Elevated Uric Acid Prevalence and Clinical Outcomes in Patients with Heart Failure with Preserved Ejection Fraction: Insights from RELAX

Hyperuricemia-induced complications: dysfunctional macrophages serve as a potential bridge

With the changes in modern life, hyperuricemia (HUA) has become a serious universal health issue, leading to rising morbidity and mortality. Characterized by elevated levels of UA, HUA has become an independent risk factor for gout, chronic kidney disease, insulin resistance, cardiovascular disease, nonalcoholic fatty liver disease, etc. As HUA is a metabolic syndrome, the immune response is likely to play an active role throughout the whole process. Moreover, macrophages, as an indispensable component of the immune system, may serve as a promising target for addressing hyperuricemia-induced inflammation. Along with their precursor cells, monocytes, macrophages play a key role in the pathogenesis of HUA, primarily through three specific aspects, all of which are associated with inflammatory cytokines. The first mechanism involves direct action on urate transporters, such as URAT1 and ABCG2. The second mechanism is the modulation of inflammation, including targeting toll-like receptors (TLRs) and the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome. The third mechanism pertains to the effects on oxidative stress mediators. In this review, we summarize the underlying mechanisms of hyperuricemia, focusing on the effects of macrophages, therapeutic approaches, and clinical trials addressing hyperuricemia-caused dysfunction. Additionally, we highlight directions for future development, aiming to support future theoretical studies.

Verinurad Plus Allopurinol for Heart Failure With Preserved Ejection Fraction: The AMETHYST Randomized Clinical Trial

Importance

Elevated serum uric acid (SUA) level may contribute to endothelial dysfunction; therefore, SUA is an attractive target for heart failure with preserved ejection fraction (HFpEF). However, to the authors' knowledge, no prior randomized clinical trials have evaluated SUA lowering in HFpEF.

Objective

To investigate the efficacy and safety of the novel urate transporter-1 inhibitor, verinurad, in patients with HFpEF and elevated SUA level.

Design, Setting, and Participants

This was a phase 2, double-blind, randomized clinical trial (32-week duration) conducted from May 2020 to April 2022. The study took place at 59 centers in 12 countries and included patients 40 years and older with HFpEF and SUA level greater than 6 mg/dL. Data were analyzed from August 2022 to May 2024.

Interventions

Eligible patients were randomized 1:1:1 to once-daily, oral verinurad, 12 mg, plus allopurinol, 300 mg; allopurinol, 300 mg, monotherapy; or placebo for 24 weeks after an 8-week titration period. Allopurinol was combined with verinurad to prevent verinurad-induced urate nephropathy, and the allopurinol monotherapy group was included to account for allopurinol effects in the combination therapy group. All patients received oral colchicine, 0.5 to 0.6 mg, daily for the first 12 weeks after randomization.

Main Outcomes and Measures

Key end points included changes from baseline to week 32 in peak oxygen uptake (VO2), Kansas City Cardiomyopathy Questionnaire total symptom score (KCCQ-TSS), and SUA level; and safety/tolerability (including adjudicated cardiovascular events).

Results

Among 159 randomized patients (53 per treatment group; median [IQR] age, 71 [40-86] years; 103 male [65%]) with median (IQR) N-terminal pro-brain natriuretic peptide level of 527 (239-1044) pg/mL and SUA level of 7.5 (6.6-8.4) mg/dL, verinurad plus allopurinol (mean change, -59.6%; 95% CI, -64.4% to -54.2%) lowered SUA level to a greater extent than allopurinol (mean change, -37.6%; 95% CI, -45.3% to -28.9%) or placebo (mean change, 0.8%; 95% CI, -11.8% to 15.2%; P < .001). Changes in peak VO2 (verinurad plus allopurinol, 0.27 mL/kg/min; 95% CI, -0.56 to 1.10 mL/kg/min; allopurinol, -0.17 mL/kg/min; 95% CI, -1.03 to 0.69 mL/kg/min; placebo, 0.37 mL/kg/min; 95% CI, -0.45 to 1.19 mL/kg/min) and KCCQ-TSS (verinurad plus allopurinol, 4.3; 95% CI, 0.3-8.3; allopurinol, 4.5; 95% CI, 0.3-8.6; placebo, 1.2; 95% CI, -3.0 to 5.3) were similar across groups. There were no adverse safety signals. Deaths or cardiovascular events occurred in 3 patients (5.7%) in the verinurad plus allopurinol group, 8 patients (15.1%) in the allopurinol monotherapy group, and 6 patients (11.3%) in the placebo group.

