Mechanisms of the cardiorenal syndromes

Cardiorenal syndrome: evolving concepts and pediatric knowledge gaps

Cardiorenal syndrome (CRS) refers to concomitant dysfunction of both the heart and kidneys. The pathology in CRS is bidirectional. Many individuals with kidney disease will develop cardiovascular complications. Conversely, rates of acute kidney injury and chronic kidney disease are high in cardiac patients. While our understanding of CRS has greatly increased over the past 15 years, most research has occurred in adult populations. Improving cardiorenal outcomes in children and adolescents requires increased collaboration and research that spans organ systems. The purpose of this review is to discuss key features of CRS and help bring to light future opportunities for pediatric-specific research.

Renal ultrasonography predicts worsening renal function in patients with heart failure under tolvaptan administration

AIMS

Renal dysfunction in patients with chronic heart failure predicts a poor prognosis. Tolvaptan has a diuretic effect in patients with chronic kidney disease and heart failure without adverse effects on renal function. We aimed to determine the effects of tolvaptan and predictors of worsening renal function in patients with heart failure.

METHODS AND RESULTS

This post hoc analysis was a sub-analysis of a single-centre prospectively randomized trial on the early and short-term tolvaptan administration. We enrolled 201 participants with decompensated heart failure between January 2014 and March 2019 (early group, n = 104; age: 79.0 ± 12.8 years; late group, n = 97; age: 80.3 ± 10.8 years). Renal ultrasonography was performed before and after the administration of tolvaptan. Urine output and oral water intake significantly increased during tolvaptan administration. The difference between water intake and urine volume increased during tolvaptan administration. Changes in body weight, blood pressure, heart rate, and estimated glomerular filtration rate (eGFR) in both groups were comparable. The changes in peak-systolic velocity (PSV), acceleration time (AT) of the renal arteries, and resistance index were comparable. The changes in PSV and end-diastolic velocity (EDV) of the interlobar arteries increased following tolvaptan administration (Δmax PSV: 0.0 ± 14.8 cm/s before tolvaptan vs. 5.6 ± 15.7 cm/s after tolvaptan, P = 0.002; Δmean PSV: 0.4 ± 12.3 vs. 4.9 ± 12.7 cm/s, P = 0.002; Δmax EDV: -0.2 ± 3.5 vs. 1.4 ± 4.0 cm/s, P = 0.001; Δmean EDV: -0.0 ± 3.1 vs. 1.1 ± 3.4 cm/s, P = 0.003). The renal artery AT was negatively correlated with the eGFR (Δmax AT: beta = -0.2354, P = 0.044; Δmean AT: beta = -0.2477, P = 0.035).

CONCLUSIONS

Tolvaptan increased the PSV and EDV of the interlobar artery, which may mean tolvaptan increased renal blood flow. The renal artery AT may be a surrogate for worsening renal function.

The Combined Effects of the Most Important Dietary Patterns on the Incidence and Prevalence of Chronic Renal Failure: Results from the US National Health and Nutrition Examination Survey and Mendelian Analyses

BACKGROUND

We aimed to comprehensively assess the relationship of specific dietary patterns and various nutrients with chronic kidney disease (CKD) and its progression.

METHODS

The observational study data were from the NHANES 2005-2020. We calculated four dietary pattern scores (healthy eating index 2020 (HEI-2020), dietary inflammatory index (DII), alternative mediterranean diet (aMed), and dietary approaches to stop hypertension (DASH)) and the intakes of various nutrients and defined CKD, CKD-very high risk, and kidney dialysis. Associations between dietary patterns and nutrients and disease were assessed by means of two logistic regression models. Two-sample MR was performed with various food and nutrients as the exposure and CKD, kidney dialysis as the outcome. Sensitivity analyses were conducted to verify the reliability of the results.

RESULTS

A total of 25,167 participants were included in the analyses, of whom 4161 had CKD. HEI-2020, aMed, and DASH were significantly negatively associated with CKD and CKD-very high risk at higher quartiles, while DII was significantly positively associated. A higher intake of vitamins and minerals may reduce the incidence and progression of CKD to varying degrees. The MR results, corrected for false discovery rates, showed that a higher sodium intake was associated with a higher prevalence of CKD (OR: 3.91, 95%CI: 2.55, 5.99).

CONCLUSIONS

Adhering to the three dietary patterns of HEI-2020, aMed, and DASH and supplementing with vitamins and minerals benefits kidney health.

Systematic Review of Cardiovascular Benefits and Safety of Sacubitril-Valsartan in End-Stage Kidney Disease

Introduction

Patients with end-stage kidney disease (ESKD) frequently develop heart failure, contributing to high mortality. Limited data exist on cardiovascular benefits and safety of sacubitril-valsartan in this population. Our systematic review aims to evaluate the efficacy and safety of sacubitril-valsartan versus standard care in patients with ESKD who are on dialysis.

Methods

We conducted a search in Embase, MEDLINE, and Cochrane databases to identify relevant studies and assessed outcomes using random-effect model and generic inverse variance approach.

Results

Analysis of 12 studies involving 799 eligible patients with ESKD revealed improvement in left ventricular ejection fraction (LVEF) with sacubitril-valsartan compared to a control group with pooled mean difference (MD) 6.58% (95% confidence interval [CI]: 1.86, 11.29). LVEF significantly improved in patients with LVEF <50% (heart failure with reduced ejection fraction [HFrEF] and heart failure with moderately reduced ejection fraction [HFmrEF]) with MD 12.42% (95% CI: 9.39, 15.45). However, patients with LVEF >50% (heart failure with preserved ejection fraction [HFpEF]) did not exhibit statistically significant effect, MD 2.6% (95% CI: 1.15, 6.35). Sacubitril-valsartan significantly enhanced LVEF in patients with HFrEF, with MD 13.8% (95% CI: 12.04, 15.82). Safety analysis indicated no differences in incidence of hyperkalemia (pooled odds ratio [OR] 0.72; 95% CI: 0.38, 1.36) or hypotension (pooled risk ratio [RR] 1.03; 95% CI: 0.36, 2.98). No cases of angioedema were reported. However, safety analysis relies on evidence of limited robustness due to the observational nature of the studies.

Conclusion

Our systematic review suggests that sacubitril-valsartan benefits patients with ESKD with HFrEF and HFmrEF by improving LVEF without increasing the risk of hyperkalemia, hypotension, or angioedema compared to standard care. However, safety analysis based on observational studies inherently has limitations for establishing causal relationships.

