection fraction <50% or the presence of regional wall motion abnormalities). Descriptive statistics were used to analyze clinical characteristics and describe longitudinal echocardiogram findings in a subgroup of patients. We examined for heterogeneity between cardiac dysfunction with respect to cause of brain death.

MEASUREMENT AND MAIN RESULTS

We identified 60 potential pediatric cardiac donors (age ≤ 18 yr) with at least one transthoracic echocardiogram following brain death. Cardiac dysfunction was present in 23 patients (38%) with brain death. Mean ejection fraction (37.6% vs 62.2%) and proportion of procured hearts (56.5% vs 83.8%) differed significantly between the groups with and without cardiac dysfunction, respectively. Of the 11 subjects with serial transthoracic echocardiogram data, the majority of patients with cardiac dysfunction (73%) improved over time, leading to organ procurement. No heterogeneity between cardiac dysfunction and particular causes of brain death was observed.

CONCLUSION

The frequency of cardiac dysfunction in children with brain death is high. Serial transthoracic echocardiograms in patients with cardiac dysfunction showed improvement of cardiac function in most patients, suggesting that initial decisions to procure should not solely depend on the initial transthoracic echocardiogram examination results.

Medium-term outcome of recipients of marginal donor hearts selected with new stress-echocardiographic techniques over standard criteria

BACKGROUND

Heart transplantation is limited by severe donor organ shortage. Regardless of the changes made in the acceptance of marginal donors, any such mechanism cannot be considered successful unless recipient graft survival rates remain acceptable. A stress echo-driven selection of donors has proven successful in older donors with normal left ventricular resting function and in standard donors with reversible resting left ventricular dysfunction acutely improving during stress, or slowly improving (over hours) during intensive hormonal treatment. Aim of this study is to assess the medium-term outcome of recipients of marginal donor hearts selected with new echocardiographic techniques over standard criteria.

METHODS AND RESULTS

We enrolled 43 recipients of marginal donor hearts: age > 55 years, or < 55 years but with concomitant risk factors, n = 32; acutely improving during stress, n = 3; or slowly improving during hormonal treatment, n = 8. At follow-up (median, 30 months; interquartile range, 21-52 months), 37 of the recipients were still alive. One-year survival was 93%.

CONCLUSION

The strict use of new stress-echocardiographic techniques over standard criteria of marginal donor management, together with comprehensive monitoring of the donor, has the potential to substantially increase the number of donor hearts without adverse effects on recipient medium-term outcome.

Current practice of heart donor evaluation in Germany: multivariable risk factor analysis confirms practicability of guidelines

Background. Organ shortage has liberalised the acceptance criteria of grafts for heart transplantation, but which donor characteristics ultimately influence the decision to perform transplantation? For the first time this was evaluated using real-time donor data from the German organ procurement organization (DSO). Observed associations are discussed with regard to international recommendations and guidelines. Methods. 5291 German donors (2006–2010) were formally eligible for heart donation. In logistic regression models 160 donor parameters were evaluated to assess their influence on using grafts for transplantation (random split of cases: 2/3 study sample, 1/3 validation sample). Results. Successful procurement was determined by low donor age (OR 0.87 per year; 95% CI [0.85–0.89], P < 0.0001), large donor height (OR 1.04 per cm; 95% CI [1.02–1.06], P < 0.0001), exclusion of impaired left ventricular function or wall motion (OR 0.01; 95% CI [0.002–0.036], P < 0.0001), arrhythmia (OR 0.05; 95% CI [0.009–0.260], P = 0.0004), and of severe coronary artery disease (OR 0.003; 95% CI [<0.001–0.01], P < 0.0001). Donor characteristics differed between cases where the procedure was aborted without and with allocation initiated via Eurotransplant.

Transplant of stunned donor hearts rescued by pharmacological stress echocardiography: a "proof of concept" report

Background

Due to the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Hearts with regional or global left ventricular dysfunction are excluded from donation, but stress echo might be useful to identify patients with reversible wall motion abnormalities, potentially eligible for donation.

Methods

Six marginal candidate donors (mean age, 40 ± 13 years; three men) were enrolled. Resting echocardiography showed in all subjects a LV ejection fraction ≥ 45% (mean 51 ± 5%), but multiple risk factors were present. All donors had either global or discrete wall motion abnormalities: Wall Motion Score Index (WMSI) rest = 1.33 ± 0.25. Stress echocardiography was performed with the dipyridamole high dose of 0.84 mg/kg given over 6 min.