Conclusions and Relevance

Results of this randomized clinical trial show that despite substantial SUA lowering, verinurad plus allopurinol did not result in a significant improvement in peak VO2 or symptoms compared with allopurinol monotherapy or placebo in HFpEF.

Trial Registration

ClinicalTrials.gov Identifier: NCT04327024.

The Role of Hyperuricemia in Cardiac Diseases: Evidence, Controversies, and Therapeutic Strategies

Hyperuricemia (HUA) may lead to myocardial cell damage, thereby promoting the occurrence and adverse outcomes of heart diseases. In this review, we discuss the latest clinical research progress, and explore the impact of HUA on myocardial damage-related diseases such as myocardial infarction, arrhythmias, and heart failure. We also combined recent findings from basic research to analyze potential mechanisms linking HUA with myocardial injury. In different pathological models (such as direct action of high uric acid on myocardial cells or combined with myocardial ischemia-reperfusion model), HUA may cause damage by activating the NOD-like receptor protein 3 inflammasome-induced inflammatory response, interfering with cardiac cell energy metabolism, affecting antioxidant defense systems, and stimulating reactive oxygen species production to enhance the oxidative stress response, ultimately resulting in decreased cardiac function. Additionally, we discuss the impact of lowering uric acid intervention therapy and potential safety issues that may arise. However, as the mechanism underlying HUA-induced myocardial injury is poorly defined, further research is warranted to aid in the development novel therapeutic strategies for HUA-related cardiovascular diseases.

Gender differences in the relationship between serum uric acid and the long-term prognosis in heart failure: a nationwide study

BACKGROUND

Serum uric acid (SUA) is an important pathogenetic and prognostic factor for heart failure (HF). Gender differences are apparent in HF. Furthermore, gender differences also exist in the association between SUA and prognosis in various cardiovascular diseases. However, the gender difference for SUA in the prediction of long-term prognosis in HF is still ambiguous.

METHODS

A total of 1593 HF patients (897 men, 696 women) from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 cycle were enrolled in our final analysis. Participants were categorized according to gender-specific SUA tertile. We assessed the association between SUA and long-term prognosis of HF patients, defined as all-cause mortality and cardiovascular mortality, in different genders via Kaplan-Meier curve analysis, Cox proportional hazard model, and Fine-Gray competing risk model. The restricted cubic spline (RCS) was performed to investigate the dose-response relationship between SUA and outcomes.

RESULTS

Gender differences exist in demographic characteristics, clinical parameters, laboratory tests, and medication of HF patients. After a median follow-up of 127 months (95% CI 120-134 months), there were 853 all-cause deaths (493 events in men, 360 events in women) and 361 cardiovascular deaths (206 events in men, 155 events in women). Kaplan-Meier analysis showed that SUA had gender difference in the prediction of cardiovascular mortality (Log-rank p < 0.001, for male, Log-rank p = 0.150, for female), but not in all-cause mortality. Multivariate Cox regression analysis revealed that elevated SUA levels were associated with higher all-cause mortality and cardiovascular mortality in men (HR 1.11, 95% CI 1.05-1.18, p < 0.001, for all-cause death; HR 1.18, 95% CI 1.09-1.28, p < 0.001, for cardiovascular death), but not in women (HR 1.05, 95% CI 0.98-1.12, p = 0.186, for all-cause death; HR 1.01, 95% CI 0.91-1.12, p = 0.902, for cardiovascular death). Even using non-cardiovascular death as a competitive risk, adjusted Fine-Gray model also illustrated that SUA was an independent predictor of cardiovascular death in men (SHR 1.17, 95% CI 1.08-1.27, p < 0.001), but not in women (SHR 0.98, 95% CI 0.87 - 1.10, p = 0.690).

