New evidence of direct oral anticoagulation therapy on cardiac valve calcifications, renal preservation and inflammatory modulation.

BACKGROUND: Rivaroxaban is a direct inhibitor of activated Factor X (FXa), an anti-inflammatory protein exerting a protective effect on the cardiac valve and vascular endothelium. We compare the effect of Warfarin and Rivaroxaban on inflammation biomarkers and their contribution to heart valve calcification progression and renal preservation in a population of atrial fibrillation (AF) patients with chronic kidney disease (CKD) stage 3b - 4. METHODS: This was an observational, multicenter, prospective study enrolling 347 consecutive CKD stage 3b - 4 patients newly diagnosed with AF: 247 were treated with Rivaroxaban and 100 with Warfarin. Every 12 months, we measured creatinine levels and cardiac valve calcification via standard trans-thoracic echocardiogram, while plasma levels of inflammatory mediators were quantified by ELISA at baseline and after 24 months. RESULTS: Over a follow-up of 24 months, long-term treatment with Rivaroxaban was associated with a significative reduction of cytokines. Patients treated with Rivaroxaban experienced a more frequent stabilization/regression of valve calcifications comparing with patients treated with Warfarin. Rivaroxaban use was related with an improvement in kidney function in 87.4% of patients, while in those treated with Warfarin was reported a worsening of renal clearance in 98% of cases. Patients taking Rivaroxaban experienced lower adverse events (3.2% vs 49%, p-value <0.001). CONCLUSIONS: Our findings suggest that Rivaroxaban compared to Warfarin is associated with lower levels of serum markers of inflammation. The inhibition of FXa may exert an anti-inflammatory effect contributing to reduce the risk of cardiac valve calcification progression and worsening of renal function.

Pro-Inflammatory Effects of Indoxyl Sulfate in Mice: Impairment of Intestinal Homeostasis and Immune Response.

The intestines are recognized as the main source of chronic inflammation in chronic kidney disease (CKD) and, among other cells, macrophages are involved in modulating this process as well as in the impaired immune response which also occurs in CKD patients. In this study, we evaluated the effect of Indoxyl Sulfate (IS), a protein bound uremic toxin poorly eliminated by hemodialysis, on inflammatory, oxidative stress and pro-apoptotic parameters, at the intestinal level in mice, on intestinal epithelial cells (IEC-6) and on primary murine peritoneal macrophages. C57BL/6J mice were treated with IS (800 mg/kg i.p.) for 3 or 6 h and histopathological analysis showed that IS induced intestinal inflammation and increased cyclooxygenase-2 (COX-2), nitrotyrosine and Bax expression in intestinal tissue. In IEC-6 cells, IS (125-1000 µM) increased tumor necrosis factor-α levels, COX-2 and inducible nitric oxide synthase expression and nitrotyrosine formation. Moreover, IS increased pro-oxidant, pro-inflammatory and pro-apoptotic parameters in peritoneal macrophages from IS-treated mice. Also, the serum concentration of IS and pro-inflammatory levels of cytokines resulted increased in IS-treated mice. Our results indicate that IS significantly contributes to affect intestinal homeostasis, immune response, and to induce a systemic pro-inflammatory state thus highlighting its potential role as therapeutic target in CKD patients.

Cardiac valve calcification and use of anticoagulants: Preliminary observation of a potentially modifiable risk factor.

