Densitometric threshold and vertebral fractures in heart transplant patients

Prevention and rehabilitation after heart transplantation: A clinical consensus statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Bone Loss after Solid Organ Transplantation: A Review of Organ-Specific Considerations

This review article investigates solid organ transplantation-induced osteoporosis, a critical yet often overlooked issue, emphasizing its significance in post-transplant care. The initial sections provide a comprehensive understanding of the prevalence and multifactorial pathogenesis of transplantation osteoporosis, including factors such as deteriorating post-transplantation health, hormonal changes, and the impact of immunosuppressive medications. Furthermore, the review is dedicated to organ-specific considerations in transplantation osteoporosis, with separate analyses for kidney, liver, heart, and lung transplantations. Each section elucidates the unique challenges and management strategies pertinent to transplantation osteoporosis in relation to each organ type, highlighting the necessity of an organ-specific approach to fully understand the diverse manifestations and implications of transplantation osteoporosis. This review underscores the importance of this topic in transplant medicine, aiming to enhance awareness and knowledge among clinicians and researchers. By comprehensively examining transplantation osteoporosis, this study contributes to the development of improved management and care strategies, ultimately leading to improved patient outcomes in this vulnerable group. This detailed review serves as an essential resource for those involved in the complex multidisciplinary care of transplant recipients.

Osteoporosis and risk of fracture in heart transplant patients

Introduction

Significant bone loss occurs after heart transplantation, predominantly in the first year, with increased risk of incident fractures. The goal of this study was to evaluate the prevalence of fragility fractures in a population of heart transplantation patients and to identify the independent risk factors for fractures.

Methods

This was a prospective monocentric study that included patients with heart transplantation occurring < 10 years who were undergoing heart transplantation monitoring. All patients underwent bone mineral density evaluation by dual-energy X-ray absorptiometry and radiographies to establish the presence of vertebral fractures.

Results

We included 79 patients (61 men); the mean age was 56.8 ± 10.8 years. The mean time between transplantation and inclusion was 32.3 ± 35.0 months. Incident fractures were diagnosed in 21 (27%) patients after heart transplantation. Vertebral fractures were the most frequent (30 vertebral fractures for 15 patients). Osteoporosis was confirmed in 22 (28%) patients. Mean bone mineral density at the femoral neck and total hip was lower with than without fracture (femoral neck: 0.777 ± 0.125 vs 0.892 ± 0.174 g/cm2, p<0.01; total hip: 0.892 ± 0.165 vs 0.748 ± 0.07 g/cm2, p<0.001), with a significant result on multivariate analysis. The mean time from transplantation to the first fracture was 8.0 ± 7.6 months.

Discussion

Our study confirmed a high vertebral fracture risk in heart transplant patients, especially during the first year after transplantation.

Factors associated with degraded trabecular bone score in heart transplant recipients

Trabecular bone score (TBS) is a textural index that provides indirect evaluation of trabecular microarchitecture. It improves fracture risk assessment in several high-risk populations. We aimed to evaluate the role of TBS assessment in heart transplant recipients (HTR). In a cross-sectional study with 87 HTR (69 males and 18 females), we assessed TBS and evaluated potential associations between TBS and factors related to increased fracture risk. We also evaluated the correlations between the presence of vertebral fractures (VF) and degraded TBS. We confirmed degraded TBS in the majority of HTR. 27.6% of HTR had partially degraded, 27.6% had degraded TBS. HTR with degraded TBS were older, had higher body mass index, lower bone mineral density (BMD), and T-score. As opposed to stable BMD over different time points, TBS significantly differed among different post-transplant time periods. TBS did not correlate with current methylprednisolone or past zoledronic acid treatment, presence of hypogonadism or diabetes. TBS did not have additional value over BMD in predicting the presence of VF. Most fractures occurred in patients with osteopenia and in patients with partly degraded TBS. Studies with longitudinal designs and larger sample sizes are warranted to further assess the potential role of TBS in HRT.

Endocrine disorders after heart transplantation: national cohort study

BACKGROUND

Endocrine disorders in patients after heart transplantation (HT) remain understudied. We aimed to assess endocrine profiles and management of HT recipients in the early post- transplant period.

