Peripartum cardiomyopathy: a global effort to find the cause and cure for the rare and little understood disease.

In this review, we present our current understanding of peripartum cardiomyopathy (PPCM) based on reports of the incidence, diagnosis and current treatment options. We summarise opinions on whether PPCM is triggered by vascular and/or hormonal causes and examine the influence of comorbidities such as preeclampsia. Two articles published in 2021 strongly support the hypothesis that PPCM may be a familial disease. Using large cohorts of PPCM patients, they summarised the available genomic DNA sequence data that are expressed in human cardiomyocytes. While PPCM is considered a disease predominately affecting the left ventricle, there are data to suggest that some cases also involve right ventricular failure. Finally, we conclude that there is sufficient evidence to warrant an RNAseq investigation and that this would be most informative if performed at the cardiomyocytes level rather than analysing genomic DNA from the peripheral circulation. Given the rarity of PPCM, the combined resources of international human heart tissue biobanks have assembled 30 ventricular tissue samples from PPCM patients, and we are actively seeking to enlarge this patient base by collaborating with human heart tissue banks and research laboratories who would like to join this endeavour.

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-1ß, 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.

Endothelin receptor antagonist improves donor lung function in an ex vivo perfusion system.

BACKGROUND: A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). METHODS: After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). RESULTS: Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin-eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. CONCLUSIONS: These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.

In vivo tissue reaction within the outflow conduit in patients supported by HeartWare HVAD.

AIM: The frequency, extent, and nature of tissue ingrowth within the continuous-flow left ventricular assist device (cf-LVAD) outflow conduit has not been systematically assessed. We sought to characterize conduit histopathology at explantation in a cohort of patients with HeartWare ventricular assist device (HVAD) and assess the effect on pump performance. METHODS: Patients undergoing routine histopathological assessment of a HeartWare HVAD removed at transplantation or autopsy were assessed. Outflow conduits were examined macroscopically, and visible tissue was sectioned for microscopic evaluation. In patients who had undergone prior contrast-enhanced computerized tomography (CT) with HVAD in situ, the outflow conduit was measured at the aortic anastomosis and 5 cm proximal to the anastomosis, in the axial and sagittal planes. All patients had their pump flow, flow pulsatility, current, and speed determined from log files examined at 1, 3, 6, 9, and 12 months after LVAD implantation. RESULTS: Twenty-five consecutive patients were assessed (24 LVAD, 1 biventricular assist device (BiVAD)). Of the 26 outflow grafts assessed, there was evidence of tissue ingrowth reaction in 24 (92%) grafts. The most common site was the distal anastomosis (18/24, 75%), with the graft body involved in 14 of 24 (58%) grafts. Microscopic evaluation revealed acute inflammatory infiltrate in 4 of 24 grafts (17%), chronic inflammatory infiltrate in 14 of 24 (58%), neointima formation in 18 of 24 (75%) and fibrosis in 18 of 24 (75%) grafts. The median depth of tissue was 1 mm (range, 0-2 mm). The mean conduit diameter was 9.5 ± 0.6 mm at the aortic anastomosis compared with 11.1 ± 0.5 mm 5 cm proximal to the anastomosis (p < 0.0001). In patients with unchanged pump speed one month after implantation, analysis of log files revealed a significant (5.8 ± 8.6%) decrease in pump flow (4.65 ± 0.86 vs 4.38 ± 0.92 L/min, p = 0.01) and flow pulsatility (5.00 ± 1.10 vs 4.16 ± 1.05 L/min, p = 0.006). CONCLUSIONS: There is evidence of tissue formation within the HVAD outflow conduit in the vast majority of patients, most commonly located at the aortic anastomosis. This is associated with significantly decreased pump flow over time.

Correction to: The Sydney Heart Bank: improving translational research while eliminating or reducing the use of animal models of human heart disease.

In the original version of this article, the name of one of the authors is not correct. The correct name should be W. A. Linke, which is shown correctly in the authorgroup section above.

The Sydney Heart Bank: improving translational research while eliminating or reducing the use of animal models of human heart disease.

