Combining phosphate binder therapy with vitamin K2 inhibits vascular calcification in an experimental animal model of kidney failure

BACKGROUND

Hyperphosphataemia is strongly associated with cardiovascular disease and mortality. Recently, phosphate binders (PBs), which are used to bind intestinal phosphate, have been shown to bind vitamin K, thereby potentially aggravating vitamin K deficiency. This vitamin K binding by PBs may offset the beneficial effects of phosphate reduction in reducing vascular calcification (VC). Here we assessed whether combining PBs with vitamin K2 supplementation inhibits VC.

METHODS

We performed 3/4 nephrectomy in rats, after which warfarin was given for 3 weeks to induce vitamin K deficiency. Next, animals were fed a high phosphate diet in the presence of low or high vitamin K2 and were randomized to either control or one of four different PBs for 8 weeks. The primary outcome was the amount of thoracic and abdominal aorta VC measured by high-resolution micro-computed tomography (µCT). Vitamin K status was measured by plasma MK7 levels and immunohistochemically analysed in vasculature using uncarboxylated matrix Gla protein (ucMGP) specific antibodies.

RESULTS

The combination of a high vitamin K2 diet and PB treatment significantly reduced VC as measured by µCT for both the thoracic (P = 0.026) and abdominal aorta (P = 0.023), compared with MK7 or PB treatment alone. UcMGP stain was significantly more present in the low vitamin K2-treated groups in both the thoracic (P < 0.01) and abdominal aorta (P < 0.01) as compared with high vitamin K2-treated groups. Moreover, a high vitamin K diet and PBs led to reduced vascular oxidative stress.

CONCLUSION

In an animal model of kidney failure with vitamin K deficiency, neither PB therapy nor vitamin K2 supplementation alone prevented VC. However, the combination of high vitamin K2 with PB treatment significantly attenuated VC.

Calcific Plaque Modification by Acoustic Shockwaves: Intravascular Lithotripsy in Cardiovascular Interventions

PURPOSE OF REVIEW

To provide a review of recent literature on the treatment of moderate-to-severe calcification in coronary and peripheral vasculature with intravascular lithotripsy (Shockwave Medical, Santa Clara, CA).

RECENT FINDINGS

Moderate-to-severe calcific plaques constitute a significant proportion of lesions treated with transcatheter interventions in the coronary and peripheral vascular beds and portend lower procedural success rates, increased periprocedural major adverse events, and unfavorable long-term clinical outcomes compared to non-calcific plaques. Intravascular lithotripsy (IVL) is a new technique that uses acoustic shock waves in a balloon-based system to induce fracture in the calcium deposits to facilitate luminal gain and stent expansion. IVL demonstrated high procedural success and low complication rates in the management of moderate-to-severe calcification in coronary and peripheral vascular beds and led to large luminal gain by modification of calcific plaque as assessed by optical coherence tomography. Further studies will determine the role of IVL in an integrated, protocolized approach to the treatment of severely calcified plaques in the coronary and peripheral vascular beds.

Interventions to Attenuate Vascular Calcification Progression in Chronic Kidney Disease: A Systematic Review of Clinical Trials

Background Vascular calcification is associated with cardiovascular morbidity and mortality in people with chronic kidney disease (CKD). Evidence-based interventions that may attenuate its progression in CKD remain uncertain.

Methods We conducted a systematic review of prospective clinical trials of interventions to attenuate vascular calcification in people with CKD, compare with placebo, another comparator, or standard of care. We included prospective clinical trials (randomized and nonrandomized) involving participants with stage 3-5D CKD or kidney transplant recipients; the outcome was vascular calcification measured using radiological methods. Quality of evidence was determined by the Cochrane risk of bias assessment tool and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) method.

Results There were 77 trials (63 randomized) involving 6898 participants eligible for inclusion (median sample size, 50; median duration, 12 months); 58 involved participants on dialysis, 15 involved individuals with nondialysis CKD, and 4 involved kidney transplant recipients. Risk of bias was moderate over all. Trials involving magnesium and sodium thiosulfate consistently showed attenuation of vascular calcification. Trials involving intestinal phosphate binders, alterations in dialysate calcium concentration, vitamin K therapy, calcimimetics, and antiresorptive agents had conflicting or inconclusive outcomes. Trials involving vitamin D therapy and HMG-CoA reductase inhibitors did not demonstrate attenuation of vascular calcification. Mixed results were reported for single studies of exercise, vitamin E-coated or high-flux hemodialysis membranes, interdialytic sodium bicarbonate, SNF472, spironolactone, sotatercept, nicotinamide, and oral activated charcoal.

