Uric acid in chronic heart failure

An Overview of Circulating Pulmonary Arterial Hypertension Biomarkers

Pulmonary arterial hypertension (PAH), also known as Group 1 Pulmonary Hypertension (PH), is a PH subset characterized by pulmonary vascular remodeling and pulmonary arterial obstruction. PAH has an estimated incidence of 15-50 people per million in the United States and Europe, and is associated with high mortality and morbidity, with patients' survival time after diagnosis being only 2.8 years. According to current guidelines, right heart catheterization is the gold standard for diagnostic and prognostic evaluation of PAH patients. However, this technique is highly invasive, so it is not used in routine clinical practice or patient follow-up. Thereby, it is essential to find new non-invasive strategies for evaluating disease progression. Biomarkers can be an effective solution for determining PAH patient prognosis and response to therapy, and aiding in diagnostic efforts, so long as their detection is non-invasive, easy, and objective. This review aims to clarify and describe some of the potential new candidates as circulating biomarkers of PAH.

The Association of Serum Uric Acid with Beta-Cell Function and Insulin Resistance in Nondiabetic Individuals: A Cross-Sectional Study

PURPOSE

Higher serum levels of uric acid (SUA) are associated with an increased risk of developing type 2 diabetes. Meanwhile, insulin resistance and beta-cell dysfunction are critical factors that mediate the progression from normal glucose tolerance to impaired fasting glucose (IFG) and type 2 diabetes. We aimed to investigate the association between SUA levels and insulin resistance and beta-cell dysfunction in individuals without diabetes, thus explicating the role of uric acid in the early stage of the natural history of type 2 diabetes.

PATIENTS AND METHODS

We used cross-sectional data from the China Health and Nutrition Survey to examine the association. Insulin resistance and beta-cell dysfunction were estimated using the homeostasis model assessment of insulin resistance (HOMA-IR) index and homeostasis model assessment of beta-cell function (HOMA-beta) index, respectively. The associations were analyzed by using partial correlation analysis and multivariate logistic regressionl analysis.

RESULTS

SUA levels were positively associated with fasting glucose, fasting insulin, HOMA-IR in the total population. After adjustment for age, drinking, smoking, living area, daily dietary nutrient intake, body mass index (BMI), estimated glomerular filtration rate (eGFR), hypertension, and dyslipidemia, compared with participants in the lowest quartile of SUA, the adjusted odds ratios for the fourth quartiles were 1.56(1.09-2.24) for IFG, 1.51(1.27-1.78) for insulin resistance, and 1.06(0.88-1.27) for beta-cell dysfunction. In the subgroup analysis, no interactions were found between serum uric acid and age, drinking status, smoking status, BMI, hypertension, or dyslipidemia (all p for interaction>0.05).

CONCLUSION

In nondiabetic individuals, SUA levels are independently associated with IFG and insulin resistance, while no significant association exists between SUA and beta-cell dysfunction.

Hyperuricemia and pulse pressure are predictive of incident heart failure in an elderly population

OBJECTIVE

This study investigated the associations between hyperuricemia, pulse pressure (PP) and heart failure (HF) hospitalization among the elders in a community population.

BACKGROUND

Hyperuricemia and PP have been related to the development of HF. Whether PP acts synergistically with hyperuricemia or mediates the causal relationship of HF, especially in the elderly, remains elucidated.

METHODS

This cohort included 1665 adults aged ≥65 years from the National Nutrition and Health Survey in Taiwan Elderly were followed. HF hospitalization (ICD-9-CM:428) was defined by the National Health Insurance Dataset. A Cox proportional hazard model and a Fine and Grays model were adjusted for the conventional cardiovascular risk factors and death as a competing risk to estimate the association between hyperuricemia, PP and HF hospitalization.

RESULTS

A total of 228 elders occurred HF hospitalization, and 692 died during a median of 12 years follow-up period, from 1999 to 2012. The incidence of HF was 14.2 per 1000 person-years. High PP (top quartile) and hyperuricemia (≥6.0 mg/dL [women] and 7.0 mg/dL [Men]) significantly correlated with incident HF (hazard ratio and 95% confidence intervals: 2.131;1.625-2.794 and 1.433;1.071-1.918, respectively). Compared with normal uric acid level and PP, combined hyperuricemia and high PP was additively related to incident HF (4.186:2.874-6.099). The associations remained after accounting for traditional cardiovascular risks, coronary heart disease as a time-dependent covariate, and mortality as a competing risk factor in the study population.

