Post-Transplant Cardiovascular Disease

Left Ventricular Hypertrophy After Renal Transplantation: Systematic Review and Meta-analysis

Background

Left ventricular hypertrophy (LVH) in patients with end stage renal disease undergoing renal replacement is linked to an increased risk for cardiovascular diseases. Dialysis does not completely prevent or correct this abnormality, and the evidence for kidney transplantation (KT) varies. This analysis aims to explore the relationship between KT and LVH.

Methods

MEDLINE and Scopus were systematically searched in October 2023. All cross-sectional and longitudinal studies that fulfilled our inclusion criteria were included. Outcome was left ventricular mass index (LVMI) changes. We conducted a meta-analysis using a random effects model. Meta-regression was applied to examine the LVMI changes dependent on various covariates. Sensitivity analysis was used to handle outlying or influential studies and address publication bias.

Results

From 7416 records, 46 studies met the inclusion criteria with 4122 included participants in total. Longitudinal studies demonstrated an improvement of LVMI after KT -0.44 g/m2 (-0.60 to -0.28). Blood pressure was identified as a predictor of LVMI change. A younger age at the time of KT and well-controlled anemia were also associated with regression of LVH. In studies longitudinally comparing patients on dialysis and renal transplant recipients, no difference was detected -0.09 g/m2 (-0.33 to 0.16). Meta-regression using changes of systolic blood pressure as a covariate showed an association between higher blood pressure and an increase in LVMI, regardless of the modality of renal replacement treatment.

Conclusions

In conclusion, our results indicated a potential cardiovascular benefit, defined as the regression of LVH, after KT. This benefit was primarily attributed to improved blood pressure control rather than the transplantation itself.

New Insights on Cardiac Arrhythmias in Patients With Kidney Disease

The risk of arrhythmia and its management become increasingly complex as kidney disease progresses. This presents a multifaceted clinical challenge. Our discussion addresses these specific challenges relevant to patients as their kidney disease advances. We highlight numerous opportunities for enhancing the current standard of care within this realm. Additionally, this review delves into research concerning early detection, prevention, diagnosis, and treatment of various arrhythmias spanning the spectrum of kidney disease.

Post-Transplant Cardiovascular Disease in Kidney Transplant Recipients: Incidence, Risk Factors, and Outcomes in the Era of Modern Immunosuppression

Introduction: Post-transplant cardiovascular disease (PTCVD) poses a significant challenge in kidney transplantation, potentially impacting graft outcomes and patient survival. This retrospective study aimed to investigate the incidence, risk factors, and consequential impact of PTCVD in kidney transplant recipients (KTRs) devoid of pre-existing cardiovascular disease (CVD). Method: The cohort comprised 1114 KTRs, with 749 individuals included after excluding those with pre-existing CVD and early graft loss. PTCVD encompasses ischemic heart disease, myocardial infarction, arrhythmias, heart failure, stroke, peripheral vascular disease, and valvular heart disease. Competing risk regression analysis was performed to identify predictors of PTCVD, while Cox proportional hazards analysis assessed the impact of PTCVD on graft and recipient survival. Results: The cumulative incidence of PTCVD at 5, 10, and 20 years was 5.4%, 14.3%, and 22.5%, respectively. Competing risk regression identified increased age (sub-hazard ratio [SHR], 1.22; p = 0.036) per decade, duration of dialysis (SHR, 1.07; p = 0.048) per year on dialysis, and the slope of the estimated glomerular filtration rate (SHR, 1.08; p = 0.008) mL/min/year decline as independent predictors of higher-risk PTCVD. A higher baseline estimated glomerular filtration rate (eGFR) was protective (SHR, 0.98; p = 0.032). PTCVD was not significantly associated with death-censored graft loss (adjusted hazard ratio [aHR] 1.31; p = 0.48) but was correlated with higher all-cause graft loss (aHR, 1.71; p = 0.011) and recipient mortality (aHR, 1.97; p = 0.004). Conclusion: This study provides insights into PTCVD predictors. Although not directly associated with graft loss, PTCVD significantly correlates with heightened mortality in kidney transplant recipients, emphasizing the need for enhanced clinical management and surveillance strategies.

Phase angle and donor type are determinants of coronary artery calcification in stable kidney transplant recipients at twelve months after transplantation

BACKGROUND AND AIM

Coronary artery calcification (CAC) partially explains the excess cardiovascular morbidity and mortality after kidney transplantation. This study aimed to investigate determinants of CAC in stable kidney transplant recipients at 12 months post-transplantation.

METHODS AND RESULTS

CAC-score was quantified by the Agatston method using non-contrast enhanced computed tomography, and age- and sex-standardized CAC-percentiles were calculated. Univariable and multivariable multinomial logistic regression was performed to study potential determinants of CAC. The independent determinants were included in multivariable multinomial logistic regression adjusting for potential confounders. 203 KTRs (age 54.0 ± 14.7 years, 61.1% male) were included. Participants were categorized into four groups according to CAC percentiles (p = 0 [CAC-score = 0], n = 68; p ≥ 1%-p ≤ 50% [CAC score = 29.0 (4.0-166.0)], n = 31; p > 50 ≤ 75% [CAC score = 101.0 (23.8-348.3)], n = 26; and p>75% [CAC score = 581.0 (148.0-1652)], n = 83). Upon multivariable multinomial logistic regression, patients with a narrower phase angle and patients who had received a graft from a deceased donor had a higher risk of being in the >75th CAC-percentile.

