Supplementation of Antioxidants in Chronic Kidney Disease: Clinical Necessity or Wishful Thinking? A Bench to Bedside Translational Research.

Chronic Kidney Disease (CKD) patients are at increased risk for atherosclerosis, cardiovascular disease (CVD) and progression to end stage kidney disease (ESKD). This heavy CVD risk cannot be solely at-tributed to traditional Framingham risk factors. Oxidative stress (OS), defined as the disruption of balance between prooxidants and antioxidants in favor of the former, has emerged as a novel risk factor for CVD and CKD progression. Specifically, lipid peroxidation has been identified as a trigger for endothelial dys-function, the first step towards atherogenesis and protein oxidation has been associated with CKD progres-sion. The oxidation of proteins and lipids starts early in CKD, increases gradually with disease progression and is further exacerbated in ESKD, due to dialysis related factors. In order to counteract the deleterious effects of free radicals and thereby ameliorate, or delay, CV disease and progression of CKD, exogenous administration of antioxidants has been proposed. Here, we attempt to summarize existing data from ex-perimental and clinical studies that test antioxidants for their possible beneficial effects against CVD and CKD progression such as vitamins E and C, statins, omega-3 fatty acids, trace elements, polyphenols and N-acetylcysteine.

The association of home blood pressure with all-cause mortality in hemodialysis patients: A prospective observational study.

INTRODUCTION: Prior observational studies conducted in the hemodialysis population have suggested a reverse association between dialysis-unit blood pressure (BP) and mortality. The present study aimed to investigate the prognostic association of home versus dialysis-unit BP with all-cause mortality in hemodialysis patients. METHODS: At baseline, 146 patients receiving maintenance hemodialysis underwent assessment of their BP with the following methods: (i) 2-week averaged routine predialysis and postdialysis BP measurements; (ii) home BP monitoring for 1 week that included duplicate morning and evening BP measurements with the use of validated devices. RESULTS: Over a median follow-up period of 38 months (interquartile range [IQR]: 22-54), 44 patients (31.1%) died. In Kaplan-Meier curves, predialysis and postdialysis systolic BP (SBP) was not associated with all-cause mortality, while home SBP appeared to be of prognostic significance (log rank p = 0.029). After stratifying patients into quartiles, all-cause mortality was lowest when home SBP was ranging from 128.1 to 136.8 mmHg (quartile 2). In univariate Cox regression analysis, using quartile 2 as a referent category, the risk of all-cause mortality was 3.32-fold higher in quartile 1, 1.53-fold higher in quartile 3 and 3.25-fold higher in quartile 4. The risk-association remained unchanged after adjustment for several confounding factors (adjusted hazard ratio: 4.79, 1.79, 3.63 for quartiles 1, 3, and 4 of home systolic BP, respectively). CONCLUSION: Our findings suggest that among hemodialysis patients, 1-week averaged home SBP is independently associated with all-cause mortality. In sharp contrast, SBP recorded either before or after dialysis over 2 weeks is not prognostically informative.

Resistant Hypertension in Dialysis: Epidemiology, Diagnosis, and Management.

Apparent treatment-resistant hypertension is defined as an elevated BP despite the use of ≥3 antihypertensive medications from different classes or the use of ≥4 antihypertensives regardless of BP levels. Among patients receiving maintenance hemodialysis or peritoneal dialysis, using this definition, the prevalence of apparent treatment-resistant hypertension is estimated to be between 18% and 42%. Owing to the lack of a rigorous assessment of some common causes of pseudoresistance, the burden of true resistant hypertension in the dialysis population remains unknown. What distinguishes apparent treatment-resistance from true resistance is white-coat hypertension and adherence to medications. Accordingly, the diagnostic workup of a dialysis patient with apparent treatment-resistant hypertension on dialysis includes the accurate determination of BP control status with the use of home or ambulatory BP monitoring and exclusion of nonadherence to the prescribed antihypertensive regimen. In a patient on dialysis with inadequately controlled BP, despite adherence to therapy with maximally tolerated doses of a ß -blocker, a long-acting dihydropyridine calcium channel blocker, and a renin-angiotensin system inhibitor, volume-mediated hypertension is the most important treatable cause of resistance. In daily clinical practice, such patients are often managed with intensification of antihypertensive therapy. However, this therapeutic strategy is likely to fail if volume overload is not adequately recognized or treated. Instead of increasing the number of prescribed BP-lowering medications, we recommend diet and dialysate restricted in sodium to facilitate achievement of dry weight. The achievement of dry weight is facilitated by an adequate time on dialysis of at least 4 hours for delivering an adequate dialysis dose. In this article, we review the epidemiology, diagnosis, and management of resistant hypertension among patients on dialysis.