METHODS

We conducted a retrospective cohort study on 123 consecutive HT recipients in the Advanced Heart Failure and Transplantation Programme between 2009 and 2018. All recipients had per-protocol endocrine follow-up within the first postoperative year. The median time to first post-transplant endocrine follow-up was 3 months (IQR 2-4). We assessed the incidence of vitamin D deficiency, bone mineral density, history of low energy fractures, hypogonadism in male recipients, posttransplant diabetes mellitus, and thyroid and parathyroid function.

RESULTS

We enrolled 22 women and 101 men of median age 57 years (IQR 50-63). Post-transplant diabetes mellitus developed in 14 patients (11.4%). 18 of 25 patients (14.6%) with preexisting type 2 diabetes mellitus required intensification of antidiabetic therapy. 38 male patients (40.4%) had hypogonadism. 5 patients (4.6%) were hypothyroid and 10 (9.3%) latent hyperthyroid. Secondary hyperparathyroidism was present in 19 (17.3%), 25-hydroxyvitamin D deficiency in 64 (54.7%) of patients. Osteoporosis was present in 26 (21.1%), osteopenia in 59 (48.0%) patients. 47 vertebral fractures, 3 hip and 1 humerus fractures occurred in 21 patients. Most of the patients had coincidence of two or three disorders, while less than 5% did not have any endocrine irregularities. All patients received calcium and vitamin D supplements. Forty-six patients (37.4%) were treated with zoledronic acid, 12 (9.8%) with oral bisphosphonates. Two patients were treated with teriparatide.

CONCLUSIONS

The prevalence of multiple endocrine disorders early after heart transplantation is high. Assessment and management of increased fracture risk and all other potentially affected endocrine axes should be considered as a standard of care in this early period.

Bone disease following solid organ transplantation: A narrative review and recommendations for management from The European Calcified Tissue Society

INTRODUCTION

Solid organ transplantation is an established therapy for end-stage organ failure. Both pre-transplantation bone disease and immunosuppressive regimens result in rapid bone loss and increased fracture rates.

METHODS

The European Calcified Tissue Society (ECTS) formed a working group to perform a systematic review of existing literature on the consequences of end-stage kidney, liver, heart, and lung disease on bone health. Moreover, we assessed the characteristics of post-transplant bone disease and the skeletal effects of immunosuppressive agents and aimed to provide recommendations for the prevention and treatment of transplantation-related osteoporosis.

RESULTS

Characteristics of bone disease may differ depending on the organ that fails, but patients awaiting solid organ transplantation frequently depict a wide spectrum of bone and mineral abnormalities. Common features are a decreased bone mass and impaired bone strength with consequent high fracture risk, all of which are aggravated in the early post-transplantation period.

CONCLUSION

Both the underlying disease leading to end-stage organ failure and the immunosuppression regimens implemented after successful organ transplantation have detrimental effects on bone mass, quality and strength. Given existing ample data confirming the high frequency of bone disease in patients awaiting solid organ transplantation, we recommend that all transplant candidates should be assessed for osteoporosis and fracture risk and, if indicated, treated before and after transplantation. Since bone loss in the early post-transplantation period occurs in virtually all solid organ recipients and is associated with glucocorticoid administration, the goal should be to use the lowest possible dose and to taper and withdraw glucocorticoids as early as possible.

Vitamin D Concentration in Patients After Heart and Kidney Transplantation

BACKGROUND

One of the main actions of vitamin D is bone mineralization regulation. Vitamin D is linked also to hypertension, diabetes, and cardiovascular disease. Vitamin D deficiency may result in osteomalacia, but its excess may result in bone calcium mobilization. Kidney transplant recipients are also at risk of hypovitaminosis D because of impaired graft function. The aim of the study was to assess vitamin D concentration in patients after heart and kidney transplantation.

MATERIAL AND METHODS

Ninety-eight stable heart transplant recipients were enrolled in the study; 80 kidney transplant recipients and 22 healthy volunteers served as controls. The laboratory tests, including parameters of 25-hydroxyvitamin D (calcidiol), were assayed using commercially available kits.

