Elevated donor cardiac troponin T and procalcitonin indicate two independent mechanisms of early graft failure after heart transplantation

Severe primary graft dysfunction of the heart transplant is associated with increased plasma and intragraft proinflammatory cytokine expression

INTRODUCTION

Heart transplant results have constantly improved but primary left ventricle graft dysfunction (LV-PGD) remains a devastating complication early after transplantation. Donor and recipient systemic inflammatory response may be involved in immune activation of the transplant, and LV-PGD development. Here, we investigated donor and recipient plasma and intragraft cytokine profiles preoperatively and during LV-PGD and searched for predictive markers for LV-PGD.

METHODS

Donor and recipient plasma samples (n = 74) and myocardial biopsies of heart transplants (n = 64) were analyzed. Plasma and intragraft cytokine levels were determined by multiplexed and next-generation sequencing platforms, respectively. The development of LV-PGD during the first 24 hours, and graft function and mortality up to 1 year after transplantation, were examined.

RESULTS

Severe LV-PGD, but not mild or moderate LV-PGD, was significantly associated with early mortality, plasma high-sensitivity troponin elevation, and an increase in intragraft and plasma proinflammatory cytokines during reperfusion. Preoperative donor and recipient plasma cytokine levels failed to predict LV-PGD. Cytokine network analysis identified interleukins -6, -8, -10, and -18 as key players during reperfusion. Prolonged cold and total ischemia time, and increased need for red blood cell transfusions during operation were identified as clinical risk factors for severe LV-PGD.

CONCLUSIONS

Severe LV-PGD was associated with a poor clinical outcome. Donor and recipient plasma cytokine profile failed to predict LV-PGD, but severe LV-PGD was associated with an increase in post-reperfusion intragraft and recipient plasma proinflammatory cytokines. Identified key cytokines may be potential therapeutic targets to improve early and long-term outcomes after heart transplantation.

Suppression of tumorigenicity-2 (ST2) is a promising biomarker in heart transplantation

BACKGROUND

To evaluate the association between donors' and recipients' serum levels of soluble ST2 (sST2) and recipients' outcome after heart transplantation (HT).

METHODS

Blood samples were collected in 50 heart donors before organ procurement and in 50 recipients before HT (D0), a week after HT (D7) and at every first year's endomyocardial biopsy (EMB); sST2 levels were evaluated by ELISA.

RESULTS

Donors who sustained a cardiac arrest, had significantly higher sST2 levels. Recipients on national high emergency waiting list had significantly higher preoperative sST2 levels compared to recipients who did not. Recipients with postoperative sepsis or continuous renal replacement therapy had significantly higher sST2 levels at D7. Recipients who needed a postoperative ECMO for allograft dysfunction had significantly higher sST2 levels in their corresponding donors. Recipients who died during the hospitalization after the transplantation had significantly higher sST2 levels at D7 compared to recipients who did not. No difference was observed in sST2 levels in recipients who had mild allograft rejection and recipient who did not.

CONCLUSIONS

Higher sST2 levels in donors are associated to allograft dysfunction requiring ECMO in recipients; higher postoperative sST2 levels in recipients are associated with in-hospital mortality.

Donor Cardiac Troponin for Prognosis of Adverse Outcomes in Cardiac Transplantation Recipients: a Systematic Review and Meta-analysis

BACKGROUND

Cardiac troponin is a highly specific and widely available marker of myocardial injury, and elevations in cardiac transplant donors may influence donor selection. We aimed to investigate whether elevated donor troponin has a role as a prognostic biomarker in cardiac transplantation.

METHODS

In a systematic review and meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library, without language restriction, from inception to December 2020. We included studies reporting the association of elevated donor troponin with recipient outcome after cardiac transplant. We generated summary odds ratios and hazard ratios for the association of elevated donor troponin with short- and long-term adverse outcomes. Methodological quality was monitored using the Quality In Prognosis Studies tool, and interstudy heterogeneity was assessed using a series of sensitivity and subgroup analyses.