Kidney disease and thyroid dysfunction: the chicken or egg problem

Patients with non-dialysis-dependant chronic kidney disease (NDD-CKD) and dialysis-dependant chronic kidney disease (DD-CKD) frequently also suffer from thyroid disorders, especially hypothyroidism which is found two to five times more often among them compared to the general population. Emerging research has illustrated the potential prognostic implications of this association as NDD-CKD and DD-CKD patients with hypothyroidism have been shown to have higher mortality rates, and treatment of subclinical hypothyroidism in NDD-CKD patients has been reported to attenuate the decline of glomerular filtration rate over time. This review illustrates the bidirectional, multi-layered interplay between the kidneys and the thyroid gland explaining how pathologies in one organ will affect the other and vice versa. Additionally, it outlines the impact of thyroid disorders on routine parameters of kidney function (especially serum creatinine and serum cystatin C) that nephrologists should be aware of in their clinical practice. Lastly, it summarizes the emerging evidence from clinical studies on how treatment of subclinical hypothyroidism in NDD-CKD and DD-CKD patients may potentially have beneficial effects on kidney function as well as mortality. While most of the research in this area has been performed on adult patients, we specifically discuss what is currently known about thyroid dysfunctions in paediatric CKD patients as well and provide management suggestions. The evidence accumulated so far clearly indicates that further, prospective studies with meticulous methodology are warranted to refine our understanding of thyroid disorders in paediatric and adult CKD patients and establish optimal treatment pathways.

Dietary choline, via gut microbe- generated trimethylamine-N- oxide, aggravates chronic kidney disease-induced cardiac dysfunction by inhibiting hypoxia-induced factor 1α

Chronic kidney disease (CKD) is a global public health problem that shortens lifespan primarily by increasing the risk of cardiovascular diseases. Trimethylamine-N-oxide (TMAO), a gut microbiota-derived toxin produced by metabolizing high-choline or carnitine foods, is associated with cardiovascular events in patients with CKD. Although the deleterious effect of TMAO on CKD-induced cardiac injury has been confirmed by various researches, the mechanisms remain unclear. Here, we tested the hypothesis that TMAO aggravates CKD-induced cardiac injury and explores the potential mechanism. CD1 mice underwent 5/6 nephrectomy to induce CKD, and then fed with a diet supplemented with choline (1.2% total) for 8 weeks. Serum TMAO levels were elevated in CKD mice compared with SHAM group, and higher TMAO levels were found in choline-supplemented CKD mice compared with CKD group. Dietary choline aggravated CKD-induced cardiac dysfunction, and reducing TMAO levels via medicinal charcoal tablets improved cardiac dysfunction. RNA-seq analysis revealed that dietary choline affected cardiac angiogenesis in CKD mice. Reduced cardiac capillary density and expressions of angiogenesis-related genes were observed in choline-treated CKD mice. Furthermore, dietary choline inhibited cardiac Hif-1α protein level in CKD mice, and Hif-1α stabilizer FG-4592 could improve cardiac angiogenesis and dysfunction in CKD mice on a high-choline diet. In conclusion, these data indicate that dietary choline, via gut microbe-generated TMAO, inhibits cardiac angiogenesis by reducing Hif-1α protein level, ultimately aggravates cardiac dysfunction in CKD mice.

Insights of Worsening Renal Function in Type 1 Cardiorenal Syndrome: From the Pathogenesis, Biomarkers to Treatment

Type-1 cardiorenal syndrome refers to acute kidney injury induced by acute worsening cardiac function. Worsening renal function is a strong and independent predictive factor for poor prognosis. Currently, several problems of the type-1 cardiorenal syndrome have not been fully elucidated. The pathogenesis mechanism of renal dysfunction is unclear. Besides, the diagnostic efficiency, sensitivity, and specificity of the existing biomarkers are doubtful. Furthermore, the renal safety of the therapeutic strategies for acute heart failure (AHF) is still ambiguous. Based on these issues, we systematically summarized and depicted the research actualities and predicaments of the pathogenesis, diagnostic markers, and therapeutic strategies of worsening renal function in type-1 cardiorenal syndrome.

Estimated Glomerular Filtration Rate Is Associated With an Increased Risk of Death in Heart Failure Patients With Preserved Ejection Fraction

Background: Renal dysfunction is associated with adverse cardiovascular outcomes in patients with heart failure (HF), but its impact on patients with heart failure with preserved ejection fraction (HFpEF) remains unclear.

Methods: 3,392 subjects of the TOPCAT (Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist) trial were assigned to two groups by estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m² or 30–59 ml/min/1.73 m². The outcomes, including all-cause death, cardiovascular death and HF hospitalization, were examined by multivariable cox models.

Results: Over a median follow-up of 3.4 ± 1.7 years, a total of 524 all-cause deaths, 334 cardiovascular deaths and 440 HF hospitalizations occurred. Compared with patients with eGFR ≥ 60 ml/min/1.73 m², those with eGFR 30–59 ml/min/1.73 m² were associated with an increased risk of the all-cause death [adjusted hazard ratio (HR), 1.47; 95% confidence interval (CI), 1.24–1.76; P < 0.001], cardiovascular death (adjusted HR, 1.53; 95% CI: 1.23–1.91; p < 0.001), and HF hospitalization (adjusted HR: 1.21; 95% CI: 1.00–1.47; p = 0.049) after multivariable adjustment for potential confounders.

Conclusions: eGFR 30–59 ml/min/1.73 m² was related to an increased risk of all-cause death, cardiovascular death and HF hospitalization in HFpEF patients.

Activation of hypoxia-sensing pathways promotes renal ischemic preconditioning following myocardial infarction

Ischemic heart disease is the leading cause of death worldwide and is frequently comorbid with chronic kidney disease. Physiological communication is known to occur between the heart and the kidney. Although primary dysfunction in either organ can induce dysfunction in the other, a clinical entity known as cardiorenal syndrome, mechanistic details are lacking. Here, we used a model of experimental myocardial infarction (MI) to test effects of chronic cardiac ischemia on acute and chronic kidney injury. Surprisingly, chronic cardiac damage protected animals from subsequent acute ischemic renal injury, an effect that was accompanied by evidence of chronic kidney hypoxia. The protection observed post-MI was similar to protection observed in a separate group of healthy animals housed in ambient hypoxic conditions prior to kidney injury, suggesting a common mechanism. There was evidence that chronic cardiac injury activates renal hypoxia-sensing pathways. Increased renal abundance of several glycolytic enzymes following MI suggested that a shift toward glycolysis may confer renal ischemic preconditioning. In contrast, effects on chronic renal injury followed a different pattern, with post-MI animals displaying worsened chronic renal injury and fibrosis. These data show that although chronic cardiac injury following MI protected against acute kidney injury via activation of hypoxia-sensing pathways, it worsened chronic kidney injury. The results further our understanding of cardiorenal signaling mechanisms and have implications for the treatment of heart failure patients with associated renal disease.NEW & NOTEWORTHY Experimental myocardial infarction (MI) protects from subsequent ischemic acute kidney injury but worsens chronic kidney injury. Observed protection from ischemic acute kidney injury after MI was accompanied by chronic kidney hypoxia and increased renal abundance of hypoxia-inducible transcripts. These data support the idea that MI confers protection from renal ischemic injury via chronic renal hypoxia and activation of downstream hypoxia-inducible signaling pathways.

