Hyperuricemia in acute heart failure. More than a simple spectator?

Acute heart failure: mechanisms and pre-clinical models-a Scientific Statement of the ESC Working Group on Myocardial Function

While chronic heart failure (CHF) treatment has considerably improved patient prognosis and survival, the therapeutic management of acute heart failure (AHF) has remained virtually unchanged in the last decades. This is partly due to the scarcity of pre-clinical models for the pathophysiological assessment and, consequently, the limited knowledge of molecular mechanisms involved in the different AHF phenotypes. This scientific statement outlines the different trajectories from acute to CHF originating from the interaction between aetiology, genetic and environmental factors, and comorbidities. Furthermore, we discuss the potential molecular targets capable of unveiling new therapeutic perspectives to improve the outcome of the acute phase and counteracting the evolution towards CHF.

Associations of long-term mortality with serum uric acid at admission in acute decompensated heart failure with different phenotypes

BACKGROUND AND AIMS

It remains unclear whether the long-term prognostic value of serum uric acid (SUA) at admission differs in acute decompensated heart failure (HF) patients across the spectrum of left ventricular ejection fraction (EF).

METHODS AND RESULTS

In 2375 patients (38.9% women; mean age, 68.8 years), we assessed the risk of long-term (>1 year) all-cause mortality associated with per 1-SD increase in SUA at admission, using multivariable Cox regression in HF with preserved (HFpEF), mildly reduced (HFmrEF) and reduced (HFrEF) EF. During a median follow-up of 4.1 years, the long-term mortality rate was 39.9%. In all patients, the multivariable-adjusted hazard ratio (HR) expressing the risk of long-term mortality associated with SUA was 1.18 (95% CI, 1.11-1.26; P < 0.001). Compared with the low tertile of the SUA distribution, the sex- and age-adjusted cumulative incidence of long-term mortality was higher in the top tertile. In patients with HFpEF and HFrEF, SUA predicted the risk of long-term mortality with HRs amounting to 1.12 (95% CI, 1.02-1.21; P = 0.012) and 1.28 (95% CI, 1.12-1.47; P < 0.001), respectively. However, there were no associations between the risk of mortality and SUA in HFmrEF. Furthermore, age, sex, NYHA class, and the prevalence of coronary heart disease interacted significantly with SUA for predicting long-term mortality.

CONCLUSION

Higher levels of SUA at admission were associated with higher risk of long-term mortality in patients with different HF subtypes. The risk conferred by SUA was age and sex dependent. Our observations highlight that measuring SUA at admission may help to improve risk stratification.

Prognostic impacts of serum uric acid levels in patients with chronic heart failure: insights from the CHART-2 study

AIMS

Prognostic impacts of serum uric acid (UA) levels in patients with chronic heart failure (CHF) remain inconclusive, especially for the whole range of serum UA levels.

METHODS AND RESULTS

In the Chronic Heart Failure Registry and Analysis in the Tohoku District-2 (CHART-2) study, we enrolled 4652 consecutive patients with CHF and classified them into four groups based on baseline serum UA levels by the Classification and Regression Tree: G1 (<3.8 mg/dL, N = 313), G2 (3.8-7.1 mg/dL, N = 3070), G3 (7.2-9.2 mg/dL, N = 1018), and G4 (>9.2 mg/dL, N = 251). Mean age was 71 ± 12, 69 ± 12, 68 ± 13, and 69 ± 15 years in G1, G2, G3, and G4, respectively (P < 0.001). During the median follow-up of 6.3 years, in G1, G2, G3, and G4, 111 (35%), 905 (29%), 370 (36%), and 139 (55%) patients died and 79 (25%), 729 (24%), 300 (29%), and 115 (46%) experienced heart failure hospitalization, respectively (both P < 0.001). G1 was characterized by a significantly high prevalence of women as compared with G2, G3, and G4 (59%, 32%, 24%, and 23%, respectively). Serum creatinine levels (0.8 ± 0.4, 0.9 ± 0.4, 1.2 ± 0.6, and 1.4 ± 0.8 mg/dL, respectively), prevalence of atrial fibrillation (34%, 39%, 45%, and 50%, respectively), and diuretics use (36%, 45%, 67%, and 89%, respectively) increased from G1, G2, G3 to G4 (all P < 0.001), while left ventricular ejection fraction decreased from G1, G2, G3 to G4 (59 ± 15, 58 ± 15, 54 ± 15, and 52 ± 17%, respectively, P < 0.001). Multivariable Cox proportional hazards models showed that, as compared with G2, both G1 and G4 had increased incidence of all-cause death [adjusted hazard ratio (aHR) 1.34, 95% confidence interval (CI) 1.08-1.67, P = 0.009; aHR 1.28, 95% CI 1.02-1.61, P = 0.037, respectively] and heart failure admission (aHR 1.39, 95% CI 1.09-1.78, P = 0.008 and aHR 1.35, 95% CI, 1.06-1.71, P = 0.014, respectively). This U-shaped relationship was evident in the elderly patients. Furthermore, abnormal transitions to either higher or lower levels of serum UA from G2 were associated with increased mortality (aHR 1.29, 95% CI 1.06-1.57, P = 0.012; aHR 1.57, 95% CI 1.12-2.20, P = 0.009).

