Albuminuria in chronic heart failure: prevalence and prognostic importance

Proteinuria and its relation to cardiovascular disease

Chronic kidney disease (CKD) and its associated morbidity pose a worldwide health problem. As well as risk of endstage renal disease requiring renal replacement therapy, cardiovascular disease is the leading cause of premature death among the CKD population. Proteinuria is a marker of renal injury that can often be detected earlier than any tangible decline in glomerular filtration rate. As well as being a risk marker for decline in renal function, proteinuria is now widely accepted as an independent risk factor for cardiovascular morbidity and mortality. This review will address the prognostic implications of proteinuria in the general population as well as other specific disease states including diabetes, hypertension and heart failure. A variety of pathophysiological mechanisms that may underlie the relationship between renal and cardiovascular disease have been proposed, including insulin resistance, inflammation, and endothelial dysfunction. As proteinuria has evolved into a therapeutic target for cardiovascular risk reduction in the clinical setting we will also review therapeutic strategies that should be considered for patients with persistent proteinuria.

Renal dysfunction, restrictive left ventricular filling pattern and mortality risk in patients admitted with heart failure: a 7-year follow-up study

Background

Renal dysfunction is associated with a variety of cardiac alterations including left ventricular (LV) hypertrophy, LV dilation, and reduction in systolic and diastolic function. It is common and associated with an increased mortality risk in heart failure (HF) patients. This study was designed to evaluate whether severe diastolic dysfunction contribute to the increased mortality risk observed in HF patients with renal dysfunction.

Methods

Using Cox Proportional Hazard Models on data (N = 669) from the EchoCardiography and Heart Outcome Study (ECHOS) study we evaluated whether estimated glomerular filtration rate (eGFR) was associated with mortality risk before and after adjustment for severe diastolic dysfunction. Severe diastolic dysfunction was defined by a restrictive left ventricular filling pattern (RF) (=deceleration time < 140 ms) by Doppler echocardiography.

Results

Median eGFR was 58 ml/min/1.73 m², left ventricular ejection fraction was 33% and RF was observed in 48%. During the 7 year follow up period 432 patients died. Multivariable adjusted eGFR was associated with similar mortality risk before (Hazard Ratio(HR)_{eGFR 10 ml increase}: 0.94 (95% CI: 0.89-0.99, P = 0.024) and after (HR_{eGFR 10 ml increase}: 0.93 (0.89-0.99), P = 0.012) adjustment for RF (HR: 1.57 (1.28-1.93), P < 0.001).

Conclusions

In patients admitted with HF RF does not contribute to the increased mortality risk observed in patients with a decreased eGFR. Factors other than severe diastolic dysfunction may explain the association between renal function and mortality risk in HF patients.

Correlation of chronic renal dysfunction and albuminuria with severity of coronary artery lesions in patients with coronary artery disease

This study was conducted to investigate the possible correlation of chronic renal dysfunction and albuminuria with the severity of coronary artery lesions in patients with coronary artery disease (CAD). Two-hundred and ninety-nine patients who had undergone coronary angiography for suspected CAD were stratified into three groups according to the glomerular filtration rate (GFR): group I included 144 patients with normal renal function GFR >90 ml/(min × 1.73 m(2)), group II included 97 patients with mild renal impairment GFR 60-89 ml/(min × 1.73 m(2)), and group III included 58 patients with moderate renal impairment GFR <60 ml/(min × 1.73 m(2)). Patients were then stratified into two groups according to the albuminuria level (0; minimal, 1+, 2+, 3+): the albuminuria negative group (negative = 0) included 171 patients and the albuminuria positive group (positive = minimal, 1+, 2+, 3+) included 128 patients. Clinical features and coronary lesion characteristics were compared among these groups. Patients with more severe renal dysfunction and positive albuminuria had a higher incidence of CAD (66.7 vs. 70.1 vs. 72.4%, p = 0.025 and 64.2 vs. 75.0%, p = 0.032), more multi-vessel disease (31.2 vs. 41.2 vs. 53.4 %, p = 0.004 and 33.3 vs. 46.1%, p = 0.015), more left anterior descending branch lesions (50.7 vs. 56.7 vs. 60.3%, p = 0.012 and 49.1 vs. 61.7 %, p = 0.009), and a higher Gensini score (42.3 ± 14.7 vs. 46.1 ± 19.9 vs. 52.8 ± 21.2, p = 0.026 and 44.0 ± 16.0 vs. 50.5 ± 20.2, p = 0.017). In conclusion, chronic renal dysfunction and albuminuria may be important factors determining the occurrence and the severity of CAD. Albuminuria was an especially significant indicator at the early stage of renal dysfunction.

Association of renal biomarkers with 3-month and 1-year outcomes among critically ill acute stroke patients

Background

The comparative relationships of widely recognized biomarkers of renal injury with short-term and long-term outcomes among critically ill acute stroke patients are unknown. We evaluated the impact of baseline albuminuria [urine albumin-creatinine ratio (UACR)≥30 mg/g] or low estimated glomerular filtration rate (eGFR<60 ml/min per 1.73 m²) on stroke patients admitted to the intensive care unit (ICU).

Methods

We reviewed data on consecutive stroke patients admitted to a hospital ICU in Taiwan from September 2007 to August 2010 and followed-up for 1 year. Baseline UACR was categorized into <30 mg/g (normal), 30–299 mg/g (microalbuminuria), and ≥300 mg/g (macroalbuminuria), while eGFR was divided into ≥60, 45–59, and <45 ml/min per 1.73 m². The outcome measure was death or disability at 3-month and 1-year after stroke onset, assessed by dichotomizing the modified Rankin Scale at 3–6 versus 0–2.