Diuretics or ultrafiltration in the treatment of acute decompensated heart failure: An updated systematic review and meta-analysis.

INTRODUCTION: Hospitalization for decompensated heart failure is a major public health issue. METHODS: We performed a meta-analysis to summarize and analyze if there is a benefit in using ultrafiltration over diuretics in terms of reducing mortality or hospital readmissions, primarily and identified 10 randomized controlled trials (RCTs) including 941 patients. RESULTS: Compared to diuretics, treatment with ultrafiltration was associated with a significant reduction in heart failure hospitalizations (risk ratio [RR]: 0.72; 95% confidence interval [CI]: 0.55-0.96, p = 0.02) and significant increase in weight and net fluid loss (mean difference [MD]: -1.55, CI: -2.36 to -0.74, p = 0.0002) and (MD: -2.10, CI: -3.32 to -0.89, p = 0.0007), respectively. There was no significant difference among treatments regarding the duration of hospitalization, the increase in serum creatinine levels, and mortality. CONCLUSION: Among patients with decompensated heart failure, compared to diuretics, ultrafiltration is associated with reduced rehospitalizations and increased weight/net fluid loss.

Hypertension in chronic kidney disease-treatment standard 2023.

Hypertension is very common and remains often poorly controlled in patients with chronic kidney disease (CKD). Accurate blood pressure (BP) measurement is the essential first step in the diagnosis and management of hypertension. Dietary sodium restriction is often overlooked, but can improve BP control, especially among patients treated with an agent to block the renin-angiotensin system. In the presence of very high albuminuria, international guidelines consistently and strongly recommend the use of an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker as the antihypertensive agent of first choice. Long-acting dihydropyridine calcium channel blockers and diuretics are reasonable second- and third-line therapeutic options. For patients with treatment-resistant hypertension, guidelines recommend the addition of spironolactone to the baseline antihypertensive regimen. However, the associated risk of hyperkalemia restricts the broad utilization of spironolactone in patients with moderate-to-advanced CKD. Evidence from the CLICK (Chlorthalidone in Chronic Kidney Disease) trial indicates that the thiazide-like diuretic chlorthalidone is effective and serves as an alternative therapeutic opportunity for patients with stage 4 CKD and uncontrolled hypertension, including those with treatment-resistant hypertension. Chlorthalidone can also mitigate the risk of hyperkalemia to enable the concomitant use of spironolactone, but this combination requires careful monitoring of BP and kidney function for the prevention of adverse events. Emerging agents, such as the non-steroidal mineralocorticoid receptor antagonist ocedurenone, dual endothelin receptor antagonist aprocitentan and the aldosterone synthase inhibitor baxdrostat offer novel targets and strategies to control BP better. Larger and longer term clinical trials are needed to demonstrate the safety and efficacy of these novel therapies in the future. In this article, we review the current standards of treatment and discuss novel developments in pathophysiology, diagnosis, outcome prediction and management of hypertension in patients with CKD.

Gender-Related Differences in the Levels of Ambulatory BP and Intensity of Antihypertensive Treatment in Patients Undergoing Peritoneal Dialysis.