Clinical Impact of Worsening Renal Function in Elderly Patients with Acute Decompensated Heart Failure

Background and Objectives

The clinical significance of worsening renal function (WRF) in elderly patients with acute decompensated heart failure (ADHF) is not completely understood. We compared the clinical conditions between younger and elderly patients with ADHF after the appearance of WRF to establish its prognostic influence.

Methods

We included 654 consecutive patients (37% women) admitted for ADHF. We divided the patients into four groups according to their age (<80 years, under-80, n=331; ≥80 years, over-80, n=323) and to their WRF statuses (either WRF or non-WRF group). We defined WRF as an increase in serum creatinine level ≥0.3 mg/dL or ≥150% within 48 hours after hospital arrival (under-80, n=62; over-80, n=75). The primary endpoint was a composite of cardiac events within 1 year.

Results

The survival analyses revealed that the WRF group had significantly more cardiac events than the non-WRF group in patients in the over-80 group (log-rank p=0.025), but not in those of the under-80 group (log-rank p=0.50). The patients in the over-80, WRF group presented more significant mean blood pressure (MBP) drops than those in the over-80 non-WRF group (p=0.003). Logistic regression analyses revealed that higher MBP at admission was a significant predictor of WRF.

Conclusions

WRF is a predictor of poor outcomes in elderly patients with ADHF.

Dietary Potassium Intake and Risk of Chronic Kidney Disease Progression in Predialysis Patients with Chronic Kidney Disease: A Systematic Review

The prevalence of chronic kidney disease (CKD) is increasing and dietary interventions may be a strategy to reduce this burden. In the general population, higher potassium intake is considered protective for cardiovascular health. Due to the risk of hyperkalemia in CKD, limiting potassium intake is often recommended. However, given that poor cardiovascular function can cause kidney damage, following a low-potassium diet may be deleterious for patients with CKD. The aim of this systematic review was to summarize the evidence on dietary potassium intake and CKD progression. Multiple databases were searched on 7 June 2019 and data were managed with Covidence. No intervention trials met the inclusion criteria. Eleven observational studies met the inclusion criteria (10 post hoc analyses, 1 retrospective cohort), representing 49,573 stage 1-5 predialysis patients with CKD from 41 different countries. Of the 11 studies, 6 studies reported exclusively on early CKD (stage 1-2), 4 studies separately reported analyses on both early and late (stage 3-5) CKD, and 2 studies reported exclusively on late CKD. A total of 9 studies reported risk of disease progression in early CKD; in 4 studies high potassium intake was associated with lower risk, while in 2 studies the low intake showed a higher progression of risk, and 3 studies reported no relation. In late CKD, results are mixed: 2 studies suggested benefit of higher potassium intake and 1 suggested benefit of lower potassium intake, whereas 3 studies were neutral. These results should be interpreted with caution, as considerations preventing firm conclusions include 1) the overall low range of dietary potassium intake, with all studies reporting an average intake below the 2004 Kidney Disease Outcomes Quality Initiatives guidelines, and 2) the method used to assess potassium intake in most studies (i.e., urine) in late stages of CKD. Ideally, well-controlled intervention studies are needed to understand how dietary potassium intake is linked to CKD progression.

Successful Kidney Transplantation Alone With Severe Left Ventricular Systolic Dysfunction of Ejection Fraction 14%: A Case Report

It is well known that correction of uremia by kidney transplantation alone (KTA) improves left ventricular systolic dysfunction (LVSD). However, for kidney transplant candidates with extremely severe LVSD, KTA is considered to be contraindicated because of the high risk of peri-operative management. We report a case of successful kidney transplantation with severe LVSD with an ejection fraction (EF) of 14% and low systolic blood pressure (SBP) of approximately 65 to 80 mm Hg. In this case, in spite of an extremely low EF and SBP, functional capacity was assessed using metabolic equivalents (METs) and showed a level of almost 4. The operation was performed carefully, considering the cardiac, operative, and anesthetic risks. No surgical complications occurred, and the patient received intensive care during the peri-operative period. His postoperative course was almost favorable, and he was discharged on postoperative day 29. The present report concludes that evaluation of METs may expand the indication for KTA in patients with extremely severe LVSD.

Benefits of peritoneal ultrafiltration in HFpEF and HFrEF patients

Background

Peritoneal ultrafiltration (pUF) in refractory heart failure (HF) reduces the incidence of decompensation episodes, which is of particular significance as each episode incrementally adds to mortality. Nevertheless, there are insufficient data about which patient cohort benefits the most. The objective of this study was to compare pUF in HFrEF and HFpEF, focusing on functional status, hospitalizations, surrogate endpoints and mortality.

Methods

This study involves 143 patients, who could be classified as either HFpEF (n = 37, 25.9%) or HFrEF (n = 106, 74.1%) and who received pUF due to refractory HF.

Results

Baseline eGFR was similar in HFrEF (23.1 ± 10.6 mg/dl) and HFpEF (27.8 ± 13.2 mg/dl). Significant improvements in NYHA class were found in HFpEF (3.19 ± 0.61 to 2.72 ± 0.58, P <  0.001) and HFrEF (3.45 ± 0.52 to 2.71 ± 0.72, P <  0.001). CRP decreased in HFrEF (19.4 ± 17.6 mg/l to 13.7 ± 21.4 mg/l, P = 0.018) and HFpEF (33.7 ± 52.6 mg/l to 17.1 ± 26.3 mg/l, P = 0.004). Body weight was significantly reduced in HFrEF (81.1 ± 14.6 kg to 77.2 ± 15.6 kg, P = 0.003) and HFpEF (86.9 ± 15.8 kg to 83.1 ± 15.9 kg, P = 0.005). LVEF improved only in HFrEF (25.9 ± 6.82% to 30.4 ± 12.2%, P = 0.046). BCR decreased significantly in HFrEF and HFpEF (55.7 ± 21.9 to 34.3 ± 17.9 P > 0.001 and 50.5 ± 68.9 to 37.6 ± 21.9, P = 0.006). Number of hospitalization episodes as well as number of hospitalization days decreased significantly only in HFpEF (total number 2.88 ± 1.62 to 1.25 ± 1.45, P <  0.001, days 40.4 ± 31.7 to 18.3 ± 22.5 days, P = 0.005).