Results

Of 184 consecutive patients, 153 (83%) met study entry criteria. Mean age was 67.9 years and median admission NIHSS score was 16. Among the renal biomarkers, only macroalbuminuria was associated with poorer 3-month outcome (OR 8.44, 95% CI 1.38 to 51.74, P = 0.021) and 1-year outcome (OR 18.06, 95% CI 2.59 to 125.94, P = 0.003) after adjustment of relevant covariates. When ischemic and hemorrhagic stroke were analyzed separately, macroalbuminuria was associated with poorer 1-year outcome among ischemic (OR 17.10, 95% CI 1.04 to 280.07, P = 0.047) and hemorrhagic stroke patients (OR 1951.57, 95% CI 1.07 to 3561662.85, P = 0.048), respectively, after adjustment of relevant covariates and hematoma volume.

Conclusions

Presence of macroalbuminuria indicates poor 3-month and 1-year outcomes among critically ill acute stroke patients.

The cardiorenal syndrome: what the cardiologist needs to know

Interactions between the heart and the kidneys are increasingly acknowledged among both cardiologists and nephrologists. The term cardiorenal syndrome now applies to the bidirectional nature of how disease in one organ system affects the function of the other organ system. Cardiovascular disease is a major threat to patients with chronic kidney disease, while renal dysfunction is prevalent in patients with cardiac disease and is a significant predictor of prognosis in cardiac patients. Still, renal patients with cardiac disease have largely been excluded from the clinical trials that have been the basis of modern cardiologic treatment. In this review, the current understanding of the pathophysiological mechanisms involved in the cardiorenal syndrome and potential therapeutic implications will be summarized from a nephrologist's point of view. Probably, fragile cardiorenal patients will benefit from an enhanced collaboration between cardiologists and nephrologists to secure the best treatment given under safe conditions.

Urinary markers of intrarenal renin-angiotensin system activity in vivo

Recent interest focuses on urinary renin and angiotensinogen as markers of renal renin-angiotensin system activity. Before concluding that these components are independent markers, we need to exclude that their presence in urine, like that of albumin (a protein of comparable size), is due to (disturbed) glomerular filtration. This review critically discusses their filtration, reabsorption and local release. Given the close correlation between urinary angiotensinogen and albumin in human studies, it concludes that, in humans, urinary angiotensinogen is a filtration barrier damage marker with the same predictive power as urinary albumin. In contrast, in animals, tubular angiotensinogen release may occur, although tubulus-specific knockout studies do not support a functional role for such angiotensinogen. Urinary renin levels, relative to albumin, are >200-fold higher and unrelated to albumin. This may reflect release of renin from the urinary tract, but could also be attributed to activation of filtered, plasma-derived prorenin and/or incomplete tubular reabsorption.

Low-grade albuminuria is associated with early but not late carotid atherosclerotic lesions in community-based patients with type 2 diabetes

BACKGROUND

Low-grade albuminuria is associated with cardiovascular risk factors and mortality. Our aim was to investigate the association between low-grade albuminuria and carotid atherosclerotic lesions in community-based patients with type 2 diabetes.

METHODS

A cross-sectional study was performed in 475 community-based patients with type 2 diabetes (190 males and 285 females) with normal urinary albumin-to-creatinine ratios (UACR) (< 3.5 mg/mmol) from Shanghai, China. The subjects were stratified into tertiles based on UACR levels (the lowest tertile was UACR ≤ 1.19 mg/mmol, and the highest tertile was UACR ≥ 2 mg/mmol). Carotid intima-media thickness (CIMT), carotid atherosclerotic plaque formation and stenosis were assessed and compared among the three groups based on ultrasonography. The urinary albumin excretion rate was determined as the mean of the values obtained from three separate early morning urine samples.

RESULTS

Compared with the subjects with UACR in the lowest tertile, the subjects with UACR in the middle and highest tertiles had greater CIMT values (0.88 ± 0.35 mm, 0.99 ± 0.43 mm and 1.04 ± 0.35 mm, respectively; all p < 0.05) and a higher prevalence of carotid atherosclerotic plaques (25.3%, 39.0% and 46.2%, respectively; all p < 0.05) after adjusting for sex and age. Fully adjusted multiple linear regression and logistic regression analyses revealed that UACR tertiles were significantly associated with elevated CIMT (p = 0.007) and that, compared with the subjects in the first tertile of UACR, those in the second and third tertiles had 1.878- and 2.028-fold risk of carotid plaques, respectively. However, there was no statistical association between UACR tertile and the prevalence of carotid stenosis.

CONCLUSIONS

Higher UACR within the normal range was independently associated with early but not late carotid atherosclerotic lesions in community-based patients with type 2 diabetes. Low-grade albuminuria contributes to the risk of carotid atherosclerosis and may be used as an early marker for the detection of atherosclerosis in patients with type 2 diabetes.

Current and novel renal biomarkers in heart failure

Renal function is the most important predictor of clinical outcome in heart failure (HF). It is therefore essential to have accurate and reliable measurement of renal function and early specific markers of renal impairment in patients with HF. Several renal functional entities exist, including glomerular filtration (GFR), glomerular permeability, tubulointerstitial damage, and endocrine function. Different markers have been studied that can be used to determine changes and the effect of treatment in these entities. In the present review, we summarize current and novel markers that give an assessment of renal function and prognosis in the setting of acute and chronic HF.

The Effect of Continuous Infusion Loop Diuretics in Patients With Acute Decompensated Heart Failure With Hypoalbuminemia

Purpose:

Hypoalbuminemia is believed to decrease diuretic effectiveness and contribute to diuretic resistance that is observed in patients with nephrotic syndrome. Hypoalbuminemia is also seen in patients with acute decompensated heart failure (ADHF). However, the role of hypoalbuminemia on the effectiveness of continuous infusion diuretics in patients with ADHF is not known.

Methods:

To evaluate hypoalbuminemia (albumin ≤3 g/dL) and diuretic effectiveness, we performed a retrospective study in 162 patients admitted to a tertiary care center for treatment of ADHF over a 3-year period. All patients received continuous infusion diuretic for at least a 2-day time period.