Prior studies have shown that among patients with chronic kidney disease not yet on dialysis, the faster progression of kidney injury in men than in women is, at least partly, explained by sex differences in ambulatory blood pressure (BP) control. The present study aimed to investigate potential differences in the levels of ambulatory BP and intensity of antihypertensive treatment between men and women with end-stage kidney disease undergoing long-term peritoneal dialysis (PD). In a case-control design, 48 male PD patients were matched for age and heart failure status with 48 female patients in a 1:1 ratio. Ambulatory BP monitoring was performed with an oscillometric device, the Mobil-O-Graph (IEM, Stolberg, Germany). The BP-lowering medications actually taken by the patients were prospectively recorded. No gender-related differences were observed in 24 h systolic BP (129.0 ± 17.9 vs. 128.5 ± 17.6 mmHg, p = 0.890). In contrast, 24 h diastolic BP was higher in men than in women (81.5 ± 12.1 vs. 76.8 ± 10.3 mmHg, p = 0.042). As compared with women, men were being treated with a higher average number of antihypertensive medications daily (2.4 ± 1.1 vs. 1.9 ± 1.1, p = 0.019) and were more commonly receiving calcium-channel-blockers (70.8% vs. 43.8%, p = 0.007) and ß-blockers (85.4% vs. 66.7%, p = 0.031). In conclusion, the present study shows that among PD patients, the levels of ambulatory BP and intensity of antihypertensive treatment are higher in men than in women. Longitudinal studies are needed to explore whether these gender-related differences in the severity of hypertension are associated with worse cardiovascular outcomes for male patients undergoing PD.

Albuminuria and cardiorenal risk.

PURPOSE OF REVIEW: This article explores the prognostic association of albuminuria with the risk of adverse health outcomes and also provides an overview of novel guideline-directed therapies that confer cardiorenal protection in chronic kidney disease (CKD) patients with or without type 2 diabetes. RECENT FINDINGS: Although the identification of CKD is based on the simultaneous assessment of estimated glomerular filtration rate and albuminuria, recent studies have shown that the regular screening rate for an increased urinary albumin-to-creatinine ratio is very low in daily clinical practice. Accordingly, a large proportion of high-risk patients with early-stage CKD remain unidentified, missing the opportunity to receive optimized treatment with novel agents that are effective in causing regression of albuminuria and in improving adverse cardiorenal outcomes. SUMMARY: The broader implementation of albuminuria assessment in daily clinical practice facilitates the identification of high-risk patients with early-stage CKD who are candidates for treatment with sodium-glucose co-transporter type 2 inhibitors, glucagon-like peptide-1 receptor agonists and the nonsteroidal mineralocorticoid receptor antagonist finerenone. These novel drug categories have modified the role of albuminuria from a powerful cardiorenal risk predictor to a modifiable target of therapy.

Therapeutic Advances in Diabetic Kidney Disease.

Although sodium glucose co-transporter type 2 (SGLT-2) inhibitors were initially introduced as glucose-lowering medications, it was later discovered that cardiorenal protection is the most important treatment effect of these agents. A triad of landmark trials consistently showed the benefits of SGLT-2 inhibitors on kidney and cardiovascular outcomes in patients with chronic kidney disease (CKD), irrespective of the presence or absence of Type 2 diabetes (T2D). Furthermore, finerenone is a novel, selective, nonsteroidal mineralocorticoid receptor antagonist (MRA) that safely and effectively improved cardiorenal outcomes in a large Phase 3 clinical trial program that included >13,000 patients with T2D and a wide spectrum of CKD. These two drug categories have shared and distinct mechanisms of action, generating the hypothesis that an overadditive cardiorenal benefit with their combined use may be biologically plausible. In this article, we describe the mechanism of action, and we provide an overview of the evidence for cardiorenal protection with SGLT-2 inhibitors and the nonsteroidal MRA finerenone in patients with CKD associated with T2D.

Effect of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers on cardiovascular outcomes in dialysis patients: a systematic review and meta-analysis.