Conclusions

pUF offers various benefits in HFpEF and HFrEF, but there are also substantial differences. In particular, hospitalization rates were found to be significantly reduced in HFpEF patients, indicating a greater medical and economical advantage. However, LVEF was only found to be improved in HFrEF patients. While pUF can now be regarded as an option to supplement classical HF therapy, further studies are desirable to obtain specifications about pUF in HFpEF, HFmEF and HFrEF patients.

Specific impact of past and new major cardiovascular events on acute kidney injury and end-stage renal disease risks in diabetes: a dynamic view

BACKGROUND

Interconnections between major cardiovascular events (MCVEs) and renal events are recognized in diabetes, however, the specific impact of atrial fibrillation (AF), heart failure (HF) and acute coronary syndrome (ACS) on the risk of end-stage renal disease (ESRD) on top of established renal risk factors is unclear in type 2 diabetes mellitus.

METHODS

We conducted a retrospective study in 861 consecutive patients followed in a nephrology setting during the 2000-13 period.

RESULTS

The mean age was 70 ± 10 years, 65.1% were men and the estimated glomerular filtration rate (eGFR) was 42.4 ± 21.0 mL/min/1.73 m2. During follow-up (median 59 months), 194 patients reached ESRD. A history of AF, HF or ACS was associated with an increased risk of reduced baseline eGFR. In turn, reduced baseline eGFR resulted in a greater risk of new MCVE (especially HF) during follow-up. Finally, all new MCVEs were risk factors for subsequent acute kidney injury (AKI) {HF: hazard ratio [HR] 8.99 [95% confidence interval (CI) 7.06-11.4]; AF: HR 5.42 (3.91-7.52); ACS: HR 8.82 (6.24-12.5); all P < 0.0001} and ESRD [HF: HR 5.52 (95% CI 4.01-7.60), P < 0.0001; AF: HR 3.48 (2.30-5.21), P < 0.0001; ACS: HR 2.31 (1.43-3.73), P = 0.0006]. The AF- and HF-associated risks of ESRD were significant after adjustments on all renal risks of ESRD (gender, blood pressure, eGFR, albuminuria, renin-angiotensin blockers, retinopathy and AKI), but the association was less strong for ACS. Importantly, no association was noted between other major events such as stroke or infections and the risk of ESRD.

CONCLUSIONS

Past and new cardiovascular events (more HF and AF than ACS) have a strong, independent impact on the development of ESRD above and beyond established risk factors in diabetes.

Importance of sodium-glucose cotransporter 2 inhibitor use in diabetic patients with acute heart failure

BACKGROUND

It is known that once heart failure occurs in older patients with diabetes, the overall prognosis is extremely poor. We investigated whether early initiation of SGLT2 inhibitor therapy after admission was beneficial for diabetic patients requiring inpatient treatment for acute heart failure.

METHODS

We retrospectively assessed consecutive patients with comorbid diabetes who were admitted to the Department of Cardiology in Tosei General Hospital for treatment of acute heart failure. Patients were divided into two groups: those who initiated SGLT2 inhibitor therapy (SGLT2 inhibitor group; mean age: 73 ± 9 years) and those who did not receive the inhibitors during hospitalization (conventional treatment group; mean age: 75 ± 10 years).

RESULTS

No intergroup differences were observed in the distribution of either the severity or classes of heart failure on admission. Glycosylated hemoglobin levels were significantly higher in the SGLT2 inhibitor group (HbA1c: 8.1% ± 0.8%) than in the conventional treatment group (HbA1c: 7.1% ± 0.8%) (p = 0.003). After admission, patients in both groups recovered equally well, and in almost the same period of time, before discharge. The rate of diuretics use at the time of discharge in the SGLT2 inhibitor group (n = 8, 67%) was significantly lower than that in the conventional treatment group (n = 19, 100%) (p = 0.016). In particular, the dose of loop diuretics in the conventional treatment group was 34 ± 4 mg/day while that in the SGLT2 inhibitor group was significantly lower at 13 ± 5 mg/day (p = 0.008). During hospitalization, the incidence of acute kidney injury was significantly higher in the conventional treatment group (n = 11, 58%) than in the SGLT2 inhibitor group (n = 2, 16%) (p = 0.031).

CONCLUSIONS

For the treatment and management of heart failure in patients with diabetes, early initiation of SGLT2 inhibitor therapy appears to be effective.

Preeclampsia: a gestational cardiorenal syndrome

It is generally accepted today that there are two different types of preeclampsia: an early-onset or placental type and a late-onset or maternal type. In the latent phase, the first one presents with a low output/high resistance circulation eventually leading in the late second or early third trimester to an intense and acutely aggravating systemic disorder with an important impact on maternal and neonatal mortality and morbidity; the other type presents initially as a high volume/low resistance circulation, gradually evolving to a state of circulatory decompensation usually in the later stages of pregnancy, with a less severe impact on maternal and neonatal outcome. For both processes, numerous dysfunctions of the heart, kidneys, arteries, veins and interconnecting systems are reported, most of them presenting earlier and more severely in early- than in late-onset preeclampsia; however, some very specific dysfunctions exist for either type. Experimental, clinical and epidemiological observations before, during and after pregnancy are consistent with gestation-induced worsening of subclinical pre-existing chronic cardiovascular dysfunction in early-onset preeclampsia, and thus sharing the pathophysiology of cardiorenal syndrome type II, and with acute volume overload decompensation of the maternal circulation in late-onset preeclampsia, thus sharing the pathophysiology of cardiorenal syndrome type 1. Cardiorenal syndrome type V is consistent with the process of preeclampsia superimposed upon clinical cardiovascular and/or renal disease, alone or as part of a systemic disorder. This review focuses on the specific differences in haemodynamic dysfunctions between the two types of preeclampsia, with special emphasis on the interorgan interactions between heart and kidneys, introducing the theoretical concept that the pathophysiological processes of preeclampsia can be regarded as the gestational manifestations of cardiorenal syndromes.

Plasma fatty acid-binding protein 4 (FABP4) level is associated with abnormal QTc interval in patients with stable angina and chronic kidney disease

BACKGROUND

Fatty acid-binding protein 4 (FABP4) (also known as adipocyte FABP or adipocyte P2) is expressed in adipocytes, macrophages, and capillary endothelial cells. Previous studies have shown associations among plasma FABP4, insulin resistance, metabolic syndrome, diabetes mellitus, greater coronary plaque burden, coronary artery disease, heart failure, and mortality. However, little is known about the relationship between FABP4 level and prolonged QT interval. The aim of this study was to investigate whether plasma FABP4 level is associated with a prolonged QT interval by analyzing 12-lead electrocardiograms (ECGs) in patients with stable angina and chronic kidney disease (CKD).