Conclusions Currently, there are insufficient or conflicting data regarding interventions evaluated in clinical trials for mitigation of vascular calcification in people with CKD. Therapy involving magnesium or sodium thiosulfate appears most promising, but evaluable studies were small and of short duration.

Impact of Fetuin-A, Lp(a), matrix gla protein and macrophage density on calcific aortic valve disease: a clinical study

BACKGROUND

Calcific aortic valve disease (CAVD) has a substantial and increasing burden in the ageing population with occult onset.Present study aimed to assess association of clinical characteristics of these patients and occurrence of CAVD.

METHODS

Patients diagnosed with CAVD and those receiving healthy medical examination in our hospital from January 2019 to February 2021 were enrolled in this retrospective study. Clinical characteristics, ultrasonic indicators, serological indicators and histology of CAVD were collected and compared among different groups. Logistic regression and Pearson correlation analysis was used to explore relationship between these indexes and occurrence of CAVD.

RESULTS

DBP, SBP, LVESD, LVEDD, IVS, PW, AV Vmax, TC, TG, LDL-C, Fetuin-A, Lp(a) in severe group were higher than mild, moderate and control groups (P<0.05), while those indexes of patients in moderate group were higher than that in mild and controlled groups (P<0.05). Besides, theses indexes of patients in mild group were also higher than that of controlled one (P<0.05). However, LVEF, HDL-C and MGP of patients in severe group was the lowest (P<0.05), while those in moderate group were lower than mild and controlled groups. Moreover, these indexes in mild group were also lower than control group (P<0.05). In Logistic regression analysis, MGP, Fetuin-A and Lp(a) were all independently associated with occurrence of CAVD (P<0.05). In Pearson correlation analysis, Fetuin-A and Lp(a) were positively correlated with progression of the disease, while MGP and macrophage density were negatively correlated with it.

CONCLUSIONS

Fetuin-A, MPG and Lp(a) were independently associated with the occurrence of CAVD, and they might be potential predictors for diagnosis of this disease.

Dihydromyricetin ameliorates vascular calcification in chronic kidney disease by targeting AKT signaling

Vascular calcification is highly prevalent in chronic kidney disease (CKD), and is characterized by transdifferentiation from contractile vascular smooth muscle cells (VSMCs) into an osteogenic phenotype. However, no effective and therapeutic option to prevent vascular calcification is yet available. Dihydromyricetin (DMY), a bioactive flavonoid isolated from Ampelopsis grossedentata, has been found to inhibit VSMCs proliferation and the injury-induced neointimal formation. However, whether DMY has an effect on osteogenic differentiation of VSMCs and vascular calcification is still unclear. In the present study, we sought to investigate the effect of DMY on vascular calcification in CKD and the underlying mechanism. DMY treatment significantly attenuated calcium/phosphate-induced calcification of rat and human VSMCs in a dose-dependent manner, as shown by Alizarin Red S staining and calcium content assay, associated with down-regulation of osteogenic markers including type I collagen (COL I), Runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteocalcin (OCN). These results were further confirmed in aortic rings ex vivo. Moreover, DMY ameliorated vascular calcification in rats with CKD. Additionally, we found that AKT signaling was activated during vascular calcification, whereas significantly inhibited by DMY administration. DMY treatment significantly reversed AKT activator-induced vascular calcification. Furthermore, inhibition of AKT signaling efficiently attenuated calcification, which was similar to that after treatment with DMY alone, and DMY had a better inhibitory effect on calcification as compared with AKT inhibitor. The present study demonstrated that DMY has a potent inhibitory role in vascular calcification partially by inhibiting AKT activation, suggesting that DMY may act as a promising therapeutic candidate for patients suffering from vascular calcification.

Carbamylated sortilin associates with cardiovascular calcification in patients with chronic kidney disease

Sortilin, an intracellular sorting receptor, has been identified as a cardiovascular risk factor in the general population. Patients with chronic kidney disease (CKD) are highly susceptible to develop cardiovascular complications such as calcification. However, specific CKD-induced posttranslational protein modifications of sortilin and their link to cardiovascular calcification remain unknown. To investigate this, we examined two independent CKD cohorts for carbamylation of circulating sortilin and detected increased carbamylated sortilin lysine residues in the extracellular domain of sortilin with kidney function decline using targeted mass spectrometry. Structure analysis predicted altered ligand binding by carbamylated sortilin, which was verified by binding studies using surface plasmon resonance measurement, showing an increased affinity of interleukin 6 to in vitro carbamylated sortilin. Further, carbamylated sortilin increased vascular calcification in vitro and ex vivo that was accelerated by interleukin 6. Imaging by mass spectrometry of human calcified arteries revealed in situ carbamylated sortilin. In patients with CKD, sortilin carbamylation was associated with coronary artery calcification, independent of age and kidney function. Moreover, patients with carbamylated sortilin displayed significantly faster progression of coronary artery calcification than patients without sortilin carbamylation. Thus, carbamylated sortilin may be a risk factor for cardiovascular calcification and may contribute to elevated cardiovascular complications in patients with CKD.