CONCLUSIONS

These results demonstrate that serum UA levels have the U-shaped prognostic effects and abnormal transitions to either higher or lower levels are associated with poor prognosis in the elderly patients with CHF.

Clinical Implications of Uric Acid in Heart Failure: A Comprehensive Review

Affecting more than 26 million people worldwide and with rising prevalence, heart failure (HF) represents a major global health problem. Hence, further research is needed in order to abate poor HF outcomes and mitigate significant expenses that burden health care systems. Based on available data, experts agree that there is an urgent need for a cost-effective prognostic biomarker in HF. Although a significant number of biomarkers have already been investigated in this setting, the clinical utility of adding biomarker evaluation to routine HF care still remains ambiguous. Specifically, in this review we focused on uric acid (UA), a purine metabolism detriment whose role as cardiovascular risk factor has been exhaustingly debated for decades. Multiple large population studies indicate that UA is an independent predictor of mortality in acute and chronic HF, making it a significant prognostic factor in both settings. High serum levels have been also associated with an increased incidence of HF, thus expanding the clinical utility of UA. Importantly, emerging data suggests that UA is also implicated in the pathogenesis of HF, which sheds light on UA as a feasible therapeutic target. Although to date clinical studies have not been able to prove the benefits of xanthine oxidase in HF patients, we discuss the putative role of UA and xanthine oxidase in the pathophysiology of HF as a therapeutic target.

Prognostic value of serum uric acid in patients with acute heart failure: A meta-analysis

BACKGROUND

Conflicting results have been reported on the prognostic significance of serum uric acid (SUA) in patients with acute heart failure (AHF). This meta-analysis aimed to determine the prognostic significance of SUA level in patients with AHF.

METHODS

We made a comprehensive literature search in Pubmed and Embase databases from inception to April 6, 2018. All available observational studies or post hoc analysis of randomized controlled trial that evaluated the prognostic value of SUA level in patients with AHF were eligible. Outcome of interests were all-cause mortality and the combined endpoint of death or readmission. Prognostic values of SUA level were summarized as higher vs lower SUA category or per 1 mg/ml SUA rise.

RESULTS

Ten studies involving 12,854 AHF patients were identified and analyzed. AHF patients with the highest SUA level had an increased risk of all-cause mortality (risk ratio [RR] 1.43; 95% confidence intervals [CI] 1.31-1.56) and combined endpoint of death or readmission (RR 1.68; 95% CI 1.33-2.13) after adjusting potential variables. In addition, per 1 mg/ml SUA rise significantly increased by 11% and 12% higher risk all-cause mortality and combined endpoint of death or readmission, respectively. A leave out 1 study sensitivity analysis confirmed the reliability of the pooling effect sizes.

CONCLUSION

This meta-analysis indicates that elevated SUA level independently predicts all-cause mortality and the combined endpoint of death or readmission in AHF patients. Measurement of SUA level may improve risk stratification of adverse outcomes in these patients.

Predictors of cardiovascular outcome and rehospitalization in elderly patients with heart failure

BACKGROUND

Heart failure (HF) is a major public health problem and represents the only cardiac disease continuing to increase in prevalence, in particular among elderly patients. The frequent rehospitalizations have a negative impact on quality of life of patients with HF, constituting a substantial cost for patients and the health system. The aim of this review was to look into biochemical, echocardiographic and socioeconomical parameters as predictors of clinical outcomes and rehospitalizations.

