Cardiovascular disease risk in patients receiving organ transplantation: a national cohort study

Alirocumab in Adult Patients With Hyperlipidemia After Liver Transplantation: A Short-term Observation

OBJECTIVE

To investigate the clinical efficacy of alirocumab in postoperative hyperlipidemia among liver transplant recipients.

METHODS

We conducted a retrospective analysis of clinical data from liver transplant recipients with postoperative hyperlipidemia who received alirocumab treatment at our institution.

RESULTS

Seventeen cases were observed, with a male-to-female ratio of 12:5. Patient ages ranged from 44 to 65 years, with an average age of 55.47 years. The initiation of alirocumab treatment occurred between 1 and 196 months postliver transplantation, averaging 44.88 months. Treatment duration was a minimum of 3 months. The levels of blood lipids were assessed at 4, 8, and 12 weeks during the treatment regimen. At 8 weeks, a statistically significant reduction in total cholesterol was recorded (P = .012), and this decrease was further pronounced at 12 weeks (P = .004). For LDL cholesterol, significant decreases were evident at 4 weeks (P = .011), 8 weeks (P = .005), and 12 weeks (P = .004). No significant changes were observed in high-density lipoprotein (HDL) cholesterol and triglyceride levels throughout the study period. In addition, all patients maintained stable liver function and immunosuppressant concentrations.

CONCLUSIONS

Alirocumab demonstrated a significant reduction in total cholesterol and low-density lipoprotein cholesterol levels among liver transplant recipients, with no observed increase in the risk of rejection. This suggests the potential effectiveness of alirocumab as a lipid-lowering therapy in liver transplant recipients.

Association of transplant recipient status with clinical and financial outcomes among patients undergoing major surgery

BACKGROUND

Transplant recipients undergoing surgery may represent a vulnerable population because of transplant-related comorbidities as well as reliance on immunosuppressive medications. We sought to characterize the association of prior transplant status on postoperative outcomes among patients undergoing major non-transplant-related surgical procedures.

METHODS

Data on patients who underwent a major surgical procedure (pneumonectomy, coronary artery bypass graft, abdominal aortic aneurysm repair, Whipple, colectomy) between 2016 and 2020 were obtained from the Nationwide Readmission Database. After balancing the 2 cohorts using entropy balancing, multivariable regression models were used to assess the relationship between post-transplant status and patient outcomes.

RESULTS

Among 1,818,973 patients, 0.45% (n = 8,212) had a history of solid organ transplantation (liver: n = 1,773, 21.6%; heart/lung: n = 1,087, 13.2%; kidney/pancreas: n = 4,891, 59.6%; and multiple: n = 461, 5.6%). In the unmatched cohort, patients who had a history of organ transplant were more likely to be male (64.1% vs 57.7%) and have Medicare insurance (71.7% vs 59.3%) (both P < .001). On multivariable analysis, prior transplant recipient status was associated with higher odds of postoperative complications (odds ratio 1.30, 95% confidence interval 1.22-1.38), 30-day readmission (odds ratio 1.42, 95% confidence interval 1.31-1.54), and in-hospital mortality (odds ratio 1.20, 95% confidence interval 1.03-1.40) (all P < .05). Moreover, organ transplantation was associated with higher index hospitalization costs (14.4% difference, 95% confidence interval 14.1%-14.6%) and 30-day postdischarge costs (16.2% difference, 95% confidence interval 15.3%-17.0%) (both P < .001).

CONCLUSIONS

Prior transplant recipient status was associated with adverse clinical and financial outcomes following subsequent major surgery. Prior history of transplant may be an important factor to incorporate into risk stratification of patients undergoing subsequent major surgical procedures.

Evaluation of lipid management practices for secondary atherosclerotic cardiovascular disease prevention in abdominal solid organ transplant recipients

BACKGROUND

High-intensity HMG-CoA reductase inhibitors (statins) are recommended for secondary atherosclerotic cardiovascular disease (ASCVD) prevention. Solid organ transplant (SOT) recipients are at an increased risk of ASCVD events. This study evaluated if abdominal SOT recipients who experienced an ASCVD event prior to transplant received guideline-directed pharmacotherapy for secondary ASCVD prevention post-transplant.