METHODS

This study included 397 consecutive patients with stable angina and CKD who were enrolled in a disease management program. Plasma FABP4 concentrations were measured using enzyme-linked immunosorbent assays. A 12-lead ECG recording was obtained from each patient. We assessed the relationships between FABP4 levels (both as a continuous variable and stratified by tertile) at admission and corrected QT (QTc) prolongation.

RESULTS

Patients with an abnormal QTc interval had higher median plasma FABP4 levels than those with borderline and normal QTc intervals (15.9 ng/mL vs. 10.2 ng/mL vs. 8.5 ng/mL, respectively, P < 0.0001). Statistically significant associations were observed between plasma FABP4 levels and QTc interval (β = 0.267, P < 0.0001). Using multivariate and trend analyses, a higher concentration of plasma FABP4 level was independently associated with QTc prolongation in patients with stable angina and CKD.

CONCLUSION

In this study, plasma FABP4 levels were significantly higher in the patients with an abnormal QTc interval and were correlated with QTc prolongation. Further studies are required to elucidate whether plasma FABP4 plays a role in the pathogenesis of QTc prolongation.

Heart-kidney interactions: mechanistic insights from animal models

Pathological changes in the heart or kidney can instigate the release of a cascade of cardiorenal mediators that promote injury in the other organ. Combined dysfunction of heart and kidney is referred to as cardiorenal syndrome (CRS) and has gained considerable attention. CRS has been classified into five distinct entities, each with different major pathophysiological changes. Despite the magnitude of the public health problem of CRS, the underlying mechanisms are incompletely understood, and effective intervention is unavailable. Animal models have allowed us to discover pathogenic molecular changes to clarify the pathophysiological mechanisms responsible for heart-kidney interactions and to enable more accurate risk stratification and effective intervention. Here, this article focuses on the use of currently available animal models to elucidate mechanistic insights in the clinical cardiorenal phenotype arising from primary cardiac injury, primary renal disease with special emphasis of chronic kidney disease-specific risk factors, and simultaneous cardiorenal/renocardiac dysfunction. The development of novel animal models that recapitulate more closely the cardiorenal phenotype in a clinical scenario and discover the molecular basis of this condition will be of great benefit.

Peritoneal dialysis as therapeutic option in heart failure patients

Aims

Each episode of acute decompensated heart failure (HF) incrementally adds to mortality. Peritoneal dialysis (PD) offers an alternative therapeutic option in refractory HF and reduces the incidence of decompensation episodes. The objective of this study was to determine the efficacy of PD, in terms of functional status, surrogate endpoints, rate of hospitalizations, and mortality.

Methods and results

This study is based on the registry of the German Society of Nephrology, involving 159 patients receiving PD treatment due to refractory HF between January 2010 and December 2014. Body weight was reduced by PD (82.2 ± 14.9 to 78.4 ± 14.8 kg, P < 0.001), and significant improvements in New York Heart Association functional class (3.38 ± 0.55 to 2.85 ± 0.49, P < 0.001) were found already after 3 months. Left ventricular ejection fraction did not change (31.5 ± 13.8 to 34.0 ± 15.7%, P = 0.175). C‐reactive protein improved with PD treatment (33.7 ± 52.6 to 17.1 ± 26.3 mg/L, P = 0.004). Blood urea nitrogen/creatinine ratio decreased significantly (148.7 ± 68.3 to 106.7 ± 44.8 mg/dL, P < 0.001). Hospitalization rates decreased significantly (total number 2.86 ± 1.88 to 1.90 ± 1.78, P = 0.001, and 39.2 ± 30.7 to 27.1 ± 25.2 days, P = 0.004). One year mortality was 39.6% in end‐stage HF patients treated with PD.

Conclusions

Peritoneal dialysis offers an additional therapeutic option in end‐stage HF and is associated with improved New York Heart Association classification and reduced hospitalization. Although PD treatment was associated with various benefits, further studies are necessary to identify which patients benefit the most from PD.

International Continence Society consensus on the diagnosis and treatment of nocturia

INTRODUCTION

Patients with nocturia have to face many hurdles before being diagnosed and treated properly. The aim of this paper is to: summarize the nocturia patient pathway, explore how nocturia is diagnosed and treated in the real world and use the Delphi method to develop a practical algorithm with a focus on what steps need to be taken before prescribing desmopressin.

METHODS

Evidence comes from existing guidelines (Google, PubMed), International Consultation on Incontinence-Research Society (ICI-RS) 2017, prescribing information and a Delphi panel (3 rounds). The International Continence Society initiated this study, the authors represent the ICI-RS, European Association of Urology, and Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction (SUFU).

RESULTS

Diagnostic packages: consensus on, history taking for all causalities, intake diary (fluid, food) and bladder diary, not for its duration. Pelvic (women) or rectal (men) examination, prostate-specific antigen, serum sodium check (SSC), renal function, endocrine screening: when judged necessary. Timing or empty stomach when SSC is not important. Therapeutic packages: the safe candidates for desmopressin can be phenotyped as no polydipsia, heart/kidney failure, severe leg edema or obstructive sleep apnea syndrome. Lifestyle interventions may be useful. Initiating desmopressin: risk management consensus on three clinical pictures. Follow-up of desmopressin therapy: there was consensus on SSC day 3 to 7, and at 1 month. Stop therapy if SSC is <130 mmol/L regardless of symptoms. Stop if SSC is 130 to 135 mmol/L with symptoms of hyponatremia.

CONCLUSION

A summary of the nocturia patient pathway across different medical specialists is useful in the visualization and phenotyping of patients for diagnosis and therapy. By summarizing basic knowledge of desmopressin, we aim to ease its initiation and shorten the patient journey for nocturia.

Serum albumin level and abnormal corrected QT interval in patients with coronary artery disease and chronic kidney disease

BACKGROUND

Lower concentrations of serum albumin appear to be associated with an increased risk of all-cause and cardiovascular mortality, coronary heart disease, heart failure and stroke. However, little is known about the relationship between serum albumin level and prolonged QT interval.

AIM

To investigate whether lower serum albumin is associated with prolonged QT interval by recording 12-lead electrocardiography in patients with coronary artery disease and chronic kidney disease.

METHODS

This study included 1383 consecutive patients with coronary artery disease and chronic kidney disease (841 with acute coronary syndrome and 542 with elective percutaneous coronary intervention patients) who were enrolled in a disease management programme. Twelve-lead electrocardiography was recorded in each subject. We assessed the relationship between albumin levels (both as a continuous variable and stratified by tertile) at admission and corrected QT (QTc) prolongation.

RESULTS

Patients with abnormal QTc interval had lower serum albumin levels than those with normal and borderline QTc intervals. Statistically significant negative associations were observed between serum albumin levels and QTc interval (β = -0.211, P < 0.0001). Using multivariate and trend analyses, a lower concentration of serum albumin was independently associated with QTc prolongation in both the patients with acute coronary syndrome and elective percutaneous coronary intervention patients.

