Serum Uric Acid and Atrial Fibrillation: Meta-analysis

Prognosis of Older Adult Patients Suffering from Atrial Fibrillation and Hypokalemia

Objective

To examine the effects of hypokalemia on the prognosis of older adult patients with atrial fibrillation (AF).

Methods

We enrolled 794 older adult patients ≥ 75 years suffering from AF, and divided them into two groups according to the inclusion and exclusion criteria: Group 1, (hypokalemia group), 246 cases, serum K+<3.5 mmol/L; Group 2, (normal blood potassium group), 548 cases, 3.5mmol/L≤serum K+<5.5 mmol/L. The two groups of patients were followed for 70 months to observe the occurrence of clinical events. The primary endpoint was cardiovascular death and the secondary endpoint was all-cause death.

Results

The median follow-up time was 15.00 months. In terms of baseline profile characteristics, serum creatinine levels were significantly lower in Group 1 than in Group 2 patients (P=0.002). In terms of the relationship between hypokalemia and clinical outcomes, Kaplan-Meier survival analysis revealed that the incidence of clinical primary endpoint in Group 1 was significantly higher than that in Group 2 (P < 0.001), and the incidence of the secondary endpoint did not differ significantly between the two groups (P> 005). Based on multivariate Cox regression risk model analysis, coronary heart disease, hemoglobin content, serum uric acid and usage of anticoagulant drugs were the independent variables related to the primary endpoint of cardiovascular death (all P< 0.01).

Conclusion

The incidence of hypokalemia in older adult patients with AF was 30.98%. Hypokalemia was closely related to the cardiovascular death, and coronary heart disease, hemoglobin content, serum uric acid level, and usage of anticoagulant drugs were the independent risk factors for the primary endpoint event.

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.

The Impact of the Duration of Cardiac Troponin I Elevation on the Clinical Prognosis as Well as Incidence of New-Onset Atrial Fibrillation Respectively in Elderly Non-ST-Elevation Acute Myocardial Infarction Patients without PCI

Objective

This study aimed to investigate the impact of the duration of cardiac troponin I (TnI) elevation on the prognosis and incidence of new-onset atrial fibrillation (NOAF) in elderly patients with non-ST-elevation acute myocardial infarction (NSTE-AMI).

Methods

A total of 383 NSTE-AMI patients ≥75 years old were enrolled in this study and divided into two groups: in 194 cases, the duration of TnI elevation was ≥14 days (group 1), and in 189 cases, the duration of TnI elevation was <14 days (group 2). The patients were followed up for 60 months. The effect of TnI on prognosis was studied by cohort. The primary endpoint was a composite endpoint of cardiovascular death, reinfarction, ischemic stroke, and hospitalization for heart failure, and the secondary endpoint was all-cause death. A case–control study design was adopted to analyze the influencing factors of NOAF occurrence in Group 1 and Group 2.

Results

The median duration of follow-up was 26 months. Multivariate Cox’s regression analysis revealed that the duration of TnI elevation ≥14 days and diuretic use were independent variables of the major composite endpoint (p < 0.01 for both), and the left ventricular ejection fraction and the duration of TnI elevation ≥14 days were independent related variables of all-cause death (p < 0.05). The duration of TnI elevation ≥14 days was correlated with the occurrence of NOAF, but, in the multivariate logistic regression model, only uric acid and high-sensitivity C-reactive protein were independently associated with NOAF (p < 0.05).

Conclusion

The duration of TnI elevation ≥14 days was the independent correlation factor of the major composite endpoint and all-cause death; high sensitivity C-reactive protein and uric acid are independent risk factors for NOAF.

Relationship Between Radiation Exposure and Incident Atrial Fibrillation Among Atomic Bomb Survivors

Background: Atrial fibrillation (AF) is a common arrhythmia. Although radiation exposure is associated with an elevated risk of cardiovascular disease, the effects of radiation on arrhythmia, especially AF, are unclear. We evaluated the relationship between radiation and AF in a cohort of atomic bomb survivors. Methods and Results: From a baseline enrollment period (1967-1969) to 2009, 7,379 Hiroshima and Nagasaki atomic bomb survivors (mean baseline age 50.6 years, 65.8% women, 72.9% from Hiroshima) without AF and who had been exposed to estimated radiation doses between 0 and 3.614 Gy were followed-up once every 2 years. AF was identified by 12-lead electrocardiograms and medical records. Treating age as the time scale, AF incidence was modeled with Cox proportional hazards models adjusting for demographics, AF risk factors, and radiation. We modeled radiation as both a continuous variable and categorized according to radiation dose (Control [<0.005 Gy] and 5 equal-sized groups based on radiation dose quintiles in the cohort). Over 4 decades of follow-up, we identified 276 AF cases in 176,687 person-years, for an incidence rate of 1.56 per 1,000 person-years. After adjusting for sex and city, neither categorized, linear, nor linear-quadratic models showed substantive evidence of radiation effects. Similar results were obtained after adjusting for AF risk factors. Conclusions: There were no clear positive associations between radiation dose and AF risk, rather null or non-significant inverse associations.