CONCLUSIONS

This study identifies not only metabolic and transplant-related factors, but also phase angle, a composite marker of cell integrity, as an independent determinant of CAC at 12 months after kidney transplantation. This study offers new perspectives for future research into the value of bioelectrical impedance analysis in relation to vascular calcification in kidney transplant recipients.

Triglyceride-Glucose Index and Cardiovascular Events in Kidney Transplant Recipients

Introduction

Kidney transplant recipients (KTRs) have an increased risk of cardiovascular (CV) events (CVEs) compared with the general population. The impact of insulin resistance on CV risk after transplantation is not well defined.

Methods

We tested whether triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, may predict posttransplant CVEs in a cohort of 715 consecutive KTRs all included 1 year after transplant.

Results

Follow-up was 9.1 ± 4.6 years. Mean TyG at inclusion was 4.75 ± 0.29 (median, 4.73 [4.14-5.84]). In multiple regression analysis, having a TyG above the median value was associated with higher body mass index (BMI), low high-density lipoprotein (HDL) cholesterol level, and greater urinary protein excretion. A total of 127 CVEs (17.7%) occurred during the study period. In univariate analysis, TyG was strongly associated with CVE occurrence (hazard ratio [HR] 2.06, 95% CI 1.42-3.50, for each increase of 0.1 in TyG, P < 0.001). The best predictive value was 4.87 (HR 6.32, 95% CI 3.30-12.11, P < 0.001). The risk of CVE gradually increased with higher TyG index (quartile 2, HR 1.71, 95% CI 0.84-5.20, P = 0.139; quartile 3, HR 3.12, 95% CI 1.61-6.02, P < 0.001; quartile 4, HR 7.46, 95% CI 4.03-13.80, P < 0.001, vs. quartile 1). TyG remained associated with CVE in multivariate analysis (HR 2.11, 95% CI 1.22-3.68, for each increase of 0.1 in TyG, P < 0.001).

Conclusion

Insulin resistance, as measured by the TyG index is strongly associated with CVE in KTRs. Improving insulin sensitivity seems to be a major issue to prevent CV morbidity and mortality in this high-risk population.

The Role of Vascular Biomarkers in Outcomes of Patients with Kidney Disease

BACKGROUND

Vascular biomarkers may explain the link between acute kidney injury (AKI) and poor long-term outcomes such as cardiovascular disease (CVD). Vessel injury is exceedingly common in AKI and contributes to the development of kidney fibrosis and CVD. As prominent determinants of vessel stability in the body, angiopoietins and other prominent vascular biomarkers may explain this biological link.

SUMMARY

Angiopoietin-1 (Angpt-1) promotes vessel stability by decreasing inflammation, apoptosis, and vessel permeability. By contrast, angiopoietin-2 (Angpt-2) blocks the binding of Angpt-1 to its receptor and thus contributes to vessel instability and permeability. Based on our findings, higher levels of Angpt-1 relative to Angpt-2 were strongly associated with less risk of kidney disease progression, heart failure, and death in hospitalized patients with AKI. In chronic kidney disease patients, it has been shown that endothelial damage in glomerular vasculature triggers Angpt-2 secretion, leading to poor outcomes such as CVD and mortality. Furthermore, in kidney transplant recipients, Angpt-2 levels significantly decrease after transplantation suggesting that transplantation may reduce Angpt-2 levels and decrease rates of poor outcomes. Other vascular health pathways - such as vascular endothelial growth factor and placental growth factor - were associated with improved rates of survival after cardiac surgery in participants with and without AKI.

KEY MESSAGES

Vascular health biomarkers provide actionable pathways for clinical intervention in reducing CVD and mortality for AKI patients. There is great need for future research that focuses on developing robust prognostic vascular biomarker panels in order to help identify high-risk AKI survivors who may benefit from targeted follow-up and therapy, with the intention to prevent kidney and cardiac complications.

Overview of Renal Transplantation for Primary Care Physicians: Workup, Complications, and Management

Kidney transplantation remains the treatment of choice for eligible patients with end-stage kidney disease. The last few decades have seen an expansion in the transplant recipient pool with over 250,000 patients living with a kidney transplant today. Because of limited bandwidth for ongoing follow-up and management of chronic medical conditions, transplant centers are directing more and more patients back to their general nephrologists and primary care doctors for longitudinal care. As a result, it is becoming increasingly important for primary care physicians to have a nuanced understanding of medications, complications, and chronic medical problems unique to transplant recipients. This article reviews the role of the primary care office in helping streamline the pretransplant evaluation process and long-term posttransplant care.

dECM based dusal-responsive vascular graft with enzyme-controlled adenine release for long-term patency