METHODS

This narrative review is based on the material searched for and obtained via PubMed from January 2000 up to March 2018. The search terms we used were as follows: "elderly, heart failure, cardiovascular" in combination with "biomarker, echocardiography and hospitalization."

RESULTS

This review analyses the potential predictive role of biochemical and echocardiographic and socioeconomical parameters on clinical outcomes (particularly cardiovascular) and hospital readmissions in patients with chronic HF. We focused on risk stratification of elderly patients with HF, who constitute a category of frail subjects at higher risk for readmission to hospital.

CONCLUSIONS

In elderly subjects with chronic HF, the risk stratification could benefit of a multiparametric approach combining biochemical, echocardiographic, demographic and socioeconomical parameters, thus ensuring a better quality of life and at the same time a better allocation of financial resources.

The prognostic impact of uric acid in patients with severely decompensated acute heart failure

BACKGROUND

The serum level of uric acid (UA) is a well-known prognostic factor for heart failure (HF) patients. However, the prognostic impact of hyperuricemia and the factors that induce hyperuricemia in acute HF (AHF) patients are not well understood.

METHODS AND RESULTS

Eight hundred eighty-nine AHF patients were enrolled in this study. The patients were assigned into a low UA group (UA≤7.0mg/dl, n=495) or a high UA group (UA>7.0mg/dl, n=394) according to their UA level on admission. A Kaplan-Meier curve showed that the survival rate of the low UA group was significantly higher than that of the high UA group. A multivariate Cox regression model identified that a high UA level (HR: 1.192, 95%CI 1.112-1.277) was an independent predictor of 180-day mortality. A multivariate logistic regression model for a high serum UA level on admission indicated that chronic kidney disease (CKD) (OR: 2.030, 95%CI: 1.298-3.176, p=0.002) and the administration of loop diuretics before admission (OR: 1.556, 95%CI: 1.010-2.397, p=0.045) were independent factors. The prognosis, including all-cause death and HF events, was significantly poorer among patients who had a high UA level who had previously used loop diuretics and among CKD patients with a high UA level than among other patients.

CONCLUSIONS

The serum UA level was an independent predictor in patients who were hospitalized during an emergent situation for AHF. An elevated serum UA level on admission was associated with the presence of CKD and the use of loop diuretics. These factors were also associated with adverse outcomes in hyperuricemic patients with AHF.

Serum uric acid is associated with mortality and heart failure hospitalizations in patients with complicated myocardial infarction: findings from the High-Risk Myocardial Infarction Database Initiative

AIMS

Serum uric acid (SUA) levels are associated with poorer outcomes in healthy cohorts and patients with stable and unstable coronary heart disease. We investigated the relationship between SUA and clinical outcomes in subjects with acute myocardial infarction (MI) complicated by reduced left ventricular (LV) function, heart failure (HF), or both.

METHODS AND RESULTS

Univariable and multivariable Cox proportional hazards modelling was performed to study the association of baseline SUA and all-cause mortality, cardiovascular (CV) mortality, and HF hospitalization in an individual patient meta-analysis of four merged large randomized trials (CAPRICORN, EPHESUS, OPTIMAAL, and VALIANT). Three trials (excluding VALIANT) reported SUA, which was available in a total of 12 677 subjects. The ranges of SUA for quartiles I-IV were 45-280, 281-344, 345-420, and 420-1640 mmol/L, respectively. While almost 90% of patients in the lowest SUA quartile were alive after a mean follow-up of 23 ± 11 months, <70% were alive in the highest SUA quartile. Compared with the lowest SUA quartile as reference, hazard ratios (HRs) and 95% confidence intervals (CIs) of SUA quartiles III and IV showed an increase in all-cause mortality [HR 1.18, 95% CI 0.95-1.46, and HR 1.36, 95% CI 1.11-1.67) and CV mortality (HR 1.27, 95% 1.01-1.61, and HR 1.47, 95% CI 1.17-1.83). SUA quartiles III and IV also exhibited increased HF hospitalization (HR 1.22, 95% CI 1.09-1.36, and HR 1.28, 95% CI 1.14-1.43; P < 0.001 for all comparisons) in multivariable analyses. The addition of SUA was associated with a significant improvement in reclassification to predict CV mortality (net reclassification improvement 17.6%, 95% CI 14.9-20.5%, P < 0.001).