AIMS: Direct oral anticoagulant (DOAC) has been recently introduced in the clinical practice. Rather than interfering with vitamin K-dependent posttranscriptional modification of various proteins, DOACs selectively inhibit factors involved in the coagulation cascade. In particular, in contrast with Warfarin, Rivaroxabn does not interfere with activation of matrix Gla Protein (MGP), a potent vascular calcification Inhibitor. We herein sought to investigate the impact of Rivaroxaban and Warfarin on cardiac valve calcifications in a cohort of moderate-to advanced CKD patients. METHODS AND RESULTS: This is a multicenter, observational, retrospective, longitudinal study. Consecutive CKD stage 3b - 4 (according to KDIGO guidelines) patients from 8 cardiologic outpatient clinics were enrolled between May 2015 and October 2017. All patients received anticoagulation (100 Warfarin vs 247 Rivaroxaban) as part of their non-valvular atrial fibrillation management. Cardiac valve calcification was evaluated via standard trans-thoracic echocardiogram. 347 patients (mean age: 66 years; mean eGFR: 37 ml/min/1.73 m2) were studied. Over a mean follow-up period of 16 months, Rivaroxaban compared to Warfarin reduced both mitral and aortic valve calcifications (p < 0.001) independently of the degree of calcifications at baseline and potential confounders. Notably, Rivaroxaban use was also associated with a significant reduction in C reactive protein (CRP) (p < 0.001) during follow-up. CONCLUSION: This study generates the hypothesis that the use of Rivaroxaban associates with a reduction of cardiac valve calcification deposition and progression as compared to Warfarin, in a cohort of CKD stage 3b-4 patients. Future endeavors are needed to confirm and to establish the mechanisms responsible for these findings.

Predictors of haemoglobin levels and resistance to erythropoiesis-stimulating agents in patients treated with low-flux haemodialysis, haemofiltration and haemodiafiltration: results of a multicentre randomized and controlled trial.

BACKGROUND: Predictors of haemoglobin (Hb) levels and resistance to erythropoiesis-stimulating agents (ESAs) in dialysis patients have not yet been clearly defined. Some mainly uncontrolled studies suggest that online haemodiafiltration (HDF) may have a beneficial effect on Hb, whereas no data are available concerning online haemofiltration (HF). The objectives of this study were to evaluate the effects of convective treatments (CTs) on Hb levels and ESA resistance in comparison with low-flux haemodialysis (HD) and to evaluate the predictors of these outcomes. METHODS: Primary multivariate analysis was made of a pre-specified secondary outcome of a multicentre, open-label, randomized controlled study in which 146 chronic HD patients from 27 Italian centres were randomly assigned to HD (70 patients) or CTs: online pre-dilution HF (36 patients) or online pre-dilution HDF (40 patients). RESULTS: CTs did not affect Hb levels (P = 0.596) or ESA resistance (P = 0.984). Hb correlated with polycystic kidney disease (P = 0.001), C-reactive protein (P = 0.025), ferritin (P = 0.018), ESA dose (P < 0.001) and total cholesterol (P = 0.021). The participating centres were the main source of Hb variability (partial eta(2) 0.313, P < 0.001). ESA resistance directly correlated with serum ferritin (P = 0.030) and beta2 microglobulin (P = 0.065); participating centres were again a major source of variance (partial eta(2) 0.367, P < 0.001). Transferrin saturation did not predict either outcome variables (P = 0.277 and P = 0.170). CONCLUSIONS: In comparison with low-flux HD, CTs did not significantly improve Hb levels or ESA resistance. The main sources of variability were participating centres, ESA dose and the underlying disease.

Vascular calcification and QT interval in incident hemodialysis patients.

This study proposes [corrected] to evaluate the impact of different phosphate binders on the slowing of [corrected]cardiovascular calcification [corrected] and QT dispersion in incident haemodialysis patients with a follow-up of [corrected] 36 months. This is to be a [corrected] randomized, multicenter, perspective, [corrected] interventional study. Inclusion criteria are age over 18 years and being an [corrected] incident patient [corrected] on hemodialysis. Exclusion criteria are congenital prolongation of QT segment syndrome, QT-c >440 ms, bradycardia <50 beats per minute, symptomatic [corrected] arrhythmia or any other significant heart problems; electrolyte imbalances [corrected] (especially hypokalemia, hypomagnesemia or [corrected] hypocalcemia); abnormal liver function tests and [corrected] hypothyroidism. An informed consent will be taken at study entry. The patients will be randomized to 2 cohorts: [corrected] 180 patients in the sevelamer [corrected] group and 180 patients in calcium-binder phosphate group. Related vascular calcification mortality is the principal end point [corrected] and will be evaluated at 36 months.