RESULTS

We included 17 studies involving 15 443 patients undergoing cardiac transplantation. Elevated donor troponin was associated with increased odds of graft rejection at 1 y (odds ratio, 2.54; 95% confidence interval, 1.22-5.28). No significant prognostic relationship was found between donor troponin and primary graft failure, short- to long-term mortality, cardiac allograft vasculopathy, and pediatric graft loss.

CONCLUSIONS

Elevated donor troponin is not associated with an increased short- or long-term mortality postcardiac transplant despite increasing the risk of graft rejection at 1 y. Accordingly, an elevated donor troponin in isolation should not exclude donation.

Brain stem death induces pro-inflammatory cytokine production and cardiac dysfunction in sheep model

Introduction

Organs procured following brain stem death (BSD) are the main source of organ grafts for transplantation. However, BSD is associated with inflammatory responses that may damage the organ and affect both the quantity and quality of organs available for transplant. Therefore, we aimed to investigate plasma and bronchoalveolar lavage (BAL) pro-inflammatory cytokine profiles and cardiovascular physiology in a clinically relevant 6-h ovine model of BSD.

Methods

Twelve healthy female sheep (37–42 Kg) were anaesthetized and mechanically ventilated prior to undergoing BSD induction and then monitored for 6 h. Plasma and BAL endothelin-1 and cytokines (IL-1β, 6, 8 and tumour necrosis factor alpha (TNF-α)) were assessed by ELISA. Differential white blood cell counts were performed. Cardiac function during BSD was also examined using echocardiography, and cardiac biomarkers (A-type natriuretic peptide and troponin I were measured in plasma.

Results

Plasma concentrations big ET-1, IL-6, IL-8, TNF-α and BAL IL-8 were significantly (p < 0.01) increased over baseline at 6 h post-BSD. Increased numbers of neutrophils were observed in the whole blood (3.1 × 10⁹ cells/L [95% confidence interval (CI) 2.06–4.14] vs. 6 × 10⁹ cells/L [95%CI 3.92–7.97]; p < 0.01) and BAL (4.5 × 10⁹ cells/L [95%CI 0.41–9.41] vs. 26 [95%CI 12.29–39.80]; p = 0.03) after 6 h of BSD induction vs baseline. A significant increase in ANP production (20.28 pM [95%CI 16.18–24.37] vs. 78.68 pM [95%CI 53.16–104.21]; p < 0.0001) and cTnI release (0.039 ng/mL vs. 4.26 [95%CI 2.69–5.83] ng/mL; p < 0.0001), associated with a significant reduction in heart contractile function, were observed between baseline and 6 h.

Conclusions

BSD induced systemic pro-inflammatory responses, characterized by increased neutrophil infiltration and cytokine production in the circulation and BAL fluid, and associated with reduced heart contractile function in ovine model of BSD.

Primary Graft Dysfunction after Heart Transplantation - Unravelling the Enigma

Primary graft dysfunction (PGD) remains the main cause of early mortality following heart transplantation despite several advances in donor preservation techniques and therapeutic strategies for PGD. With that aim of establishing the aetiopathogenesis of PGD and the preferred management strategies, the new consensus definition has paved the way for multiple contemporaneous studies to be undertaken and accurately compared. This review aims to provide a broad-based understanding of the pathophysiology, clinical presentation and management of PGD.

Circulating growth differentiation factor-15 as a novel biomarker in heart transplant

Aims

This study aimed to examine (i) whether circulating growth differentiation factor‐15 (GDF‐15) is associated with acute cellular cardiac allograft rejection (ACR); (ii) a longitudinal trend of GDF‐15 after heart transplantation; and (iii) the prognostic value of GDF‐15 in predicting a composite outcome of severe primary graft dysfunction (PGD) and 30 day mortality post‐transplant.