METHODS

Single-center, retrospective, cohort study that evaluated lipid-lowering therapy prescribing practices in SOT recipients transplanted at Duke University Hospital. The primary objective was the percentage of patients receiving a high-intensity statin regimen during the first year post-transplant. Secondary objectives included reason for change in statin therapy, other lipid-lowering medications prescribed, percentage of patients who had lipid panel(s) drawn, safety of statin therapy, and the incidence of recurrent ASCVD or death secondary to an ASCVD event within the first year post-transplant.

RESULTS

Sixty-three transplant patients were included, 46 (73%) received a kidney, 12 (19%) a liver, and 5 (7.9%) a multi-organ transplant. Twenty-four patients (38.1%) were maintained on a high-intensity statin during the first year post-transplant. Reason for statin dose change included elevated lipids (35.3%), statin-related safety event (11.8%), and undocumented reason (52.9%). Statins were well tolerated. Two (3.2%) patients experienced a recurrent myocardial infarction within the first year post-transplant.

CONCLUSION

Less than half of the abdominal transplant patients were maintained on guideline-directed high-intensity statin therapy for secondary ASCVD prevention at 1 year post-transplant. Our findings demonstrate an opportunity to optimize the prescribing practices of lipid-lowering therapy following abdominal transplant in a high cardiovascular risk population.

Solid Organ Transplant Recipients Exhibit More TET2-Mutant Clonal Hematopoiesis of Indeterminate Potential Not Driven by Increased Transplantation Risk

PURPOSE

Solid organ transplant recipients comprise a unique population of immunosuppressed patients with increased risk of malignancy, including hematologic neoplasms. Clonal hematopoiesis of indeterminate potential (CHIP) represents a known risk factor for hematologic malignancy and this study describes the prevalence and patterns of CHIP mutations across several types of solid organ transplants.

EXPERIMENTAL DESIGN

We use two national biobank cohorts comprised of >650,000 participants with linked genomic and longitudinal phenotypic data to describe the features of CHIP across 2,610 individuals who received kidney, liver, heart, or lung allografts.

RESULTS

We find individuals with an allograft before their biobank enrollment had an increased prevalence of TET2 mutations (OR, 1.90; P = 4.0e-4), but individuals who received transplants post-enrollment had a CHIP mutation spectrum similar to that of the general population, without enrichment of TET2. In addition, we do not observe an association between CHIP and risk of incident transplantation among the overall population (HR, 1.02; P = 0.91). And in an exploratory analysis, we do not find evidence for a strong association between CHIP and rates of transplant complications such as rejection or graft failure.

CONCLUSIONS

These results demonstrate that recipients of solid organ transplants display a unique pattern of clonal hematopoiesis with enrichment of TET2 driver mutations, the causes of which remain unclear and are deserving of further study.

The Biological Parallels Between Atherosclerosis and Cardiac Allograft Vasculopathy: Implications for Solid Organ Chronic Rejection

Atherosclerosis and solid organ chronic rejection are pervasive chronic disease states that account for significant morbidity and mortality in developed countries. Recently, a series of shared molecular pathways have emerged, revealing biological parallels from early stages of development up to the advanced forms of pathology. These shared mechanistic processes are inflammatory in nature, reflecting the importance of inflammation in both disorders. Vascular inflammation triggers endothelial dysfunction and disease initiation through aberrant vasomotor control and shared patterns of endothelial activation. Endothelial dysfunction leads to the recruitment of immune cells and the perpetuation of the inflammatory response. This drives lesion formation through the release of key cytokines such as IFN-y, TNF-alpha, and IL-2. Continued interplay between the adaptive and innate immune response (represented by T lymphocytes and macrophages, respectively) promotes lesion instability and thrombotic complications; hallmarks of advanced disease in both atherosclerosis and solid organ chronic rejection. The aim of this study is to identify areas of overlap between atherosclerosis and chronic rejection. We then discuss new approaches to improve current understanding of the pathophysiology of both disorders, and eventually design novel therapeutics.