CONCLUSIONS

Gender differences in the association between SUA and long-term prognosis of HF existed. SUA was an independent prognostic predictor for long-term outcomes of HF in men, but not in women.

HFpEF as systemic disease, insight from a diagnostic prediction model reminiscent of systemic inflammation and organ interaction in HFpEF patients

Systemic inflammation and reciprocal organ interactions are associated with the pathophysiology of heart failure with preserved ejection fraction (HFpEF). However, the clinical value, especially the diagnositc prediction power of inflammation and extra-cardiac organ dysfunction for HfpEF is not explored. In this cross-sectional study, 1808 hospitalized patients from January 2014 to June 2022 in ChiHFpEF cohort were totally enrolled according to inclusion and exclusion criteria. A diagnostic model with markers from routine blood test as well as liver and renal dysfunction for HFpEF was developed using data from ChiHFpEF-cohort by logistic regression and assessed by receiver operating characteristic curve (ROC) and Brier score. Then, the model was validated by the tenfold cross-validation and presented as nomogram and a web-based online risk calculator as well. Multivariate and LASSO regression analysis revealed that age, hemoglobin, neutrophil to lymphocyte ratio, AST/ALT ratio, creatinine, uric acid, atrial fibrillation, and pulmonary hypertension were associated with HFpEF. The predictive model exhibited reasonably accurate discrimination (ROC, 0.753, 95% CI 0.732-0.772) and calibration (Brier score was 0.200). Subsequent internal validation showed good discrimination and calibration (AUC = 0.750, Brier score was 0.202). In additoin to participating in pathophysiology of HFpEF, inflammation and multi-organ interactions have diagnostic prediction value for HFpEF. Screening and optimizing biomarkers of inflammation and multi-organ interactions stand for a new field to improve noninvasive diagnostic tool for HFpEF.

A Possible Therapeutic Application of the Selective Inhibitor of Urate Transporter 1, Dotinurad, for Metabolic Syndrome, Chronic Kidney Disease, and Cardiovascular Disease

The reabsorption of uric acid (UA) is mainly mediated by urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) in the kidneys. Dotinurad inhibits URAT1 but does not inhibit other UA transporters, such as GLUT9, ATP-binding cassette transporter G2 (ABCG2), and organic anion transporter 1/3 (OAT1/3). We found that dotinurad ameliorated the metabolic parameters and renal function in hyperuricemic patients. We consider the significance of the highly selective inhibition of URAT1 by dotinurad for metabolic syndrome, chronic kidney disease (CKD), and cardiovascular disease (CVD). The selective inhibition of URAT1 by dotinurad increases urinary UA in the proximal tubules, and this un-reabsorbed UA may compete with urinary glucose for GLUT9, reducing glucose reabsorption. The inhibition by dotinurad of UA entry via URAT1 into the liver and adipose tissues increased energy expenditure and decreased lipid synthesis and inflammation in rats. Such effects may improve metabolic parameters. CKD patients accumulate uremic toxins, including indoxyl sulfate (IS), in the body. ABCG2 regulates the renal and intestinal excretion of IS, which strongly affects CKD. OAT1/3 inhibitors suppress IS uptake into the kidneys, thereby increasing plasma IS, which produces oxidative stress and induces vascular endothelial dysfunction in CKD patients. The highly selective inhibition of URAT1 by dotinurad may be beneficial for metabolic syndrome, CKD, and CVD.