Methods and results

Serum samples were collected before heart transplantation and at every endomyocardial biopsy (EMB) post‐heart transplantation in de novo transplant patients. A total of 60 post‐transplant serum samples were matched to the corresponding EMBs. Seven (12%) were considered International Society for Heart Lung Transplantation Grade 1R ACR, and one (2%) was identified as Grade 2R ACR. GDF‐15 levels in patients with ACR were not different from those in the non‐rejection group (6230 vs. 6125 pg/mL, P = 0.27). GDF‐15 concentration gradually decreased from 8757 pg/mL pre‐transplant to 5203 pg/mL at 4 weeks post‐transplant. The composite adverse outcome of PGD and 30 day mortality was significantly associated with increased post‐operative GDF‐15 (odds ratio: 40; 95% confidence interval: 2.01–794.27; P = 0.005) and high inotrope score post‐transplant (odds ratio: 18; 95% confidence interval: 1.22–250.35; P = 0.01).

Conclusions

Circulating GDF‐15 concentration was markedly elevated in patients with end‐stage heart failure and decreased after heart transplantation. GDF‐15 was significantly associated with post‐transplant PGD and mortality. A lack of association between ACR and GDF‐15 did not support routine use of GDF‐15 as a biomarker to detect ACR. However, GDF‐15 may be potentially useful to determine heart transplant recipients at high risk for adverse post‐transplant outcomes. We suggest that GDF‐15 levels in recipient serum can provide risk stratification for severe PGD including death during post‐operative period. This novel biomarker may serve to inform and guide timely interventions against severe PGD and adverse outcomes during the first 4 weeks after transplantation. Further studies to support the utility of GDF‐15 in heart transplantation are required.

Cardiac Graft Assessment in the Era of Machine Perfusion: Current and Future Biomarkers

Heart transplantation remains the treatment of reference for patients experiencing end‐stage heart failure; unfortunately, graft availability through conventional donation after brain death is insufficient to meet the demand. Use of extended‐criteria donors or donation after circulatory death has emerged to increase organ availability; however, clinical protocols require optimization to limit or prevent damage in hearts possessing greater susceptibility to injury than conventional grafts. The emergence of cardiac ex situ machine perfusion not only facilitates the use of extended‐criteria donor and donation after circulatory death hearts through the avoidance of potentially damaging ischemia during graft storage and transport, it also opens the door to multiple opportunities for more sensitive monitoring of graft quality. With this review, we aim to bring together the current knowledge of biomarkers that hold particular promise for cardiac graft evaluation to improve precision and reliability in the identification of hearts for transplantation, thereby facilitating the safe increase in graft availability. Information about the utility of potential biomarkers was categorized into 5 themes: (1) functional, (2) metabolic, (3) hormone/prohormone, (4) cellular damage/death, and (5) inflammatory markers. Several promising biomarkers are identified, and recommendations for potential improvements to current clinical protocols are provided.

C-Reactive protein level and left ventricular mass are associated with acute cellular rejection after heart transplant

OBJECTIVES

Acute cellular rejection (ACR) remains a major complication of heart transplant (HT). The gold standard for its diagnosis is endomyocardial biopsy (EMB), whereas the role of non-invasive biomarkers for detecting ACR is unclear. This study aimed to identify non-invasive biomarkers for the diagnosis of ACR in patients undergoing HT and presenting with normal left ventricular function.

METHODS

We evaluated patients who underwent HT at a single center between January 2010 and June 2019. Patients were enrolled after HT, and those with left ventricular (LV) systolic dysfunction before EMB were excluded. We included only the results of the first EMB performed at least 30 days after HT (median, 90 days). Troponin, B-type natriuretic peptide (BNP), and C-reactive protein (CRP) levels were measured and echocardiography was performed up to 7 days before EMB. ACR was defined as International Society for Heart and Lung Transplantation grade 2R or 3R on EMB. We performed logistic regression analysis to identify the non-invasive predictors of ACR (2R or 3R) and evaluated the accuracy of each using area under the receiver operator characteristic curve analysis.