CONCLUSIONS

Elevated SUA is associated with poor outcomes in patients after MI complicated by reduced LV function, HF, or both. The quantification of SUA, a low-cost routinely available biomarker, could improve risk stratification of patients with complicated MI.

Uric acid and xanthine oxidase in heart failure - Emerging data and therapeutic implications

The role of hyperuricaemia as cardiovascular risk factor has exhaustingly been debated for decades. While the association of elevated uric acid (UA) levels with increased mortality risk as convincingly been shown, the question whether UA is independently predictive of just a related effect within a more complex risk factor profile (including metabolic, inflammatory and haemodynamic risk factors) is still a matter of dispute. In heart failure the independent prognostic and functional impact of elevated UA has not only been shown but also the pathophysiologic mechanism(s) and the potential of targeted therapeutic interventions have been investigated in some detail. The emerging picture suggests the increased activity of the enzyme xanthine oxidase (XO) with corresponding increased production of free oxygen radical (ROS) as a main underlying principle with the resulting increase in UA levels being mostly a marker of this up-regulated pathway. While this concept will not diminish the value of UA as a prognostic marker, it provides the basis for a novel metabolic treatment option and the means to identify those patients most eligible for this tailored therapy. This review will summarize the recent evidence on XO as a novel and promising therapeutic target in heart failure.

Relation of serum uric acid levels and outcomes among patients hospitalized for worsening heart failure with reduced ejection fraction (from the efficacy of vasopressin antagonism in heart failure outcome study with tolvaptan trial)

We investigated the clinical profiles associated with serum uric acid (sUA) levels in a large cohort of patients hospitalized for worsening chronic heart failure with ejection fraction (EF) ≤40%, with specific focus on gender, race, and renal function based interactions. In 3,955 of 4,133 patients (96%) with baseline sUA data, clinical characteristics and outcomes were compared across sUA quartiles. The primary end points were all-cause mortality and a composite of cardiovascular mortality or heart failure hospitalization. Interaction analyses were performed for gender, race, and baseline renal function. Median follow-up was 9.9 months. Mean sUA was 9.1 ± 2.8 mg/dl and was higher in men than in women (9.3 ± 2.7 vs 8.7 ± 3.0 mg/dl, p <0.001) and in blacks than in whites (10.0 ± 2.7 vs 9.0 ± 2.8 mg/dl, p <0.001). Higher sUA was associated with lower systolic blood pressure and EF, higher natriuretic peptides, and more impaired renal function. After accounting for 24 baseline covariates, in patients with enrollment estimated glomerular filtration rate ≥30 ml/min/1.73 m(2), sUA was strongly associated with increased all-cause mortality (hazard ratio 1.44, 95% confidence interval 1.22 to 1.69, p <0.001) and the composite end point (hazard ratio 1.44, 95% confidence interval 1.26 to 1.64, p <0.001). However, in patients with estimated glomerular filtration rate <30 ml/min/1.73 m(2), sUA was not related with either end point (both p >0.4). Adjusted interaction analyses for gender, race, and admission allopurinol use were not significant. In conclusion, sUA is commonly elevated in patients hospitalized for worsening chronic heart failure and reduced EF, especially in men and blacks. The prognostic use of sUA differs by baseline renal function, suggesting different biologic and pathophysiologic significance of sUA among those with and without significant renal dysfunction.