CONCLUSION

Both hyperuricemia and high PP were associated with HF hospitalization in this elderly population. Combine hyperuricemia and high PP would further improve the risk stratification in the prediction of incident HF.

HEARTEN KMS - A knowledge management system targeting the management of patients with heart failure

The aim of this work is to present the HEARTEN Knowledge Management System, one of the core modules of the HEARTEN platform. The HEARTEN platform is an mHealth collaborative environment enabling the Heart Failure patients to self-manage the disease and remain adherent, while allowing the other ecosystem actors (healthcare professionals, caregivers, nutritionists, physical activity experts, psychologists) to monitor the patient's health progress and offer personalized, predictive and preventive disease management. The HEARTEN Knowledge Management System is a tool which provides multiple functionalities to the ecosystem actors for the assessment of the patient's condition, the estimation of the patient's adherence, the prediction of potential adverse events, the calculation of Heart Failure related scores, the extraction of statistics, the association of patient clinical and non-clinical data and the provision of alerts and suggestions. The innovation of this tool lays in the analysis of multi-parametric personal data coming from different sources, including for the first time breath and saliva biomarkers, and the use of machine learning techniques. The HEARTEN Knowledge Management System consists of nine modules. The accuracy of the KMS modules ranges from 78% to 95% depending on the module/functionality.

A computational approach for the estimation of heart failure patients status using saliva biomarkers

The aim of this work is to present a computational approach for the estimation of the severity of heart failure (HF) in terms of New York Heart Association (NYHA) class and the characterization of the status of the HF patients, during hospitalization, as acute, progressive or stable. The proposed method employs feature selection and classification techniques. However, it is differentiated from the methods reported in the literature since it exploits information that biomarkers fetch. The method is evaluated on a dataset of 29 patients, through a 10-fold-cross-validation approach. The accuracy is 94 and 77% for the estimation of HF severity and the status of HF patients during hospitalization, respectively.

Serum Uric Acid level in the severity of Congestive Heart Failure (CHF)

BACKGROUND AND OBJECTIVE

It has been observed that in a clinical condition like hypoxemia there is an increase in the serum Uric acid level. The objective of our study was to find out the relationship between serum uric acid levels in the severity of Heart failure.

METHODS

We analyze 285 patients with a diagnosis of Congestive heart failure admitted in Lady Reading Hospital Peshawar from March 1st to August 2016. Age group of patients was 17- 67 years. New York Health Association (NYHA) scoring were used to access the severity of Congestive Heart Failure. Serum UA level >7.0 mg/dl was considered high.

RESULTS

Total 285 patients with CHF were analyzed with a mean age of 54±2.8 years in which males were 65.96% and 34.03% were female. 40% were in class II of New York Health Association (NYHA), 32.63% in class III and 25.61% in class IV and 1.75% were in class I. Out of 285, 59.29% met the definition of hyperuricemia. In which 83.43% were male and 16.57% were female. Most of the Hyperuricemic patients 62.13% were in age group of 51- 60 years, with a mean age of 57±4.5 years. We found a significant correlation between uric acid level and BNP (p= <0.001), and use of diuretics (p=<0.001). 34.93% of the Hyperuricemic CHF patients were in NYHA III and NYHA IV whose SUA was above 8 mg/dl as compared to 31.57% Hyperuricemic CHF patients whose SUA was below 8 mg/dl.

CONCLUSION

High serum Uric acid was observed in 59.29% of patients with CHF. The observed significant correlation between UA level and some established prognostic markers in these patients may indicate that serum UA could provide additional prognostic information in this population. SUA as a marker can be measured anywhere at a low cost to help identify high-risk patients with CHF. Lowing uric acid is expected to be a new approach for prevention and therapy of HF.