RESULTS

We analyzed 72 patients after HT (51.31±13.63 years; 25 [34.7%] women); of them, 9 (12.5%) developed ACR. Based on multivariate logistic regression analysis, we performed forward stepwise selection (entry criteria, p<0.05). The only independent predictors that remained in the model were CRP level and LV mass index. The optimal cut-off point for CRP level was ≥15.9 mg/L (odds ratio [OR], 11.7; p=0.007) and that for LV mass index was ≥111 g/m2 (OR, 13.6; p=0.003). The area under the receiver operating characteristic curve derived from this model was 0.87 (95% confidence interval [CI], 0.75-0.99), with sensitivity of 85.7% (95% CI, 42.1%-99.6%), specificity of 78.4% (95% CI, 64.7%-88.7%), positive predictive value of 35.3% (95% CI, 14.3%-61.7%), and negative predictive value of 97.6% (95% CI, 87.1%-99.9%).

CONCLUSIONS

Among patients undergoing HT, CRP level and LV mass were directly associated with ACR, but troponin and BNP levels were not.

Primary graft dysfunction after heart transplantation: a thorn amongst the roses

Primary graft dysfunction (PGD) remains the leading cause of early mortality post-heart transplantation. Despite improvements in mechanical circulatory support and critical care measures, the rate of PGD remains significant. A recent consensus statement by the International Society of Heart and Lung Transplantation (ISHLT) has formulated a definition for PGD. Five years on, we look at current concepts and future directions of PGD in the current era of transplantation.

Management of primary graft failure after heart transplantation: Preoperative risks, perioperative events, and postoperative decisions

Primary graft failure (PGF) after heart transplantation (HT) is a devastating and unexpected event characterized by failure of the graft to adequately support recipient circulation necessitating high doses of vasopressors and inotropes and/or temporary mechanical circulatory support. Although it represents an increasingly common event in the current era, there remains a high degree of variability in prevalence, reported risk factors, and approach to this clinical entity. The purpose of the current review is to highlight preoperative considerations including known incidence and risk factors, perioperative issues involving the identification and management of PGF, and postoperative decisions related to weaning of mechanical circulatory support and titration of immunosuppressive therapy. Lastly, we highlight future directions in PGF research, involving basic and translational research, that have the potential to uncover novel strategies of risk stratification and treatment. CASE: Our patient is a 53-year-old man with end-stage non-ischemic dilated cardiomyopathy complicated by ventricular tachycardia (VT), post-capillary pulmonary hypertension, and renal insufficiency. After progressing to NYHA Class IV symptoms, he underwent implantation of a durable left ventricular assist device (LVAD) as bridge to transplant (BTT). On device support, he developed recurrent VT resulting in multiple defibrillator discharges and hospital admission for intravenous anti-arrhythmic therapy. He is subsequently upgraded to a higher status on the waiting list. A suitable donor is identified, with an appropriate predicted heart mass and an anticipated ischemic time of <4 hours. He is taken to the operating room, where at the time of anesthesia induction he develops vasodilatory shock, requiring high-dose vasopressors, and cardiopulmonary bypass (CPB) support for dissection. After surgical anastomosis, cross clamp removal and reperfusion, graft function is extremely poor, there is significant bradycardia requiring pacing, and the patient is unable to be weaned successfully from CPB. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is initiated, and the patient is transferred to the intensive care unit. Retrospective flow crossmatch is negative. This patient is suffering from severe primary graft failure.

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.

Associated Clinical and Laboratory Markers of Donor on Allograft Function After Heart Transplant

Introduction

Primary graft dysfunction is a major cause of mortality after heart transplantation.

Objective

To evaluate correlations between donor-related clinical/biochemical markers and the occurrence of primary graft dysfunction/clinical outcomes of recipients within 30 days of transplant.

Methods

The prospective study involved 43 donor/recipient pairs. Data collected from donors included demographic and echocardiographic information, noradrenaline administration rates and concentrations of soluble tumor necrosis factor receptors (sTNFR1 and sTNFR2), interleukins (IL-6 and IL-10), monocyte chemoattractant protein-1, C-reactive protein and cardiac troponin I. Data collected from recipients included operating, cardiopulmonary bypass, intensive care unit and hospitalization times, inotrope administration and left/right ventricular function through echocardiography.