Hydrogen sulfide prevents arterial medial calcification in rats with diabetic nephropathy

BACKGROUND

Arterial medial calcification (AMC) is associated with a high incidence of cardiovascular risk in patients with type 2 diabetes and chronic kidney disease. Here, we tested whether hydrogen sulfide (H2S) can prevent AMC in rats with diabetic nephropathy (DN).

METHODS

DN was induced by a single injection of streptozotocin and high-fat diet (45% kcal as fat) containing 0.75% adenine in Sprague-Dawley rats for 8 weeks.

RESULTS

Rats with DN displayed obvious calcification in aorta, and this was significantly alleviated by Sodium Hydrosulfide (NaHS, a H2S donor, 50 μmol/kg/day for 8 weeks) treatment through decreasing calcium and phosphorus content, ALP activity and calcium deposition in aorta. Interestingly, the main endogenous H2S generating enzyme activity and protein expression of cystathionine-γ-lyase (CSE) were largely reduced in the arterial wall of DN rats. Exogenous NaHS treatment restored CSE activity and its expression, inhibited aortic osteogenic transformation by upregulating phenotypic markers of smooth muscle cells SMα-actin and SM22α, and downregulating core binding factor α-1 (Cbfα-1, a key factor for bone formation), protein expressions in rats with DN when compared to the control group. NaHS administration also significantly reduced Stat3 activation, cathepsin S (CAS) activity and TGF-β1 protein level, and improved aortic elastin expression.

CONCLUSIONS

H2S may have a clinical significance for treating AMC in people with DN by reducing Stat3 activation, CAS activity, TGF-β1 level and increasing local elastin level.

HAP-Multitag, a PET and Positive MRI Contrast Nanotracer for the Longitudinal Characterization of Vascular Calcifications in Atherosclerosis

Vascular microcalcifications are associated with atherosclerosis plaque instability and, therefore, to increased mortality. Because of this key role, several imaging probes have been developed for their in vivo identification. Among them, [¹⁸F]FNa is the gold standard, showing a large uptake in the whole skeleton by positron emission tomography. Here, we push the field toward the combined anatomical and functional early characterization of atherosclerosis. For this, we have developed hydroxyapatite (HAP)-multitag, a bisphosphonate-functionalized ⁶⁸Ga core-doped magnetic nanoparticle showing high affinity toward most common calcium salts present in microcalcifications, particularly HAP. We characterized this interaction in vitro and in vivo, showing a massive uptake in the atherosclerotic lesion identified by positron emission tomography (PET) and positive contrast magnetic resonance imaging (MRI). In addition, this accumulation was found to be dependent on the calcification progression, with a maximum uptake in the microcalcification stage. These results confirmed the ability of HAP-multitag to identify vascular calcifications by PET/(T₁)MRI during the vulnerable stages of the plaque progression.

Atrial flutter following Shockwave Intravascular Lithotripsy during percutaneous intervention of left anterior descending disease

A 72-year-old woman undergoing percutaneous intervention to a calcified proximal left anterior descending (LAD) coronary artery lesion using Shockwave Intravascular Lithotripsy (S-IVL) developed new atrial flutter. She then returned to sinus rhythm after treatment with amiodarone. S-IVL can cause cardiomyocyte depolarization. We hypothesize that pacing can occur during atrial repolarization, inducing supraventricular tachyarrhythmias and even triggering atrial macro re-entrant circuits. We recommend synchronizing shock wave delivery with R waves on the electrocardiogram to lower the risk of arrhythmias.

IL-6 Is Associated with Progression of Coronary Artery Calcification and Mortality in Incident Dialysis Patients

INTRODUCTION

Inflammation is important in the pathogenesis of atherosclerosis. Elevated interleukin-6 (IL-6) is associated with cardiovascular events and also predicts mortality in individuals with CKD. Our goal was to determine the association between IL-6, FGF23, and high-sensitivity C-reactive protein (hsCRP) on coronary artery calcification (CAC) progression and mortality in incident dialysis patients without prior coronary events.

METHODS

A prospective cohort of incident adult dialysis participants had CAC measured by ECG-triggered multislice CT scans at baseline and at least 12 months later. Lipids, mineral metabolism markers, FGF23, and inflammatory markers, such as IL-6 and hsCRP, were measured at the baseline visit.