Determinants and Prognostic Impact of Hyperuricemia in Hospitalization for Acute Heart Failure

BACKGROUND

Hyperuricemia is a prognostic factor in patients with chronic heart failure, but whether uric acid level can predict clinical outcome of acute heart failure (AHF) remains to be elucidated. We therefore investigated the association of uric acid with mortality in patients hospitalized for AHF.

METHODS AND RESULTS

Data for patients hospitalized for AHF were drawn from an intramural registry. Biochemistry data, echocardiographic characteristics, and uric acid level were collected. National Death Registry was linked for the identification of mortality data. Among a total of 1,835 participants (age, 75 ± 13 years, 68% men), 794 patients died during follow-up. Patients who died were older, had lower hemoglobin and estimated glomerular filtration rate, and higher pulmonary artery systolic pressure, NT-proBNP, and uric acid. Uric acid was a significant predictor of mortality on univariate analysis (HR per 1 SD, 1.18; 95% CI: 1.11-1.26) and in multivariate Cox models (HR, 1.15; 95% CI: 1.02-1.29). Survival analysis showed an increasing risk of death along the quartile distribution of uric acid level. Given renal function, cardiac performance, and kidney perfusion as major determinants of hyperuricemia, the prognostic impact of uric acid level was diminished as renal function deteriorated.

CONCLUSIONS

Uric acid level was an independent predictor of mortality in patients hospitalized for AHF, but the prognostic impact of hyperuricemia was attenuated by worsening renal function.

Serum and aqueous xanthine oxidase levels, and mRNA expression in anterior lens epithelial cells in pseudoexfoliation

PURPOSE

The aim of this study was to determine serum and aqueous xanthine oxidase (XO) levels, and mRNA expression in anterior lens epithelial cells in pseudoexfoliation (PEX).

METHODS

In this prospective study, serum, aqueous and anterior lens capsules were taken from 21 patients with PEX and 23 normal subjects who had undergone routine cataract surgery. Serum and aqueous XO levels were analyzed using the colorimetric method. mRNA expression of XO in anterior lens epithelial cells was evaluated using reverse transcription polymerase chain reaction analysis.

RESULTS

Serum XO levels (means ± standard deviations) were 207.0 ± 86.1 IU/mL and 240.6 ± 114.1 IU/mL in the normal and PEX groups, respectively (p = 0.310). Aqueous XO levels (means ± standard deviations) were 65.5 ± 54.3 IU/mL in the normal group and 130.5 ± 117.4 IU/mL in the PEX group (p = 0.028). There was a 2.9 fold decrease in mRNA expression in anterior lens epithelial cells of PEX, which is significantly lower than the normal group (p = 0.01).

CONCLUSIONS

Higher aqueous XO levels lacking associated different serum XO suggests higher oxidative stress in the aqueous. Higher aqueous XO levels in PEX with decreased mRNA expression in anterior lens epithelial cells indicate possible overexpression of XO in other structures related to the aqueous.

Beyond gout: uric acid and cardiovascular diseases

OBJECTIVES

This article discusses the results of clinical and experimental studies that examine the association of hyperuricemia and gout with cardiovascular (CV) disease.

METHODS

Key papers for inclusion were identified by a PubMed search, and articles were selected for their relevance to the topic, according to the authors' judgment.

RESULTS AND CONCLUSIONS

Significant progress has been made in confirming an association, possibly causal, between hyperuricemia and CV outcomes. Xantine-oxidase (XO) inhibitors appear to be the most promising agents for prevention and treatment of CV consequences associated with hyperuricemia. Several small and medium sized studies have examined the effect of these agents on CV function in a variety of patient populations. Improvements in measures of endothelial function, oxidative stress, cardiac function, hemodynamics, and certain inflammatory indices have been demonstrated. Compounds for XO inhibition with more specific clinical effects and fewer side effects than allopurinol may be promising options to further explore the therapeutic potential in patients with CV disease. It is too early to make clinical recommendations with regard to the benefits of using XO inhibitor allopurinol or the novel febuxostat in patients with asymptomatic increased UA levels and high CV risk because only a small number of studies have shown that they may be beneficial in terms of CV outcomes. More studies are therefore needed to determine the potential of these drugs for reducing the risk of developing CV disease.