The Sydney Heart Bank (SHB) is one of the largest human heart tissue banks in existence. Its mission is to provide high-quality human heart tissue for research into the molecular basis of human heart failure by working collaboratively with experts in this field. We argue that, by comparing tissues from failing human hearts with age-matched non-failing healthy donor hearts, the results will be more relevant than research using animal models, particularly if their physiology is very different from humans. Tissue from heart surgery must generally be used soon after collection or it significantly deteriorates. Freezing is an option but it raises concerns that freezing causes substantial damage at the cellular and molecular level. The SHB contains failing samples from heart transplant patients and others who provided informed consent for the use of their tissue for research. All samples are cryopreserved in liquid nitrogen within 40 min of their removal from the patient, and in less than 5-10 min in the case of coronary arteries and left ventricle samples. To date, the SHB has collected tissue from about 450 failing hearts (>15,000 samples) from patients with a wide range of etiologies as well as increasing numbers of cardiomyectomy samples from patients with hypertrophic cardiomyopathy. The Bank also has hearts from over 120 healthy organ donors whose hearts, for a variety of reasons (mainly tissue-type incompatibility with waiting heart transplant recipients), could not be used for transplantation. Donor hearts were collected by the St Vincent's Hospital Heart and Lung transplantation team from local hospitals or within a 4-h jet flight from Sydney. They were flushed with chilled cardioplegic solution and transported to Sydney where they were quickly cryopreserved in small samples. Failing and/or donor samples have been used by more than 60 research teams around the world, and have resulted in more than 100 research papers. The tissues most commonly requested are from donor left ventricles, but right ventricles, atria, interventricular system, and coronary arteries vessels have also been reported. All tissues are stored for long-term use in liquid N or vapor (170-180 °C), and are shipped under nitrogen vapor to avoid degradation of sensitive molecules such as RNAs and giant proteins. We present evidence that the availability of these human heart samples has contributed to a reduction in the use of animal models of human heart failure.

Potential role of coenzyme Q10 in facilitating recovery from statin-induced rhabdomyolysis.

Rhabdomyolysis is a rare, but serious complication of statin therapy, and represents the most severe end of the spectrum of statin-induced myotoxicity. We report a case where coenzyme Q10 facilitated recovery from statin-induced rhabdomyolysis and acute renal failure, which had initially persisted despite statin cessation and haemodialysis. This observation is biologically plausible due to the recognised importance of coenzyme Q10 in mitochondrial bioenergetics within myocytes, and the fact that statins inhibit farnesyl pyrophosphate production, a biochemical step crucial for coenzyme Q10 synthesis. Coenzyme Q10 is generally well tolerated, and may potentially benefit patients with statin-induced rhabdomyolysis.

Normothermic ex vivo perfusion provides superior organ preservation and enables viability assessment of hearts from DCD donors.

The shortage of donors in cardiac transplantation may be alleviated by the use of allografts from donation after circulatory death (DCD) donors. We have previously shown that hearts exposed to 30 min warm ischemic time and then flushed with Celsior supplemented with agents that activate ischemic postconditioning pathways, show complete recovery on a blood-perfused ex vivo working heart apparatus. In this study, these findings were assessed in a porcine orthotopic heart transplant model. DCD hearts were preserved with either normothermic ex vivo perfusion (NEVP) using a clinically approved device, or with standard cold storage (CS) for 4 h. Orthotopic transplantation into recipient animals was subsequently undertaken. Five of six hearts preserved with NEVP demonstrated favorable lactate profiles during NEVP and all five could be weaned off cardiopulmonary bypass posttransplant, compared with 0 of 3 hearts preserved with CS (p < 0.05, Fisher's exact test). In conclusion, DCD hearts flushed with supplemented Celsior solution and preserved with NEVP display viability before and after transplantation. Viability studies of human DCD hearts using NEVP are warranted.

Increasing the tolerance of DCD hearts to warm ischemia by pharmacological postconditioning.

Donation after circulatory death (DCD) offers a potential additional source of cardiac allografts. We used a porcine asphyxia model to evaluate viability of DCD hearts subjected to warm ischemic times (WIT) of 20­40 min prior to flushing with Celsior (C) solution. We then assessed potential benefits of supplementing C with erythropoietin, glyceryl trinitrate and zoniporide (Cs), a combination that we have shown previously to activate ischemic postconditioning pathways. Hearts flushed with C/Cs were assessed for functional, biochemical and metabolic recovery on an ex vivo working heart apparatus. Hearts exposed to 20-min WIT showed full recovery of functional and metabolic profiles compared with control hearts (no WIT). Hearts subjected to 30- or 40-min WIT prior to C solution showed partial and no recovery, respectively. Hearts exposed to 30-min WIT and Cs solution displayed complete recovery, while hearts exposed to 40-min WIT and Cs solution demonstrated partial recovery. We conclude that DCD hearts flushed with C solution demonstrate complete recovery up to 20-min WIT after which there is rapid loss of viability. Cs extends the limit of WIT tolerability to 30 min. DCD hearts with ≤30-min WIT may be suitable for transplantation and warrant assessment in a transplant model.