Results

Recipients who developed moderate/severe left ventricular dysfunction had received organs from significantly older donors (P =0.020). Recipients from donors who required moderate/high doses of noradrenaline (>0.23 µg/kg/min) around harvesting time exhibited lower post-transplant ventricular ejection fractions (P =0.002) and required longer CPB times (P =0.039). Significantly higher concentrations of sTNFR1 (P =0.014) and sTNFR2 (P =0.030) in donors were associated with reduced intensive care unit times (≤5 days) in recipients, while higher donor IL-6 (P =0.029) and IL-10 (P =0.037) levels were correlated with reduced hospitalization times (≤25 days) in recipients. Recipients who required moderate/high levels of noradrenaline for weaning off cardiopulmonary bypass were associated with lower donor concentrations of sTNFR2 (P =0.028) and IL-6 (P =0.001).

Conclusion

High levels of sTNFR1, sTNFR2, IL-6 and IL-10 in donors were associated with enhanced evolution in recipients. Allografts from older donors, or from those treated with noradrenaline doses >0.23 µg/kg/min, were more frequently affected by primary graft dysfunction within 30 days of surgery.

Procalcitonin for infections in the first week after pediatric liver transplantation

Background

Procalcitonin (PCT) has become a commonly used serum inflammatory marker. Our aim was to describe the kinetics and usefulness of serial post-operative PCT measurements to detect bacterial infection in a cohort of children immediately after pediatric liver transplantation (pLT).

Methods

We performed a retrospective chart review of a cohort of pLT recipients with serial serum PCT measurements in the first week following pLT. The presence of infection was determined on clinical and biological parameters. Normal PCT was defined as < 0.5 (ng/ml).

Results

Thirty-nine patients underwent 41 pLT. PCT was measured daily during the first week post pLT. Values first increased following surgery and then decreased, nearing 0.5 ng/ml at day seven. Peak PCT reached a median of 5.61 ng/ml (IQR 3.83-10.8). Seventeen patients were considered to have an infection. There was no significant difference in daily PCT or peak PCT between infected and non infected patients during the first post-operative week. AUC of ROC curve for PCT during first week was never higher than 0.6.

Conclusions

We conclude that serial PCT measurements during the first week after pLT is not useful to identify patients with bacterial infections. Rather, we propose that serum PCT may be useful after the first week post pLT.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2234-y) contains supplementary material, which is available to authorized users.

Successful transplantation of a heart with an atrial septal defect caused by blunt trauma

We report a case of a successful heart transplantation from a donor after multiple trauma. A traumatic atrial septal defect was repaired, and the postoperative course was uneventful.

Preoperative serum albumin levels predict 1-year postoperative survival of patients undergoing heart transplantation

BACKGROUND

Serum albumin concentration has been recognized as a marker of nutrition, severity of inflammation, and hepatic function in patients with various chronic diseases. The purpose of this study was to investigate the impact of pretransplant serum albumin concentration on post-transplant outcome in heart transplant recipients.

METHODS AND RESULTS

Preoperative laboratory variables, including albumin concentration and donor-related information, were obtained from 822 consecutive patients undergoing heart transplant at Columbia University Medical Center between 1999 and 2010. The association between pretransplant albumin concentration and post-transplant 1-year survival was analyzed. Available data from the United Network for Organ Sharing (n=13671) were also analyzed to evaluate the impact of preoperative albumin levels on post-transplant outcome. In our cohort, multivariable analysis revealed that preoperative albumin (mg/dL; hazard ratio, 0.46; P<0.0001) and preoperative total bilirubin (mg/dL; hazard ratio, 1.26; P=0.0002) were associated with post-transplant 1-year mortality. This implied that for every 1 mg/dL increase in albumin concentration, the post-transplant 1-year mortality rate decreased by 54%. The Kaplan-Meier analysis based on our patients cohort and the United Network for Organ Sharing dataset showed lower survival rate at 1-year post-transplant in patients with albumin levels ≤ 3.5 mg/dL compared with those with >3.5 mg/dL (our patients, 91.3 versus 72.4%; P<0.0001; United Network for Organ Sharing, 88.4 versus 84.8%; P<0.0001).