BACKGROUND: Angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs) are recommended by guidelines as first-line antihypertensive therapies in the general population or in patients with earlier stages of kidney disease. However, the cardioprotective benefit of these agents among patients on dialysis remains uncertain. METHODS: We searched the MEDLINE, PubMed and Cochrane databases from inception through February 2022 to identify randomized controlled trials (RCTs) comparing the efficacy of ACEIs/ARBs relative to placebo or no add-on treatment in patients receiving dialysis. RCTs were eligible if they assessed fatal or non-fatal cardiovascular events as a primary efficacy endpoint. RESULTS: We identified five RCTs involving 1582 dialysis patients. Compared with placebo or no add-on treatment, the use of ACEIs/ARBs was not associated with a significantly lower risk of cardiovascular events {risk ratio [RR] 0.79 [95% confidence interval (CI) 0.57-1.11]}. Furthermore, there was no benefit in cardiovascular mortality [RR 0.82 (95% CI 0.59-1.14)] and all-cause mortality [RR 0.86 (95% CI 0.64-1.15)]. These results were consistent when the included RCTs were stratified by subgroups, including hypertension, ethnicity, sample size, duration of follow-up and quality. CONCLUSION: The present meta-analysis showed that among patients on dialysis, the use of ACEIs/ARBs is not associated with a significantly lower risk of cardiovascular events and all-cause mortality as compared with placebo or no add-on treatment.

The Nonsteroidal Mineralocorticoid-Receptor-Antagonist Finerenone in Cardiorenal Medicine: A State-of-the-Art Review of the Literature.

Steroidal mineralocorticoid-receptor-antagonists (MRAs), such as spironolactone and eplerenone, are guideline-directed therapies in patients with heart failure with reduced ejection fraction or resistant hypertension. However, the associated risk of hyperkalemia and hormonal side effects limit their broad use and downstream cardiorenal protection in high-risk patients with type 2 diabetes mellitus (T2DM) and moderate-to-advanced chronic kidney disease (CKD). The critical unmet need to improve long-term cardiorenal outcomes in such patients with CKD has sparked considerable efforts to the discovery and development of a new class of compounds. Finerenone is a novel, nonsteroidal MRA that has recently received regulatory approval with the indication of cardiorenal protection in patients with CKD associated with T2DM. Two landmark phase 3 clinical trials, FIDELIO-DKD and FIGARO-DKD, demonstrated that among patients with T2DM and a broad spectrum of CKD, finerenone reduced the risk of "hard" cardiovascular and kidney failure outcomes as compared with placebo, with a minimal risk of hyperkalemia. Subgroup analyses of these trials also provided preliminary evidence that the efficacy and safety profile of finerenone was similar and irrespective of background therapy with other guideline-directed therapies, such as sodium-glucose co-transporter type 2 (SGLT-2) inhibitors and glucagone-like peptide 1 receptor agonists. Whether the combination of finerenone with a SGLT-2 inhibitor is more beneficial in patients with T2DM and CKD as compared with either therapy alone is a crucial research question that is currently under investigation in an ongoing clinical trial.

Hypertension in Dialysis Patients: Diagnostic Approaches and Evaluation of Epidemiology.

Whereas hypertension is an established cardiovascular risk factor in the general population, the contribution of increased blood pressure (BP) to the huge burden of cardiovascular morbidity and mortality in patients receiving dialysis continues to be debated. In a large part, this controversy is attributable to particular difficulties in the accurate diagnosis of hypertension. The reverse epidemiology of hypertension in dialysis patients is based on evidence from large cohort studies showing that routine predialysis or postdialysis BP measurements exhibit a U-shaped or J-shaped association with cardiovascular or all-cause mortality. However, substantial evidence supports the notion that home or ambulatory BP measurements are superior to dialysis-unit BP recordings in diagnosing hypertension, in detecting evidence of target-organ damage and in prognosticating the all-cause death risk. In the first part of this article, we explore the accuracy of different methods of BP measurement in diagnosing hypertension among patients on dialysis. In the second part, we describe how the epidemiology of hypertension is modified when the assessment of BP is based on dialysis-unit versus home or ambulatory recordings.