Nutrition intervention to decrease symptoms in patients with advanced heart failure

For a majority of patients with advanced heart failure, there is a need for complementary, non-pharmacologic interventions that could be easily implemented by health care providers to provide palliative care. Three major pathologic pathways underlying heart failure symptoms have been identified: fluid overload, inflammation, and oxidative stress. Prior research has demonstrated that three nutrients-sodium, omega-3 fatty acids, and lycopene-can alter these pathologic pathways. Therefore, the purposes of this study are to test the effects of a 6-month nutrition intervention of dietary sodium reduction combined with supplementation of lycopene and omega-3 fatty acids on heart failure symptoms, health-related quality of life, and time to heart failure rehospitalization or all-cause death. The aims of this double blind-placebo controlled study are (1) to determine the effects of a 6-month nutrition intervention on symptom burden (edema, shortness of air, and fatigue) and health-related quality of life at 3 and 6 months, and time to heart failure rehospitalization or all-cause death over 12 months from baseline; (2) compare dietary sodium intake, inflammation, and markers of oxidative stress between the nutrition intervention group and a placebo group at 3 and 6 months; and (3) compare body weight, serum lycopene, and erythrocyte omega-3 index between the nutrition intervention group and a placebo group at 3 and 6 months. A total of 175 patients with advanced heart failure will be randomized to either the nutrition intervention or placebo group.

Hyperuricemia and incident heart failure

BACKGROUND

Hyperuricemia, a known correlate of oxidative stress, is a marker for adverse prognosis among individuals with heart failure. However, the relationship between hyperuricemia and the risk for incidence of heart failure in a community-based population has not been studied.

METHODS AND RESULTS

We prospectively analyzed the relationship between serum uric acid concentration at baseline and subsequent heart failure among the participants of the Framingham Offspring cohort (n=4912; mean baseline age, 36 years; 52% women). By using Cox regressions, we calculated the risk of heart failure with increasing serum uric acid after adjusting for sex, age, smoking, body mass index, renal dysfunction, diuretics, systolic blood pressure, valvular heart disease, diabetes, alcohol, and use of antihypertensive medications. The incidence rates of heart failure were approximately 6-fold higher among those at the highest quartile of serum uric acid (>6.3 mg/dL) compared with those at the lowest quartile (<3.4 mg/dL). The adjusted hazard ratio for the highest quartile of serum uric acid compared with the lowest was 2.1 (1.04 to 4.22). The relationship between hyperuricemia and heart failure was found in participants without metabolic syndrome and other subgroups as well.

CONCLUSIONS

Hyperuricemia is a novel, independent risk factor for heart failure in a group of young general community dwellers. This has implications for development of preventive strategies for heart failure.

Role of urate, xanthine oxidase and the effects of allopurinol in vascular oxidative stress

Oxidative stress plays an important role in the progression of vascular endothelial dysfunction. The two major systems generating vascular oxidative stress are the NADPH oxidase and the xanthine oxidase pathways. Allopurinol, a xanthine oxidase inhibitor, has been in clinical use for over 40 years in the treatment of chronic gout. Allopurinol has also been shown to improve endothelial dysfunction, reduce oxidative stress burden and improve myocardial efficiency by reducing oxygen consumption in smaller mechanistic studies involving various cohorts at risk of cardiovascular events. This article aims to explain the role of xanthine oxidase in vascular oxidative stress and to explore the mechanisms by which allopurinol is thought to improve vascular and myocardial indices.

Association between hyperuricemia and incident heart failure among older adults: a propensity-matched study

BACKGROUND

The association between hyperuricemia and incident heart failure (HF) is relatively unknown.

METHODS

Of the 5461 community-dwelling older adults, >or=65 years, in the Cardiovascular Health Study without HF at baseline, 1505 had hyperuricemia (baseline serum uric acid >or=6 mg/dL for women and >or=7 mg/dL for men). Using propensity scores for hyperuricemia, estimated for each participant using 64 baseline covariates, we were able to match 1181 pairs of participants with and without hyperuricemia.