Performance of a Prospective Anticoagulation Stratification Algorithm After Liver Transplantation

Venous thromboembolism (VTE) occurs in 0.4% to 15.5% and bleeding occurs in 20% to 35% of patients after liver transplantation (LT). Balancing the risk of bleeding from therapeutic anticoagulation and risk of thrombosis in the postoperative period is challenging. Little evidence exists regarding the best treatment strategy for these patients. We hypothesized that a subset of LT patients who develop postoperative deep vein thromboses (DVTs) could be managed without therapeutic anticoagulation. We implemented a quality improvement (QI) initiative using a standardized Doppler ultrasound-based VTE risk stratification algorithm to guide parsimonious implementation of therapeutic anticoagulation with heparin drip.

Methods

In a prospective management QI initiative for DVT management, we compared 87 LT historical patients (control group; January 2016-December 2017) to 182 LT patients (study group; January 2018-March 2021). We analyzed the rates of immediate therapeutic anticoagulation after DVT diagnosis within 14 d of LT, clinically significant bleeding, return to the operating room, readmission, pulmonary embolism, and death within 30 d of LT before and after the QI initiative.

Results

Ten patients (11.5%) in the control group and 23 patients (12.6%; P = 0.9) in the study group developed DVTs after LT. Immediate therapeutic anticoagulation was used in 7 of 10 and 5 of 23 patients in the control and study groups, respectively (P = 0.024). The study group had lower odds of receiving immediate therapeutic anticoagulation after VTE (21.7% versus 70%; odds ratio = 0.12; 95% confidence interval, 0.019-0.587; P = 0.013) and a lower rate of postoperative bleeding (8.7% versus 40%; odds ratio = 0.14, 95% confidence interval, 0.02-0.91; P = 0.048). All other outcomes were similar.

Conclusions

Implementing a risk-stratified VTE treatment algorithm for immediate post-LT patients appears to be safe and feasible. We observed a decrease in the use of therapeutic anticoagulation and a lower rate of postoperative bleeding without adverse impacts on early outcomes.

De novo major cardiovascular events in kidney transplant recipients: a comparative matched cohort study

BACKGROUND

Although cardiovascular disease is known to be one of the leading causes of death after kidney transplantation (KT), evidence on the risk difference of de novo major adverse cardiovascular events (MACEs) in kidney transplant recipients (KTRs) compared with that in dialysis patients or the general population (GP) remains rare.

METHODS

We identified KTRs using the nationwide health insurance database in South Korea and then 1:1 matched them with the dialysis and GP controls without a pre-existing MACE. The primary endpoint was defined as de novo MACEs consisting of myocardial infarction, coronary revascularization and ischemic stroke. The secondary endpoints were all-cause mortality and death-censored graft failure (DCGF) in KTRs.

RESULTS

We included 4156 individuals in each of the three groups and followed them up for 4.7 years. De novo MACEs occurred in 3.7, 21.7 and 2.5 individuals per 1000 person-years in the KTRs, dialysis controls and GP controls, respectively. KTRs showed a lower MACE risk {adjusted hazard ratio (aHR) 0.16 [95% confidence interval (CI) 0.12-0.20], P < .001} than dialysis controls, whereas a similar MACE risk to GP controls [aHR 0.81 (95% CI 0.52-1.27), P = .365]. In addition, KTRs showed a similar MACE risk compared with the GP group, regardless of age, sex and the presence of comorbidities, including hypertension, diabetes and dyslipidemia. Among KTRs, de novo MACEs were associated with an increased risk of all-cause mortality, but not with DCGF.

CONCLUSIONS

De novo MACEs in KTRs were much lower than that in dialysis patients and had a similar risk to the GP, but once it occurred it caused elevated mortality risk in KTRs.