CONCLUSIONS

Pretransplant serum albumin concentration is a strong prognostic marker for post-transplant survival in heart transplant recipients.

Donor predictors of allograft use and recipient outcomes after heart transplantation

BACKGROUND

Despite a national organ-donor shortage and a growing population of patients with end-stage heart disease, the acceptance rate of donor hearts for transplantation is low. We sought to identify donor predictors of allograft nonuse, and to determine whether these predictors are in fact associated with adverse recipient post-transplant outcomes.

METHODS AND RESULTS

We studied a cohort of 1872 potential organ donors managed by the California Transplant Donor Network from 2001 to 2008. Forty-five percent of available allografts were accepted for heart transplantation. Donor predictors of allograft nonuse included age >50 years, female sex, death attributable to cerebrovascular accident, hypertension, diabetes mellitus, a positive troponin assay, left-ventricular dysfunction and regional wall motion abnormalities, and left-ventricular hypertrophy. For hearts that were transplanted, only donor cause of death was associated with prolonged recipient hospitalization post-transplant, and only donor diabetes mellitus was predictive of increased recipient mortality.

CONCLUSIONS

Whereas there are many donor predictors of allograft discard in the current era, these characteristics seem to have little effect on recipient outcomes when the hearts are transplanted. Our results suggest that more liberal use of cardiac allografts with relative contraindications may be warranted.

Baseline evaluation of serum markers of inflammation and their utility in clinical practice in paediatric liver transplant recipients

BACKGROUND

Several biomarkers of penetrating infections vs. rejection in liver transplant (LT) have been suggested; however, baseline values in paediatric LT recipients have not been studied.

AIM

We evaluated the baseline concentration of procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6) in a post-LT paediatric group.

METHODS

We measured serum PCT, CRP and IL-6 in 58 consecutive paediatric LT recipients. Specimens were collected for group 1 (n=22) at day 1, group 2 (n=12) at day 7 post-LT and group 3 (n=24) at onset of febrile episode. Day 7 samples were obtained from patients who had no graft dysfunction or signs/symptoms of sepsis.

RESULTS

Median values for PCT were: group 1 was 5.16 μg/L (95% CI, 2.18-21.13); group 2: 0.170 μg/L (95% CI, 0.15-0.36) and, group 3: 1.93 μg/L (95% CI, 1.36-2.66) for bacterial and fungal infection, 0.19 μg/L (95% CI, 0.10-0.48) for rejection, and 0.31 μg/L (95% CI, 0.15-0.44) for viral infection. The area under the ROC (AUROC) for PCT, CRP and IL-6 in bacterial infection vs. rejection was 1.0 (P<0.0001), 0.842 (95% CI 0.686-0.998; P<0.0001) and 0.739 (95% CI 0.559-0.919; P 0.0046), respectively.

CONCLUSION

PCT levels were significantly higher in bacterial and fungal infection in comparison to other inflammatory markers. PCT proved to be the most specific parameter in differentiating bacterial infection from viral infection and allograft rejection.

Endocrine changes in brain death and transplantation

Following brain death (BD) many hormonal changes occur. These include an increase and then a fall in the levels of circulating catecholamines, reduced levels of anti-diuretic hormone and cortisol as well as alterations in the hypothalamic-pituitary thyroid axis consistent with the non-thyroidal illness syndrome. In an era when the numbers of potential recipients listed for transplantation are greater than the number of donors, with an increasing donor age, a detailed knowledge of the endocrine changes and pathophysiological consequences of these is essential to optimise the management of the brain-stem dead organ donor. There still remains significant debate as to whether hormone replacement therapy to correct the observed changes is beneficial.