Results:

A total of 33 patients were determined to have hypoalbuminemia. Average net urine output over a 2-day study period was similar between patients with and without hypoalbuminemia (−1462 ± 1734 vs −1233 ± 1560 mL, P = .46, respectively). In addition, diuretic doses (furosemide equivalent/24 hours) were similar between the 2 groups (788 ± 671 vs 778 ± 713 mg, P = .91, respectively) as was baseline serum creatinine (1.6 ± 0.6 vs 1.6 ± 0.6 mg/dL, P = .5, respectively).

Conclusion:

Overall, hypoalbuminemia did not decrease the diuretic effectiveness when measured by the net urine output in patients receiving continuous infusion diuretics for the treatment of ADHF.

Early evolution and correlates of urine albumin excretion in patients presenting with acutely decompensated heart failure

BACKGROUND

Urine albumin excretion is an important predictor of adverse cardiovascular events in various populations. Its correlation in patients with acute heart failure has not been described.

METHODS AND RESULTS

This prospective, observational study included 115 patients presenting with acute heart failure. The urine albumin/creatinine ratio (UACR) was measured from spot urine samples collected on days 1 and 7 of hospitalization. Median UACR decreased from 83 to 22 mg/gCr on days 1 and 7, respectively (P<0.0001). The proportion of patients with normoalbuminuria (UACR <30 mg/gCr) increased from 31% on day 1 to 60% on day 7, whereas the proportion with microalbuminuria (UACR between 30 and 299 mg/gCr) and macroalbuminuria (UACR ≥300 mg/gCr) decreased, respectively, from 42% and 27% on day 1 to 30% and 10% on day 7 (P<0.0001). These changes in UACR were correlated with changes in serum bilirubin and N-terminal pro b-type natriuretic peptide concentrations (correlation coefficients 1.087 and 0.384, respectively; 95% confidence interval, 0.394-1.781 and 0.087-0.680, respectively; and P=0.003 and 0.013, respectively), although they were not correlated with change in estimated glomerular filtration rate.

CONCLUSIONS

In this sample of patients presenting with acute heart failure, urine albumin excretion was often increased at admission to the hospital and decreased significantly within 7 days of treatment. The decrease was correlated with serum N-terminal pro b-type natriuretic peptide and bilirubin concentrations, although neither with baseline nor with changes in indices of renal function.

New-onset microalbuminuria following allogeneic myeloablative SCT is a sign of near-term decrease in renal function

The emergence of microalbuminuria following conditioning chemotherapy may predict the development of renal dysfunction. To confirm this, a 1-year retrospective cohort study was conducted in 31 myeloablative allogeneic SCT patients who received five consecutive measurements of albuminuria before conditioning therapy and on days 0, 7, 14 and 28 following SCT. The cohort had neither microalbuminuria nor renal dysfunction at baseline. Microalbuminuria was defined as an albumin-creatinine (Cr) ratio over 30 mg/g, and renal dysfunction was as an estimated glomerular filtration rate <60 mL/min per 1.73 m(2). Cumulative incidence of renal dysfunction over time was analyzed by the Kaplan-Meier method. Multivariate Cox proportional hazards analysis was used to examine an association of de novo microalbuminuria with the incidence of renal dysfunction. In all, 16 patients (52%) developed microalbuminuria that was positive at least two times among the four measurements after SCT. The actuarial occurrence of chronic kidney disease was significantly higher in patients who developed microalbuminuria than in those who did not. Incidence of microalbuminuria had a significant risk of subsequent renal dysfunction (hazard ratio (95% confidence interval), 7.3 (1.2-140)). In conclusion, de novo microalbuminuria following conditioning therapy is a warning of near-term loss of renal function.

Microalbuminuria predicts silent myocardial ischaemia in type 2 diabetes patients

PURPOSE

Myocardial ischaemia is frequently silent in patients with type 2 diabetes. Although it has been proposed as a potential screening tool, the role of myocardial perfusion single photon emission computed tomography (MPS) has recently been questioned, due to the low prevalence of positive scans and the low rate of cardiac events. The aim of this study was to assess if pretest clinical variables can identify a subgroup of asymptomatic patients with type 2 diabetes at risk of silent myocardial ischaemia and a subsequent poor outcome

METHODS

This prospective study included 77 patients (50 men, mean age 63 ± 9 years) with type 2 diabetes and no known coronary artery disease (CAD) or angina pectoris who underwent gated MPS to screen for CAD between March 2006 and October 2008. MPS images were interpreted using a semiquantitative visual 20-segment model to define summed stress, rest and difference scores. Ischaemia was defined as a sum difference score (SDS) ≥2. Patients were followed-up (median 4.1 years, range 0.8 - 6.1 years) and cardiac hard events (cardiac death or nonfatal myocardial infarction) were recorded.

RESULTS

Silent ischaemia was detected in 25 of the 77 patients (32 %). Specifically, 10 patients (13 %) had mild ischaemia (SDS 2 to ≤4) and 15 patients (19 %) had severe ischaemia (SDS >4). In univariate binary logistic analysis, microalbuminuria was the only significant predictor of silent ischaemia on MPS (odds ratio 4.42, 95 % CI 1.27 - 15.40; P = 0.019). The overall accuracy of microalbuminuria for predicting silent ischaemia was 71.4 % and was 89.6 % for predicting severe ischaemia. Kaplan-Meier curves showed no significant group differences in 5-year cardiac event-free survival between patients with and those without microalbuminuria, or between patients with SDS ≥2 and those with SDS <2. In contrast, 5-year event-free survival was significantly lower in patients with SDS >4 than in patients with SDS ≤4: 55.6 % (95 % CI 39.0 - 72.2 %) vs. 94.5 % (95 % CI: 91.4 - 97.6 %), respectively (Breslow test, chi-square 20.9, P < 0.001). Median cardiac event-free survival was not observed in the whole group, while the 25th percentile of cardiac event-free survival was reached only in patients with SDS >4 (2.3 years). In univariate Cox regression analysis, SDS >4 predicted cardiac event-free survival (hazard ratio 12.87, 95 % CI 2.86 - 27.98; P = 0.001), while SDS ≥2 did not (hazard ratio 2.78, 95 % CI 0.62 - 12.46, P = 0.16).

