Aspirin Use and Incident Cardiovascular Disease, Kidney Failure, and Death in Stable Kidney Transplant Recipients: A Post Hoc Analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial

Cardioprotective Effect of SGLT2 Inhibitor in Diabetic Kidney Transplant Recipients: A Multicenter Propensity Score Matched Study

Introduction

Kidney transplantation (KT) improves the cardiovascular outcomes of patients with end-stage kidney disease. However, cardiovascular disease remains the leading cause of premature death and graft loss in KT recipients (KTRs) with diabetes. We evaluated the cardioprotective effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in KTRs with diabetes.

Methods

A total of 750 KTRs with diabetes were enrolled from 6 tertiary hospitals. Among them, 129 patients (17.2%) were prescribed SGLT2i. The primary outcome was the incidence of major adverse cardiovascular events (MACE), which comprised myocardial infarction (MI), death from cardiovascular causes, hospitalization for heart failure, and stroke. Multivariable Cox regression analysis and propensity score matching were used to investigate the effect of SGLT2i on clinical outcomes.

Results

In the matched cohort, MACE occurred in 5 patients (3.9%) in the SGLT2i group and 15 patients (11.8%) in the non-SGLT2i group, out of 127 patients in each group over 55.3 months. The incidence of MACE and MI was lower in the SGLT2i group than in the non-SGLT2i group (P = 0.036 and 0.008, respectively). In multivariate analysis, the SGLT2i group had a lower risk of MACE and MI than the non-SGLT2i group (adjusted hazard ratio [HR], 0.30 and 0.04; 95% confidence interval [CI], 0.10-0.88 and 0.004-0.40; P = 0.028 and 0.006, respectively). There was no difference in the incidence of urinary tract infection (UTI) between the 2 groups.

Conclusion

SGLT2i significantly decreased the risk of cardiovascular events in KTRs with diabetes, particularly lowering the incidence of MI and death from cardiovascular causes. SGLT2i can be used to reduce the burden of cardiovascular disease in KTRs with diabetes.

A Thorough Literature Review of the Potential Benefits and Drawbacks of Long-Term Aspirin Use for the Primary Prevention of Cardiovascular Disease

This article examines the role of aspirin in the primary prevention of cardiovascular disease. It highlights findings from major studies such as ASPREE (ASPirin in Reducing Events in the Elderly), ARRIVE (Aspirin to Reduce Risk of Initial Vascular Events), and ASPREE-XT (ASPirin in Reducing Events in the Elderly - eXTension) , among others. The review focuses on aspirin's role in primary prevention for specific populations including older adults, diabetics, hypertension patients, rheumatoid arthritis patients, kidney transplant recipients, and those with specific lipoprotein(a) genotypes, among other groups. We review these studies, noting aspirin's role in reducing events such as myocardial infarctions and its potential for increasing bleeding risks. The review also considers the implications for patients with kidney disease, referencing the Chronic Renal Insufficiency Cohort (CRIC) study and the International Polycap Study-3 (TIPS-3) trial. Additionally, it addresses the shifting paradigms in guidelines from the US Preventive Services Task Force and other entities, underscoring the importance of individualized aspirin use by balancing benefits against bleeding risks. The article further explores the concept of platelet reactivity, discusses strategies for improving adherence to aspirin therapy, and identifies existing research gaps, such as the phenomenon of aspirin resistance. It concludes by suggesting potential areas for future investigation to enhance understanding and application of aspirin in cardiovascular disease prevention.

Cardiovascular Protection of Aspirin in Chronic Kidney Disease Patients: An Updated Systematic Review and Meta-Analysis

PURPOSE

To evaluate aspirin's cardiovascular (CV) protective effect in chronic kidney disease (CKD) patients.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science (up to December 2022) for randomized controlled trials (RCTs) and observational studies comparing aspirin with placebo in CKD patients for the prevention of CV disease (CVD). Efficacy outcomes included CVD, heart failure, myocardial infarction, stroke, CV and all-cause mortality; safety outcomes included major bleeding, minor bleeding, and renal events.

