Mechanisms of cardiovascular complications in chronic kidney disease: research focus of the Transregional Research Consortium SFB TRR219 of the University Hospital Aachen (RWTH) and the Saarland University

Chemokine CCL9 Is Upregulated Early in Chronic Kidney Disease and Counteracts Kidney Inflammation and Fibrosis

Inflammation and fibrosis play an important pathophysiological role in chronic kidney disease (CKD), with pro-inflammatory mediators and leukocytes promoting organ damage with subsequent fibrosis. Since chemokines are the main regulators of leukocyte chemotaxis and tissue inflammation, we performed systemic chemokine profiling in early CKD in mice. This revealed (C-C motif) ligands 6 and 9 (CCL6 and CCL9) as the most upregulated chemokines, with significantly higher levels of both chemokines in blood (CCL6: 3–4 fold; CCL9: 3–5 fold) as well as kidney as confirmed by Enzyme-linked Immunosorbent Assay (ELISA) in two additional CKD models. Chemokine treatment in a mouse model of early adenine-induced CKD almost completely abolished the CKD-induced infiltration of macrophages and myeloid cells in the kidney without impact on circulating leukocyte numbers. The other way around, especially CCL9-blockade aggravated monocyte and macrophage accumulation in kidney during CKD development, without impact on the ratio of M1-to-M2 macrophages. In parallel, CCL9-blockade raised serum creatinine and urea levels as readouts of kidney dysfunction. It also exacerbated CKD-induced expression of collagen (3.2-fold) and the pro-inflammatory chemokines CCL2 (1.8-fold) and CCL3 (2.1-fold) in kidney. Altogether, this study reveals for the first time that chemokines CCL6 and CCL9 are upregulated early in experimental CKD, with CCL9-blockade during CKD initiation enhancing kidney inflammation and fibrosis.

Use and outcomes of dual antiplatelet therapy for acute coronary syndrome in patients with chronic kidney disease: insights from the Canadian Observational Antiplatelet Study (COAPT)

Chronic kidney disease (CKD) increases the risk of adverse outcomes in acute coronary syndrome (ACS). The optimal regimen of dual antiplatelet therapy (DAPT) post-percutaneous coronary intervention (PCI) in CKD poses a challenge due to the increased bleeding and clotting tendencies, particularly since patients with CKD were underrepresented in randomized controlled trials. We examined the practice patterns of DAPT prescription stratified by the presence of CKD. The multicentre prospective Canadian Observational Antiplatelet Study (COAPT) enrolled patients with ACS between December 2011 and May 2013. The present study is a subgroup analysis comparing type and duration of DAPT and associated outcomes among patients with and without CKD (eGFR < 60 ml/min/1.73 m², calculated by CKD-EPI). Patients with CKD (275/1921, 14.3%) were prescribed prasugrel/ticagrelor less (18.5% vs 25.8%, p = 0.01) and had a shorter duration of DAPT therapy versus patients without CKD (median 382 vs 402 days, p = 0.003). CKD was associated with major adverse cardiovascular events (MACE) at 12 months (p < 0.001) but not bleeding when compared to patients without CKD. CKD was associated with MACE in both patients on prasugrel/ticagrelor (p = 0.017) and those on clopidogrel (p < 0.001) (p for heterogeneity = 0.70). CKD was associated with increased bleeding only among patients receiving prasugrel/ticagrelor (p = 0.007), but not among those receiving clopidogrel (p = 0.64) (p for heterogeneity = 0.036). Patients with CKD had a shorter DAPT duration and were less frequently prescribed potent P2Y₁₂ inhibitors than patients without CKD. Overall, compared with patients without CKD, patients with CKD had higher rates of MACE and similar bleeding rates. However, among those prescribed more potent P2Y₁₂ inhibitors, CKD was associated with more bleeding than those without CKD. Further studies are needed to better define the benefit/risk evaluation, and establish a more tailored and evidence-based DAPT regimen for this high-risk patient group.