RESULTS

Participants in the high IL-6 tertile had the highest baseline CAC score (133.25 [10.35-466.15]) compared to the low (0.25 [0-212.2]) and intermediate (29.55 [0-182.85]) tertiles. Almost half of the participants with high IL-6 (15 of 32 [46.9%]) experienced progression of CAC compared to participants with low (8 of 32 [25%]) and intermediate (9 of 32 [28.1%]) (p = 0.05) IL-6 levels. Each log increase in IL-6 was associated with increase in death (hazard ratio 2.2, 95% CI: 1.2-3.8; p = 0.01). After adjusting for smoking, age, gender, race, diabetes, phosphate, and baseline calcium score, IL-6 (log) was associated with 2.2 times (95% CI: 1.1-4.6; p = 0.03) increase in death.

CONCLUSION

IL-6 is associated with progression of CAC and mortality in incident dialysis patients.

Medial Arterial Calcification: JACC State-of-the-Art Review

Medial arterial calcification (MAC) is a chronic systemic vascular disorder distinct from atherosclerosis that is frequently but not always associated with diabetes mellitus, chronic kidney disease, and aging. MAC is also a part of more complex phenotypes in numerous less common diseases. The hallmarks of MAC include disseminated and progressive precipitation of calcium phosphate within the medial layer, a prolonged and clinically silent course, and compromise of hemodynamics associated with chronic limb-threatening ischemia. MAC increases the risk of complications during vascular interventions and mitigates their outcomes. With the exception of rare monogenetic defects affecting adenosine triphosphate metabolism, MAC pathogenesis remains unknown, and causal therapy is not available. Implementation of genetics and omics-based approaches in research recognizing the critical importance of calcium phosphate thermodynamics holds promise to unravel MAC molecular pathogenesis and to provide guidance for therapy. The current state of knowledge concerning MAC is reviewed, and future perspectives are outlined.

BGP-15 Inhibits Hyperglycemia-Aggravated VSMC Calcification Induced by High Phosphate

Vascular calcification associated with high plasma phosphate (Pi) level is a frequent complication of hyperglycemia, diabetes mellitus, and chronic kidney disease. BGP-15 is an emerging anti-diabetic drug candidate. This study was aimed to explore whether BGP-15 inhibits high Pi-induced calcification of human vascular smooth muscle cells (VSMCs) under normal glucose (NG) and high glucose (HG) conditions. Exposure of VSMCs to Pi resulted in accumulation of extracellular calcium, elevated cellular Pi uptake and intracellular pyruvate dehydrogenase kinase-4 (PDK-4) level, loss of smooth muscle cell markers (ACTA, TAGLN), and enhanced osteochondrogenic gene expression (KLF-5, Msx-2, Sp7, BMP-2). Increased Annexin A2 and decreased matrix Gla protein (MGP) content were found in extracellular vesicles (EVs). The HG condition markedly aggravated Pi-induced VSMC calcification. BGP-15 inhibited Pi uptake and PDK-4 expression that was accompanied by the decreased nuclear translocation of KLF-5, Msx-2, Sp7, retained VSMC markers (ACTA, TAGLN), and decreased BMP-2 in both NG and HG conditions. EVs exhibited increased MGP content and decreased Annexin A2. Importantly, BGP-15 prevented the deposition of calcium in the extracellular matrix. In conclusion, BGP-15 inhibits Pi-induced osteochondrogenic phenotypic switch and mineralization of VSMCs in vitro that make BGP-15 an ideal candidate to attenuate both diabetic and non-diabetic vascular calcification.

Up-regulation of heme oxygenase-1 by celastrol alleviates oxidative stress and vascular calcification in chronic kidney disease

Vascular calcification is very commonly observed in patients with chronic kidney disease (CKD), but there is no efficient therapy available. Oxidative stress plays critical roles in the progression of vascular calcification. Celastrol (Cel), a natural constituent derived from Chinese herbals, exhibits anti-oxidative stress activity. Here, we investigated the effect of celastrol on vascular calcification using vascular smooth muscle cells (VSMCs), arterial rings and CKD rats. Alizarin red staining and gene expression analysis showed that Cel dose-dependently inhibited rat VSMC calcification and osteogenic differentiation. Similarly, ex vivo study revealed that Cel inhibited calcification of rat and human arterial rings. In addition, micro-computed tomography, alizarin red staining and calcium content analysis confirmed that Cel inhibited aortic calcification in CKD rats. Interestingly, Cel treatment increased the mRNA and protein levels of heme oxygenase-1 (HMOX-1), and reduced the levels of reactive oxygen species (ROS) in VSMCs. Furthermore, both pharmacological inhibition of HMOX-1 and knockdown of HMOX-1 by siRNA independently counteracted the inhibitory effect of Cel on vascular calcification. Moreover, knockdown of HMOX-1 prevented Cel treatment-mediated reduction in ROS levels. Finally, Cel treatment reduced Vitamin D3-induced aortic calcification in mice and this effect was blocked by HMOX-1 inhibitor ZnPP9. Collectively, our results suggest that up-regulation of HMOX-1 is required for the inhibitory effect of Cel on vascular calcification. Modulation of HMOX-1 may provide a novel strategy for the treatment of vascular calcification in CKD.