Enhanced preservation of pig cardiac allografts by combining erythropoietin with glyceryl trinitrate and zoniporide.

Erythropoietin has a tissue-protective effect independent of its erythropoietic effect that may be enhanced by combining it with the nitric oxide donor glyceryl trinitrate (GTN) and the sodium-hydrogen exchange inhibitor zoniporide in rat hearts stored with an extracellular-based preservation solution (EBPS). We thus sought to test this combination of agents in a porcine model of orthotopic heart transplantation incorporating donor brain death and total ischaemic time of approximately 260 min. Pig hearts were stored in one of four storage solutions: unmodified EBPS (CON), EBPS supplemented with GTN and zoniporide (GZ), EBPS supplemented with erythropoietin and zoniporide (EZ), or EBPS supplemented with all three agents (EGZ). A total of 4/5 EGZ hearts were successfully weaned from cardiopulmonary bypass compared with only 2/5 GZ hearts, 0/5 CON hearts and 0/5 EG hearts (p = 0.017). Following weaning from bypass EGZ hearts demonstrated superior contractility and haemodynamics than GZ hearts. All weaned hearts displayed impaired diastolic function. Release of troponin I from EGZ hearts was lower than all other groups. In conclusion, supplementation of EBPS with erythropoietin, glyceryl trinitrate and zoniporide provided superior donor heart preservation than all other strategies tested.

Critical role of the STAT3 pathway in the cardioprotective efficacy of zoniporide in a model of myocardial preservation - the rat isolated working heart.

BACKGROUND AND PURPOSE: Ischemia-reperfusion injury plays an important role in the development of primary allograft failure after heart transplantation. Inhibition of the Na+/H+ exchanger is one of the most promising therapeutic strategies for treating ischemia-reperfusion injury. Here we have characterized the cardioprotective efficacy of zoniporide and the underlying mechanisms in a model of myocardial preservation using rat isolated working hearts. EXPERIMENTAL APPROACH: Rat isolated hearts subjected to 6 h hypothermic (1-4°C) storage followed by 45 min reperfusion at 37°C were treated with zoniporide at different concentrations and timing. Recovery of cardiac function, levels of total and phosphorylated protein kinase B, extracellular signal-regulated kinase 1/2, glycogen synthase kinase-3ß and STAT3 as well as cleaved caspase 3 were measured at the end of reperfusion. Lactate dehydrogenase release into coronary effluent before and post-storage was also measured. KEY RESULTS: Zoniporide concentration-dependently improved recovery of cardiac function after reperfusion. The functional recovery induced by zoniporide was accompanied by up-regulation of p-extracellular signal-regulated kinase 1/2 and p-STAT3, and by reduction in lactate dehydrogenase release and cleaved caspase 3. There were no significant differences in any of the above indices when zoniporide was administered before, during or after ischemia. The STAT3 inhibitor, stattic, abolished zoniporide-induced improvements in functional recovery and up-regulation of p-STAT3 after reperfusion. CONCLUSIONS AND IMPLICATIONS: Zoniporide is a potent cardioprotective agent and activation of STAT3 plays a critical role in the cardioprotective action of zoniporide. This agent shows promise as a supplement to storage solutions to improve preservation of donor hearts.

Combining cariporide with glyceryl trinitrate optimizes cardiac preservation during porcine heart transplantation.