Rapid occlusion is the culprit leading to implantation failure of biological blood vessels. Although adenosine is a clinical-proven drug to overcome the problem, its short half-life and turbulent burst-release limit its direct application. Thus, a pH/temperature dual-responsive blood vessel possessed controllable long-term adenosine secretion was constructed based on acellular matrix via compact crosslinking by oxidized chondroitin sulfate (OCSA) and functionalized with apyrase and acid phosphatase. These enzymes, as adenosine micro-generators, controlled the adenosine release amount by "real-time-responding" to acidity and temperature of vascular inflammation sites. Additionally, the macrophage phenotype was switched from M1 to M2, and related factors expression proved that adenosine release was effectively regulated with the severity of inflammation. What's more, the ultra-structure for degradation resisting and endothelialization accelerating was also preserved by their "double-crosslinking". Therefore, this work suggested a new feasible strategy providing a bright future of long-term patency for transplanted blood vessels.

Indoxyl Sulphate Retention Is Associated with Microvascular Endothelial Dysfunction after Kidney Transplantation

Kidney transplantation (KTx) is the preferred form of renal replacement therapy in chronic kidney disease (CKD) patients, owing to increased quality of life and reduced mortality when compared to chronic dialysis. Risk of cardiovascular disease is reduced after KTx; however, it is still a leading cause of death in this patient population. Thus, we aimed to investigate whether functional properties of the vasculature differed two years post-KTx (postKTx) compared to baseline (time of KTx). Using the EndoPAT device in 27 CKD patients undergoing living-donor KTx, we found that vessel stiffness significantly improved while endothelial function worsened postKTx vs. baseline. Furthermore, baseline serum indoxyl sulphate (IS), but not p-cresyl sulphate, was independently negatively associated with reactive hyperemia index, a marker of endothelial function, and independently positively associated with P-selectin postKTx. Finally, to better understand the functional effects of IS in vessels, we incubated human resistance arteries with IS overnight and performed wire myography experiments ex vivo. IS-incubated arteries showed reduced bradykinin-mediated endothelium-dependent relaxation compared to controls via reduced nitric oxide (NO) contribution. Endothelium-independent relaxation in response to NO donor sodium nitroprusside was similar between IS and control groups. Together, our data suggest that IS promotes worsened endothelial dysfunction postKTx, which may contribute to the sustained CVD risk.

Cardiovascular Disease Assessment Prior to Kidney Transplantation

Cardiovascular disease is highly prevalent and the leading cause of mortality in patients with chronic kidney disease, end-stage kidney disease, and kidney transplantation. However, kidney transplantation offers improved survival and quality of life, with an overall reduction in cardiovascular disease events; therefore, it remains the optimal treatment choice for those with advanced kidney disease. Pretransplantation cardiovascular assessment is performed prior to wait-listing and at routine intervals with the principal goal of screening for asymptomatic cardiac disease, intervening when necessary to improve long-term patient and allograft survival. Current clinical practice guidelines are based on expert opinion, with a lack of high-quality evidence to guide standardized screening practices. Recent studies support de-escalation in screening with avoidance of preemptive revascularization in asymptomatic patients, but they fail to provide clear guidance on how best to assess the cardiovascular fitness of this high-risk group. Herein we summarize current practice guidelines, discuss key study findings, highlight the role of optimal medical therapy, and evaluate future directions for cardiovascular disease assessment in this population.

Top Ten Tips Palliative Care Clinicians Should Know About Solid Organ Transplantation

Solid organ transplantation (SOT) is a life-saving procedure for people with end-stage organ failure. However, patients experience significant symptom burden, complex decision making, morbidity, and mortality during both pre- and post-transplant periods. Palliative care (PC) is well suited and historically underdelivered for the transplant population. This article, written by a team of transplant specialists (surgeons, cardiologists, nephrologists, hepatologists, and pulmonologists), PC clinicians, and an ethics specialist, shares 10 high-yield tips for PC clinicians to consider when caring for SOT patients.

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) in kidney transplant recipients: what is the evidence?

Several recent randomized controlled trials (RCTs) have demonstrated the wide clinical application of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in improving kidney and cardiovascular outcomes in patients with native kidney disease. In April 2021, Dapagliflozin became the first SGLT2 inhibitor to be approved by the Food and Drug Administration (FDA) for the treatment of chronic kidney disease (CKD) regardless of diabetic status. However, while these agents have drawn much acclaim for their cardiovascular and nephroprotective effects among patients with native kidney disease, little is known about the safety and efficacy of SGLT2i in the kidney transplant setting. Many of the mechanisms by which SGLT2i exert their benefit stand to prove equally as efficacious or more so among kidney transplant recipients as they have in patients with CKD. However, safety concerns have excluded transplant recipients from all large RCTs, and clinicians and patients alike are left to wonder if the benefits of these amazing drugs outweigh the risks. In this review, we will discuss the known mechanisms SGLT2i exploit to provide their beneficial effects, the potential benefits, and risks of these agents in the context of kidney transplantation, and finally, we will discuss current findings of the published literature for SGLT2i use in kidney transplant recipients and propose potential directions for future research.