Recovery of limb perfusion and function after hindlimb ischemia is impaired by arterial calcification

Medial artery calcification results from deposition of calcium hydroxyapatite crystals on elastin layers, and osteogenic changes in vascular smooth muscle cells. It is highly prevalent in patients with chronic kidney disease, diabetes, and peripheral artery disease (PAD), and when identified in lower extremity vessels, it is associated with increased amputation rates. This study aims to evaluate the effects of medial calcification on perfusion and functional recovery after hindlimb ischemia in rats. Medial artery calcification and acute limb ischemia were induced by vitamin D3 (VitD3 ) injection and femoral artery ligation in rats. VitD3 injection robustly induced calcification in the medial layer of femoral arteries in vivo. Laser Doppler perfusion imaging revealed that perfusion decreased and then partially recovered after hindlimb ischemia in vehicle-injected rats. In contrast, VitD3 -injected rats showed markedly impaired recovery of perfusion following limb ischemia. Accordingly, rats with medial calcification showed worse ischemia scores and delayed functional recovery compared with controls. Immunohistochemical and histological staining did not show differences in capillary density or muscle morphology between VitD3 - and vehicle-injected rats at 28 days after femoral artery ligation. The evaluation of cardiac and hemodynamic parameters showed that arterial stiffness was increased while cardiac function was preserved in VitD3 -injected rats. These findings suggest that medial calcification may contribute to impaired perfusion in PAD by altering vascular compliance, however, the specific mechanisms remain poorly understood. Reducing or slowing the progression of arterial calcification in patients with PAD may improve clinical outcomes.

A combined microRNA and target protein-based panel for predicting the probability and severity of uraemic vascular calcification: a translational study

AIMS

Vascular calcification (VC) increases the future risk of cardiovascular events in uraemic patients, but effective therapies are still unavailable. Accurate identification of those at risk of developing VC using pathogenesis-based biomarkers is of particular interest and may facilitate individualized risk stratification. We aimed to uncover microRNA (miRNA)-target protein-based biomarker panels for evaluating uraemic VC probability and severity.

METHODS AND RESULTS

We created a three-tiered in vitro VC model and an in vivo uraemic rat model receiving high phosphate diet to mimic uraemic VC. RNAs from the three-tiered in vitro and in vivo uraemic VC models underwent miRNA and mRNA microarray, with results screened for differentially expressed miRNAs and their target genes as biomarkers. Findings were validated in original models and additionally in an ex vivo VC model and human cells, followed by functional assays of identified miRNAs and target proteins, and tests of sera from end-stage renal disease (ESRD) and non-dialysis-dependent chronic kidney disease (CKD) patients without and with VC. Totally 122 down-regulated and 119 up-regulated miRNAs during calcification progression were identified initially; further list narrowing based on miRNA-mRNA pairing, anti-correlation, and functional enrichment left 16 and 14 differentially expressed miRNAs and mRNAs. Levels of four miRNAs (miR-10b-5p, miR-195, miR-125b-2-3p, and miR-378a-3p) were shown to decrease throughout all models tested, while one mRNA (SULF1, a potential target of miR-378a-3p) exhibited the opposite trend concurrently. Among 96 ESRD (70.8% with VC) and 59 CKD patients (61% with VC), serum miR-125b2-3p and miR-378a-3p decreased with greater VC severity, while serum SULF1 levels increased. Adding serum miR-125b-2-3p, miR-378a-3p, and SULF1 into regression models for VC substantially improved performance compared to using clinical variables alone.

CONCLUSION

Using a translational approach, we discovered a novel panel of biomarkers for gauging the probability/severity of uraemic VC based on miRNAs/target proteins, which improved the diagnostic accuracy.

MiR-93 inhibits the vascular calcification of chronic renal failure by suppression of Wnt/β-catenin pathway

OBJECTIVE

To explore the effect of miR-93-mediated Wnt/β-catenin pathway on the vascular calcification (VC) of chronic renal failure (CRF).