Hyperuricemia is associated with heart failure readmission in patients with heart failure and preserved ejection fraction-an observational study in Chinese

BACKGROUND AND AIMS

This study aimed to explore the association between hyperuricemia and heart failure (HF) readmission in HF patients with preserved ejection fraction (HFpEF) because the impact of hyperuricemia on the prognosis of these patients has not been fully understood.

METHODS AND RESULTS

This retrospective observational study included 538 hospitalized patients diagnosed with HFpEF. A total of 57.6 % of patients with HFpEF suffered from hyperuricemia (serum uric acid (SUA) was >7 mg/dL in men and >6 mg/dL in women). Compared to those without hyperuricemia, patients with hyperuricemia were more likely to be female (62.6 % vs. 53.9 %, p = 0.044) and older (78.0 ± 8.4 vs. 75.9 ± 9.0 years, p = 0.008). Our Cox analysis revealed that SUA level (hazard ratio (HR) = 1.158, 95 % confidence interval (CI): 1.087-1.234, p<0.001) and hyperuricemia (HR = 1.846, 95 % CI: 1.308-2.606, p<0.001) were associated with HF readmission in patients with HFpEF, respectively. Kaplan-Meier analysis showed that patients with hyperuricemia had a significantly worse prognosis (p<0.001). The receiver operating characteristic analysis revealed that the area under the ROC curve of SUA for predicting HF readmission was 0.6276 (95 % CI: 0.5763-0.6790) and a designated cut-off value of 7.53 mg/dL.

CONCLUSIONS

Hyperuricemia is a common comorbidity among patients with HFpEF. Moreover, SUA level and hyperuricemia have been shown to be associated with HF readmission. Therefore, it is meaningful to monitor SUA levels in patients with HFpEF during the whole treatment period of HF. Whereas, whether intervention of hyperuricemia could benefit patients with HFpEF needs further studies.

Serum uric acid: A risk factor for right ventricular dysfunction and prognosis in heart failure with preserved ejection fraction

BACKGROUND

Hyperuricemia and right ventricular dysfunction (RVD) are both widespread in heart failure with preserved ejection fraction (HFpEF) patients. RVD is associated with a poor prognosis in HFpEF. The correlation between serum uric acid (UA) levels and right ventricular function is unclear. The prognostic performance of UA in patients with HFpEF needs further validation.

METHODS AND RESULTS

A total of 210 patients with HFpEF were included in the study and divided into two groups according to UA level: the normal UA group (≤7 mg/dl) and the high UA group (>7 mg/dl). The variables examined included clinical characteristics, echocardiography, and serum biochemical parameters. Right ventricular function was assessed by tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (TAPSV). Baseline characteristics were compared between the two groups, and the correlation between baseline UA and RVD was assessed using multifactorial binary logistic regression. Kaplan-Meier curves were used to describe all-cause mortality and heart failure readmission. Results showed that right ventricular function parameters were worse in the high UA group. After adjusting for UA, left ventricular posterior wall thickness (LVPWT), N-terminal B-type natriuretic peptide (NT-proBNP), atrial fibrillation (AF), and low-density lipoprotein cholesterol (LDL-C), UA (odds ratio = 2.028; p < 0.001) was independently associated with RVD, and UA >7 mg/dl (HR = 2.98; p < 0.001) was associated with heart failure readmission in patients with HFpEF.

CONCLUSION

Elevated serum UA is closely associated with RVD and significantly associated with the heart failure readmission rate in patients with HFpEF.

Risk factors of short-term, intermediate-term, and long-term cardiac events in patients hospitalized for HFmrEF

AIMS

Clinical data on the prognostic determinants over varying periods within the same cohort of heart failure with mid-range or mildly reduced ejection fraction (HFmrEF) remain scarce. This study aimed to identify the short-term, intermediate-term, and long-term risk factors of adverse cardiovascular (CV) outcomes in patients hospitalized for HFmrEF.