CONCLUSION

In this group of patients with type 2 diabetes, microalbuminuria was the only predictor of silent ischaemia on MPS. Assessment of microalbuminuria should be routinely considered among the first risk stratification steps for CAD in patients with type 2 diabetes, even though severe ischaemia on MPS is a major predictor of cardiac event-free survival.

Contrast induced exacerbation of renal dysfunction in the advanced chronic kidney disease

Contrast media affects renal function, especially in the patients with advanced chronic kidney disease (CKD). The aim of this study was to investigate the characteristics of contrast induced exacerbation of renal dysfunction in the patients with advanced CKD (estimated glomerular filtration rate <30 ml/min/1.73 m(2)). We enrolled 102 advanced CKD patients who underwent cardiac catheterization. Delta creatinine (post-catheterization creatinine minus pre-catheterization creatinine) were calculated. The patients were divided into three groups according to delta creatinine. The highest tertile of the delta creatinine was defined as the exacerbation group. Multivariate logistic regression analyses were performed to find the characteristics of the exacerbation group. Anemia (odds ratio (OR): 15.53, 95% Confidence Interval (95%CI): 1.81-133.27, p = 0.01) and proteinuria (OR: 5.91, 95%CI: 1.64-21.28, p < 0.01) were significant characteristics of the exacerbation group after adjusting confounding factors. In conclusion, anemia and proteinuria were associated with contrast induced exacerbation of renal dysfunction in the advanced CKD patients.

Adding thiazide to a rennin-angiotensin blocker regimen to improve left ventricular relaxation in diabetes and nondiabetes patients with hypertension

The urinary albumin to creatinine ratio (UACR) is an independent predictor of outcomes in patients with diastolic dysfunction. Thus, we investigated the relationship between diastolic dysfunction, UACR, and diabetes mellitus (DM) in the EDEN study. We investigated the effect of switching from an angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) to a combination of losartan and hydrochlorothiazide on left ventricular (LV) relaxation in patients with hypertension and diastolic dysfunction. We enrolled 106 patients with and 265 patients without DM. All patients had diastolic dysfunction and had not achieved their treatment goals with an ACEi or ARB. The measurements of e′ velocity and E/e′ ratio was performed with echocardiography as markers of LV diastolic function. We switched the ACEi or ARB to losartan/hydrochlorothiazide and followed these patients for 24 weeks. UACR was decreased in patients with DM (123.4 ± 288.4 to 66.5 ± 169.2 mg/g creatinine; P = 0.0024), but not in patients without DM (51.2 ± 181.8 to 39.2 ± 247.9 mg/g creatinine; P = 0.1051). Among DM patients, there was a significant relationship between changes in UACR and changes in e′ velocity (r = −0.144; P = 0.0257) and between changes in estimated glomerular filtration rate and changes in the E/e′ ratio (r = −0.130; P = 0.0436). Among patients without DM, there was a significant relationship between changes in high-sensitivity C-reactive protein (hs-CRP) and changes in E/e′ (r = 0.205; P = 0.0010). Multivariate analysis demonstrated changes in hemoglobin A_1c levels as one of the determinants of change of e′ and E/e′ in patients with DM, whereas hs-CRP was the determinant of change of e′ among patients without DM. These data suggest that improvement in LV diastolic function is associated with an improvement of DM and a concomitant reduction in UACR among DM patients, and with a reduction of hs-CRP in patients without DM when thiazide is added to a renin–angiotensin blocker treatment regimen.

Renal dysfunction in heart failure

Renal dysfunction is a common, important comorbidity in patients with both chronic and acute heart failure (HF). Chronic kidney disease and worsening renal function (WRF) are associated with worse outcomes, but our understanding of the complex bidirectional interactions between the heart and kidney remains poor. When addressing these interactions, one must consider the impact of intrinsic renal disease resulting from medical comorbidities on HF outcomes. WRF may result from any number of important processes. Understanding the role of each of these factors and their interplay are essential in understanding how to improve outcomes in patients with renal dysfunction and HF.

The role of the kidney in heart failure

Renal dysfunction is common in patients with heart failure and is associated with high morbidity and mortality. Cardiac and renal dysfunction may worsen each other through multiple mechanisms such as fluid overload and increased venous pressure, hypo-perfusion, neurohormonal and inflammatory activation, and concomitant treatment. The interaction between cardiac and renal dysfunction may be critical for disease progression and prognosis. Renal dysfunction is conventionally defined by a reduced glomerular filtration rate, calculated from serum creatinine levels. This definition has limitations as serum creatinine is dependent on age, gender, muscle mass, volume status, and renal haemodynamics. Changes in serum creatinine related to treatment with diuretics or angiotensin-converting enzyme inhibitors are not necessarily associated with worse outcomes. New biomarkers might be of additional value to detect an early deterioration in renal function and to improve the prognostic assessment, but they need further validation. Thus, the evaluation of renal function in patients with heart failure is important as it may reflect their haemodynamic status and provide a better prognostic assessment. The prevention of renal dysfunction with new therapies might also improve outcomes although strong evidence is still lacking.