METHODS

SD rats were utilized to construct CRF models and divided into Control, CRF, CRF + LV (lentiviral vector)-miR-93 and CRF + LV-Con groups. Renal tissues collected from rats were performed hematoxylin and eosin (HE) staining and Masson staining, while the abdominal aorta was dissected for alizarin red staining and Von Kossa staining. VC-related genes were determined by qRT-PCR while Wnt/β-catenin pathway-related proteins were examined by Western blotting.

RESULTS

As compared to Control group, the serum levels of blood urea nitrogen (BUN), serum creatinine (Scr), phosphorus (P), cystatin C (Cys-C) and 24-h urea protein (24 h Upro), and the scores of renal interstitial lesion and fibrotic area in rats from CRF group were elevated, with the increased calcified area of aorta as well as the enhanced calcium content and ALP. Meanwhile, rats in the CRF group had up-regulated expression of OPN, OCN, RUNX2 and BMP-2 and down-regulated expression of miR-93. As for the expression of Wnt/β-catenin pathway, rats in the CRF group had sharp increases in the protein expression of TCF4 and β-catenin, while α-SMA was down-regulated. However, changes of the above were reversed in rats from CRF + LV-miR-93 group, and TCF4 was confirmed to be a target gene of miR-93.

CONCLUSION

MiR-93, via inhibiting the activity of Wnt/β-catenin pathway by targeting TCF4, can improve the renal function of CRF rats, thereby mitigating the vascular calcification of CRF.

Roles of Nuclear Receptors in Vascular Calcification

Vascular calcification is defined as an inappropriate accumulation of calcium depots occurring in soft tissues, including the vascular wall. Growing evidence suggests that vascular calcification is an actively regulated process, sharing similar mechanisms with bone formation, implicating both inhibitory and inducible factors, mediated by osteoclast-like and osteoblast-like cells, respectively. This process, which occurs in nearly all the arterial beds and in both the medial and intimal layers, mainly involves vascular smooth muscle cells. In the vascular wall, calcification can have different clinical consequences, depending on the pattern, localization and nature of calcium deposition. Nuclear receptors are transcription factors widely expressed, activated by specific ligands that control the expression of target genes involved in a multitude of pathophysiological processes, including metabolism, cancer, inflammation and cell differentiation. Some of them act as drug targets. In this review we describe and discuss the role of different nuclear receptors in the control of vascular calcification.

Effect of Treating Hyperphosphatemia With Lanthanum Carbonate vs Calcium Carbonate on Cardiovascular Events in Patients With Chronic Kidney Disease Undergoing Hemodialysis: The LANDMARK Randomized Clinical Trial

Importance

Among patients with hyperphosphatemia undergoing dialysis, it is unclear whether non-calcium-based phosphate binders are more effective than calcium-based binders for reducing cardiovascular events.

Objective

To determine whether lanthanum carbonate reduces cardiovascular events compared with calcium carbonate in patients with hyperphosphatemia at risk of vascular calcification undergoing hemodialysis.

Design, Setting, and Participants

Open-label, randomized, parallel-group clinical trial with blinded end point adjudication performed in 2374 patients with chronic kidney disease from 273 hemodialysis facilities in Japan. Eligible patients had hyperphosphatemia and 1 or more risk factors for vascular calcification (ie, ≥65 years, postmenopausal, diabetes). Enrollment occurred from November 2011 to July 2014; follow-up ended June 2018.

Interventions

Patients were randomized to receive either lanthanum carbonate (n = 1154) or calcium carbonate (n = 1155) and titrated to achieve serum phosphate levels of between 3.5 mg/dL and 6.0 mg/dL.

Main Outcomes and Measures

The primary outcome was a composite cardiovascular event (cardiovascular death, nonfatal myocardial infarction or stroke, unstable angina, transient ischemic attack, or hospitalization for heart failure or ventricular arrhythmia). Secondary outcomes included overall survival, secondary hyperparathyroidism-free survival, hip fracture-free survival, and adverse events.