METHODS AND RESULTS

This retrospective study included 1691 consecutive HFmrEF patients admitted to our hospital between January 2015 and August 2020. Baseline data including clinical characteristics, laboratory and cardiac imaging examinations were obtained. Patients completed at least 1 year clinical follow-up after discharge by telephone interview, clinical visit, or community visit. The primary endpoint was defined as a composite of CV death or rehospitalization for heart failure (CV events) at 3, 12, and 33 months after the diagnosis of HFmrEF. Mean age of the whole cohort was 69 (61-77) years and 64.8% were male. The median clinical follow-up was 33 (20-50) months. CV events were 17.5%, 28.2%, and 57.8% at 3, 12, and 33 months after discharge, respectively. Independent risk factors for CV events were uric acid >382 μmol/L, creatinine >100 μmol/L, N-terminal pro-B type natriuretic peptide (NT-proBNP) > 3368 pg/mL and haemoglobin <120 g/L for men and <110 g/L for women at 3 and 12 months. Pulmonary artery systolic pressure >35 mmHg and the ratio of early transmitral flow velocity to early mitral annular velocity >18 served as independent risk factors for CV events at 12 months. At 33 months, uric acid > 382 μmol/L, NT-proBNP >3368 pg/mL, and pulmonary artery systolic pressure >35 mmHg were the independent risk factors of CV events.

CONCLUSIONS

Higher uric acid, creatinine, NT-proBNP, and lower haemoglobin levels at baseline are valuable serum biomarkers for risk stratification of short-term and long-term CV outcomes of HFmrEF patients. Future studies are needed to verify if intensive heart failure therapy for identified high-risk HFmrEF patients based on these four serum biomarkers could improve their short-term and long-term CV outcomes or not.

Pharmacokinetics, pharmacodynamics, and safety of verinurad with and without allopurinol in healthy Asian, Chinese, and non-Asian participants

Verinurad is a selective inhibitor of uric acid transporter 1 (URAT1). Here, we assessed the safety, pharmacokinetics, and pharmacodynamics of verinurad + allopurinol and verinurad monotherapy in healthy participants. Studies 1 (NCT03836599) and 2 (NCT02608710) were randomized Phase 1 studies. In Study 1, 12 healthy Asian participants received 24 mg verinurad + 300 mg allopurinol or placebo, and 9 healthy Chinese participants received 12 mg verinurad + 300 mg allopurinol. In Study 2, 24 healthy non-Asian male participants received 12 mg verinurad. Safety analyses included assessment of adverse events (AEs). Pharmacokinetic parameters included maximum concentration (Cmax ) and area under plasma concentration-time curve (AUC) over 24 h (AUCτ ). Pharmacodynamic parameters included percentage change from baseline (day -1) in serum uric acid (sUA) and urinary uric acid (uUA). There were no serious AEs or deaths in either study. In Study 1, steady-state geometric mean (gCV%) Cmax and AUCτ values of verinurad after 7 days' dosing were 73.6 (29.0) ng/mL and 478 (18.4) ng·h/mL, respectively, in healthy Asian participants, and 42.0 (40.1) ng/mL and 264 (36.1) ng·h/mL, respectively, in healthy Chinese participants; in Study 2, gCV% values were 36.3 (36.5) ng/mL and 271 (31.0) ng·h/mL, respectively. sUA decreased and uUA excretion increased compared with baseline following verinurad + allopurinol (Study 1) or verinurad (Study 2). When accounting for dose, the steady-state pharmacokinetics of verinurad following multiple dosing were comparable between healthy Asian and Chinese participants and healthy non-Asian participants. Verinurad treatments were well tolerated, including at higher verinurad exposures than previously evaluated after repeated dosing.

Effect of orlistat on serum uric acid level in adults: A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Hyperuricemia increases the risk of gout and cardiovascular diseases. Obesity increases the risk of hyperuricemia while weight loss (>5 kg) has been reported to decrease urate. The effects of orlistat on serum uric acid (SUA) are still controversial. The aim of this meta-analysis was to evaluate the influence of orlistat on SUA levels in adults.