RESULTS

Calcidiol deficiency (level below 10 ng/mL) was observed in 10% of the transplant group and in 55 % of the orthotopic heart transplant recipients (OHT). There was positive correlation between calcidiol concentration, hemoglobin, kidney function, and serum glucose in kidney transplant recipients. In OHT, vitamin D correlated with age, kidney function, hemoglobin, cholesterol, low-density lipoprotein cholesterol, and glucose. Both groups had similar kidney function. In both groups of patients with estimated glomerular filtration rate above 60 mL/min/1.72 m², vitamin D was significantly higher. In OHT, vitamin D was higher in nondiabetic patients. In OHT in multivariate analysis, vitamin D was predicted in 24% by kidney function (beta = -0.30; P = .02) and hemoglobin concentration (beta = 0.25; P = .03).

CONCLUSIONS

Vitamin D deficiency is more common in patients after heart transplantation than in kidney allograft recipients despite similar kidney function. The possible associations between the cardiovascular system and vitamin D merit further studies.

Current Status of Research on Osteoporosis after Solid Organ Transplantation: Pathogenesis and Management

Improved survival following organ transplantation has brought to the forefront some long-term complications, among which osteoporosis and associated fractures are the major ones that adversely affect the quality of life in recipients. The pathogenesis of osteoporosis in transplant recipients is complex and multifactorial which may be related to increased bone resorption, decreased bone formation, or both. Studies have shown that the preexisting underlying metabolic bone disorders and the use of immunosuppressive agents are the major risk factors for osteoporosis and fractures after organ transplantation. And rapid bone loss usually occurs in the first 6–12 months with a significant increase in fracture risk. This paper will provide an updated review on the possible pathogenesis of posttransplant osteoporosis and fractures, the natural history, and the current prevention and treatment strategies concerning different types of organ transplantation.

Bone disease after transplantation: osteoporosis and fractures risk

Organ transplantation is the gold standard therapy for several end-stage diseases. Bone loss is a common complication that occurs in transplant recipients. Osteoporosis and fragility fractures are serious complication, mainly in the first year post transplantation. Many factors contribute to the pathogenesis of bone disease following organ transplantation. This review address the mechanisms of bone loss including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and management of bone loss in the transplant recipient should be included in their post transplant follow-up in order to prevent fractures.

Calcidiol deficiency in end-stage organ failure and after solid organ transplantation: status quo

Among patients with organ failure, vitamin D deficiency is extremely common and frequently does not resolve after transplantation. This review crystallizes and summarizes existing data on the status quo of vitamin D deficiency in patients with organ failure and in solid organ transplant recipients. Interventional studies evaluating different treatment strategies, as well as current clinical practice guidelines and recommendations on the management of low vitamin D status in these patients are also discussed.

Bone density, bone quality, and FRAX: changing concepts in osteoporosis management

Bone densitometry was originally developed to diagnose a high risk for fragility fractures in older postmenopausal women who may have primary osteoporosis. Its widespread availability, however, has led to its use in healthy peri- and premenopausal patients and the unexpected findings of low bone density in this group of patients. Their low bone density caused much uncertainty about the likelihood of fracture risk and what treatment might be needed. Conceptually, bone density reflected bone strength, and so a low density reflected increased fracture risk. Clinical experience and the results of pivotal studies of therapy for osteoporosis suggested that bone density was only partly responsible for skeletal strength. Many structural and material properties of bone, not measured by bone density, made it resist fracturing. Clinical risk factors helped determine these characteristics, albeit imperfectly, and aided clinicians decide whether and what treatment was needed. But now, new fracture risk assessment protocols (namely, FRAX, the WHO risk assessment tool) are available to help resolve this dilemma. This paper reviews some of the clinical observations that led to rethinking the concept bone density and bone strength and how it changes the clinical approach to therapy for the healthy young patient.

Osteoporosis after transplantation

Transplantation is an established therapy for end-stage diseases of kidney, lung, liver, and heart among others. Osteoporosis and fragility fractures are serious complications of organ transplantation, particularly in the first post-transplant year. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. This review addresses the mechanisms of bone loss that occurs both in the early and late post-transplant periods, including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac, and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient are also discussed.