Serelaxin: a novel therapy for acute heart failure with a range of hemodynamic and non-hemodynamic actions

Acute heart failure (AHF) is characterized by high morbidity and mortality and high costs. Although the treatment of AHF has not changed substantially in recent decades, it is becoming clear that treatment strategies for AHF need to address both the immediate hemodynamic abnormalities giving rise to congestion as well as prevent organ damage that can influence long-term prognosis. Serelaxin, the recombinant form of human relaxin-2, a naturally occurring peptide hormone, has been found to significantly improve symptoms and signs of AHF, prevent in-hospital worsening heart failure, as well as significantly improve 180-day cardiovascular and all-cause mortality after a 48-h infusion commenced within 16 h of presentation (RELAX-AHF study). Available data suggest that the clinical benefits may be attributable to a potential combination of multiple actions of serelaxin, including improving systemic, cardiac, and renal hemodynamics, and protecting cells and organs from damage via anti-inflammatory, anti-cell death, anti-fibrotic, anti-hypertrophic, and pro-angiogenic effects. This manuscript describes the short- and long-term effects of serelaxin in AHF patients, analyzing how these effects can be explained by taking into account the range of hemodynamic and non-hemodynamic actions of serelaxin. In addition, this paper also addresses several aspects related to the role of serelaxin in the therapy of AHF that remain to be clarified and warrant further investigation.

Uric acid in heart failure: a biomarker or therapeutic target?

There is a need for a cost-effective prognostic biomarker in heart failure (HF). Substantial evidence suggests that uric acid (UA) is an independent marker for adverse prognosis in acute and chronic HF of varying severity. Whether UA is a merely a marker of poor prognosis or is an active participant in disease pathogenesis is currently unknown. In the setting of HF, at least two different processes can be responsible for increased UA: increased production, which may result from oxidative stress, and decreased excretion due to renal insufficiency, which can be a consequence of cardio-renal syndrome, renal congestion, or comorbidities. While pioneer studies have raised the possibility of preventing HF through the use of UA lowering agents, namely xanthine oxidase inhibitors and uricosurics, the literature is still conflicting on whether the reduction in UA will result in a measurable clinical benefit. In this review, we examine the evidence relating UA to HF prognosis, the mechanisms that contribute to increased UA levels in HF, and future novel treatments aimed at reducing UA levels.

Association and interaction analysis of metabolic syndrome and serum uric acid on diastolic heart failure

BACKGROUND

We aimed to assess the extent to which metabolic syndrome (MetS) and serum uric acid (UA) and its interaction impact on diastolic heart failure (DHF).

MATERIALS AND METHODS

A total of 133 patients with DHF and 118 age- and gender-matched control subjects were studied. Echocardiography was used to assess left ventricular (LV) diastolic function. MetS was defined by suggestions of international diabetes federation (IDF, 2005). The association between MetS or UA and DHF was assessed by multivariate logistic regression analysis (MLR) controlling confounders. The interaction between MetS and UA on DHF was assessed by generalized linear model (GLM) and MLR analysis.

RESULTS

MetS and UA were independent predictors of DHF after adjustment for all variables (OR=0.833~2.27, ORUA=1.003 and p<0.05 for all). There was an interaction effect of MetS and UA on DHF (ORInt=2.41~2.66, pInt<0.05).

CONCLUSION

The findings of the present study suggested that MetS or UA is associated with DHF, and that MetS interacts with UA to impact on DHF.

Potentials of cystatin C and uric acid for predicting prognosis of heart failure

Few studies have explored the clinical potentials of combined Cystatin C (Cys) and uric acid (UA) in heart failure (HF). The authors evaluated Cys and UA as predictors of clinical outcomes compared with conventional renal biomarkers. This prospective cohort study included 587 HF patients presenting with dyspnea. At admission, Cys, UA, and other renal measures including serum urea nitrogen (BUN), creatinine (Cr), and glomerular filtration rate (GFR) were obtained. The primary endpoint was the composite of cardiac death and rehospitalization for worsening HF. During a 25-month median follow-up period, 68 patients experienced clinical outcomes: 9 cardiac deaths and 59 HFs. They showed higher BUN and Cr values and lower GFR. Within these parameters, Cys and UA had the most favorable area under the curves, and patients with Cys ≥0.8 mg/L and UA ≥6.6 mg/dL showed more frequent events. The net reclassification improvement analysis showed the combination of Cys and UA had a greater incremental effect for cardiac prognosis. On multivariate Cox hazard analysis, Cys and UA were independent predictive markers for clinical outcomes. In HF patients presenting with dyspnea, Cys and UA appear to be more useful predictors of clinical events than other renal measures.

Relationship between Uric Acid Levels and Diagnostic and Prognostic Outcomes in Acute Heart Failure

OBJECTIVES

We evaluated the association of plasma uric acid alone and in combination with b-type natriuretic peptide (BNP) for emergency department (ED) diagnosis and 30-day prognosis in patients evaluated for acute heart failure (AHF).