RESULTS

Six RCTs and 6 observational studies, including 35,640 participants, met the inclusion criteria and reported relevant CV outcomes, with a mean follow-up of 46.83 months. The pooled data showed aspirin had no significant preventive effect on CVD events (RR=1.03; 95% CI, 0.84-1.27). However, CV mortality was significantly reduced in the aspirin group (RR=0.74; 95% CI, 0.58-0.95). Furthermore, aspirin use did not increase the risk of major bleeding and renal events but significantly increased minor bleeding events (RR=2.11; 95% CI, 1.30-3.44). Renal events were significantly increased after sensitivity analysis (RR=1.10; 95% CI, 1.04-1.16).

CONCLUSION

Aspirin did not prevent CV events, with a significantly increased risk of minor bleeding and renal events. Besides, aspirin use had no statistically significant reduction in the risk of all-cause mortality but had a statistically significant reduction in the risk of CV mortality.

Aspirin for Primary and Secondary Prevention of Mortality, Cardiovascular Disease, and Kidney Failure in the Chronic Renal Insufficiency Cohort (CRIC) Study

Rationale and Objective

Chronic kidney disease is a risk enhancing factor for cardiovascular disease (CVD) and mortality, and the role of aspirin use is unclear in this population. We investigated the risk and benefits of aspirin use in primary and secondary prevention of CVD in the Chronic Renal Insufficiency Cohort Study.

Study Design

Prospective observational cohort.

Setting & Participants

3,664 Chronic Renal Insufficiency Cohort participants.

Exposure

Aspirin use in patients with and without preexisting CVD.

Outcomes

Mortality, composite and individual CVD events (myocardial infarction, stroke, and peripheral arterial disease), kidney failure (dialysis and transplant), and major bleeding.

Analytical Approach

Intention-to-treat analysis and multivariable Cox proportional hazards model to examine associations of time varying aspirin use.

Results

The primary prevention group was composed of 2,578 (70.3%) individuals. Mean age was 57 ± 11 years, 46% women, 42% Black, and 47% had diabetes. The mean estimated glomerular filtration rate was 45 mL/min/1.73 m2. Median follow-up was 11.5 (IQR, 7.4-13) years. Aspirin was not associated with all-cause mortality in those without preexisting cardiovascular disease (CVD) (HR, 0.84; 95% CI, 0.7-1.01; P = 0.06) or those with CVD (HR, 0.88; 95% CI, 0.77-1.02, P = 0.08). Aspirin was not associated with a reduction of the CVD composite in primary prevention (HR, 0.97; 95% CI, 0.77-1.23; P = 0.79) and in secondary prevention because the original study design was not meant to study the effects of aspirin.

Limitations

This is not a randomized controlled trial, and therefore, causality cannot be determined.

Conclusions

Aspirin use in chronic kidney disease patients was not associated with reduction in primary or secondary CVD events, progression to kidney failure, or major bleeding.

Racial Differences in Medication Utilization for Secondary Prevention of Cardiovascular Disease in Kidney Transplant Recipients: A Post Hoc Analysis of the FAVORIT Trial Cohort

Rationale & Objective

Black kidney transplant recipients have higher prevalences of cardiovascular disease (CVD) risk factors and less intensive risk factor control than White kidney transplant recipients. Our objective was to evaluate racial disparities in receipt of statins and aspirin for secondary CVD prevention among kidney transplant recipients in the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial.

Study Design

Cohort study.

Setting & Participants

FAVORIT participants of White, Black, and Other races from the United States and Canada with a history of CVD at study entry or who experienced a nonfatal CVD event during follow-up.

Predictor

Race.

Outcome

Receipt of statins and aspirin for secondary CVD prevention.