Cardiorenal syndrome type 1: pathophysiological crosstalk leading to combined heart and kidney dysfunction in the setting of acutely decompensated heart failure

Cardiorenal syndrome (CRS) type 1 is characterized as the development of acute kidney injury (AKI) and dysfunction in the patient with acute cardiac illness, most commonly acute decompensated heart failure (ADHF). There is evidence in the literature supporting multiple pathophysiological mechanisms operating simultaneously and sequentially to result in the clinical syndrome characterized by a rise in serum creatinine, oliguria, diuretic resistance, and in many cases, worsening of ADHF symptoms. The milieu of chronic kidney disease has associated factors including obesity, cachexia, hypertension, diabetes, proteinuria, uremic solute retention, anemia, and repeated subclinical AKI events all work to escalate individual risk of CRS in the setting of ADHF. All of these conditions have been linked to cardiac and renal fibrosis. In the hospitalized patient, hemodynamic changes leading to venous renal congestion, neurohormonal activation, hypothalamic-pituitary stress reaction, inflammation and immune cell signaling, systemic endotoxemic exposure from the gut, superimposed infection, and iatrogenesis all contribute to CRS type 1. The final common pathway of bidirectional organ injury appears to be cellular, tissue, and systemic oxidative stress that exacerbate organ function. This review explores in detail the pathophysiological pathways that put a patient at risk and then effectuate the vicious cycle now recognized as CRS type 1.

Effects of Candesartan on Left Ventricular Function, Aldosterone and BNP in Chronic Heart Failure

PURPOSE: Heart failure (HF) is characterized by activation of neurohormonal systems such as aldosterone and natriuretic peptides. In the absence of published data, CandHeart trial was designed to assess the effects on left ventricular (LV) function, aldosterone and brain natriuretic peptide (BNP) of candesartan in patients with HF and preserved (LVEF ≥ 40%) or depressed (LVEF <40%) LV systolic function. METHODS: A total of 514 patients with stable symptomatic NYHA II-IV HF and any left ventricular ejection fraction (LVEF)were randomized to candesartan (target dose 32 mg once daily) as add-on therapy or standard medical therapy alone. Standardized echocardiographic exams were performed locally under central quality control, whereas biomarkers were assayed in a core laboratory. RESULTS: The majority of patients (73.3%) were NYHA II and on ACE inhibitors (91.8%) and beta-blockers (85.4%). Mean age was 66 ± 11 years. Mean LVEF was 36.2 ± 9.7% and 24.9% of patients had LVEF ≥ 40%. LVEF increased significantly more in the candesartan group (p = 0.09 at 12 weeks and p = 0.01 at 48 weeks) and left ventricular end-diastolic diameter decreased in candesartan group (p = 0.05 at 12 weeks). Candesartan significantly reduced aldosterone at 48 weeks (p = 0.009). BNP was reduced similarly over time in both study groups (p = 0.35 and p = 0.98 at 12 and 48 weeks, respectively). There were 6.6% of discontinuations of candesartan for adverse events. CONCLUSIONS: In CandHeart, the addition of candesartan to standard medical treatment did not reduce circulating BNP more than standard therapy (primary endpoint), but it significantly improved LV function and produced a marked decrease in aldosterone levels at study end.

The relationship between renal impairment and left ventricular structure, function, and ventricular-arterial interaction in hypertension

OBJECTIVES

Our objective was to define the relationship between renal dysfunction--both albuminuria and reduced estimated glomerular filtration rate (eGFR)--and cardiac structure and diastolic dysfunction among patients with chronic hypertension.

METHODS

Both albuminuria and eGFR were measured in 540 asymptomatic patients with hypertension and diastolic dysfunction assessed by reduced early mitral annular relaxation velocity (E'). The majority of patients were white, mean age was 60 ± 10 years, mean SBP was 149 ± 18 mmHg, and there was a low prevalence comorbid conditions. Albuminuria was undetectable in 148 (27%), within the normal to low range [urine albumin-to-creatinine ratio (UACR) 1-25 mg/g for men, 1-17 mg/g for women] in 292 (54%), and high or very high (UACR >25 mg/g for men, >17 mg/g for women) in 100 (19%). Estimated GFR was 60 ml/min per 1.73 m² or less in 75 (14%), 61-90 ml/min per 1.73 m² in 244 (45%), and more than 90 ml/min per 1.73 m² in 221 (41%).

RESULTS

Albuminuria, even within the normal range, was associated with greater left ventricular wall thickness (P = 0.01), higher relative wall thickness (P = 0.004), worse diastolic function reflected in lower E' (P = 0.01), greater arterial and left ventricular end-systolic stiffness (P < 0.0001 and P = 0.003, respectively), and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) level (P = 0.0025), even after adjustment for differences in baseline characteristics. In contrast, no independent relationship was observed between eGFR and parameters of cardiac structure or function.

CONCLUSION

Among asymptomatic hypertensive patients with evidence of diastolic dysfunction, the presence of albuminuria, even within the normal range, is associated with greater concentric remodeling, greater left ventricular end-systolic stiffness, and worse diastolic function.

[Serum albumin and heart failure: recent advances on a new paradigm]

Hypoalbuminemia is a common condition in patients with heart failure and is mainly related to the malnutrition-inflammation complex syndrome. Other causal factors can be involved, which include hemodilution, liver dysfunction, increased transcapillary escape rate, renal and enteral loss. Evidence is growing that hypoalbuminemia independently predicts incident heart failure in patients with end-stage renal disease and elderly patients, as well as mortality in patients with heart failure regardless of left ventricular ejection fraction and clinical presentation. Hypoalbuminemia induces a low plasma oncotic pressure, which facilitates pulmonary edema in patients without critical increase in pulmonary capillary hydrostatic pressures. Hypoalbuminemia may also contribute to the progression of heart failure by favoring myocardial edema, volume overload, diuretic resistance and exacerbation of oxidative stress and inflammation. If relevant, removal of subclinical excess of fluid and renutrition may be indicated in patients with heart failure and hypoalbuminemia. Additional research is warranted to determine the specific role of serum albumin in the pathophysiologic process of heart failure and the potential benefits of targeted therapeutic interventions.