A systematic review and meta-analysis of murine models of uremic cardiomyopathy

Chronic kidney disease (CKD) triggers the risk of developing uremic cardiomyopathy as characterized by cardiac hypertrophy, fibrosis and functional impairment. Traditionally, animal studies are used to reveal the underlying pathological mechanism, although variable CKD models, mouse strains and readouts may reveal diverse results. Here, we systematically reviewed 88 studies and performed meta-analyses of 52 to support finding suitable animal models for future experimental studies on pathological kidney-heart crosstalk during uremic cardiomyopathy. We compared different mouse strains and the direct effect of CKD on cardiac hypertrophy, fibrosis and cardiac function in "single hit" strategies as well as cardiac effects of kidney injury combined with additional cardiovascular risk factors in "multifactorial hit" strategies. In C57BL/6 mice, CKD was associated with a mild increase in cardiac hypertrophy and fibrosis and marginal systolic dysfunction. Studies revealed high variability in results, especially regarding hypertrophy and systolic function. Cardiac hypertrophy in CKD was more consistently observed in 129/Sv mice, which express two instead of one renin gene and more consistently develop increased blood pressure upon CKD induction. Overall, "multifactorial hit" models more consistently induced cardiac hypertrophy and fibrosis compared to "single hit" kidney injury models. Thus, genetic factors and additional cardiovascular risk factors can "prime" for susceptibility to organ damage, with increased blood pressure, cardiac hypertrophy and early cardiac fibrosis more consistently observed in 129/Sv compared to C57BL/6 strains.

Lipoproteins and fatty acids in chronic kidney disease: molecular and metabolic alterations

Chronic kidney disease (CKD) induces modifications in lipid and lipoprotein metabolism and homeostasis. These modifications can promote, modulate and/or accelerate CKD and secondary cardiovascular disease (CVD). Lipid and lipoprotein abnormalities - involving triglyceride-rich lipoproteins, LDL and/or HDL - not only involve changes in concentration but also changes in molecular structure, including protein composition, incorporation of small molecules and post-translational modifications. These alterations modify the function of lipoproteins and can trigger pro-inflammatory and pro-atherogenic processes, as well as oxidative stress. Serum fatty acid levels are also often altered in patients with CKD and lead to changes in fatty acid metabolism - a key process in intracellular energy production - that induce mitochondrial dysfunction and cellular damage. These fatty acid changes might not only have a negative impact on the heart, but also contribute to the progression of kidney damage. The presence of these lipoprotein alterations within a biological environment characterized by increased inflammation and oxidative stress, as well as the competing risk of non-atherosclerotic cardiovascular death as kidney function declines, has important therapeutic implications. Additional research is needed to clarify the pathophysiological link between lipid and lipoprotein modifications, and kidney dysfunction, as well as the genesis and/or progression of CVD in patients with kidney disease.

Targeting the chemokine network in atherosclerosis

Chemokines and their receptors represent a potential target for immunotherapy in chronic inflammation. They comprise a large family of cytokines with chemotactic activity, and their cognate receptors are expressed on all cells of the body. This network dictates leukocyte recruitment and activation, angiogenesis, cell proliferation and maturation. Dysregulation of chemokine and chemokine receptor expression as well as function participates in many pathologies including cancer, autoimmune diseases and chronic inflammation. In atherosclerosis, a lipid-driven chronic inflammation of middle-sized and large arteries, chemokines and their receptors participates in almost all stages of the disease from initiation of fatty streaks to mature atherosclerotic plaque formation. Atherosclerosis and its complications are the main driver of mortality and morbidity in cardiovascular diseases (CVD). Hence, exploring new fields of therapeutic targeting of atherosclerosis is of key importance. This review gives an overview of the recent advances on the role of key chemokines and chemokine receptors in atherosclerosis, addresses chemokine-based biomarkers at biochemical, imaging and genetic level in human studies, and highlights the clinial trials targeting atherosclerosis.

Tissue sodium content in hypertension and related organ damage

: Most textbooks state that sodium (Na) accumulation goes hand in hand with fluid retention to maintain the environmental isotonicity. In the last century, several studies found, however, that Na is stored in the extravascular space leading to an activation of the monocyte phagocytic system cells that work as a regulator of the interstitial electrolyte homeostasis. Na-MRI was developed to quantify noninvasively, accurately and reliably tissue Na content. In this review, we give an up-to-date overview of clinical studies utilizing this Na-MRI technique to elucidate the importance of tissue Na content in patients with cardiovascular risk factors leading to microvascular and macrovascular complications. Na storage leads ultimately to organ damage such as left ventricular hypertrophy or hypertrophic vascular remodeling of resistance vessels. Elevated Na content in muscle and skin has been detected in patients with treatment resistant hypertension, type 2 diabetes mellitus, acute and chronic heart failure, chronic kidney disease and end-stage renal failure. Pharmacological interventions have shown that a mobilization of extracellular accumulated Na is possible and may emerge as a new therapeutic approach in some diseases.