Results

The stress echo results were abnormal in three donors (WMSI rest = 1.51 ± 0.19 vs peak = 1.41 ± 0.30). These hearts were excluded from donation and cardiac pathology verification was available in two cases of confirmed LV myocardial fibrosis and/or severe coronary stenosis. The remaining three hearts improved during stress (WMSI rest = 1.15 ± 0.13 vs peak = 1.04 ± 0.06) and were transplanted uneventfully. Recipients (three males, mean age 53 ± 4 years) underwent post-TX coronary angiography, IVUS and endomyocardial biopsies. No recipient had primary graft failure, and all showed normal coronary angiography and normal LV function (EF = 57 ± 6%; WMSI = 1 ± 0) at 1-month post-TX. The recipients were alive at 12-month median follow-up.

Conclusions

Dipyridamole stress echo performed in brain-dead potential donors with LV resting global or discrete wall motion abnormalities identifies hearts with severe morphologic abnormalities excluded from donation (with fixed response during stress echo) from hearts eligible for donation, showing improvement in regional wall motion during stress (viability response) and normal function and coronary anatomy following transplantation.

Combined donor simvastatin and methylprednisolone treatment prevents ischemia-reperfusion injury in rat cardiac allografts through vasculoprotection and immunomodulation

BACKGROUND

Ischemia-reperfusion injury (IRI) and allograft dysfunction remain as two of the major clinical challenges after heart transplantation. Here, we investigated the effect of donor treatment with simvastatin and methylprednisolone on microvascular dysfunction and immunomodulation during IRI in rat cardiac allografts subjected to prolonged ischemia time.

METHODS

The DA rats received simvastatin, methylprednisolone, or both 2 hr before heart donation. The allografts were subjected to 4-hr hypothermic preservation and transplanted to the fully major histocompatibility complex-mismatched WF rat recipients.

RESULTS

Six hours after reperfusion, donor treatment either with simvastatin alone or with high dose of methylprednisolone alone or in combination with simvastatin and methylprednisolone significantly reduced cardiac troponin T release and the number of allograft infiltrating ED1 macrophages MPO neutrophils. However, the combination donor treatment was superior in the prevention of IRI and significantly prolonged allograft survival. Donor simvastatin treatment inhibited allograft microvascular RhoA GTPase pathway activation, whereas methylprednisolone prevented activation of innate immune response and mRNA expression of hypoxia-inducible factor-1α and its multiple target genes.

CONCLUSIONS

Our results show that donor treatment in combination with simvastatin and methylprednisolone prevents IRI and has beneficial effect on allograft survival in rat cardiac allografts. Minimizing microvascular injury and the activation of innate immunity may offer a novel therapeutic strategy to expand the donor pool and furthermore improve the function of the marginal donor organs.

Beta-adrenergic receptor polymorphisms and cardiac graft function in potential organ donors

Prior studies have demonstrated associations between beta-adrenergic receptor (βAR) polymorphisms and left ventricular dysfunction-an important cause of allograft nonutilization for transplantation. We hypothesized that βAR polymorphisms predispose donor hearts to LV dysfunction after brain death. A total of 1043 organ donors managed from 2001-2006 were initially studied. The following βAR single nucleotide polymorphisms were genotyped: β1AR 1165C/G (Arg389Gly), β1AR 145A/G (Ser49Gly), β2AR 46G/A (Gly16Arg) and β2AR 79C/G (Gln27Glu). In multivariable regression analyses, the β2AR46 SNP was significantly associated with LV systolic dysfunction, with each minor allele additively decreasing the odds for LV ejection fraction <50%. The β1AR1165 and β2AR46 SNPs were associated with higher dopamine requirement during the donor management period: donors with the GG and AA genotypes had ORs of 2.64 (95% CI 1.52-4.57) and 2.70 (1.07-2.74) respectively for requiring >10 μg/kg/min of dopamine compared to those with the CC and GG genotypes. However, no significant associations were found between βAR SNPs and cardiac dysfunction in 364 donors managed from 2007-2008, perhaps due to changes in donor management, lack of power in this validation cohort, or the absence of a true association. βAR polymorphisms may be associated with cardiac dysfunction after brain death, but these relationships require further study in independent donor cohorts.

Wait, treat and see: echocardiographic monitoring of brain-dead potential donors with stunned heart

BACKGROUND

Heart transplantation is limited by a severe donor organ shortage. Potential donors with brain death (BD) and left ventricular dysfunction due to neurogenic stunning are currently excluded from donation--although such abnormalities can be reversible with aggressive treatment including Hormonal Treatment (HT) and deferred organ retrieval.

AIM

To assess the recovery of left ventricular dysfunction in potential brain-dead donors with hemodynamic instability treated by aggressive treatment and HT.