The contribution of chronic kidney disease to the global burden of major noncommunicable diseases

Noncommunicable diseases (NCDs) are the most common causes of premature death and morbidity and have a major impact on health-care costs, productivity, and growth. Cardiovascular disease, cancer, diabetes, and chronic respiratory disease have been prioritized in the Global NCD Action Plan endorsed by the World Health Assembly, because they share behavioral risk factors amenable to public-health action and represent a major portion of the global NCD burden. Chronic kidney disease (CKD) is a key determinant of the poor health outcomes of major NCDs. CKD is associated with an eight- to tenfold increase in cardiovascular mortality and is a risk multiplier in patients with diabetes and hypertension. Milder CKD (often due to diabetes and hypertension) affects 5-7% of the world population and is more common in developing countries and disadvantaged and minority populations. Early detection and treatment of CKD using readily available, inexpensive therapies can slow or prevent progression to end-stage renal disease (ESRD). Interventions targeting CKD, particularly to reduce urine protein excretion, are efficacious, cost-effective methods of improving cardiovascular and renal outcomes, especially when applied to high-risk groups. Integration of these approaches within NCD programs could minimize the need for renal replacement therapy. Early detection and treatment of CKD can be implemented at minimal cost and will reduce the burden of ESRD, improve outcomes of diabetes and cardiovascular disease (including hypertension), and substantially reduce morbidity and mortality from NCDs. Prevention of CKD should be considered in planning and implementation of national NCD policy in the developed and developing world.

Dextran fractional clearance studies in acute dengue infection

Background

Although increased capillary permeability is the major clinical feature associated with severe dengue infections the mechanisms underlying this phenomenon remain unclear. Dextran clearance methodology has been used to investigate the molecular sieving properties of the microvasculature in clinical situations associated with altered permeability, including during pregnancy and in various renal disorders. In order to better understand the characteristics of the vascular leak associated with dengue we undertook formal dextran clearance studies in Vietnamese dengue patients and healthy volunteers.

Methodology/Principal Findings

We carried out serial clearance studies in 15 young adult males with acute dengue and evidence of vascular leakage a) during the phase of maximal leakage and b) one and three months later, as well as in 16 healthy control subjects. Interestingly we found no difference in the clearance profiles of neutral dextran solutions among the dengue patients at any time-point or in comparison to the healthy volunteers.

Conclusions/Significance

The surface glycocalyx layer, a fibre-matrix of proteoglycans, glycosaminoglycans, and plasma proteins, forms a complex with the underlying endothelial cells to regulate plasma volume within circumscribed limits. It is likely that during dengue infections loss of plasma proteins from this layer alters the permeability characteristics of the complex; physical and/or electrostatic interactions between the dextran molecules and the glycocalyx structure may temporarily restore normal function, rendering the technique unsuitable for assessing permeability in these patients. The implications for resuscitation of patients with dengue shock syndrome (DSS) are potentially important. It is possible that continuous low-dose infusions of dextran may help to stabilize the permeability barrier in patients with profound or refractory shock, reducing the need for repeated boluses, limiting the total colloid volume required. Formal clinical studies should help to assess this strategy as an alternative to conventional fluid resuscitation for severe DSS.

Dengue is a potentially serious common viral infection with no specific treatment. Plasma leakage from small blood vessels is the major severe problem, but we do not understand how this occurs. Techniques using controlled infusions of carbohydrate solutions, combined with careful measurement of the rate that the different-sized molecules clear from the circulation, have been successfully used to investigate leakage in other situations. We performed carbohydrate clearance studies in 15 Vietnamese adult males with dengue and plasma leakage, comparing results obtained during the acute illness with recovery values, and results from a group of healthy volunteers. However, we found no differences between any of the clearance profiles measured. One possible explanation may be that the carbohydrate molecules interact with blood vessels, temporarily restoring their normal barrier function. Although this means that the technique is unsuitable for investigating leakage in dengue patients, the implications for management of patients with severe leakage resulting in shock are potentially important. Patients with profound shock are usually managed with intermittent large boluses of carbohydrate or similar solutions, sometimes causing severe side-effects; however if continuous low-dose infusions actually stabilized the permeability barrier, this might reduce the need for repeated boluses, thereby minimizing these adverse effects.

Biomarkers: optimizing treatment guidance in heart failure

Heart failure is a frequent and life-threatening syndrome which is not only the result of myocardial injury or hemodynamic overload as commonly perceived, but appears to be the result of an interplay among genetic, neurohormonal, inflammatory, and biochemical factors, collectively referred to as biomarkers. Biomarkers can become risk factors in case their therapeutic modification results in an improvement of clinical outcomes. Among those markers identified in patients with heart failure, a number appears to have direct clinical relevance in aiding diagnosis, risk stratification, monitoring therapy, and treating to targets in order to improve clinical outcomes. These include brain natriuretic peptides (e.g., BNP, NT-proBNP), inflammatory markers (e.g., hsCRP), neurohormones (e.g., aldosterone), cardiorenal markers (e.g., cycstatin C), and novel markers (e.g., galectin-3). While their utility to indicate risk is mostly well established, there are less data to establish that a treatment using biomarkers as a guidance results in better outcomes than a more generalized intensified treatment of patients with heart failure. Future directions may involve larger platforms that facilitate to simultaneously analyze hundreds of biomarkers and may help to tailor heart failure therapy on a single patient basis, considering the specific pathogenesis and prognosis. Also from a therapeutic perspective there are data that a single intervention such as aldosterone blockade may affect multiple biomarkers at the same time. Taken together the data indicate that biomarkers are evolving into a valuable addendum to the diagnostic and therapeutic armamentarium.

Clinical outcome of renal tubular damage in chronic heart failure

AIMS

Both reduced glomerular filtration and increased urinary albumin excretion independently determine outcome in patients with chronic heart failure (HF). However, tubulo-interstitial injury might indicate renal damage, even in the presence of normal glomerular filtration. We studied the relationship between tubular damage, glomerular filtration, urinary albumin excretion, and outcome in HF patients.