Management of cardiac diseases in liver transplant recipients: Comprehensive review and multidisciplinary practice-based recommendations

Cardiac diseases are one of the most common causes of morbidity and mortality following liver transplantation (LT). Prior studies have shown that cardiac diseases affect close to one-third of liver transplant recipients (LTRs) long term and that their incidence has been on the rise. This rise is expected to continue as more patients with advanced age and/or non-alcoholic steatohepatitis undergo LT. In view of the increasing disease burden, a multidisciplinary initiative was developed to critically review the existing literature (between January 1, 1990 and March 17, 2021) surrounding epidemiology, risk assessment, and risk mitigation of coronary heart disease, arrhythmia, heart failure, and valvular heart disease and formulate practice-based recommendations accordingly. In this review, the expert panel emphasizes the importance of optimizing management of metabolic syndrome and its components in LTRs and highlights the cardioprotective potential for the newer diabetes medications (e.g., sodium glucose transporter-2 inhibitors) in this high-risk population. Tailoring the multidisciplinary management of cardiac diseases in LTRs to the cardiometabolic risk profile of the individual patient is critical. The review also outlines numerous knowledge gaps to pave the road for future research in this sphere with the ultimate goal of improving clinical outcomes.

Dyslipidemia in Transplant Patients: Which Therapy?

Cardiovascular disease is the most important cause of death worldwide in recent years; an increasing trend is also shown in organ transplant patients subjected to immunosuppressive therapies, in which cardiovascular diseases represent one of the most frequent causes of long-term mortality. This is also linked to immunosuppressant-induced dyslipidemia, which occurs in 27 to 71% of organ transplant recipients. The aim of this review is to clarify the pathophysiological mechanisms underlying dyslipidemia in patients treated with immunosuppressants to identify immunosuppressive therapies which do not cause dyslipidemia or therapeutic pathways effective in reducing hypercholesterolemia, hypertriglyceridemia, or both, without further adverse events.

Safety of Non-Vitamin K Antagonist Oral Anticoagulant Treatment in Patients with Chronic Kidney Disease and Kidney Transplant Recipients

The use of novel oral anticoagulants in patients with impaired renal function or undergoing immunosuppressive therapy is limited due to the risk of drug-to-drug interactions and anticoagulation-related adverse events. This article aims to assess the current data on the safety of direct-acting oral anticoagulant-based therapy in the population of kidney transplant recipients and patients with impaired renal function. The most important factors affecting the safety of treatment are the incidence of bleeding events, thromboembolic events, deaths and drug-to-drug interactions. The available data were compared to the findings on warfarin-based anticoagulation. Findings on the use of novel oral anticoagulants in kidney transplant recipients are limited yet promising in terms of safety and efficacy of use. However, current recommendations state that the co-administration of non-vitamin K antagonist oral anticoagulants with several immunosuppressive agents is contraindicated.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors Use for Atherogenic Dyslipidemia in Solid Organ Transplant Patients

Dyslipidemia is a widespread risk factor in solid organ transplant patients, due to many reasons, such as the use of immunosuppressive drugs, with a consequent increase in cardiovascular diseases in this population. PCSK9 is an enzyme mainly known for its role in altering LDL levels, consequently increasing cardiovascular risk. Monoclonal antibody PCSK9 inhibitors demonstrated remarkable efficacy in the general population in reducing LDL cholesterol levels and preventing cardiovascular disease. In transplant patients, these drugs are still poorly used, despite having comparable efficacy to the general population and giving fewer drug interactions with immunosuppressants. Furthermore, there is enough evidence that PCSK9 also plays a role in other pathways, such as inflammation, which is particularly dangerous for graft survival. In this review, the current evidence on the function of PCSK9 and the use of its inhibitors will be discussed, particularly in transplant patients, in which they may provide additional benefits.

