Relationship between serum uric acid levels and different types of atrial fibrillation: An updated meta-analysis

Serum uric acid and pulmonary arterial hypertension: A two-sample Mendelian randomization study

BACKGROUND

Observational studies have suggested a correlation between hyperuricemia and pulmonary arterial hypertension (PAH), yet the causal relationship remains uncertain. We aimed to establish this link using Mendelian Randomization (MR) methods.

OBJECTIVES

Based on publicly accessible data, our study employs MR to determine the causal relationship between uric acid (UA) and PAH.

METHOD

MR analysis was conducted among individuals of European descent. Genetic instruments linked to UA (p-value < 5 × 10-8) were extracted from the Chronic Kidney Disease Genetic Consortium and genome-wide association study databases. PAH risk genetic associations were sourced separately. We employed four MR methods (MR-Egger, weighted median, inverse variance weighted, and weighted mode) with selected instrumental variables to assess the causal association between UA and PAH. MR-PRESSO was used to evaluate pleiotropy and outlier Single Nucleotide Polymorphisms (SNPs), while Cochran's Q test and funnel plot assessed SNP heterogeneity. Leave-one-out analysis examined SNP impacts on causal assessment.

RESULT

Two-sample MR analysis revealed a positive, causal relationship between UA levels and PAH.

CONCLUSION

Our MR analysis provides robust evidence of a causal link between serum UA and PAH, suggesting UA's potential as a biomarker and therapeutic target for PAH.

Uric acid to albumin ratio as a novel predictor for coronary slow flow phenomenon in patients with chronic coronary syndrome and non-obstructive coronary arteries

BACKGROUND

The plasma uric acid to albumin ratio (UAR) is considered as a novel indicator for Inflammation. However, the association between UAR and coronary slow flow phenomenon (CSFP) remains unclear.

METHODS

A total of 1328 individuals with chronic coronary syndrome (CCS) receiving coronary angiography (CAG) and found no obvious obstructive stenosis (< 40%) were included in this study. 79 individuals developed CSFP and were divided into CSFP group. The 1:2 age-matched patients with normal coronary blood flow were allocated to the control group (n = 158). The clinical characteristics, laboratory parameters including uric acid, albumin ratio, UAR and the angiographic characteristics were compared between the two groups.

RESULTS

Patients with CSFP had a higher level of uric acid (392.3 ± 85.3 vs. 273.8 ± 71.5, P < 0.001), UAR (10.7 ± 2.2 vs. 7.2 ± 1.9, P < 0.001), but a lower level of plasma albumin (36.9 ± 4.2 vs. 38.5 ± 3.6, P = 0.003). Moreover, UAR increased as the numbers of vessels involved in CSFP increased. The logistic regression analysis demonstrated that UAR was independent predictors for CSFP. The Receiver operating characteristic (ROC) curve analysis showed that when UAR was more than 7.9, the AUC was 0.883 (95% CI: 0.840-0.927, p < 0.001), with the sensitivity and specificity were 78.2% and 88.2% respectively.

CONCLUSION

Combined uric acid with plasma albumin, UAR could serve as an independent predictor for CSFP.

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.

Association of Serum Uric Acid with Non-Valvular Atrial Fibrillation: A Retrospective Study in China

Purpose

The association between serum uric acid (SUA) and atrial fibrillation (AF) has been widely focused on and studied in recent years. However, the exact association between SUA and AF is unclear, and the effect of gender on the association between SUA levels and AF has been controversial. This study aimed to investigate the association between SUA levels and non-valvular AF (NVAF) and the potential effect of gender on it.

Patients and Methods

A total of 866 NVAF patients (463 males, age 69.44 ± 8.07 years) and 646 sex-matched control patients in sinus rhythm, with no history of arrhythmia were included in this study. t-test, ANOVA, and chi-square test were used for baseline data analysis. The receiver operating characteristic curve, logistic regression and Pearson correlation analysis were used for correlation analysis.

Results

Compared to controls, NVAF patients exhibited higher SUA (P<0.001). After adjusting for confounders of NVAF, SUA remained significantly associated with NVAF, regardless of gender (OR= 1.31, 95% CI 1.18-1.43, P<0.001). SUA demonstrated higher predictability and sensitivity in predicting the occurrence of female NVAF compared to male (area under the curve was 0.68 (95% CI 0.64-0.72, P<0.001), sensitivity 87.3%), with the optimal cut-off point identified as 5.72 mg/dL. Furthermore, SUA levels correlated with APOA1, Scr and NT-proBNP in NVAF patients. SUA levels varied significantly among NVAF subtypes.