Complement-dependent inflammation and injury in a murine model of brain dead donor hearts

RATIONALE

Donor brain death (BD) is an unavoidable occurrence in heart transplantation and results in profound physiological derangements that render the heart more susceptible to ischemia/reperfusion injury in the recipient and likely has negative long-term consequences to allograft survival.

OBJECTIVE

We developed a novel mouse model of BD and investigated the role of complement in BD-induced myocardial inflammation and injury.

METHODS AND RESULTS

BD was induced by inflation of a balloon catheter in the cranial cavity. BD in wild-type mice resulted in a significant increase in serum concentrations of the complement activation product complement component (C)3a, and immunohistochemical analysis of heart sections demonstrated C3 deposition on the vascular endothelium and surrounding myocytes. Following induction of BD in complement (C3)-deficient mice, cardiac troponin levels, and histological evidence of injury were significantly reduced compared to wild-type mice. C3 deficiency was also associated with reduced myocardial leukocyte infiltration and reduced or absent expression of P-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, tumor necrosis factor-alpha, and interleukin-1beta.

CONCLUSIONS

These data indicate an important role for complement in BD-induced inflammation and injury and suggest that a complement inhibitory strategy applied to the donor (in addition to the recipient) may provide graft protection.

Procalcitonin in liver transplantation: are high levels due to donors or recipients?

Introduction

To date, a specific marker to evaluate and predict the clinical course or complication of the liver-transplanted patient is not available in clinical practice. Increased procalcitonin (PCT) levels have been found in infectious inflammation; poor organ perfusion and high PCT levels in the cardiac donor appeared to predict early graft failure. We evaluated PCT as a predictor of early graft dysfunction and postoperative complications.

Methods

PCT serum concentrations were measured in samples collected before organ retrieval from 67 consecutive brain-dead donors and in corresponding recipients from day 0, before liver transplantation, up to day 7 after liver transplantation. The following parameters were recorded in donors: amount of vasopressive drug doses, cardiac arrest history 24 hours before retrieval, number of days in the intensive care unit, age of donor, and infection in donor, and the following parameters were recorded in recipients: cold and warm ischemia time, veno-venous bypass, transfusion amount during orthotopic liver transplantation (OLT), and occurrence of postoperative complication or hepatic dysfunction.

Results

In the donor, the preoperative level of PCT was associated with cardiac arrest and high doses of catecholamines before organ retrieval. In the recipient, elevated PCT levels were observed early after OLT, with a peak at day 1 or 2 after OLT, then a decrease until day 7. A postoperative peak of PCT levels was associated neither with preoperative PCT levels in the donor or the recipients nor with hepatic post-OLT dysfunction or other postoperative complications, but with two donor parameters: infection and cardiac arrest.

Conclusion

PCT level in the donor and early PCT peak in the recipient are not predictive of post-OLT hepatic dysfunction or other complications. Cardiac arrest and infection in the donor, but not PCT level in the donor, are associated with high post-OLT PCT levels in the recipient.

Relationship between procalcitonin values and infection in brain-dead organ donors

BACKGROUND AND AIMS

An association between the inflammatory reactions estimated by several biomarkers and organ dysfunction has been reported in brain-dead organ donors (BDOD). Procalcitonin (PCT), a biomarker of inflammation due to bacterial infection, is increased among BDOD. However, is not known whether infection changes PCT values in BDOD.

MATERIALS AND METHODS

We retrospectively analyzed 82 BDOD including several demographic and clinical parameters, bacterial culture results, antibiotics prescription, and plasma values of PCT measured before organ harvesting. Infection was diagnosed to be either a positive bacterial culture (restricted definition) and/or prescription of antibiotics (extended definition).

RESULTS

The median PCT value was 1.5 (interquartile range [IQR], 0.4 to 6.9; range, 0 to 526 ng/mL; n=82). Thirty-eight (46%) and 24 (29%) patients had PCT values>2 ng/mL and >5 ng/mL, respectively. Median PCT values among infected (1.18; IQR, 0.27 to 6.55 ng/mL) versus noninfected (1.57; IQR, 0.53 to 7.15 ng/mL) BDOD (restricted definition) were not different (P=.36). The area under the receiver operating characteristic curve using PCT to predict infection (restricted definition) was 0.52. Specificity of PCT to predict infection was above 80% at PCT values>9 ng/mL.