Sodium-hydrogen exchange inhibitors, such as cariporide, are potent cardioprotective agents, however, safety concerns have been raised about intravenously (i.v.) administered cariporide in humans. The aim of this study was to develop a preservation strategy that maintained cariporide's cardioprotective efficacy during heart transplantation while minimizing recipient exposure. We utilized a porcine model of orthotopic heart transplantation that incorporated donor brain death and 14 h static heart storage. Five groups were studied: control (CON), hearts stored in Celsior; CAR1, hearts stored in Celsior with donors and recipients receiving cariporide (2 mg/kg i.v.) prior to explantation and reperfusion, respectively; CAR2, hearts stored in Celsior supplemented with cariporide (10 mumol/L); GTN, hearts stored in Celsior supplemented with glyceryl trinitrate (GTN) (100 mg/L); and COMB, hearts stored in Celsior supplemented with cariporide (10 mumol/L) plus GTN (100 mg/L). A total of 5/5 CAR1 and 5/6 COMB recipients were weaned from cardiopulmonary bypass compared with 1/5 CON, 1/5 CAR2 and 0/5 GTN animals (p = 0.001). Hearts from the CAR1 and COMB groups demonstrated similar cardiac function and troponin release after transplantation. Supplementation of Celsior with cariporide plus GTN provided superior donor heart preservation to supplementation with either agent alone and equivalent preservation to that observed with systemic administration of cariporide to the donor and recipient.

Stenosis at the area of transposition - an under-recognized complication of transposed brachiobasilic fistulas.

BACKGROUND: With an increased focus on native AV fistula creation in hemodialysis patients, a transposed brachiobasilic fistula (tBBF) is becoming an increasingly utilized option. This study describes the outcomes of tBBFs in a chronic hemodialysis population. In particular, we focus on the incidence and location of stenosis, and review the impact of angioplasty on these lesions. METHODS: A retrospective cohort study using all patients with a tBBF created between January 2001 and December 2004. RESULTS: Of the 543 fistulas created during the study period, 93 were tBBFs. The mean age of patients was 65 years, 56% were male and 55% were diabetic. Stenosis occurred in 54% (46/85) of fistulas; the location of stenosis in the majority (74%) was at or near the area of basilic vein transposition and 50% of fistulas with stenosis in this location required three or more angioplasties. Primary (unassisted) patency was 42% at one year in this cohort. Secondary patency was 68% at 1 year and 58% and 53% at 2 and 3 years respectively. CONCLUSION: In a cohort of hemodialysis patients who received a tBBF, we describe a reasonable primary and secondary patency rate and a high rate of stenosis at the point of transposition of the basilic vein. Such stenosis usually requires multiple percutaneous or surgical interventions to ensure or reestablish conduit patency. Further study is required regarding the optimal surgical technique, monitoring, and treatment of stenosis of this fistula type including the utility of repeat angioplasty.

The effects of hormone resuscitation on cardiac function and hemodynamics in a porcine brain-dead organ donor model.

We compared the effects of hormone resuscitation (HR) with a norepinephrine-based protocol on cardiac function, hemodynamics and need for vasopressor support after brain death in a porcine model. Following brain death induction, animals were treated with norepinephrine and fluids for 3 h. In the following 3 h, they continued on norepinephrine and fluids (control) or received additional HR (triiodothyronine, methylprednisolone, vasopressin, insulin). Data were collected pre-brain death, 3 and 6 h post-brain death. At 6 h, median norepinephrine use was higher in controls (0.563 vs. 0 microg/kg/min; p < 0.005), with 6/8 HR animals weaned off norepinephrine compared with 0/9 controls. Mean arterial pressure was higher in HR animals at 6 h (74 +/- 17 vs. 54 +/- 14 mmHg; p < 0.05). Cardiac contractility was also significantly higher in HR animals at 6 h (stroke work index 1.777 vs. 1.494). After collection of 6 h data, all animals were placed on the same low dose of norepinephrine. At 6.25 h, HR animals had higher stroke work (3540 +/- 1083 vs. 1536 +/- 702 mL.mmHg; p < 0.005), stroke volume (37.2 +/- 8.2 vs. 21.5 +/- 9.8 mL; p < 0.01) and cardiac output (5.8 +/- 1.4 vs. 3.2 +/- 1.2 L/min; p < 0.005). HR in a porcine model of brain death reduces norepinephrine requirements, and improves hemodynamics and cardiac function. These results support the use of HR in the management of the brain-dead donor.

Short-term natural history of isolated gastrocnemius and soleal vein thrombosis.