CONCLUSION

Concentrations of serum albumin were significantly lower in the patients with an abnormal QTc interval and were associated with QTc prolongation. Further studies are needed to clarify whether lower serum albumin plays a role in the pathogenesis of QTc prolongation.

Presence of Kidney Disease as an Outcome Predictor in Patients with Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) may lead to right heart failure and subsequently alter glomerular filtration rates (GFR). Chronic kidney disease (CKD, GFR <60 mL/min/1.73 m2) may also adversely affect PAH prognosis. This study aimed to assess how right heart hemodynamics was associated with reduced estimated GFR (eGFR) and the association of CKD with survival in PAH patients.

METHODS

In a prospective PAH cohort (2003-2012), invasive hemodynamics and eGFR were collected at diagnosis (179 patients) and during follow-up (159 patients). The prevalence of CKD was assessed at PAH diagnosis. Variables, including hemodynamics, associated with reduced eGFR at diagnosis and during follow-up were tested in multivariate analysis. The association of CKD with survival was evaluated using a multivariate Cox regression model.

RESULTS

At diagnosis, mean age was 60.4 ± 16.5 years, mean pulmonary arterial pressure was 43 ± 12 mm Hg, and eGFR was 74.4 ± 26.4 mL/min/1.73 m2. CKD was observed in 52 incident patients (29%). Independent determinants of reduced eGFR at diagnosis were age, systemic hypertension, and decreased cardiac index. Independent determinants of reduced eGFR during follow-up were age, female gender, PAH etiology, systemic hypertension, decreased cardiac index, and increased right atrial pressure. Age ≥60 years, female gender, NYHA 4, and CKD at diagnosis were independently associated with decreased survival. The adjusted hazards ratio for death associated with CKD was 1.81 (95% confidence interval [1.01-3.25]).

CONCLUSION

CKD is frequent at PAH diagnosis and is independently associated with increased mortality. Right heart failure may induce renal hypoperfusion and congestion, and is associated with eGFR decrease.

Acute Kidney Injury in Pediatric Heart Failure

Acute kidney injury (AKI) is very common in pediatric medical and surgical cardiac patients. Not only is it an independent risk factor for increased morbidity and mortality in the short run, but repeated episodes of AKI lead to chronic kidney disease (CKD) especially in the most vulnerable hosts with multiple risk factors, such as heart transplant recipients. The cardiorenal syndrome, a term coined to emphasize the bidirectional nature of simultaneous or sequential cardiac-renal dysfunction both in acute and chronic settings, has been recently described in adults but scarcely reported in children. Despite the common occurrence and clinical and financial impact, AKI in pediatric heart failure outside of cardiac surgery populations remains poorly studied and there are no large-scale pediatric specific preventive or therapeutic studies to date. This article will review pediatric aspects of the cardiorenal syndrome in terms of pathophysiology, clinical impact and treatment options.

Delayed kidney injury following coronary angiography

It is occasionally observed that patients without contrast-induced nephropathy (CIN) develop kidney injury within 1-6 months after coronary angiography (CAG), termed delayed CIN or delayed kidney injury (DKI) following CAG. The present study aimed to investigate the associated risk factors of delayed CIN and its possible pathogenesis. Subjects with CAG or coronary stenting from January 2008 to December 2009 were studied. A retrospective survey on DKI after CAG was conducted and the risk factors were analyzed. There were 436 cases receiving CAG with complete medical records enrolled in the present cohort, in which the DKI incidence was 7.1% (31/436). Patients with DKI after CAG exhibited lower hemoglobin (121.2±17.3 vs. 133.8±18.6 g/l), estimated glomerular filtration rate (eGFR; 66.4±30.2 vs. 71.9±28.6 ml/min), higher serum creatinine (110.9±43.2 vs. 91.7±37.6 µmol/l), higher rate of heart failure (22.6 vs. 5.4%) and 300 mg aspirin therapy (29 vs. 5.7%) compared with non-DKI patients (all P<0.05). However, no differences were observed in morbidities of diabetes, hypertension, hyperlipidemia and proteinuria, or in the treatments with angiotensin converting enzyme (ACE) inhibitors/angiotensin II receptor-1 blockers (ARBs), diuretics, statins and other anti-platelets between the two groups (P>0.05). Logistic regression revealed that anemia, heart failure and 300 mg aspirin intake were risk factors of DKI (P<0.05), while the contrast level, isotonic contrast, diabetes, ACE inhibitors/ARBs, eGFR and other factors were not associated with DKI (P>0.05). Heart dysfunction and 300 mg aspirin therapy may contribute to DKI after CAG, and iodinated contrast media administration is not a risk factor.

Value of Virtual Touch Quantification Elastography for Assessing Liver Congestion in Patients With Heart Failure

BACKGROUND

Heart failure (HF) causes organ congestion, which is thought to increase organ stiffness. The virtual touch quantification (VTQ) method can be used to assess liver stiffness in patients with chronic liver diseases. This study aimed to measure liver and kidney stiffness using VTQ and to determine its value for assessing organ congestion in patients with HF.

METHODS AND RESULTS

This study included 10 normal subjects and 38 HF patients (age 52.3±16.7 years, left ventricular ejection fraction 27.0±9.4%, plasma B-type natriuretic peptide [BNP] 1,297.3±1,155.1 pg/ml). We investigated the relationships between clinical characteristics and hemodynamics and liver and kidney stiffness, and assessed the effects of medical treatment on these measurements. Liver stiffness was significantly higher in HF patients (1.17±0.13 m/s vs. 2.03±0.91 m/s, P=0.004) compared with normal subjects, but kidney stiffness was similar in both groups. Central venous pressure (CVP) (P=0.021) and BNP (P=0.025) were independent predictive factors for increased liver stiffness in HF patients. Liver stiffness decreased significantly from 2.37±1.09 to 1.27±0.33 m/s (P<0.001) after treatment. Changes in liver stiffness in HF patients significantly correlated with changes in CVP (R=0.636, P=0.014) and cardiac index (R=-0.557, P=0.039) according to univariate analysis, and with changes in CVP in multivariate analysis.

CONCLUSIONS

Liver stiffness measured by noninvasive VTQ methods can be used to assess liver congestion and therapeutic effects in patients with HF. (Circ J 2016; 80: 1187-1195).