A Meta-Analysis and Systematic Review on the Global Prevalence, Risk Factors, and Outcomes of Coronary Artery Disease in Liver Transplantation Recipients

The shift in the changing etiology of cirrhosis requiring liver transplantation (LT) has resulted in an increasing prevalence of coronary artery disease (CAD) that can potentially impact post-LT outcomes. This systematic review and meta-analysis evaluates the prevalence of CAD, risk factors, and outcomes of patients diagnosed with CAD before LT. MEDLINE and EMBASE were searched for articles describing CAD in pre-LT patients. Meta-analysis of proportions using the generalized linear mix model was conducted to analyze the pooled prevalence of CAD in pre-LT patients. Associated risk factors for CAD in pre-LT patients and outcomes were evaluated in conventional pairwise meta-analysis. A total of 39 studies were included. The pooled prevalence of patients diagnosed with CAD before LT was 15.9% (95% CI, 9.8%-24.7%). Age, male sex, diabetes mellitus, hypertension, hyperlipidemia, smoking, nonalcoholic steatohepatitis, hepatitis B virus, and hepatocellular carcinoma were significantly associated with CAD. Patients from high-income countries especially North America, Europe, and South America, with the associated risk factors were at increased risk for CAD before LT. CAD before LT was associated with an increased odds of overall mortality (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.4-1.4; P = 0.01) and cardiac-related mortality (OR, 1.2; 95% CI, 1.1-1.3; P = 0.03). A total of 48.7% of included articles considered the presence of cardiovascular risk factors for CAD screening. However, 10.3% of the studies screened for CAD in pre-LT patients via invasive coronary angiography only, without stress testing or risk stratification. This study demonstrates the high prevalence of CAD in pre-LT patients, associated risk factors, and outcomes. There is heterogeneity among guidelines and practice in screening for pre-LT CAD, and more studies are needed to establish consensus.

Sex and organ-specific risk of major adverse renal or cardiac events in solid organ transplant recipients with COVID-19

While older males are at the highest risk for poor coronavirus disease 2019 (COVID-19) outcomes, it is not known if this applies to the immunosuppressed recipient of a solid organ transplant (SOT), nor how the type of allograft transplanted may impact outcomes. In a cohort study of adult (>18 years) patients testing positive for COVID-19 (January 1, 2020-June 21, 2021) from 56 sites across the United States identified using the National COVID Cohort Collaborative (N3C) Enclave, we used multivariable Cox proportional hazards models to assess time to MARCE after COVID-19 diagnosis in those with and without SOT. We examined the exposure of age-stratified recipient sex overall and separately in kidney, liver, lung, and heart transplant recipients. 3996 (36.4%) SOT and 91 646 (4.8%) non-SOT patients developed MARCE. Risk of post-COVID outcomes differed by transplant allograft type with heart and kidney recipients at highest risk. Males with SOT were at increased risk of MARCE, but to a lesser degree than the non-SOT cohort (HR 0.89, 95% CI 0.81-0.98 for SOT and HR 0.61, 95% CI 0.60-0.62 for non-SOT [females vs. males]). This represents the largest COVID-19 SOT cohort to date and the first-time sex-age-stratified and allograft-specific COVID-19 outcomes have been explored in those with SOT.

Chances and risks of sodium-glucose cotransporter 2 inhibitors in solid organ transplantation: A review of literatures

Solid organ transplantation offers life-saving treatment for patients with end-organ dysfunction. Patient survival and quality of life have improved over the past few decades as a result of pharmacological development, expansion of the donor pool, technological advances and standardization of practices related to transplantation. Still, transplantation is associated with cardiovascular complications, of which post-transplant diabetes mellitus (PTDM) is one of the most important. PTDM increases mortality, which is best documented in patients who have received kidney and heart transplants. PTDM results from traditional risk factors seen in patients with type 2 diabetes mellitus, but also from specific post-transplant risk factors such as metabolic side effects of immunosuppressive drugs, post-transplant viral infections and hypomagnesemia. Oral hypoglycaemic agents are the first choice for the treatment of type 2 diabetes mellitus in non-transplanted patients. However, the evidence on the safety and efficacy of oral hypoglycaemic agents in transplant recipients is limited. The favourable risk/benefit ratio, which is suggested by large-scale and long-term studies on new glucose-lowering drug classes such as glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, makes studies warranted to assess the potential role of these agents in the management of PTDM.