OBJECTIVE: Lower extremity deep vein thrombosis is often isolated to the sinusoidal veins draining the gastrocnemius and soleus muscles. The purpose of this study was to establish the incidence rate of propagation of isolated gastrocnemius and soleal vein thrombosis (IGSVT) into the deep veins of the calf and thigh. METHODS: All patients who were referred for color flow duplex ultrasonography (CFDU) for suspected deep vein thrombosis were prospectively evaluated for IGSVT. Patients with IGSVT received no systemic anticoagulation therapy and underwent serial CFDU at 5, 9, 14, 30, and 90 days after recruitment. The incidence and extent of IGSVT propagation were noted. Factors predictive of IGSVT extension were sought, including age, gender, side, symptoms, ambulatory status, and the presence of comorbid illness, including cardiac disease, cancer, hypercoagulable states, recent surgery or trauma, and previous venous disease. RESULTS: One hundred thirty-five limbs with IGSVT were studied for 3 months, and 16.3% of cases with IGSVT extended the thrombus to the level of the adjacent tibial, or peroneal, veins or higher. Only 3% of the cases with IGSVT propagated as cephalad as the popliteal vein, and 90.9% of IGSVT propagation occurred within 2 weeks of CFDU diagnosis. No IGSVT propagated to the level of the popliteal vein beyond 2 weeks from the time of CFDU diagnosis. No IGSVT extended into the deep veins of the thigh. By the end of the 3-month study period, 45.9% of thrombi had completely resolved. Only the presence of cancer was prognostic for IGSVT progression. CONCLUSION: During the 3-month study period, the short-term incidence rate of untreated IGSVT propagation to the level of the popliteal vein, even in the presence of cancer, was only 3%. Follow-up imaging to detect IGSVT propagation beyond 2 weeks from the time of diagnosis may not be necessary.

Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study.

OBJECTIVE: To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol. DESIGN: Retrospective analysis of serial echocardiograms in 257 patients with chronic systolic heart failure at baseline and at 12-18 months after starting carvedilol. Reverse left ventricular remodelling was determined by changes in left ventricular end diastolic dimension (LVEDD), end systolic dimension (LVESD), and fractional shortening (LVFS). SETTING: Heart failure clinic within a university teaching hospital. MAIN OUTCOME MEASURES: Changes in LVEDD, LVESD, and LVFS. RESULTS: LVEDD and LVESD decreased by 2.6 (0.4) mm and 4.9 (0.5) mm, respectively (mean (SEM)), and LVFS increased by 4.3 (0.5)% (all p < 0.0001 v baseline). Simple regression revealed no significant relation between BHR or HRR and the changes in LVEDD, LVESD, or LVFS. Stratification of patients into high and low BHR groups (above and below the mean) or according to the baseline heart rhythm (sinus rhythm v atrial fibrillation) showed no differences between groups in the extent of reverse left ventricular remodelling. Improvements in left ventricular function and dimensions were associated with significant improvements in New York Heart Association functional class. CONCLUSIONS: The benefits of carvedilol in terms of reverse left ventricular remodelling and symptomatic improvement in patients with chronic heart failure are independent of BHR, heart rhythm, and the HRR that occurs in response to carvedilol.

Patency of superficial femoral vein employed as a crossover femoral artery bypass conduit.

This study assesses the patency of superficial femoral vein used as a crossover femoral artery bypass conduit in patients presenting either with localized groin sepsis, generalized sepsis or in patients with occluded or heavily diseased superficial femoral artery outflow. Twenty patients were followed prospectively with femoral crossover grafts constructed of superficial femoral vein. Twelve patients presented with sepsis and 8 with chronic ischemia from iliac artery occlusion and severely diseased superficial femoral artery outflow. Graft patency was assessed with regular duplex ultrasound examination. There was one perioperative death. Six patients died during the follow-up period. Mean follow-up time was 24.3 months. No graft occluded or required revision. There was no limb loss, graft infection, or graft hemorrhage. Superficial femoral vein offers an effective femoral crossover bypass graft in patients with either localized/generalized sepsis or disadvantaged outflow tracts.

A randomized trial of tacrolimus (FK506) versus total lymphoid irradiation for the control of repetitive rejection after cardiac transplantation.

Recurrent cardiac rejection is a major cause of morbidity during the initial 6 months following transplantation. We compared treatment with tacrolimus versus total lymphoid irradiation in 13 heart transplant recipients on a cyclosporine, azathioprine, and prednisolone regimen, who experienced repetitive rejection. The mean number of episodes of rejection significantly decreased in both groups, with no deaths and no increase in the incidence of infection, hypertension, diabetes, or renal impairment following either treatment at 12-month follow-up. Conversion to tacrolimus or a course of lymphoid irradiation are equipotent strategies, of comparable cost, for the prevention of further rejection in patients with recurrent rejection.