Results

Among 2309 randomized patients (median age, 69 years; 40.5% women), 1851 (80.2%) completed the trial. After a median follow-up of 3.16 years, cardiovascular events occurred in 147 of 1063 patients in the lanthanum calcium group and 134 of 1072 patients in the calcium carbonate group (incidence rate, 4.80 vs 4.30 per 100 person-years; difference 0.50 per 100 person-years [95% CI, -0.57 to 1.56]; hazard ratio [HR], 1.11 [95%, CI, 0.88 to 1.41], P = .37). There were no significant differences in all-cause death (difference, 0.43 per 100 person-years [95% CI, -0.63 to 1.49]; HR, 1.10 [95% CI, 0.88 to 1.37]; P = .42) or hip fracture (difference, 0.10 per 100 person-years [95% CI, -0.26 to 0.47]; HR, 1.21 [95% CI, 0.62 to 2.35]; P = .58). The lanthanum carbonate group had an increased risk of cardiovascular death (difference, 0.61 per 100 person-years [95% CI, 0.02 to 1.21]; HR, 1.51 [95% CI, 1.01 to 2.27]; P = .045) and secondary hyperparathyroidism (difference, 1.34 [95% CI, 0.49 to 2.19]; HR, 1.62 [95% CI, 1.19 to 2.20]; P = .002). Adverse events occurred in 282 (25.7%) in the lanthanum carbonate group and 259 (23.4%) in the calcium carbonate groups.

Conclusions and Relevance

Among patients undergoing hemodialysis with hyperphosphatemia and at least 1 vascular calcification risk factor, treatment of hyperphosphatemia with lanthanum carbonate compared with calcium carbonate did not result in a significant difference in composite cardiovascular events. However, the event rate was low, and the findings may not apply to patients at higher risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT01578200; UMIN Clinical Trial Registry Identifier: UMIN000006815.

Additive effect of low skeletal muscle mass and abdominal obesity on coronary artery calcification

OBJECTIVE

We aimed to investigate the interaction of reduced skeletal muscle mass and abdominal obesity on coronary artery calcification (CAC).

DESIGN AND METHODS

A total of 19 728 adults free of cardiovascular disease (CVD) who contemporaneously underwent cardiac tomography and bioelectrical impedance analysis were enrolled in a cross-sectional and longitudinal cohort. Skeletal muscle mass index (SMI) was calculated using the following formula: SMI (%) = total appendicular muscle mass (kg)/body weight (kg) × 100 according to sex. CAC presence or incidence was defined as CAC score > 0, and CAC progression was defined as √CAC score (follow-up) - √CAC score (baseline)>2.5. Pre-sarcopenia was defined as SMI ≤ -1.0 s.d. of the sex-specific mean of a young reference group. Abdominal obesity was defined as waist circumference ≥ 90 cm for men and ≥85 cm for women. All individuals were further classified into four groups: normal, abdominal obesity alone, pre-sarcopenia alone, and pre-sarcopenic obesity.

RESULTS

Individuals with pre-sarcopenic obesity showed the highest adjusted odds ratio (AOR) for CAC presence (AOR 2.16, 95% CI : 1.98-2.36, P < 0.001) as well as total CAC incidence and progression (adjusted hazard ratio: 1.54, 95% CI: 1.37-1.75, P < 0.001), compared with normal individuals. Pre-sarcopenic obesity significantly increased CAC incidence and progression compared to either pre-sarcopenia or abdominal obesity alone.

CONCLUSION

Pre-sarcopenia and abdominal obesity together were significantly associated with a higher CAC presence and increased risk of CAC incidence and progression, independent of traditional CVD risk factors.

The Relationship between Advanced Oxidation Protein Products, Vascular Calcifications and Arterial Stiffness in Predialysis Chronic Kidney Disease Patients

Background and Objectives: Cardiovascular morbidity and mortality are increased in patients with chronic kidney disease (CKD). It is likely that the accumulation of uremic toxins resulting in increased oxidative stress (OS) is a major contributing factor, but no clear link has been identified. The purpose of this research is to establish if advanced oxidation protein product (AOPP) levels in the serum of predialysis patients are a contributing factor to vascular calcification and increased arterial stiffness. Materials and Methods: After obtaining the informed consent, 46 predialysis patients (CKD stages G3-G5) were included in the study. In order to identify vascular calcifications, hand and pelvic radiographs were performed. Valvular calcifications were identified using cardiac ultrasound. AOPP were measured using a commercially available ELISA kit. The relationships between serum AOPP values and biochemical parameters relevant in the evaluation of CKD patients were analyzed. In addition to identifying the differences in AOPP levels between patients with/without vascular or valvular calcifications, the research focused on describing the relationship between OS and arterial stiffness assessed by oscillometric pulse-wave velocity (PWV) measurement. Results: No significant relationship between serum AOPP and vascular or valvular calcifications was highlighted, but significant correlations of AOPP with C-reactive protein (p = 0.025), HDL-cholesterol levels (p = 0.04), HbA1c (p = 0.05) and PWV values (p = 0.02) were identified. Conclusions: The usefulness of (OS) measurement in clinical practice remains debatable; however, the relationship between AOPP and arterial stiffness could be valuable in improving cardiovascular risk assessment of patients with CKD.