METHODS

We prospectively enrolled 322 adult ED patients with suspected AHF. Wilcoxon rank sum test, multivariable logistic regression and likelihood ratio (LR) tests were used for statistical analyses.

RESULTS

Uric acid's diagnostic utility was poor and failed to show significant associations with 30-day clinical outcomes. Uric acid also did not add significantly to BNP results.

CONCLUSION

Among ED patients with suspected AHF, uric acid has poor diagnostic and prognostic utility.

Xanthine oxidase and uric acid in cardiovascular disease: clinical impact and therapeutic options

The association between increased uric acid (UA) levels and cardiovascular disease (CVD) has been observed and studied for many decades. The value of UA as an independent factor within the metabolic risk profile for prediction of CVD in the normal population remains an issue of ongoing discussion. In turn, increasing evidence suggests that among patients with established CVD such as heart failure UA is an independent marker of disease state and prognosis. Increased UA levels may be an indicator of up-regulated activity of xanthine oxidase, a powerful oxygen radical-generating system in human physiology. Increased reactive oxygen species (ROS) accumulation contributes to endothelial dysfunction, metabolic and functional impairment, inflammatory activation, and other features of cardiovascular pathophysiology. Accordingly, inhibition of xanthine oxidase activity has been shown to improve a range of surrogate markers in patients with CVD, but this effect seems to be confined to hyperuricemic patients because disappointing results were reported in studies with normouricemic patients. In this review we summarize current evidence on hyperuricemia in CVD. The value of UA as a biomarker and as a potential therapeutic target for tailored metabolic treatment in CVD is discussed.

Altered serum selenium and uric acid levels and dyslipidemia in hemodialysis patients could be associated with enhanced cardiovascular risk

In the present study, the first objective was to follow up serum selenium (Se) concentrations in 117 hemodialysis patients (HPs) during a 2-year longitudinal study, relating concentrations to biochemical indexes (n = 6; namely lipoprotein profile, uric acid, and total protein levels). It was also evaluated whether the disease is associated with an enhanced cardiovascular risk. A healthy control group (n = 50) was also studied. Mean serum Se levels were significantly lower in HPs than in the controls (p = 0.002); mean levels significantly increased from the first to third blood sampling (p < 0.001). HPs showed a marked dyslipidemia, with a significant reduction in total cholesterol, low-density lipoprotein, and high-density lipoprotein cholesterol levels and a significant increase in triglyceride levels (p < 0.001). HPs showed a marked hyperuricemia (p < 0.001). Serum selenium levels in HPs were correlated negatively with uric acid levels (inflammation biomarker; p < 0.01). In HPs, serum Se levels are reduced due to their disease (chronic renal failure). Serum Se levels rose until the third blood sampling. The marked dyslipidemia and hyperuricemia found in HPs and the negative correlation between the serum Se and uric acid levels in these patients could imply an enhanced cardiovascular risk.

Uric acid, heart failure survival, and the impact of xanthine oxidase inhibition

Increasing evidence suggests that serum uric acid (UA), a product of xanthine oxidase (XO), may be a useful marker for metabolic, hemodynamic, and functional staging in heart failure (HF) and a valid predictor of survival in HF patients. Recent data support an expanded role for UA and the XO pathway in the pathogenesis of HF, as studies have shown that an elevation in the enzymatic activity of XO can lead to increases in oxidative stress, endothelial dysfunction, and reduced myocardial function. Numerous population studies have previously reported that elevated UA levels are an independent predictor of cardiovascular mortality, and recent evidence suggests that lowering serum levels of UA may lead to improved outcomes in HF patients. The question of whether UA is only a marker rather than a causal factor in the pathogenesis of HF remains. Regardless of whether UA levels are ready for routine clinical use, either as a prognostic factor or novel therapeutic target, further prospective studies are necessary to demonstrate that routine measurement or reduction of UA levels improves outcomes in HF patients.