METHODS AND RESULTS

In 2130 patients participating in the GISSI-HF trial, we measured urinary albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), and three urinary markers of tubular damage: N-acetyl-beta-D-glucosaminidase (NAG), kidney injury molecule 1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL). We assessed the relationship between the individual tubular damage markers and the combined endpoint of all-cause mortality and HF hospitalizations. Mean age was 67 ± 11 years, and 21% were female. Urinary NAG 13.7 (7.8-22) U/gCr, KIM-1 1939 (671-3871) ng/gCr, and NGAL 36 (14-94) µg/gCr were markedly elevated above normal levels. All individual tubular markers were independently associated with the combined endpoint: NAG: adjusted hazard ratio (HR) 1.22; 95% confidence interval (CI), 1.10-1.36; P< 0.001, KIM-1 HR 1.13; 95% CI, 1.02-1.24; P= 0.018 and NGAL HR 1.10; 95% CI, 1.00-1.20; P= 0.042; all per log standard deviation increase). Even in patients with a normal eGFR, increased tubular markers were related to a poorer outcome. The combination of impaired eGFR, increased UACR, and high NAG was associated with a HR of 3.00; 95% CI, 2.29-3.95; P< 0.001, compared with those without these abnormalities.

CONCLUSION

Tubular damage is related to a poor clinical outcome in HF patients even when eGFR is normal.

The progressive pathway of microalbuminuria: from early marker of renal damage to strong cardiovascular risk predictor

There is clear evidence that urinary albumin excretion levels, even below the cut-off values currently used to diagnose microalbuminuria, are associated with an increased risk of cardiovascular events. The relationships of microalbuminuria with a variety of risk factors, such as hypertension, diabetes and metabolic syndrome and with several indices of subclinical organ damage, may contribute, at least in part, to explain the enhanced cardiovascular risk conferred by microalbuminuria. Nonetheless, several studies showed that the association between microalbuminuria and cardiovascular disease remains when all these risk factors are taken into account in multivariate analyses. Therefore, the exact pathophysiological mechanisms explaining the association between microalbuminuria and cardiovascular risk remain incompletely understood. The simple search for microalbuminuria in hypertensive patients may enable the clinician to better assess absolute cardiovascular risk, and its identification may induce physicians to encourage patients to make healthy lifestyle changes and perhaps would prompt to more aggressive modification of standard cardiovascular risk factors.

Improving prognosis estimation in patients with heart failure and the cardiorenal syndrome

The coexistence of heart failure and renal dysfunction constitutes the “cardiorenal syndrome” which is increasingly recognized as a marker of poor prognosis. Patients with cardiorenal dysfunction constitute a large and heterogeneous group where individuals can have markedly different outcomes and disease courses. Thus, the determination of prognosis in this high risk group of patients may pose challenges for clinicians and for researchers alike. In this paper, we discuss the cardiorenal syndrome as it pertains to the patient with heart failure and considerations for further refining prognosis and outcomes in patients with heart failure and renal dysfunction. Conventional assessments of left ventricular function, renal clearance, and functional status can be complemented with identification of coexistent comorbidities, medication needs, microalbuminuria, anemia, biomarker levels, and pulmonary pressures to derive additional prognostic data that can aid management and provide future research directions for this challenging patient group.

High-normal albuminuria and risk of heart failure in the community

BACKGROUND

Albuminuria has been associated with cardiovascular risk, but the relationship of high-normal albuminuria to subsequent heart failure has not been well established.

STUDY DESIGN

Prospective observational study, the Atherosclerosis Risk in Communities (ARIC) Study.

SETTING & PARTICIPANTS

10,975 individuals free from heart failure were followed up from the fourth ARIC Study visit (1996-1998) through January 2006.

PREDICTOR

Urinary albumin-creatinine ratio (UACR), analyzed continuously and categorically as optimal (<5 mg/g), intermediate-normal (5-9 mg/g), high-normal (10-29 mg/g), microalbuminuria (30-299 mg/g), and macroalbuminuria (≥300 mg/g).

OUTCOMES & MEASUREMENTS

Incident heart failure was defined as a heart failure-related hospitalization or death. Cox proportional hazard models were used to calculate the HR of heart failure after adjustment for age, race, sex, estimated glomerular filtration rate (eGFR), and other cardiovascular risk factors.

RESULTS

Individuals were followed up for a median of 8.3 years and experienced 344 heart failure events. Compared with normal UACR, albuminuria was associated with a progressively increased risk of heart failure from intermediate-normal (adjusted HR, 1.54; 95% CI, 1.12-2.11) and high-normal UACR (adjusted HR, 1.91; 95% CI, 1.38-2.66) to microalbuminuria (adjusted HR, 2.49; 95% CI, 1.77-3.50) and macroalbuminuria (adjusted HR, 3.47; 95% CI, 2.10-5.72). Results were similar in secondary analyses of participants censored at the time of coronary heart disease event and along a range of eGFRs.

LIMITATIONS

UACR was measured as a single random sample.

CONCLUSIONS

Albuminuria is associated with subsequent heart failure, even in individuals with few cardiovascular risk factors and UACR within the normal range. Our results suggest that the association between albuminuria and heart failure may not be mediated fully by ischemic heart disease or kidney disease, measured using eGFR.