Editorial on the Special Issue "Comorbidities in Chronic Kidney Disease"

With a mean worldwide prevalence of 13 [...].

Cardiovascular Calcification in Chronic Kidney Disease-Therapeutic Opportunities

Patients with chronic kidney disease (CKD) are highly susceptible to cardiovascular (CV) complications, thus suffering from clinical manifestations such as heart failure and stroke. CV calcification greatly contributes to the increased CV risk in CKD patients. However, no clinically viable therapies towards treatment and prevention of CV calcification or early biomarkers have been approved to date, which is largely attributed to the asymptomatic progression of calcification and the dearth of high-resolution imaging techniques to detect early calcification prior to the 'point of no return'. Clearly, new intervention and management strategies are essential to reduce CV risk factors in CKD patients. In experimental rodent models, novel promising therapeutic interventions demonstrate decreased CKD-induced calcification and prevent CV complications. Potential diagnostic markers such as the serum T50 assay, which demonstrates an association of serum calcification propensity with all-cause mortality and CV death in CKD patients, have been developed. This review provides an overview of the latest observations and evaluates the potential of these new interventions in relation to CV calcification in CKD patients. To this end, potential therapeutics have been analyzed, and their properties compared via experimental rodent models, human clinical trials, and meta-analyses.

Impact of renal function on clinical outcomes after PCI in ACS and stable CAD patients treated with ticagrelor: a prespecified analysis of the GLOBAL LEADERS randomized clinical trial

BACKGROUND

Impaired renal function (IRF) is associated with increased risks of both ischemic and bleeding events. Ticagrelor has been shown to provide greater absolute reduction in ischemic risk following acute coronary syndrome (ACS) in those with versus without IRF.

METHODS

A pre-specified sub-analysis of the randomized GLOBAL LEADERS trial (n = 15,991) comparing the experimental strategy of 23-month ticagrelor monotherapy (after 1-month ticagrelor and aspirin dual anti-platelet therapy [DAPT]) with 12-month DAPT followed by 12-month aspirin after percutaneous coronary intervention (PCI) in ACS and stable coronary artery disease (CAD) patients stratified according to IRF (glomerular filtration rate < 60 ml/min/1.73 m²).

RESULTS

At 2 years, patients with IRF (n = 2171) had a higher rate of the primary endpoint (all-cause mortality or centrally adjudicated, new Q-wave myocardial infarction [MI](hazard ratio [HR] 1.64, 95% confidence interval [CI] 1.35-1.98, p_adj = 0.001), all-cause death, site-reported MI, all revascularization and BARC 3 or 5 type bleeding, compared with patients without IRF. Among patients with IRF, there were similar rates of the primary endpoint (HR 0.82, 95% CI 0.61-1.11, p = 0.192, p_int = 0.680) and BARC 3 or 5 type bleeding (HR 1.10, 95% CI 0.71-1.71, p = 0.656, p_int = 0.506) in the experimental versus the reference group. No significant interactions were seen between IRF and treatment effect for any of the secondary outcome variables. Among ACS patients with IRF, there were no between-group differences in the rates of the primary endpoint or BARC 3 or 5 type bleeding; however, the rates of the patient-oriented composite endpoint (POCE) of all-cause death, any stroke, MI, or revascularization (p_int = 0.028) and net adverse clinical events (POCE and BARC 3 or 5 type bleeding) (p_int = 0.045), were lower in the experimental versus the reference group. No treatment effects were found in stable CAD patients categorized according to presence of IRF.

CONCLUSIONS

IRF negatively impacted long-term prognosis after PCI. There were no differential treatment effects found with regard to all-cause death or new Q-wave MI after PCI in patients with IRF treated with ticagrelor monotherapy.

CLINICAL TRIAL REGISTRATION

The trial has been registered with ClinicalTrials.gov, number NCT01813435.

One-year clinical outcomes in patients with renal insufficiency after contemporary PCI: data from a multicenter registry

Background

Chronic kidney disease (CKD) is highly prevalent in patients with coronary artery disease (CAD).