Uric acid as a predictor of all-cause mortality in heart failure: a meta-analysis

Serum uric acid (SUA) is a product of xanthine oxidase (XO). Apoptosis and tissue hypoxia lead to increased purine catabolism, which, in turn, increases XO activity and subsequently SUA levels. The purpose of this study was to perform a meta-analysis to evaluate the evidence supporting SUA as a predictor of all-cause mortality in patients with heart failure (HF) and to determine the SUA cut-off for the increase in risk. A search of the MEDLINE database (1966 to March 2009) supplemented by manual searches of bibliographies of key relevant articles was performed. The authors selected all cohort studies in which SUA was measured and mortality was reported in patients with HF. The pooled relative risk (RR) with the corresponding 95% confidence interval (CI) for all-cause mortality using the fixed-effects method was calculated. The effects of SUA on all-cause mortality at different SUA cut-offs using meta-regression was evaluated. The search strategy yielded 358 studies, of which only 6 met our eligibility criteria. The studies, however, comprised 1456 evaluable patients with HF, with a median ejection fraction of 32% (range, 26%-40%). The RR of all-cause mortality was 2.13 (95% CI, 1.78-2.55) for SUA>6.5 mg/dL compared with <6.5 mg/dL SUA level. There was a linear association (P<.01) between SUA and mortality after 7 mg/dL. Uric acid is an important prognostic marker for all-cause mortality in HF. SUA levels >7 mg/dL are associated with higher all-cause mortality.

Serum uric acid levels correlate with filling pressures in systolic heart failure

The authors studied the relationship between liver function tests and serum uric acid level with clinical and hemodynamic profiles in heart failure. Fifty patients (aged 44±15 years; 74.5% men) with an ejection fraction (EF) <35% were enrolled and clinical assessment was performed. Hemodynamic indices (including pulmonary arterial pressure [PAP], pulmonary capillary wedge pressure [PCWP], and cardiac index were studied by standard Edwards Lifesciences Swan-Ganz catheters, and liver function tests and serum uric acid level were measured simultaneously. Fifty age- and sex-matched controls with normal EF were also studied. A total of 73% of patients had ischemic cardiomyopathy. Mean uric acid level was 7.2±3.8 mg/dL and was significantly higher than in the control group (P value<.001). In multivariate analysis, uric acid correlated significantly with PAP (r=.5, P<.001) and PCWP (r=.4, P=.002) and was also associated with clinical signs of rales, edema, paroxysmal nocturnal dyspnea (r=.5, P=.01), and New York Heart Association class (r=.4, P=.005). Uric acid level was also correlated inversely with left ventricular EF (r=.27, P=.006). Elevated uric acid levels in patients with systolic heart failure is associated with impaired clinical and hemodynamic profile and might be used as a noninvasive indicator of elevated left ventricular filling pressures.

Liver diseases in heart failure

Heart failure (HF) is a growing public health concern as a consequence of the ageing of the population and the improved survival of patients with HF. HF is defined as impaired organ perfusion and/or high filling pressure. It is a systemic and chronic disease and as such involves many organs, not least the liver and kidney. The complex vascular system of the liver and its high metabolic activity render it vulnerable to circulation disturbances and trigger many molecular and haemodynamic changes in patients. There are many studies describing the impact of liver disease on patient outcomes. Hepatic dysfunction is commonly seen in HF patients and is closely correlated with a poor outcome. Knowledge about the mechanisms and impacts of liver disease in HF helps us to know the stage of the disease and treat it properly. Moreover, many drugs and toxins that are metabolised in the liver and contribute to drug interactions should also be taken into account when prescribing medication for HF patients. In light of the above-mentioned points, the authors have compiled this review on congestive hepatopathy with the aim of providing physicians and cardiologists with a succinct and useful guide on the role of the liver in HF.

Uric acid level and allopurinol use as risk markers of mortality and morbidity in systolic heart failure

BACKGROUND

Previous studies have not extensively examined the association of hyperuricemia and adverse outcomes in systolic heart failure (HF) in relation to xanthine oxidase inhibitor therapy.

METHODS

The Prospective Randomized Amlodipine Survival Evaluation study included New York Heart Association class IIIB or IV patients with left ventricular ejection fraction <30%. For analysis, the population was divided into uric acid quartiles among nonallopurinol users (2.2-7.1, >7.1-8.6, >8.6-10.4, >10.4 mg/dL) and those using allopurinol. Multivariate Cox regression modeling was performed to identify predictors of mortality. Uric acid quartile and allopurinol groups were referenced to the lowest uric acid quartile.