Conclusion

High SUA levels were independently associated with NVAF, regardless of gender. SUA exhibited higher predictability and sensitivity in predicting the occurrence of NVAF in females compared to males. High SUA levels may affect other NVAF-related factors and participate in the pathophysiological process of NVAF.

Uric acid significantly correlates with the presence of low-voltage areas at the endocardial mapping in patients with non-valvular atrial fibrillation

BACKGROUND AND AIMS

Interest in the role of atrial substrate in maintaining Atrial Fibrillation (AF) is growing. Fibrosis is the culprit in the electrical derangement of the myocytes. Many cardiovascular risk factors are known to be linked to atrial scarring; among them Uric Acid (UA) is emerging. The purpose of our study is to find whether UA is associated with Left Atrium (LA) with pathological substrate.

METHODS AND RESULTS

81 patients who underwent radiofrequency transcatheter ablation for nonvalvular AF at the cardiological department of the Niguarda Hospital were enrolled in an observational, cross-sectional, single-center study. UA levels were analysed before the procedure. High density electroanatomic mapping of the LA was performed and patients were divided according to the presence or not of areas of pathological substrate (bipolar voltage <0.5 mV in sinus rhythm). 19 patients showed a LA with pathological substrate. These subjects showed a significant higher prevalence of persistent phenotype of AF (84.2 vs. 25.8%, p < 0.001). UA levels were significantly higher in the group of patients with LA with pathological substrate (6.8 ± 1.9 vs 5.3 ± 1.4 mg/dL, p < 0.001) as well as the prevalence of hyperuricemia (26.5 vs. 6.5%, p = 0.021). The association between uric acid LA with pathological substrate remains significant even after correction for confounding factors (age, left ventricular dysfunction, valvular disease, arrythmia phenotype and furosemide use) and also when the ratio UA/creatinine was evaluated.

CONCLUSIONS

In a population of patients who underwent AF ablation, higher UA levels were significantly associated with pathological LA substrate at electro-anatomical mapping.

Update in uric acid, hypertension, and cardiovascular diseases

A direct relationship between serum uric acid levels and hypertension, cardiovascular, renal and metabolic diseases has been reported in many basic and epidemiological studies. Among these, high blood pression is one of the most common features associated with hyperuricemia. In this regard, several small-scale interventional studies have demonstrated a significant reduction in blood pressure in hypertensive or prehypertensive patients on uric acid-lowering drugs. These observation or intervention studies have led to affirm that there is a causal relationship between uric acid and hypertension. While the clinical association between uric acid and high blood pressure is notable, no clear conclusion has yet been reached as to whether lowering uric acid is beneficial to prevent cardiovascular and renal metabolic diseases. Recently, several prospective randomized controlled intervention trials using allopurinol and other uric acid-lowering drugs have been reported, and the results from these trials were almost negative, suggesting that the correlation between hyperuricemia and cardiovascular disease has no causality. However, it is important to note that in some of these recent studies there were high dropout rates and an important fraction of participants were not hyperuricemic. Therefore, we should carry caution in interpreting the results of these studies. This review article presents the results of recent clinical trials using uric acid-lowering drugs, focusing on hypertension and cardiovascular and renal metabolic diseases, and discusses the future of uric acid therapy.

Association between serum uric acid levels and atrial fibrillation in different fasting glucose patterns: A case-control study

BACKGROUND

Previous studies have shown both dysglycaemia and hyperuricemia are associated with an increased risk of atrial fibrillation (AF), while the relationship between serum uric acid (SUA) levels and AF in different fasting glucose patterns (FBG) is unclear. Therefore, this study aimed to determine the association between SUA and AF in different FBG patterns.

METHODS

A total of 1840 patients in this case-control study were enrolled, including 920 AF patients and 920 controls. Patients were divided into three groups according to the different FBG patterns: normoglycemic, impaired fasting glucose (IFG), and diabetes mellitus (DM). Multivariate logistic regression models were performed to evaluate the relationship between SUA and AF in different FBG patterns. Pearson correlation analysis was used to explore the correlation between SUA and metabolic factors. Receiver operating characteristic (ROC) curve models indicated the diagnostic efficiency of SUA for diagnosing AF.