Renal impairment and worsening of renal function in acute heart failure: can new therapies help? The potential role of serelaxin

Renal dysfunction is a frequent finding in patients with acute heart failure (AHF) and an important prognostic factor for adverse outcomes. Worsening of renal function occurs in 30-50% of patients hospitalised for AHF, and is associated with increased mortality, prolonged hospital stay and increased risk of readmission. Likely mechanisms involved in the decrease in renal function include impaired haemodynamics and activation of neurohormonal factors, such as the renin-angiotensin-aldosterone system, the sympathetic nervous system and the arginine-vasopressin system. Additionally, many drugs currently used to treat AHF have a detrimental effect on renal function. Therefore, pharmacotherapy for AHF should carefully take into account any potential complications related to renal function. Serelaxin, currently in clinical development for the treatment of AHF is a recombinant form of human relaxin-2, identical in structure to the naturally occurring human relaxin-2 peptide hormone that mediates cardiac and renal adaptations during pregnancy. Data from both pre-clinical and clinical studies indicate a potentially beneficial effect of serelaxin on kidney function. In this review, we discuss the mechanisms and impact of impairment of renal function in AHF, and the potential benefits of new therapies, such as serelaxin, in this context.

Peritoneal ultrafiltration in end-stage chronic heart failure

Background

Cardiorenal syndrome type 2 (CRS-2) is common in end-stage chronic heart failure (CHF). Peritoneal ultrafiltration (pUF) may entail clinical functional improvement and a reduction in hospitalizations.

Methods

Thirty-nine consecutive end-stage CHF patients with stable CRS-2 were initiated on ambulatory pUF after interdisciplinary cardiological/nephrological evaluation and prospectively followed for 1 year. All-cause hospitalization was the primary end point. Secondary end points included mortality, treatment alteration and change in weight, NYHA functional class or quality of life (QoL). Outcomes were compared both within the pUF cohort (365 prior to initiation) and with 39 matched CHF patients receiving standard medical treatment.

Results

Compared with pretreatment, there was a trend to a reduction in 1-year hospitalization days in the pUF group (P = 0.07). One-year mortality was 33% in the pUF group and 23% in the matched control cohort. pUF was stopped in eight patients (18%) due to recurrent peritonitis (n = 3), insufficient ultrafiltration (n = 3) or cardiac recompensation (n = 1). Compared with standard medical treatment, pUF significantly improved volume overload (P < 0.05), NYHA functional class (P < 0.001) and mental health (P < 0.05). Moreover, hospitalization days for all causes as well as cardiovascular hospitalization days were significantly reduced during the interim periods in the pUF group (P < 0.05 and P < 0.001, respectively).

Conclusions

pUF is effective in improving the clinical condition of end-stage CHF patients suffering from CRS-2. Randomized controlled trials are needed to clarify the effects of pUF on hospitalization and mortality in these patients.

Diastolic dysfunction and contrast-induced nephropathy in patients undergoing coronary angiography

OBJECTIVES

It has been demonstrated that decreased left ventricular ejection fraction (LVEF) is associated with an increased risk of contrast-induced nephropathy (CIN). In this study, we aimed to assess whether there is a relationship between left ventricular (LV) diastolic dysfunction and renal function decline after coronary angiography (CAG).

PATIENTS AND METHODS

The study consisted of two groups: group I, patients with normal diastolic function; group II, patients with cardiac symptoms and abnormal diastolic function. Serum creatinine (Crea) and glomerular filtration rates (GFR) were measured before and after 48 h of CAG.

RESULTS

After the procedure, serum Crea values were higher in group II compared with group I (p = 0.051). Postprocedural 48-h GFR values determined by Cockcroft-Gault and Modification of Diet in Renal Disease (MDRD) equations were lower in group II compared with group I (p = 0.016 and p = 0.003, respectively). Delta (Δ) ΔCrea and ΔGFR determined by the Cockcroft-Gault and MDRD equations were statistically higher in group II than in group I (p = 0.005, p = 0.052, p = 0.030). The presence of higher age (p = 0.025), E/E' lateral ratio (p = 0.030), and left atrial volume index (p = 0.05) were independent predictors of worsening renal function.

CONCLUSION

The presence of diastolic dysfunction may play a role in determining the risk of CIN in patients with normal LVEF.

[Cardiorenal syndrome: limits of heart failure therapy]

The cardiorenal syndrome is an interdisciplinary challenge with increasing health economic relevance. Renal failure is a strong predictor for mortality in patients with severe congestive heart failure (CHF) and CHF is one of the fastest increasing morbidities in western countries. For successful therapy a close cooperation between cardiology und nephrology is required. Moreover, a good compliance of the patient is needed to improve symptoms and to reduce the frequency of cardiac decompensation. A broad cardiological and nephrological evaluation and consideration of optimal conservative options according to national and international guidelines are essential. However, a renal replacement therapy might be helpful in patients with refractory heart failure even if they are not dialysis-dependent. In cases of acute heart and renal failure an intensive care management might be necessary to reduce volume overload with the help of extracorporeal ultrafiltration or a dialysis modality. Nevertheless, in cases of chronic refractory CHF peritoneal dialysis should be preferred. The first analysis of the registry of the German Society of Nephrology (http://www.herz-niere.de) confirmed that there is a benefit for health-related quality of life in chronic CHF patients treated with peritoneal dialysis.

Salvage of external iliac artery dissection immediately after renal transplant

Renal transplant is the preferred treatment for patients with uremia. The renal transplant procedure is well established with a high success rate, but surgical complications are encountered occasionally. We report a case of sudden onset of anuria of the graft kidney owing to acute external iliac artery dissection diagnosed by Doppler sonography. Urgent endarterectomy with thrombus removal of false lumen prevented ischemia and occlusion of the right femoral artery. Without accurate diagnosis and management, this complication could have caused graft loss and death. We believe that renal transplant requires attentive teamwork to keep the graft functioning well.

Prevention of sudden cardiac death in patients with chronic kidney disease

Cardiovascular deaths account for about 40% of all deaths of patients with chronic kidney disease (CKD), particularly those on dialysis, while sudden cardiac death (SCD) might be responsible for as many as 60% of SCD in patients undergoing dialysis. Studies have demonstrated a number of factors occurring in hemodialysis (HD) that could lead to cardiac arrhythmias. Patients with CKD undergoing HD are at high risk of ventricular arrhythmia and SCD since changes associated with renal failure and hemodialysis-related disorders overlap. Antiarrhythmic therapy is much more difficult in patients with CKD, but the general principles are similar to those in patients with normal renal function - at first, the cause of arrhythmias should be found and eliminated. Also the choice of therapy is narrowed due to the altered pharmacokinetics of many drugs resulting from renal failure, neurotoxicity of certain drugs and their complex interactions. Cardiac pacing in elderly patients is a common method of treatment. Assessment of patients’ prognosis is important when deciding whether to implant complex devices. There are reports concerning greater risk of surgical complications, which depends also on the extent of the surgical site. The decision concerning implantation of a pacing system in patients with CKD should be made on the basis of individual assessment of the patient.