Calciprotein Particles: Balancing Mineral Homeostasis and Vascular Pathology

[Figure: see text].

Regulatory Role of Sex Hormones in Cardiovascular Calcification

Sex differences in cardiovascular disease (CVD), including aortic stenosis, atherosclerosis and cardiovascular calcification, are well documented. High levels of testosterone, the primary male sex hormone, are associated with increased risk of cardiovascular calcification, whilst estrogen, the primary female sex hormone, is considered cardioprotective. Current understanding of sexual dimorphism in cardiovascular calcification is still very limited. This review assesses the evidence that the actions of sex hormones influence the development of cardiovascular calcification. We address the current question of whether sex hormones could play a role in the sexual dimorphism seen in cardiovascular calcification, by discussing potential mechanisms of actions of sex hormones and evidence in pre-clinical research. More advanced investigations and understanding of sex hormones in calcification could provide a better translational outcome for those suffering with cardiovascular calcification.

Associations of dietary patterns and nutrients with coronary artery calcification and pericardial adiposity in a longitudinal study of adults with and without type 1 diabetes

PURPOSE

To examine the associations of dietary patterns and nutrients with coronary artery calcification (CAC) and pericardial adiposity (PAT) in adults with and without type 1 diabetes.

METHODS

We conducted a six-year longitudinal analysis of data from Coronary Artery Calcification in Type 1 Diabetes study [n = 1255; T1D: n = 563; non-DM: n = 692] collected at baseline, year 3 and year 6. Participants completed a validated food frequency questionnaire, a physical examination, and fasting (12 h overnight fast) biochemical analyses. CAC and PAT were measured using electron beam computed tomography. Dietary patterns were identified using factor analysis. Generalized estimating equations were used to examine associations of dietary patterns and nutrients with CAC and PAT in models adjusted for traditional cardiovascular risks.

RESULTS

The 'starchy veggies, meats and alcohol pattern' was associated with significantly increased risk of CAC presence in all adjusted models; an increasing trend was observed with CAC progression. Increasing intake of dietary proteins and total fats were also associated with higher risk of the presence and/or progression of CAC in adjusted models (all p < 0.05). PAT was positively associated with dietary total fats, and inversely associated with dietary intakes of saturated fats, omega-3 fats and fiber in models adjusted for age, sex, total calories, time, diabetes status, systolic blood pressure, serum lipids and physical activity.

CONCLUSION

Diets high in total fats and proteins, and in meats (processed and red) and alcohol may increase risks of CAC, while saturated fats, omega-3-fats and fiber may be protective against pericardial adiposity as a risk factor for coronary artery disease. ClinicalTrials.gov Identifier: NCT00005754.

AGEs accumulation is related to muscle degeneration and vascular calcification in peritoneal dialysis patients

BACKGROUND

Patients with chronic kidney disease (CKD) are affected by dynapenia, sarcopenia, and vascular calcification. Advanced glycation end products (AGEs) may accumulate in peritoneal dialysis (PD) patients and favor sarcopenia via changes in collagen cross-linking, muscle protein breakdown, and the calcification of arterial smooth muscle cells via p38-MAPK activation. The aim of this study is to explore the relationships between AGEs, muscle degeneration, and coronary artery calcification.

METHODS

This was a clinical observational study in patients with CKD undergoing PD, in which serum and skin AGEs (AGEs-sAF), cumulative glucose load, muscle strength and functional tests, muscle ultrasounds with elastography, coronary artery calcium (CAC) quantification, and muscle density by multislice computed tomography were measured.

RESULTS

27 patients aged 48±16 years, dialysis vintage of 27±17 months, had AGEs-sAF levels of 3.09±0.65 AU (elevated in 13 [87%] patients), grip strength levels of 26.2±9.2 kg (11 [42%] patients with dynapenia), gait speed of 1.04±0.3 m/s (abnormal in 14 [58%] patients) and "timed-up-and-go test" (TUG) of 10.5±2.2s (abnormal in 7 [26%] patients). Correlations between AGEs-sAF levels and femoral rectus elastography (R=-0.74; p=0.02), anterior-tibialis elastography (R= -0.68; p=0.04) and CAC (R=0.64; p=0.04) were detected. Cumulative glucose load correlated with femoral rectal elastography (R=-0.6; p=0.02), and serum glycated hemoglobin concentrations correlated with psoas muscle density (R= -0.58; p=0.04) and CAC correlated with psoas muscle density (R=0.57; p=0.01) and lumbar square muscle density (R=-0.63; p=0.005).

CONCLUSIONS

The study revealed associations between AGEs accumulation and lower muscle stiffness/density. Associations that linked muscle degeneration parameters with vascular calcification were observed.