Relation of albuminuria to angiographically determined coronary arterial narrowing in patients with and without type 2 diabetes mellitus and stable or suspected coronary artery disease

Albuminuria is associated with atherothrombotic events and all-cause mortality in patients with and without diabetes. However, it is not known whether albuminuria is associated with atherosclerosis per se in the same manner. The present study included 914 consecutive white patients who had been referred for coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD). Albuminuria was defined as a urinary albumin/creatinine ratio ≥ 30 μg/mg. Microalbuminuria was defined as 30 to 300 μg albumin/mg creatinine, and macroalbuminuria as a urinary albumin/creatinine ratio of ≥ 300 μg/mg. The prevalence of stenoses of ≥ 50% was significantly greater in patients with albuminuria than in those with normoalbuminuria (66% vs 51%; p <0.001). Logistic regression analysis, adjusted for age, gender, diabetes, smoking, hypertension, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, C-reactive protein, body mass index, estimated glomerular filtration rate, and the use of angiotensin-converting enzyme inhibitors/angiotensin II antagonists, aspirin, and statins, confirmed that albuminuria was significantly associated with stenoses ≥ 50% (standardized adjusted odds ratio [OR] 1.68, 95% confidence interval [CI] 1.15 to 2.44; p = 0.007). The adjusted OR was 1.54 (95% CI 1.03 to 2.30; p = 0.034) for microalbuminuria and 2.55 (95% CI 1.14 to 5.72; p = 0.023) for macroalbuminuria. This association was significant in the subgroup of patients with type 2 diabetes (OR 1.66, 95% CI 1.01 to 2.74; p = 0.045) and in those without diabetes (OR 1.42, 95% CI 1.05 to 1.92; p = 0.023). An interaction term urinary albumin/creatinine ratio*diabetes was not significant (p = 0.579). In conclusion, micro- and macroalbuminuria were strongly associated with angiographically determined coronary atherosclerosis in both patients with and those without type 2 diabetes mellitus, independent of conventional cardiovascular risk factors and the estimated glomerular filtration rate.

Associations of albuminuria in patients with chronic heart failure: findings in the ALiskiren Observation of heart Failure Treatment study

AIMS

To examine the relationships between baseline characteristics and urinary albumin excretion in the extensively phenotyped patients in the ALiskiren Observation of heart Failure Treatment (ALOFT) study.

METHODS AND RESULTS

Urinary albumin creatinine ratio (UACR) was available in 190 of 302 (63%) patients randomized in ALOFT. Of these, 107 (56%) had normal albumin excretion, 63 (33%) microalbuminuria, and 20 (11%) macroalbuminuria. Compared with patients with normoalbuminuria, those with microalbuminuria had a greater prevalence of diabetes (48 vs. 26%, P = 0.005) and a lower estimated glomerular filtration rate (eGFR) (60.7 vs. 68.3 mL/min/1.73 m(2), P = 0.01). Patients with macroalbuminuria had additional differences from those with a normal UACR, including younger age (63 vs. 69 years, P = 0.02), higher glycated haemoglobin (HbA1c; 7.9 vs. 6.2%, P < 0.001), and different echocardiographic findings. Of the non-diabetic patients, 28% had microalbuminuria and 7% had macroalbuminuria. Independent predictors of UACR in these patients included N-terminal pro B-type natriuretic peptide (NT-proBNP), HbA1c, and left ventricular diastolic dimension. Increased UACR was not associated with markers of inflammation or of renin angiotensin aldosterone system activation and was not reduced by aliskiren.

CONCLUSIONS

Increased UACR is common in patients with heart failure, including non-diabetics. Urinary albumin creatinine ratio is independently associated with HbA1c and NT-proBNP, even in non-diabetic patients.

Chronic kidney disease and CHADS(2) score independently predict cardiovascular events and mortality in patients with nonvalvular atrial fibrillation

Chronic kidney disease is a risk factor for cardiovascular events, but how it relates to the prognosis associated with clinical risk factors for thromboembolism in patients with nonvalvular atrial fibrillation (AF) is not well known. Estimated glomerular filtration rate (eGFR), score for congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and stroke/transient ischemic attack (CHADS(2)), and clinical outcomes of cardiovascular events were determined in 387 patients with nonvalvular AF (mean age 66 years, 289 men, mean follow-up 5.6 ± 3.2 years). Decreased eGFR (<60 ml/min/1.73 m(2)) combined with CHADS(2) score ≥2 was associated with higher all-cause (12.9% vs 1.4% per year, hazard ratio [HR] 6.9, p <0.001) and cardiovascular (6.5% vs 0.2% per year, HR 29.7, p <0.001) mortalities compared to preserved eGFR (≥60 ml/min/1.73 m(2)) combined with CHADS(2) score <2. This was also true for rates of cardiac events (cardiac death, nonfatal myocardial infarction, or hospitalization for worsening of heart failure, 10.4% vs 1.3% per year, HR 8.9, p <0.001), ischemic stroke (3.6% vs 0.2% per year, HR 11.0, p <0.001), and cardiovascular events (cardiac events and ischemic stroke, 13.6% vs 1.5% per year, HR 8.3, p <0.001). On multivariate analysis, CHADS(2) score ≥2, decreased eGFR, and male gender independently predicted all-cause mortality. In conclusion, combined eGFR and CHADS(2) score could be an independent powerful predictor of cardiovascular events and mortality in patients with nonvalvular AF. Long-term mortality, cardiac events, and stroke risk were >8 times higher when decreased eGFR (<60 ml/min/1.73 m(2)) was present with higher CHADS(2) score (≥2).

Cardiorenal syndrome type 4-cardiovascular disease in patients with chronic kidney disease: epidemiology, pathogenesis, and management

The term cardiorenal syndrome refers to the interaction between the heart and the kidney in disease and encompasses five distinct types according to the initial site affected and the acute or chronic nature of the injury. Type 4, or chronic renocardiac syndrome, involves the features of chronic renal disease (CKD) leading to cardiovascular injury. There is sufficient epidemiologic evidence linking CKD with increased cardiovascular morbidity and mortality. The underlying pathophysiology goes beyond the highly prevalent traditional cardiovascular risk burden affecting renal patients. It involves CKD-related factors, which lead to cardiac and vascular pathology, mainly left ventricular hypertrophy, myocardial fibrosis, and vascular calcification. Risk management should consider both traditional and CKD-related factors, while therapeutic interventions, apart from appearing underutilized, still await further confirmation from large trials.