RESULTS

SUA was independently associated with AF after adjusting for all confounding factors in different FBG patterns(normoglycemic: OR=1.313, 95% CI:1.120-1.539; IFG: OR=1.386, 95% CI:1.011-1.898; DM: OR=1.505, 95% CI:1.150-1.970). Pearson's correlation analysis suggested that SUA in AF patients was correlated with several different metabolic factors in different FBG patterns (p<0.05). ROC curve analysis showed that SUA in the normoglycemic group combined with CHD and APOB [AUC: 0.906 (95% CI: 0.888-0.923)], in the IFG group combined with CHD and Scr [AUC: 0.863 (95% CI: 0.820-0.907)], in the DM group combined with CHD and SBP [AUC: 0.858 (95% CI: 0.818-0.898)] had the highest AUC for predicting AF.

CONCLUSION

Findings implied a significant association between SUA and AF in different FBG patterns and provide specific models combined with other factors (CHD, APOB, SCr, SBP), which might contribute to the diagnosis of AF.

A case-control study to investigate association between serum uric acid levels and paroxysmal atrial fibrillation

The relationship between serum uric acid (SUA) levels and paroxysmal atrial fibrillation (AF) remains controversial. The objective of this case–control study was to investigate the association between serum SUA levels and paroxysmal AF by gender in 328 patients. This study included 328 hospitalized patients with newly diagnosed paroxysmal AF in China between January 2019 and September 2021. Controls with sinus rhythm were matched (2:1) to cases by age and gender. Baseline data were analyzed using ANOVA, T-test, and Chi-square test. Pearson correlation analyses were used to confirm the correlation between variables, and multivariate regression analyses were used to adjust for covariates. Elevated SUA levels in female patients were significantly associated with paroxysmal AF after adjusting for confounding factors (OR = 1.229, 95% CI 1.058–1.427, P = 0.007). Further results showed SUA levels were negatively correlated with high-density lipoprotein cholesterol (HDL-C) (r = − 0.182, p = 0.001) and apolipoprotein A1 (APOA1) (r = − 0.109, p = 0.049), were positively correlated with low-density lipoprotein cholesterol (LDL-C) (r = 0.169, p = 0.002) and prealbumin (PAB) (r = 0.161, p = 0.004) . Nevertheless, there was no significant complication difference between SUA levels and paroxysmal AF (P > 0.05). Increased SUA in female patients was significantly associated with paroxysmal AF in a Chinese population. This finding implies that it would be interesting to monitor and interfere with hyperuricemia in paroxysmal AF patients.

Time-varying serum uric acid predicts new-onset atrial fibrillation in treated hypertensive patients. The LIFE Study

Aim: The Losartan Intervention For Endpoint reduction in hypertension (LIFE) Study showed less new-onset atrial fibrillation (AF) in hypertensive patients receiving losartan- vs. atenolol-based treatment. Because losartan reduces serum uric acid (SUA) levels, the aim of the present study was to investigate relations of SUA with new-onset AF in the study. Methods: Hypertensive patients with electrocardiographic (ECG) left ventricular hypertrophy (LVH) and no prior AF (n = 8,243) were treated for 5.0 ± 0.4 years with losartan- or atenolol-based therapy. Associations of SUA with new-onset AF documented by Minnesota coding were assessed by Cox models using SUA and systolic blood pressure as time-varying covariates to take into account changes of SUA related to losartan or diuretic treatment, changes in renal function, and aging. Results: Time-varying SUA was associated with new AF defined by Minnesota code [hazard ratio (HR) = 1.19 per 16.8 μmol/L (1 mg/dL), (95% confidence intervals (CIs), 1.12–1.26), P < 0.0001], independent of losartan treatment [HR = 0.75 (95% CIs, 0.61–0.93), P = 0.007], older age [HR = 1.95 per 7.0 years (95% CIs, 1.73–2.20), P < 0.0001], male sex [HR = 1.46 (95% CIs, 1.09–1.94), P = 0.010] and higher Cornell voltage-duration product [HR = 1.10 per 1,023 ms·mm (95% CIs, 1.01–1.21), P = 0.034]. Similar results were obtained in Cox models with SUA levels partitioned according to baseline quartiles and in which AF was defined by physician reports or by both Minnesota coding and physician reports. Conclusions: In-treatment SUA is a strong predictor for new-onset AF in hypertensive patients, independent of effects of antihypertensive treatment, age, sex, and ECG-LVH. Further research is needed to clarify how uric acid may provoke AF (ClinicalTrials.gov identifier: NCT00338260).