CONCLUSION

Our results confirmed PCT values are increased in BDOD, suggesting that this was not related to an infectious cause (whatever definition was used) unless PCT values are high.

Sequential measurements of troponin Ic values in brain-dead patients considered as potential heart donors

It was suggested that a single value of normal or increased plasma cardiac troponin T or I (cTnT or cTnI) concentration could contribute to estimate donor myocardial damage and function in brain-dead patients. In patients with acute coronary syndromes, an initial normal value of troponin must be confirmed several hours later but no such recommendations exist for brain-dead patients. We investigated the relationship between two sequential (6 h interval) measurements of plasma cTnI concentrations in brain-dead patients considered as potential heart donors. The first and the second TnIc values were correlated with an adjusted r2 value of 0.92 (p<0.001). Our results suggest therefore that it is not necessary to repeat the measurements, when the value of plasma cTnI concentration is taken into consideration in the algorithm for cardiac harvesting.

Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

INTRODUCTION

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.

METHODS

We performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.

RESULTS

Uncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.

CONCLUSION

The dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.

Progress in heart transplantation

The field of heart transplantation was built upon the discoveries of immunity and tolerance by Landsteiner, Medawar, Burnet, and others, as well as technical advancements in surgical technique by Carrel. Since the first successful human heart transplant performed by Christiaan Barnard in 1967, there has been substantial progress in the field of heart transplantation, especially over the last several decades. With advances in immunosuppression and surgical techniques, the rates of acute rejection and infection leading to graft failure have declined. However, the detection of acute and chronic allograft rejection remains one of the most important yet unsettled matters. As such, many new horizons exist for further advancement of the field of heart transplantation and for improving the outcomes of the patients we serve.

Brain Injury and Ventricular Dysfunction: Insights Into Reversible Heart Failure

The unique syndrome of brain death is associated with cardiac dysfunction; however, if such a heart is removed from this environment and transplanted, the cardiac dysfunction often resolves. This scenario offers insight into the mechanisms of reversible forms of cardiac injury and suggests that treatment of the extra-cardiac milieu by removing the initiating insult can often result in recovery. The mechanisms leading to reversible cardiac dysfunction are discussed in this review, with concentration on the implications of such injury in determining outcomes following transplantation.

EFFECT OF ACUTE BRAIN DEATH ON RELEASE OF ATRIUM AND B-TYPE NATRIURETIC PEPTIDES IN AN ANIMAL MODEL

INTRODUCTION

Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for severity of heart failure and may be used in the quality assessment of donor hearts. Elevated cardiac troponins predict early graft failure after heart transplantation. This study evaluated the effects of acute brain death (BD) on the release of ANP, BNP, big ET-1, and cardiac troponins in an animal model.

MATERIALS AND METHODS

Pigs were randomized into a BD group (n=5) and a control group (n=5). In the first group, acute BD was induced, and anesthesia was stopped. In the control animals, a sham operation was performed, and anesthesia was continued. Parameters were measured at baseline and for 13 hours postoperatively.

RESULTS

After acute BD, there were significant hemodynamic changes. In the control group, the BNP level was higher than in the BD group and decreased over time (P =0.016). There was no significant change in BNP release in the BD group up to 13 hours (P =0.1). ANP release remained stable over time in the control group (P =0.35) but decreased in the BD group (P =0.043). The big ET-1 levels were not different between groups. Cardiac troponin I was elevated in the BD group 5 hours after BD (P< 0.05) but remained under 1.5 mg/L throughout the study.

CONCLUSION

Acute BD did not lead to an increase of BNP and ANP levels. Moreover, intact brain function seems to augment the release of natriuretic peptides from the myocardium. Further clinical evaluation of prognostic values of natriuretic peptides for the assessment of donor hearts is necessary. Cardiac troponins are a useful additional tool in the evaluation of donor hearts.