Objective

The outcome following revascularization using contemporary technologies (new-generation abluminal sirolimus-eluting stents with thin struts) in patients with CKD (i.e., glomerular filtration rate of < 60 mL/min/1.73m²) and in patients with hemodialysis (HD) is unknown.

Methods

e-Ultimaster is a prospective, single-arm, multi-center registry with clinical follow-up at 3 months and 1 year.

Results

A total of 19,475 patients were enrolled, including 1466 patients with CKD, with 167 undergoing HD. Patients with CKD had a higher prevalence of overall comorbidities, multiple/small vessel disease (≤ 2.75 mm), bifurcation lesions, and more often left main artery treatments (all p < 0.0001) when compared with patients with normal renal function (reference). CKD patients had a higher risk of target lesion failure (unadjusted OR, 2.51 [95% CI 2.04–3.08]), target vessel failure (OR, 2.44 [95% CI 2.01–2.96]), patient-oriented composite end point (OR, 2.19 [95% CI 1.87–2.56]), and major adverse cardiovascular events (OR, 2.34 [95% CI 1.93–2.83, p for all < 0.0001]) as reference. The rates of target lesion revascularization (OR, 1.17 [95% CI 0.79–1.73], p = 0.44) were not different. Bleeding complications were more frequently observed in CKD than in the reference (all p < 0.0001).

Conclusion

In this worldwide registry, CKD patients presented with more comorbidities and more complex lesions when compared with the reference population. They experienced higher rate of adverse events at 1-year follow-up.

Graphic abstract

[Cardiovascular pharmacotherapy and coronary revascularization in end-stage renal failure]

There is a close physiological relationship between the kidneys and the heart. Cardiovascular diseases are the most prevalent cause of death in patients with chronic kidney disease (CKD), whereas CKD may directly accelerate the progression of cardiovascular diseases and is considered to be a cardiovascular risk factor. In patients with mild CKD, i.e. an estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m², treatment of coronary artery disease and chronic heart failure is not essentially different from patients with preserved renal function; however, as most pivotal trials have systematically excluded patients with advanced renal failure, many treatment recommendations in this patient group are based on observational studies, post hoc subgroup analyses and meta-analyses or pathophysiological considerations, which are not supported by controlled studies. Therefore, prospective randomized studies on the management of heart failure and coronary artery disease are needed, which should specifically focus on the growing number of patients with advanced renal functional impairment.

Hyperkalaemia in Heart Failure-Pathophysiology, Implications and Therapeutic Perspectives

PURPOSE OF REVIEW

Hyperkalaemia is a frequent and sometimes life-threatening condition that may be associated with arrhythmia and cardiac dysfunction. Evaluating the prevalence of hyperkalaemia in patients with heart failure (HF) and potential treatments of this condition is essential for patients using renin-angiotensin-aldosterone system inhibitors or angiotensin receptor-neprilysin inhibitor and mineralocorticoid receptor antagonists, which represent the cornerstone and highly proven life-saving therapy.

RECENT FINDINGS

Novel findings from the past few years include data regarding the epidemiology, pathomechanisms, implications and novel therapeutic approaches to counteract hyperkalaemia in patients with HF. Whilst older potassium-binding agents are associated with serious adverse events, novel potassium-binding drugs are effective in lowering potassium levels and are generally well tolerated. Hyperkalaemia represents both a direct risk of cardiovascular complication and an indirect biomarker of the severity of the underlying disease such as neurohormonal activation and renal dysfunction. Novel potassium-binding drugs such as patiromer and sodium zirconium cyclosilicate may help to optimize therapy in HF and achieve guideline-recommended doses.

Chemokines as Therapeutic Targets in Cardiovascular Disease

With the incidence and impact of atherosclerotic cardiovascular disease and its clinical manifestations still rising, therapeutic options that target the causal mechanisms of this disorder are highly desired. Since the CANTOS trial (Canakinumab Antiinflammatory Thrombosis Outcome Study) has demonstrated that lowering inflammation can be beneficial, focusing on mechanisms underlying inflammation, for example, leukocyte recruitment, is feasible. Being key orchestrators of leukocyte trafficking, chemokines have not lost their attractiveness as therapeutic targets, despite the difficult road to drug approval thus far. Still, innovative therapeutic approaches are being developed, paving the road towards the first chemokine-based therapeutic against inflammation. In this overview, recent developments for chemokines and for the chemokine-like factor MIF (macrophage migration inhibitory factor) will be discussed.