METHODS

In a single-center, observational study design, we evaluated 15 consecutive brain-dead potential donors (DBD) (8 males, age = 48 ± 15 years) with hemodynamic instability. All underwent standard hemodynamic monitoring and transthoracic 2-dimensional echo (2-DE) with assessment of Ejection Fraction (EF). Measurements were obtained before BD and after BD within 6 h, at 24 h and within 48 h. HT (with insulin, methylprednisolone, vasopressin and T3) was started as soon as possible to treat hemodynamic instability and avoid administration of norepinephrine (NE). Eligible potential heart donors underwent coronary angiography.

RESULTS

After HT, we observed a normalization of hemodynamic conditions with improvement of mean arterial pressure (pre = 68 ± 8 mmHg vs post = 83 ± 13 mmHg, p < .01), cardiac index (pre = 2.4 ± 0.6 L/min/m2 vs post 3.7 ± 1.2 L/min/m2, p < .05), EF (pre = 48 ± 15 vs post = 59 ± 3%, p < .01) without administration of norepinephrine (NE) in 67% of cases. Five potential donors were excluded from donation (opposition, n = 3, tubercolosis n = 1, malignancy n = 1). At pre-harvesting angiography, coronary artery stenosis was present in 2 of the 10 consented donors. Eight hearts were uneventfully transplanted. No early graft failure occurred and all eight recipients were alive at 6-month follow-up.

CONCLUSION

In BD donors, intensive treatment including HT is associated with improvement of regional and global LV function and reverse remodeling detectable by transthoracic 2DE. Donor hearts with recovered LV function may be eligible for uneventful heart transplant. The wait (in brain death), treat (with HT) and see (with 2D echo) strategy can help rescue organs suitable for heart donation.

Electrocardiographic characteristics of potential organ donors and associations with cardiac allograft use

BACKGROUND

Current regulations require that all cardiac allograft offers for transplantation must include an interpreted 12-lead electrocardiogram (ECG). However, little is known about the expected ECG findings in potential organ donors or the clinical significance of any identified abnormalities in terms of cardiac allograft function and suitability for transplantation.

METHODS AND RESULTS

A single experienced reviewer interpreted the first ECG obtained after brain stem herniation in 980 potential organ donors managed by the California Transplant Donor Network from 2002 to 2007. ECG abnormalities were summarized, and associations between specific ECG findings and cardiac allograft use for transplantation were studied. ECG abnormalities were present in 51% of all cases reviewed. The most common abnormalities included voltage criteria for left ventricular hypertrophy, prolongation of the corrected QT interval, and repolarization changes (ST/T wave abnormalities). Fifty-seven percent of potential cardiac allografts in this cohort were accepted for transplantation. Left ventricular hypertrophy on ECG was a strong predictor of allograft nonuse. No significant associations were seen among corrected QT interval prolongation, repolarization changes, and allograft use for transplantation after adjusting for donor clinical variables and echocardiographic findings.

CONCLUSIONS

We have performed the first comprehensive study of ECG findings in potential donors for cardiac transplantation. Many of the common ECG abnormalities seen in organ donors may result from the heightened state of sympathetic activation that occurs after brain stem herniation and are not associated with allograft use for transplantation.

Favorable short-term outcome of transplanted hearts selected from marginal donors by pharmacological stress echocardiography

BACKGROUND

Because of the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Abnormal results on pharmacologic stress echocardiography are associated with significant coronary artery disease and/or occult cardiomyopathy on verification by cardiac autopsy. The aim of this study was to establish the feasibility of an approach based on pharmacologic stress echocardiography as a gatekeeper for extended heart donor criteria.

METHODS

From April 2005 to April 2010, 39 "marginal" candidate donors (mean age, 56 ± 6 years; 21 men) were initially enrolled. After legal declaration of brain death, marginal donors underwent rest echocardiography, and if the results were normal, dipyridamole (0.84 mg/kg over 6 min, n = 25) or dobutamine (up to 40 μg/kg/min, n = 3) stress echocardiography.

RESULTS

A total of 19 eligible hearts were found with normal findings. Of these, three were not transplanted because of the lack of a matching recipient, and verification by cardiac autopsy showed absence of significant coronary artery disease or cardiomyopathy abnormalities. The remaining 16 eligible hearts were uneventfully transplanted in marginal emergency recipients. All showed normal (n = 14) or nearly normal (minor single-vessel disease in two) angiographic, intravascular ultrasound, hemodynamic and ventriculographic findings at 1 month. At follow-up (median, 14 months; interquartile range, 4-31 months), 14 patients survived and two had died, one at 2 months from general sepsis and one at 32 months from allograft vasculopathy in recurrent multiple myeloma.

CONCLUSIONS

Pharmacologic stress echocardiography can safely be performed in candidate heart donors with brain death and shows potential for extending donor criteria in heart transplantation.