RESULTS

Incident HF occurred in 21% and 18% of participants respectively with and without hyperuricemia during 8.1 years of mean follow-up (hazard ratio {HR} for hyperuricemia versus no hyperuricemia, 1.30; 95% confidence interval {CI}, 1.05-1.60; P=0.015). The association between hyperuricemia and incident HF was significant only in subgroups with normal kidney function (HR, 1.23; 95% CI, 1.02-1.49; P=0.031), without hypertension (HR, 1.31; 95% CI, 1.03-1.66; P=0.030), not receiving thiazide diuretics (HR, 1.20; 95% CI, 1.01-1.42; P=0.044), and without hyperinsulinemia (HR, 1.35; 95% CI, 1.06-1.72; P=0.013). Used as a continuous variable, each 1 mg/dL increase in serum uric acid was associated with a 12% increase in incident HF (HR, 1.12; 95% CI, 1.03-1.22; P=0.006). Hyperuricemia had no association with acute myocardial infarction or all-cause mortality.

CONCLUSIONS

Hyperuricemia is associated with incident HF in community-dwelling older adults. Cumulative data from our subgroup analyses suggest that this association is only significant when hyperuricemia is a marker of increased xanthine oxidase activity but not when hyperuricemia is caused by impaired renal elimination of uric acid.

Association of incident gout and mortality in dialysis patients

Previous studies have shown that gout is associated with an increased risk for cardiovascular mortality in the general population, but this has not been well studied in patients with ESRD. In this study, the incidence of gout and its association with mortality was evaluated in 259,209 patients in the United States Renal Data System. Overall, the incidence of gout in the first year of dialysis was 5% and in the first 5 yr was 15.4%. Independent risk factors for gout in adjusted analyses included black race, older age, female gender, hypertension, ischemic heart disease, congestive heart failure, and alcohol use. Factors associated with a lower risk for gout included a history of diabetes, smoking, and peripheral vascular disease. Time-dependent Cox regression analysis suggested that an episode of gout was independently associated with a 1.5-fold increase in mortality risk (adjusted hazard ratio 1.49; 95% confidence interval 1.43 to 1.55). The mechanisms underlying this association require further study.

Hyperuricaemia predicts poor outcome in patients with mild to moderate chronic heart failure

BACKGROUND

In severe chronic heart failure (CHF) elevated serum levels of uric acid (UA) predict poor survival. This study investigates whether hyperuricaemia (defined as serum UA level > or = 6.5 mg/dL) extends its prognostic value on population with less advanced CHF.

METHODS

We studied 119 consecutive patients with stable, mild-moderate CHF (88 men, age: 64+/-11 years, NYHA class I/II/III: 9/65/45, LVEF: 32+/-8%).

RESULTS

Serum UA level (mean: 6.2+/-2.0 mg/dL, range: 2.0-16.2 mg/dL) increased in parallel to CHF severity expressed as NYHA class (4.9+/-1.1 vs. 5.7+/-1.5 vs. 7.2+/-2.4 mg/dL, NYHA I vs. II vs. III; NYHA I, II vs. III, p<0.01), inversely correlated with peak oxygen consumption (r=-0.39, p<0.01) and LVEF (r=-0.31, p<0.01), but not with renal function (expressed as creatinine clearance calculated from Cockcroft-Gault formula; r=-0.14, p>0.1), and predicted inflammatory status as evidenced by the correlation with C-reactive protein (r=0.31, p=0.003). Hyperuricaemia was detected in 48 (40%) patients. During follow-up (mean: 580+/-209 days, > 18 months in all survivors), 27 (23%) patients died. Hyperuricaemia was related to impaired survival in univariate (HR 2.8, 95%CI: 1.3-6.1, p=0.01) and multivariate analyses (adjusted for NYHA class and impaired renal function--the only mortality predictors in this population; p<0.05). The 18-month survival for CHF patients with hyperuricaemia was 71% (95% CI: 58-84%) vs. 89% (95% CI: 81-96%) in those with normal UA level (p=0.01).

CONCLUSION

In patients with mild-moderate CHF, hyperuricaemia predicts exercise intolerance and inflammatory activation and is strongly and independently related to poor prognosis. Whether elevated serum UA level may become a novel therapeutic target in CHF, deserves further studies.