Safety and efficacy of direct oral anticoagulants under long-term immunosuppressive therapy after liver, kidney and pancreas transplantation

The safety of direct oral anticoagulants (DOACs) in patients after solid organ transplantation (SOT) is not well defined. This study aimed at describing the safety and efficacy of DOACs in patients after SOT. Patients after kidney and/or liver transplantation under maintenance immunosuppression treated with rivaroxaban (n = 26), apixaban (n = 20) and edoxaban (n = 1) were included. Clinical data were collected retrospectively and using a questionnaire. DOAC plasma levels and thrombin generation (TG) were measured in patients after SOT and compared with nontransplanted controls receiving DOACs. DOACs were administered for 84.6 patient-years. Mean immunosuppressive trough levels after DOAC initiation increased from baseline by 18.8 ± 29.6% compared to 3.0 ± 16.5% in matched controls (P = 0.004), without significant differences in dose adjustments. No transplant rejection or significant change in liver or renal function was observed. There was one major bleeding after the observation period but no thromboembolic complication. DOAC plasma levels reached the expected range in all patients. The intrinsic hemostatic activity in transplanted patients was higher compared to nontransplant controls. Treatment with DOACs after SOT is safe and effective. Immunosuppressive trough levels should be monitored after DOAC initiation, particularly in the early phase after SOT. These data should be confirmed in a prospective study.

Management of dyslipidemia in adult solid organ transplant recipients

Solid organ transplantation (SOT) has revolutionized treatment of end-stage disease. Improvements in the SOT continuum of care have unmasked a significant burden of cardiovascular disease, manifesting as a leading cause of morbidity and mortality. Although several risk factors for development of post-transplant cardiovascular disease exist, dyslipidemia remains one of the most frequent and modifiable risks. An important contributor to dyslipidemia in SOT recipients is the off-target metabolic effects of immunosuppressive medications, which may alter lipoproteins and their metabolism. Dyslipidemia management is paramount as lipid-lowering therapy with statins has demonstrated reductions in graft vasculopathy, decreased rejection rates, and improved survival. Several nonstatin medication options are available, but data supporting their benefit in the SOT population are minimal, typically extrapolated from studies in the general population. Further compounding dyslipidemia management is the complex interplay of drug interactions between lipid-lowering and immunosuppressant medications, which can result in serious toxicity and/or therapeutic failure.

Myocardial remodeling after kidney transplantation: a case report

Background

Lupus nephritis (LN) is one of the most common manifestations of systemic lupus erythematosus (SLE) and is often the most serious organ complication and the cause of premature death of such a patient. Most of other organs and systems can be also affected. A typical complication is a cardiovascular involvement leading to the development of heart failure. According to current therapeutic standards, kidney transplantation is the treatment of choice in patients with renal failure in course of LN. On the contrary, a kidney transplantation in a patient with an additional heart disease poses a serious clinical challenge.

Case presentation

We present a case of a 49-year-old woman with renal and heart failure following a long-term SLE prepared for kidney transplantation. During the SLE course, the function of the heart and kidneys gradually deteriorated. The patient required the initiation of renal replacement therapy and was dialyzed until a kidney transplantation for 4 years. In the preparation of the patient for the surgical procedure, due to the extremely low ejection fraction, it was decided to include cardioprotective treatment with Levosimendan. The postoperative period was not straightforward but successful. In the monthly and five-month follow-up, a continuous improvement of heart function with normal renal function was noted.

Conclusions

Kidney transplantation in patients with lupus suffering from heart failure requires the involvement of a team of specialists. Patients with extremely low ejection fraction in the perioperative period should undergo careful hemodynamic supervision in the intensive care unit. Cardioprotective and thus nephroprotective Levosimendan therapy together with optimal fluid and hemodynamic therapy in the peri-transplant period may be a bridge for heart remodeling after kidney transplantation.