Analytical Approach

We used parametric (Weibull), proportional-hazards, interval-censored survival models to evaluate the independent association of race with receipt of statins and aspirin for secondary CVD prevention.

Results

Of the 4,110 kidney transplant recipients enrolled in FAVORIT trial, 978 met the inclusion criteria (78% White, 17% Black, and 6% Other race). Compared with the White race, Black and Other races were associated with lower hazards of receiving statins (Black race: adjusted HR, 0.76 [95% CI, 0.60-0.97]; Other race: adjusted HR, 0.87 [95% CI, 0.60-1.27]) and aspirin (Black race: adjusted HR, 0.85 [95% CI, 0.67-1.08]; Other race: adjusted HR, 0.63 [95% CI, 0.43-0.94]).

Limitations

Lack of granular information on potential indications or contraindications for aspirin or statin use for secondary CVD prevention.

Conclusions

Post hoc findings from the FAVORIT trial demonstrated that Black race was associated with a lower likelihood of receiving statins and Other race was associated with a lower likelihood of receiving aspirin for secondary CVD prevention. This represents a potential target to improve CVD care in non-White kidney transplant recipients.

Cardiometabolic and Kidney Protection in Kidney Transplant Recipients With Diabetes: Mechanisms, Clinical Applications, and Summary of Clinical Trials

Kidney transplantation is the therapy of choice for patients with end-stage renal disease. Preexisting diabetes is highly prevalent in kidney transplant recipients (KTR), and the development of posttransplant diabetes is common because of a number of transplant-specific risk factors such as the use of diabetogenic immunosuppressive medications and posttransplant weight gain. The presence of pretransplant and posttransplant diabetes in KTR significantly and variably affect the risk of graft failure, cardiovascular disease (CVD), and death. Among the many available therapies for diabetes, there are little data to determine the glucose-lowering agent(s) of choice in KTR. Furthermore, despite the high burden of graft loss and CVD among KTR with diabetes, evidence for strategies offering cardiovascular and kidney protection is lacking. Recent accumulating evidence convincingly shows glucose-independent cardiorenal protective effects in non-KTR with glucose-lowering agents, such as sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists. Therefore, our aim was to review cardiorenal protective strategies, including the evidence, mechanisms, and rationale for the use of these glucose-lowering agents in KTR with diabetes.

Post-Transplant Cardiovascular Disease

Cardiovascular disease remains a leading cause of death and morbidity in kidney transplant recipients and a common reason for post-transplant hospitalization. Several traditional and nontraditional cardiovascular risk factors exist, and many of them present pretransplant and worsened, in part, due to the addition of immunosuppression post-transplant. We discuss optimal strategies for identification and treatment of these risk factors, including the emerging role of sodium-glucose cotransporter 2 inhibitors in post-transplant diabetes and cardiovascular disease. We present common types of cardiovascular disease observed after kidney transplant, including coronary artery disease, heart failure, pulmonary hypertension, arrhythmia, and valvular disease. We also discuss screening, treatment, and prevention of post-transplant cardiac disease. We highlight areas of future research, including the need for goals and best medications for risk factors, the role of biomarkers, and the role of screening and intervention.

The ViKTORIES trial: A randomized, double-blind, placebo-controlled trial of vitamin K supplementation to improve vascular health in kidney transplant recipients

Premature cardiovascular disease and death with a functioning graft are leading causes of death and graft loss, respectively, in kidney transplant recipients (KTRs). Vascular stiffness and calcification are markers of cardiovascular disease that are prevalent in KTR and associated with subclinical vitamin K deficiency. We performed a single-center, phase II, parallel-group, randomized, double-blind, placebo-controlled trial (ISRCTN22012044) to test whether vitamin K supplementation reduced vascular stiffness (MRI-based aortic distensibility) or calcification (coronary artery calcium score on computed tomography) in KTR over 1 year of treatment. The primary outcome was between-group difference in vascular stiffness (ascending aortic distensibility). KTRs were recruited between September 2017 and June 2018, and randomized 1:1 to vitamin K (menadiol diphosphate 5 mg; n = 45) or placebo (n = 45) thrice weekly. Baseline demographics, clinical history, and immunosuppression regimens were similar between groups. There was no impact of vitamin K on vascular stiffness (treatment effect -0.23 [95% CI -0.75 to 0.29] × 10^-3  mmHg^-1 ; p = .377), vascular calcification (treatment effect -141 [95% CI - 320 to 38] units; p = .124), nor any other outcome measure. In this heterogeneous cohort of prevalent KTR, vitamin K supplementation did not reduce vascular stiffness or calcification over 1 year. Improving vascular health in KTR is likely to require a multifaceted approach.