RESULTS

A total of 1,152 patients were included. In general, patients in the allopurinol group and in the highest uric acid quartile had indicators of more severe HF, including worse renal function and greater proportion of New York Heart Association class IV patients, and greater diuretic use. The allopurinol group and highest uric acid quartile had the highest total mortality (41.7 and 42.4 per 100 person-years, respectively) and combined morbidity/mortality (45.6 and 51.0 per 100 person-years, respectively). Allopurinol use and highest uric acid quartile were independently associated with mortality (hazard ratio [HR] 1.65, 95% CI 1.22-2.23, P = .001 and HR 1.35, 95% CI 1.07-1.72, P = .01, respectively) and combined morbidity/mortality (uric acid quartile 4 vs 1: HR 1.32, 95% CI 1.06-1.66, P = .02; allopurinol use: HR 1.48, 95% CI 1.11-1.99, P = .008).

CONCLUSION

Elevated uric acid level was independently associated with mortality in patients with severe systolic HF, even when accounting for allopurinol use.

Is high serum uric acid a risk marker or a target for treatment? Examination of its independent effect in a large cohort with low cardiovascular risk

BACKGROUND

Cohort studies evaluating increased uric acid level as a cardiovascular disease (CVD) risk factor have shown variable results; studies are particularly lacking in lower risk populations.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

484,568 adults participating in a medical screening program in Taiwan since 1994 were followed up for a median of 8.5 years. Two subgroups were constructed: the first (n = 246,697; 51%) excluded participants with either overt CVD or overt CVD risk factors (including hypertension, diabetes, obesity, and hypertriglyceridemia) and the second (n = 157,238; 32%) further excluded individuals with early-stage CVD risk factors (including prehypertension, prediabetes, overweight, and borderline hypertriglyceridemia).

PREDICTOR

Serum uric acid.

OUTCOMES & MEASUREMENTS

All-cause and CVD mortality risk assessed using Cox proportional hazards models for categorical and continuous serum uric acid levels. As applicable, models adjusted for 14 variables. Population-attributable fraction was applied to compare contributions to mortality between high uric acid level and other CVD risk factors.

RESULTS

In the total cohort, mean age was 41.4 +/- 14.0 years and 26.2% had serum uric acid levels >or=7 mg/dL. Through 2007, there were 16,246 deaths (3.4% of all participants), with 35.2% of deaths occurring in individuals with hyperuricemia. Adjusted HRs associated with serum uric acid levels >or=7 mg/dL for all-cause and CVD mortality were 1.10 (95% CI, 1.04-1.17) and 1.38 (95% CI, 1.20-1.58), respectively. In individuals with hyperuricemia, 64.3% had overt CVD risk factors and 82.5% had either overt or early-stage CVD risk factors. Individuals with serum uric acid levels >or=8 mg/dL without overt CVD risk factors constituted 13.5% of the total study population with hyperuricemia; in analyses excluding those with overt CVD risk factors, serum uric acid level >or=8 mg/dL was significantly associated with all-cause and CVD mortality, with HRs of 1.37 (95% CI, 1.18-1.60) and 2.30 (95% CI, 1.51-3.49), respectively. In the subgroup of those with serum uric acid levels >or=8 mg/dL but who lacked both overt and early-stage CVD risk factors, the HRs for all-cause and CVD mortality were also significant and were 1.39 (95% CI, 1.08-1.78) and 2.38 (95% CI, 1.24-4.54), respectively. HRs for individuals with the same risk profiles but with serum uric acid of 7.0-7.9 mg/dL were not significant. In all groups, inclusion of proteinuria and glomerular filtration rate in models substantially attenuated the association between uric acid level and outcomes. High uric acid levels contributed a relatively insignificant portion to mortality (1.2%) and CVD deaths (4.5%) in this population.

LIMITATIONS

A single measurement of uric acid was used.

CONCLUSION

Increased serum uric acid level is a minor, but significant, risk factor for all-cause and CVD mortality. However, except for a small proportion (13.5%), increased serum uric acid level is more a risk marker than a target for treatment and is not an independent risk. Determining appropriate groups to target in clinical trials for uric acid-lowering therapy is critical.