[Renal replacement therapy for refractory heart failure]

After broad cardiological and nephrological evaluation and consideration of optimal conservative options according to national and international guidelines, renal replacement therapy might be helpful in patients with refractory heart failure even if they are not dialysis-dependent. This is even more important as renal failure is a strong predictor for mortality in patients with severe congestive heart failure (CHF) and CHF is one of the fastest growing morbidities in western countries. Although peritoneal dialysis (PD) is frequently used in patients with CHF its role remains unclear. Acute chronic volume overload in refractory CHF is still an unresolved clinical problem. In patients with acute heart and renal failure with need of management in an intensive care unit, extracorporeal ultrafiltration or a dialysis modality should be preferred. In patients with chronic refractory CHF, volume overload and renal failure, peritoneal dialysis should be the therapy of choice. Due to the limited data available, treatment and outcome parameters should be recorded in the registry of the German Society of Nephrology (http://www.herz-niere.de).

Role of coronary artery calcification score on the decrease in GFR among subjects with CT coronary angiography

OBJECTIVE

Higher levels of coronary artery calcification score (CACS) are associated not only with an increased risk for cardiovascular death, but also with lower glomerular filtration rates (GFRs). However, its role in renal disease progression in patients has not been elucidated.

MATERIALS AND METHODS

We evaluated the change of estimated GFR in 279 nondialytic outpatients, who had undergone computed tomographic coronary angiography and follow-up over a period of 3 months.

RESULTS

The mean age of the participants was 57.7 ± 10.5 years, and the mean GFR was 88.2 ± 15.7 mL/min/1.73 m(2). Although there was no difference in baseline GFR between the CACS ≤ 200 AU group (n = 240) and the CACS > 200 AU group (n = 39), the latter group had a lower level of final GFR and higher annual reduction rate of GFR than the former group after an observation period of 13.1 ± 5.97 months. After adjusting for confounding variables, including age, gender, baseline GFR, albumin, and proteinuria, high levels of CACS showed an independent association with an annual reduction rate of GFR (r = -0.142, P = .048).

CONCLUSIONS

The results suggest that CACS was related to an annual decrease in GFR and may predict the faster decline in GFR in patients with symptoms requiring computed tomographic coronary angiography.

Effect of nesiritide in isolated right ventricular failure secondary to pulmonary hypertension

Treatment of right ventricular failure (RVF) can be challenging due to the correlation between RVF and worsening renal function with diuretic therapy. Nesiritide has been studied in patients with left ventricular failure but has not been evaluated in isolated RVF. The authors retrospectively analyzed 140 patients admitted with RVF, pulmonary hypertension (PH), and preserved left ventricular systolic function. Seventy patients were treated with nesiritide while the remaining patients received only furosemide (no nesiritide group). Serum creatinine and GFR at baseline, 72 hours, discharge, and 1 month post-treatment, as well as hemodynamic data were compared between the groups. In the nesiritide group, there was a significant decrease in mean GFR (42.77±25.33, P<.001) at day of discharge and 1 month post-nesiritide infusion (41.17±24.94, P<.001) but not in the no nesiritide group. There was a significant difference in >25% decrease in GFR anytime through day 30 (47.14% vs. 25.71%, P=.036) between the two groups. On multivariate analysis, nesiritide remained an important predictor of renal function at discharge and at 1 month (P<.01) as well as a predictor of >25% decrease in GFR anytime through day 30 (P=.007). Thus, nesiritide is associated with worsening kidney function in patients with RVF in the setting of PH.

Complications of progression of CKD

CKD is a complex comorbid condition with multiple manifestations. It is closely linked with cardiovascular disease and has a very high mortality rate. Currently, it consumes 28% of Medicare expenditures. Complications of CKD include hypertension, diabetes, dyslipidemia, cardiovascular disease, anemia, and bone and mineral disorders. It is underrecognized and underdiagnosed in primary care offices. There is strong evidence that controlling blood pressure, blood glucose, and use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in albuminuric patients, as well as referral to the nephrologist when glomerular filtration rate is <30 mL/min/1.73 m(2), is associated with lower mortality, better access to kidney transplantation, improved management of comorbidities, and less frequent use of catheters for dialysis and to lower mortality.

Decongestive treatment of acute decompensated heart failure: cardiorenal implications of ultrafiltration and diuretics

In patients with acute decompensated heart failure (ADHF), treatment aimed at adequate decongestion of the volume overloaded state is essential. Despite diuretic therapy, many patients remain volume overloaded and symptomatic. In addition, adverse effects related to diuretic treatment are common, including worsening kidney function and electrolyte disturbances. The development of decreased kidney function during treatment affects the response to diuretic therapy and is associated with important clinical outcomes, including mortality. The occurrence of diuretic resistance and the morbidity and mortality associated with diuretic therapy has stimulated interest to develop effective and safe treatment strategies that maximize decongestion and minimize decreased kidney function. During the last few decades, extracorporeal ultrafiltration has been used to remove fluid from diuretic-refractory hypervolemic patients. Recent clinical studies using user-friendly machines have suggested that ultrafiltration may be highly effective for decongesting patients with ADHF. Many questions remain regarding the comparative impact of diuretics and ultrafiltration on important clinical outcomes and adverse effects, including decreased kidney function. This article serves as a summary of key clinical studies addressing these points. The overall goal is to assist practicing clinicians who are contemplating the use of ultrafiltration for a patient with ADHF.

Cardiorenal syndromes

Cardiac and kidney diseases are very common, and increasingly coexist. Classification for cardiorenal syndrome and for its specific subtypes has been developed and published recently by a consensus group of the Acute Dialysis Quality Initiative. Cardiorenal syndromes have been classified according to whether the impairment of each organ is primary, secondary or whether heart and kidney dysfunction occurs simultaneously as a systemic disease. The different syndromes were classified into five subtypes. Type-1: acute cardiorenal syndrome: an abrupt worsening of cardiac function leading to acute kidney injury and/or dysfunction. Type-2: chronic cardiorenal syndrome: chronic abnormalities in cardiac function causing kidney injury and/or dysfunction. Type-3: acute renocardiac syndrome: abrupt worsening of kidney function leading to heart injury and/or dysfunction. Type-4: chronic renocardiac syndrome: chronic kidney diseases leading to heart injury, disease and/or dysfunction. Type-5: secondary cardiorenal syndrome: acute or chronic systemic diseases leading to simultaneous injury and/or dysfunction of heart and kidney. The identification of patients and the pathophysiological mechanisms underlying each syndrome subtype will help cardiologists, nephrologists and physicians working on intensive care units to characterize groups of their patients with cardiac and renal impairment and to provide a more accurate treatment for them. Orv. Hetil., 2011, 152, 1520–1527.