Correlation between the elevated uric acid levels and circulating renin-angiotensin-aldosterone system activation in patients with atrial fibrillation

Background

The aim of the present study was to investigate the correlation between the elevated uric acid (UA) levels and activation of the circulating renin-angiotensin-aldosterone system (RAAS) in patients with atrial fibrillation (AF).

Methods

A total of 233 outpatients and inpatients of the Cardiology Department from January 1, 2019, to December 31, 2019, were selected and divided into the sinus rhythm group (SR) with 84 cases, the paroxysmal AF group (pAF) with 76 cases, and the persistent AF group (PAF) with 73 patients. The general clinical data and the serum levels of UA of the enrolled patients were collected, and the radioimmunoassay was adopted to detect the levels of renin (Renin), angiotensin II (Ang II), and aldosterone (Ald).

Results

Renin, AngII, Ald, and UA in the PAF group were significantly higher than those in the pAF group, and the levels of the above indicators in the pAF group were significantly higher than those in the SR group (P<0.001). The left atrium anteroposterior diameter (LAD) and the left ventricular end-diastolic diameter (LVEDD) were significantly increased in the PAF group (P<0.001). The Pearson correlation analysis showed that the levels of the high sensitivity C-reactive protein (hsCRP), AngII Renin, Ald, LVEDD, and LAD were positively correlated with the serum levels of UA (r=0.174, 0.273, 0.34, 0.385, 0.138, respectively, P<0.05 in all). The left ventricular ejection fraction (LVEF) was negatively correlated with the UA level (r=-0.177, P<0.05). Multiple linear regression analysis showed that UA (β=0.103) and LAD (β=2.162) were independent risk factors for Renin. The independent risk factor for Ang II was UA (β=0.167). The independent risk factor for Ald was UA (β=0.283) and LAD (β=8.721) (P<0.05).

Conclusions

Elevated UA might cause excessive activation of the RAAS, aggravate the oxidative stress, and participate in the atrial remodeling, thereby promoting the occurrence and persistence of AF.

Does Serum Uric Acid Status Influence the Association Between Left Atrium Diameter and Atrial Fibrillation in Hypertension Patients?

Objective: Both serum uric acid (SUA) levels and left atrium diameter (LAD) associate with AF. However, the influence of SUA status for the associated risk of AF related to LAD in hypertension patients is currently unknown.

Methods: We retrospectively analyzed a hospital-based sample of 9,618 hypertension patients. Standard electrocardiograms were performed on all patients and were interpreted by expert electro-physiologists.

Results: Overall 1,028 (10.69%) patients had AF out of 9,618 patients. In men >65 years of age, the prevalence of AF in the1st, 2nd, and 3rd tertiles of SUA among those grouped in the third tertile of LAD were 9, 12.3, and 21.7%, respectively. In the hyperuricemia group, the OR (95% CI) of AF for the highest tertile of LAD in men ≤ 65 years of age was 3.150 (1.756, 5.651; P < 0.001). Similarly, the hyperuricemic men in the 3rd LAD tertile had a higher likelihood of AF than those belonging to the 1st tertile. The ORs and (95% CIs) were 3.150 (1.756, 5.651; P < 0.001) and 5.522 (2.932, 10.400; P ≤ 0.001) for patients ≤ 65 and >65 years of age. An increase in SUA values was significantly associated with an increased likelihood of AF among women at the top tertiles of LAD, with the OR (95% CI) = 4.593 (1.857, 11.358; P = 0.001). Also, men> 65 years of age with large LAD, present at the third tertile of SUA, had a higher likelihood of AF, with the OR (95% CI) = 2.427 (1.039, 5.667; P < 0.05).

Conclusion: SUA levels and LAD are associated with AF in patients with hypertension and the risk of AF associated with LAD increases among those with hyperuricemia.

Uric Acid and Cardiovascular Disease: An Update From Molecular Mechanism to Clinical Perspective

Uric acid (UA) is the end product of purine nucleotide metabolism in the human body. Hyperuricemia is an abnormally high level of UA in the blood and may result in arthritis and gout. The prevalence of hyperuricemia has been increasing globally. Epidemiological studies have shown that UA levels are positively correlated with cardiovascular diseases, including hypertension, atherosclerosis, atrial fibrillation (AF), and heart failure (HF). Hyperuricemia promotes the occurrence and development of cardiovascular diseases by regulating molecular signals, such as inflammatory response, oxidative stress, insulin resistance/diabetes, endoplasmic reticulum stress, and endothelial dysfunction. Despite extensive research, the underlying molecular mechanisms are still unclear. Allopurinol, a xanthine oxidase (XO) inhibitor, has been shown to improve cardiovascular outcomes in patients with HF, coronary heart disease (CHD), type 2 diabetes (T2D), and left ventricular hypertrophy (LVH). Whether febuxostat, another XO inhibitor, can improve cardiovascular outcomes as well as allopurinol remains controversial. Furthermore, it is also not clear whether UA-lowering treatment (ULT) can benefit patients with asymptomatic hyperuricemia. In this review, we focus on the latest cellular and molecular findings of cardiovascular disease associated with hyperuricemia and clinical data about the efficacy of ULT in patients with cardiovascular disease.