Update on Treatment of Hypertension After Renal Transplantation

PURPOSE OF REVIEW

To incorporate novel findings on pathophysiology and treatment of posttransplant hypertension.

RECENT FINDINGS

(1) The sodium retaining effects of CNIs are mediated by stimulation of the thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubule and in this regard chlorthalidone was proven to be an effective antihypertensive drug in renal transplantation. (2) Local and not systemic activation of the renin-angiotensin-aldosterone system plays a crucial role in the pathogenesis of posttransplant hypertension. (3) Recent randomized controlled trials failed to prove the presumed superiority of renin-angiotensin blockers in kidney transplantation. (4) Steroid-free and mammalian target of rapamycin-based immunosuppressive drug combinations did not show favorable effects on blood pressure control. (5) In a recent report the risk of non-melanoma skin cancer was higher with thiazide diuretics. But the increased cancer risk in transplant recipients is mainly attributed to comorbidities, such as diabetes and hypertension and of course to the transplantation condition itself or the obligatory application of immunosuppression, and has little to do with the antihypertensive medication Actual recommendations about BP targets in adult renal transplant recipients are coming from a post hoc analysis of a large randomized trial with another primary endpoint. Unless convincing studies on treatment of hypertension after renal transplantation are available, the ESC/ESH Guidelines 2018 should apply for these patients.

The inflammatory state is a risk factor for cardiovascular disease and graft fibrosis in kidney transplantation

Several factors, such as donor brain death, ischemia-reperfusion injury, rejection, infection, and chronic allograft dysfunction, may induce an inflammatory state in kidney transplantation. Furthermore, inflammatory cells, cytokines, growth factors, complement and coagulation cascade create an unbalanced interaction with innate and adaptive immunity, which are both heavily involved in atherogenesis. The crosstalk between inflammation and thrombosis may lead to a prothrombotic state and impaired fibrinolysis in kidney transplant recipients increasing the risk of cardiovascular disease. Inflammation is also associated with elevated levels of fibroblast growth factor 23 and low levels of Klotho, which contribute to major adverse cardiovascular events. Hyperuricemia, glucose intolerance, arterial hypertension, dyslipidemia, and physical inactivity may create a condition called metaflammation that concurs in atherogenesis. Another major consequence of the inflammatory state is the development of chronic hypoxia that through the mediation of interleukins 1 and 6, angiotensin II, and transforming growth factor beta can result in excessive accumulation of extracellular matrix, which can disrupt and replace functional parenchyma, leading to interstitial fibrosis and chronic allograft dysfunction. Lifestyle and regular physical activity may reduce inflammation. Several drugs have been proposed to control the graft inflammatory state, including low-dose aspirin, statins, renin-angiotensin inhibitors, xanthine-oxidase inhibitors, vitamin D supplements, and interleukin-6 blockade. However, no prospective controlled trial with these measures has been conducted in kidney transplantation.