Predictors of in-hospital mortality after percutaneous coronary intervention for cardiogenic shock

OBJECTIVES

The mortality of patients with cardiogenic shock (CS) complicating ST elevation acute myocardial infarction (STEMI) remains high, despite early revascularization. Current knowledge of predictors of death is limited.

BACKGROUND

The pathophysiologic understanding of CS after acute myocardial infarction has shifted from a mere hemodynamic disorder to a more complex approach including imbalance in metabolic functions.

METHODS

In 45 consecutive patients (71.4+/-13 years) with CS complicating STEMI treated with primary percutaneous coronary intervention (PCI) serum levels of lactate, glucose and uric acid on coronary care unit (CCU) admission were measured. The end-point was in-hospital death.

RESULTS

The following parameters, on CCU admission, were univariate predictors of in-hospital mortality: serum glucose >200 mg/dl (OR=11.3, p=0.002), serum creatinine >1.5 mg/dl (OR=12.7, p=0.003), uric acid >6.5 mg/dl (OR=6.7, p=0.016), lactate >6.5 mmol/l (OR=54, p<0.0001), age > or =75 years (OR=8.5, p=0.002), history of hypertension (OR=8.3, p=0.003) and TIMI flow post PCI < or = 2 (OR=12.9, p=0.02). At multivariate analysis, after adjustment for sex, age, hypertension and diabetes, lactate >6.5 mmol/l and TIMI flow post PCI < or = 2 were still independent predictors of in-hospital mortality (OR=295, p=0.01; OR=19.5, p=0.04, respectively).

CONCLUSIONS

Hyperlactatemia, hyperglycemia and increased levels of uric acid on CCU admission are univariate predictors of in-hospital death. Moreover, at multivariate analysis, hyperlactatemia (>6.5 mmol/l) is an independent indicator of in-hospital death in CS patients complicating STEMI.

Crystal-induced arthropathies: recent investigative advances

PURPOSE OF REVIEW

To highlight recent investigations that have stimulated renewed interest in crystal-induced arthropathies.

RECENT FINDINGS

Specific diet-related and alcohol-related risks for gout have been clarified, and alternative urate-lowering treatments likely to benefit patients with difficult-to-treat gout are in development. Progress toward understanding mechanisms underlying the renal deficits defining most cases of gout includes characterization of a urate-specific renal tubule transporter explaining many aspects of renal uric acid handling and identification of mutations in the UMOD gene, resulting in altered uromodulin protein in the gout-associated disorders familial juvenile hyperuricemic nephropathy and medullary cystic kidney disease type 2. A genetic marker associated with the risk for severe allopurinol toxicity has been reported. Hyperuricemia and gout are increasing in incidence, as is complicated gout, especially among the elderly and patients with cardiovascular and renal comorbidities, organ transplants, or complex concomitant medication regimens. Asymptomatic hyperuricemia is clearly associated with hypertension, chronic kidney disease, cardiovascular disease, and the insulin resistance syndrome, and the pathogenetic significance of these associations is under intensive study. Mutation in the ANKH gene has been found among some patients with sporadic as well as familial calcium pyrophosphate deposition disease.

SUMMARY

The results of these clinical, epidemiologic, experimental, and therapeutic investigations presage advances in the management of crystal-induced arthropathies.

Therapeutic effects of xanthine oxidase inhibitors: renaissance half a century after the discovery of allopurinol

The prototypical xanthine oxidase (XO) inhibitor allopurinol, has been the cornerstone of the clinical management of gout and conditions associated with hyperuricemia for several decades. More recent data indicate that XO also plays an important role in various forms of ischemic and other types of tissue and vascular injuries, inflammatory diseases, and chronic heart failure. Allopurinol and its active metabolite oxypurinol showed considerable promise in the treatment of these conditions both in experimental animals and in small-scale human clinical trials. Although some of the beneficial effects of these compounds may be unrelated to the inhibition of the XO, the encouraging findings rekindled significant interest in the development of additional, novel series of XO inhibitors for various therapeutic indications. Here we present a critical overview of the effects of XO inhibitors in various pathophysiological conditions and also review the various emerging therapeutic strategies offered by this approach.