Brain death provokes very acute alteration in myocardial morphology detected by echocardiography: preventive effect of beta-blockers

Our objective was to evaluate immediate acute changes in myocardial function during the autonomic storm of brain death (BD). Wistar rats were divided into four groups (n = 8/group): controls without any treatment, β-blocker (Esmolol®, 10 mg/kg), calcium channel blocker (Diltiazem®, 10 mg/kg), or alpha-blocker (Prazosin®, 0.3 mg/kg). Treatments were administered intravenously 5 min before BD induction. Echocardiography (ATL-5000, 8 MHz) was performed to measure left ventricular (LV) dimensions and fractional shortening at baseline, during BD induction and 5 min and 15 min after BD. In controls, BD was immediately associated with an increase in wall thickness and a decrease in LV cavity dimension. This myocardial wall hypertrophy was completely prevented by β-blockers, but not with calcium- and alpha-blockers. Extensive myocardial interstitial edema was found in all groups, except in the β-blocker group. Myocardial wall hypertrophy was also prevented during a longer follow-up of 180 min after BD in β-blocker group as opposed to controls. In conclusion, BD is associated with an immediate and severe myocardial damage related to an important interstitial edema which is prevented by β-blockers.

[Evaluation of the potential organ donor with special regards to heart donation]

Angesichts der auch in Österreich vorherrschenden Knappheit an verfügbaren Organspendern für Herztransplantationen erscheint es dringlich notwendig, eine Optimierung von Spenderevaluierung und Management zu diskutieren. In der vorliegenden Arbeit werden allgemeine Spenderkriterien und herzspezifische Parameter detailliert diskutiert und im Zusammenhang mit der internationalen Literatur dargestellt. Es wird der "marginale" und im Gegensatz dazu der "optimale" Organspender definiert. Das Spendermanagement wird besprochen, wobei neben der hämodynamischen Optimierung auch auf zusätzliche intensivmedizinische Aspekte eingegangen wird. Erst die exakte Evaluierung erlaubt die individuelle Zuteilung des Organs zum passenden Empfänger und stellt somit insbesondere bei marginalen Spendern die Grundlage eines Therapieerfolgs dar.

Donor cardiac troponin I levels do not predict recipient survival after cardiac transplantation

BACKGROUND

Serum levels of cardiac troponin I (cTnI) are frequently measured in the evaluation of potential heart donors. However, the utility of cTnI levels for predicting recipient outcomes remains controversial. This study was performed to determine whether donor cardiac cTnI levels exceeding 1.0 microg/liter are associated with adverse recipient outcomes.

METHODS

All donors managed by the California Transplant Donor Network between January 2001 and July 2002 with consent for donor evaluation and at least 1 measured cTnI level were included in the study if 1-year recipient mortality data were available. Each study subject was classified as having elevated cTnI if any level exceeded 1.0 microg/liter. Donor variables, recipient risk of 30-day and 1-year mortality, and recipient need for mechanical circulatory support were compared between the 2 groups.

RESULTS

A total of 263 potential donors were evaluated, and 98 had elevated cTnI levels. Of these potential donors, 139 were accepted for transplantation. The cTnI levels were normal in 96 and elevated in 43. Most donors (77%) with elevated cTnI levels had levels of less than 10 microg/liter. Donor cardiopulmonary resuscitation was associated with cTnI elevations. Donors with elevated cTnI levels did not require higher doses of inotropic drugs before transplantation and had similar hemodynamic profiles compared with donors with normal cTnI levels. Although there was a trend towards longer post-transplant hospitalization in recipients of grafts from donors with elevated cTnI levels (17 days vs 15 days, p = 0.044), there was no significant difference in the recipient need for mechanical circulatory support or 30-day and 1-year mortality between the 2 groups.

CONCLUSIONS

In this study, a modestly elevated donor cTnI was not associated with a higher risk of recipient mortality or need for post-transplant mechanical circulatory support. A potential donor heart should not be discarded solely because the troponin level is elevated.

Echocardiographic detection of dysfunctions in donor hearts

Heart transplantation activity is steadily declining worldwide, despite initiatives to increase the donor pool. The yield of transplantable hearts remains low, leading to wastage of over two-thirds of donor organs. Accurate assessment and intervention is required to increase the number of transplantable hearts. The retrieval rate could be increased if techniques become available to differentiate between transplantable and nontransplantable hearts. Echocardiography is an ideally suited noninvasive investigation that may guide donor optimization. However, there are technical difficulties in acquiring high-quality views, and changes in ventricular function following catecholamine storm in brainstem death often lead to misinterpretation of standard 2D images. Current advances in technology, including the routine use of left ventricular contrast, 3D imaging and tissue doppler studies, may improve the accuracy, and thereby the utilization, of echocardiography in donor heart assessment.