Association between aspirin use and cardiovascular outcomes in ALLHAT participants with and without chronic kidney disease: A post hoc analysis

It is unclear whether aspirin is beneficial for prevention of CVD in patients with CKD. We performed a secondary analysis of the ALLHAT trial to assess the effect of baseline aspirin use on nonfatal myocardial infarction (MI) or fatal coronary heart disease (CHD), all‐cause mortality, and stroke. Baseline characteristics of aspirin users and nonusers were used to generate propensity‐matched cohorts. Using conditional Cox proportional hazard regression models, we examined the effect of aspirin on the outcomes in the cohort at large and across 3 levels of kidney function (eGFR ≥90, 60–89, and <60). 11 250 ALLHAT participants reported using aspirin at baseline. The propensity‐matched dataset included 6894 nonusers matched with replacement to achieve a balanced analysis population (n = 22 500). Risk of fatal CHD or nonfatal MI (HR = 0.94, 95% CI 0.86–1.02) and stroke (HR = 1.01, 95% CI 0.89–1.15) was not significantly different between groups. Aspirin users were at significantly lower risk of all‐cause mortality compared to nonusers (HR = 0.82, 95% CI 0.76–0.88). Aspirin use was not associated with incidence of fatal CAD or nonfatal MI in patients with CVD (HR = 0.93, CI 0.84–1.04) or without CVD at baseline (HR = 1.04, CI 0.82–1.32). Results were consistent across strata of GFR (interaction p value NS). In hypertensive patients at high cardiovascular risk, aspirin use is not associated with risk of nonfatal MI, fatal CHD, or stroke; however, aspirin use is associated with lower risk of all‐cause mortality. These results are consistent across baseline eGFR.

Cardiovascular disease in the kidney transplant recipient: epidemiology, diagnosis and management strategies

Kidney transplantation (KT) is the optimal therapy for end-stage kidney disease (ESKD), resulting in significant improvement in survival as well as quality of life when compared with maintenance dialysis. The burden of cardiovascular disease (CVD) in ESKD is reduced after KT; however, it still remains the leading cause of premature patient and allograft loss, as well as a source of significant morbidity and healthcare costs. All major phenotypes of CVD including coronary artery disease, heart failure, valvular heart disease, arrhythmias and pulmonary hypertension are represented in the KT recipient population. Pre-existing risk factors for CVD in the KT recipient are amplified by superimposed cardio-metabolic derangements after transplantation such as the metabolic effects of immunosuppressive regimens, obesity, posttransplant diabetes, hypertension, dyslipidemia and allograft dysfunction. This review summarizes the major risk factors for CVD in KT recipients and describes the individual phenotypes of overt CVD in this population. It highlights gaps in the existing literature to emphasize the need for future studies in those areas and optimize cardiovascular outcomes after KT. Finally, it outlines the need for a joint 'cardio-nephrology' clinical care model to ensure continuity, multidisciplinary collaboration and implementation of best clinical practices toward reducing CVD after KT.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Pros and Cons of Aspirin Prophylaxis for Prevention of Cardiovascular Events in Kidney Transplantation and Review of Evidence

Kidney transplant recipients have traditional and nontraditional risk factors which can lead to coronary artery disease and sudden death with a functional graft loss. Aspirin has been used traditionally for prevention of cardiovascular and cerebrovascular accidents. It has beneficial effects in secondary prevention of cardiovascular events in general population. Its use for primary prophylaxis is still disputed. Bleeding and theoretical risk of nephrotoxicity are the major concerns about its use. The data on aspirin in kidney transplant population is sparse. This review will focus on various pros and cons of aspirin use for prevention of cardiovascular events in kidney transplant recipients and a way forward.