METHODS

Relevant studies, published up to May 2020, were searched systematically through PubMed/Medline, Scopus and Google Scholar. All relevant randomised controlled clinical trials were included. Meta-analysis was performed using random-effect model. Subgroup analysis, sensitivity analysis and meta-regression were also carried out.

RESULTS

Overall 7 trials (9 datasets) that enrolled 1786 subjects were included. Orlistat showed in a significant change in SUA level (Difference in means: -17.661 μmol, 95% CI: -31.615 to -3.707, P = .01). A low heterogeneity observed across the studies (I² = 25.119%). After categorising studies on the basis of duration and sample size, the effect of orlistat on SUA was significant. The results of meta-regression were showed that significant relationships were not found between orlistat and SUA in the duration of intervention.

CONCLUSION

We found a significant reduction in SUA following orlistat therapy in adults.

The Relationship between Serum Uric Acid and Ejection Fraction of the Left Ventricle

Study basis: As a byproduct of protein metabolism, serum uric acid is a controversial risk factor and is the focus of several recent studies in the field of cardiovascular disease. Whether serum uric acid is involved in the development of these pathologies alone or in conjunction with other factors is a matter of debate. Objective: The objective of this study is to assess the direct relationship between serum uric acid and the ejection fraction. Methods: A retrospective study of 303 patients with heart failure, classified according to the ESC guidelines, was conducted, and several parameters, along with the relationship between serum uric acid and ejection fraction, were characterized. Results: A direct relationship between the level of serum uric acid and the ejection fraction was established (p = 0.03); patients with higher uric acid had an increased risk of having a lower ejection fraction. Conclusions: Serum uric acid, even when asymptomatic, is linked with the level of the ejection fraction of the left ventricle.

In Vitro Assessment of the Drug-Drug Interaction Potential of Verinurad and Its Metabolites as Substrates and Inhibitors of Metabolizing Enzymes and Drug Transporters

Verinurad is a selective uric acid transporter 1 (URAT1) inhibitor in development for the treatment of chronic kidney disease and heart failure. In humans, two major acyl glucuronide metabolites have been identified: direct glucuronide M1 and N-oxide glucuronide M8. Using in vitro systems recommended by regulatory agencies, we evaluated the interactions of verinurad, M1, and M8 with major drug-metabolizing enzymes and transporters and the potential for clinically relevant drug-drug interactions (DDIs). The IC50 for inhibition of CYP2C8, CYP2C9, and CYP3A4/5 for verinurad was ≥14.5 µM, and maximum free plasma concentration (Iu,max)/IC50 was <0.02 at the anticipated therapeutic Cmax and therefore not considered a DDI risk. Verinurad was not an inducer of CYP1A2, CYP2B6, or CYP3A4/5. Verinurad was identified as a substrate of the hepatic uptake transporter organic anion-transporting polypeptide (OATP) 1B3. Since verinurad hepatic uptake involved both active and passive transport, there is a low risk of clinically relevant DDIs with OATP, and further study is warranted. Verinurad was a substrate of the efflux transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), and renal transporter organic anion transporter 1 (OAT1), although it is not considered a DDI risk in vivo because of dose-proportional pharmacokinetics (P-gp and BCRP) and limited renal excretion of verinurad (OAT1). M1 and M8 were substrates of multidrug resistance-associated protein (MRP) 2 and MRP4 and inhibitors of MRP2. Apart from verinurad being a substrate of OATP1B3 in vitro, the potential for clinically relevant DDIs involving verinurad and its metabolites as victims or perpetrators of metabolizing enzymes or drug transporters is considered low. SIGNIFICANCE STATEMENT: Drug transporters and metabolizing enzymes have an important role in the absorption and disposition of a drug and its metabolites. Using in vitro systems recommended by regulatory agencies, we determined that, apart from verinurad being a substrate of organic anion-transporting polypeptide 1B3, the potential for clinically relevant drug-drug interactions involving verinurad and its metabolites M1 and M8 as victims or perpetrators of metabolizing enzymes or drug transporters is considered low.