Induction immunosuppression agents as risk factors for incident cardiovascular events and mortality after kidney transplantation

Low T cell counts and acute rejection are associated with increased cardiovascular events (CVEs); T cell-depleting agents decrease both. Thus, we aimed to characterize the risk of CVEs by using an induction agent used in kidney transplant recipients. We conducted a secondary data analysis of patients who received a kidney transplant and used Medicare as their primary insurance from 1999 to 2010. Outcomes of interest were incident CVE, all-cause mortality, CVE-related mortality, and a composite outcome of mortality and CVE. Of 47 258 recipients, 29.3% received IL-2 receptor antagonist (IL-2RA), 33.3% received anti-thymocyte globulin (ATG), 7.3% received alemtuzumab, and 30.0% received no induction. Compared with IL-2RA, there was no difference in the risk of CVE in the ATG (adjusted hazard ratio [aHR] 0.98, 95% confidence interval [CI] 0.92-1.05) and alemtuzumab group (aHR 1.01, 95% CI 0.89-1.16), but slightly higher in the no induction group (aHR 1.06, 95% CI 1.00-1.14). Acute rejection did not modify this association in the latter group but did increase CVE by 46% in the alemtuzumab group. There was no difference in the hazard of all-cause or CVE-related mortality. Only in the ATG group, a 7% lower hazard of the composite outcome of mortality and CVE was noted. Induction agents are not associated with incident CVE, although prospective trials are needed to determine a personalized approach to prevention.

Cardiovascular Disease After Kidney Transplant

Renal transplantation is the preferred treatment for patients with end-stage kidney disease. However, despite successful kidney transplantation, cardiovascular disease (CVD) remains one of the major causes of patient death and hence graft loss. The antecedents of this increased risk reside within the development of end-stage kidney disease and dialysis. Risk factors for the development of CVD include diabetes, hypertension, and dyslipidemia. Other transplant-specific factors include the presence of a patent arteriovenous fistula and immunosuppressive therapy. Efforts to modify these factors should be strongly encouraged to improve long-term outcomes of transplant patients and reduce death from CVD in this at-risk patient population.

Pathophysiology and treatment of cardiovascular disease in pediatric chronic kidney disease

Life expectancy in patients with all stages of chronic kidney disease (CKD) falls far short of that in the general population. Cardiovascular disease is the leading cause of mortality in pediatric patients with CKD. In contrast to the intimal atherosclerotic lesions that characterize cardiovascular disease in the general population, vascular endothelial dysfunction, medial arterial calcification, and cardiac dysfunction contribute to cardiovascular pathological conditions in CKD. The pathogenesis of these lesions, the origins of which can be identified in the absence of traditional cardiovascular risk factors, is incompletely understood. CKD-mediated vascular calcification in CKD is characterized by a transition of vascular smooth muscle cells to an osteoblast-like phenotype and altered bone and mineral metabolism are strongly linked to progressive cardiovascular disease in this population. Renal osteodystrophy therapies, including phosphate binders, vitamin D analogs, and calcimimetics, have an impact on the progression of cardiovascular disease. However, cardiovascular disease has its origins before the development of secondary hyperparathyroidism, and optimal therapeutic regimens that minimize cardiac dysfunction, vascular calcification, and early mortality remain to be defined.

Successful kidney transplantation normalizes platelet function

Background

Uraemic platelet dysfunction is not completely understood, in part due to non-physiological platelet function assays. We have developed a physiological flow-based assay that quantifies platelet function in microlitre volumes of blood under arterial shear. The aim of this study was to characterize platelet function before and after kidney transplantation.

Methods

Ten patients scheduled for living donor kidney transplant surgery and nine healthy controls were analysed using the assay. The motional parameters of platelet behaviour on von Willebrand factor (VWF) were recorded using customized platelet tracking software. The assay was repeated 3–8 weeks post-transplant in the transplant group and at an interval of >3 weeks in normal healthy volunteers.

Results

Platelet–VWF interactions were markedly reduced in the 10 pre-transplant patients compared with the healthy controls. In seven patients with immediate graft function, dynamic platelet function returned to normal (despite a small decrease in haemoglobin and haematocrit), but remained markedly abnormal in the three patients with delayed graft function (DGF).

Conclusions

Dynamic platelet function returned to normal following transplantation in those with immediate graft function. This early improvement was not observed in those with DGF. There may be important clinical implications, as patients with DGF are more likely to undergo invasive procedures, including transplant biopsies and insertion of central venous catheters.