Association of hyperuricemia and pulmonary hypertension: A systematic review and meta-analysis

Predictive nomogram models for atrial fibrillation in COPD patients: A comprehensive analysis of risk factors and prognosis

The aim of the present study was to identify the independent risk factors and prognostic indicators for atrial fibrillation (AF) in patients with chronic obstructive pulmonary disease (COPD) and to develop predictive nomogram models. This retrospective study included a total of 286 patients with COPD who were admitted to the Second Affiliated Hospital of Guilin Medical College between January 2020 and May 2022. The average age of the patients was 77.11±8.67 years. Based on the presence or absence of AF, the patients were divided into two groups: The AF group (n=87) and the non-AF group (n=199). Logistic regression analysis was conducted to identify variables with significant differences between the two groups. Nomogram models were constructed to predict the occurrence of AF in COPD patients and to assess prognosis. Survival analysis was performed using the Kaplan-Meier method. The follow-up period for the present study extended until April 31, 2023. Survival time was defined as the duration from the date of the interview to the date the participant succumbed or the end of the follow-up period. In the present study, age, uric acid (UA) and left atrial diameter (LAD) were found to be independent risk factors for the development of AF in patients diagnosed with COPD. The stepwise logistic regression analysis revealed that age had an odds ratio (OR) of 1.072 [95% confidence interval (CI): 1.019-1.128; P=0.007], UA had an OR of 1.004 (95% CI: 1.001-1.008; P=0.010) and LAD had an OR of 1.195 (95% CI: 1.098-1.301; P<0.001). Univariate and multivariate Cox regression analysis revealed that LAD and UA were independent prognostic factors for long-term mortality in COPD patients with AF. LAD had a hazard ratio (HR) of 1.104 (95% CI: 1.046-1.165; P<0.001) and UA had an HR of 1.004 (95% CI: 1.000-1.008; P=0.042). Based on these findings, predictive nomogram models were developed for AF in COPD patients, which demonstrated good discrimination ability with an area under the curve of 0.886. The prognostic nomogram for COPD patients with AF also showed good predictive accuracy with a concordance index of 0.886 (95% CI: 0.842-0.930). These models can provide valuable information for risk assessment and prognosis evaluation in clinical practice. Age, UA and LAD are independent risk factors for AF in COPD patients. The developed nomogram models provide a reliable tool for predicting AF in COPD patients and for prognosis assessment.

Association between uric acid and cardiac outcomes mediated by neutrophil-to-lymphocyte ratio in patients with left ventricular diastolic dysfunction and pulmonary hypertension

To evaluate the association of uric acid (UA) with adverse outcomes and its potential mediator in patients with left ventricular diastolic dysfunction (LVDD) and pulmonary hypertension (PH). We retrospectively analyzed 234 patients with LVDD and PH. The baseline characteristics of patients with low UA (≤ 330 µmol/L) group were compared with high UA (> 330 µmol/L) group. Adverse outcomes included all-cause mortality, cardiac death and heart failure (HF) hospitalization. Their association with UA and the mediator were evaluated using Cox regression and mediation analysis. The mediation proportion was further quantified by the R mediation package. During a mean follow-up of 50 ± 18 months, there were 27 all-cause deaths, 18 cardiovascular deaths and 41 incidents of HF hospitalization. Multivariable Cox regression analysis showed UA was an independent risk factor of adverse outcomes in LVDD and PH patients, even after adjusting for age, sex, body mass index, medical histories, systolic blood pressure, fasting blood glucose, total cholesterol, triglyceride, eGFR, BNP and medications. The hazard ratios (HRs) for UA (per 10 µmol/L increase) were as below: for all-cause mortality, HR 1.143, 95% CI 1.069-1.221, P < 0.001; for cardiac death, HR 1.168, 95% CI 1.064-1.282, P = 0.001; for HF hospitalization, HR 1.093, 95% CI 1.035-1.155, P = 0.001. Neutrophil-to-lymphocyte ratio (NLR) played a partial mediation role in the association, and the mediation proportion for NLR on the UA-adverse outcomes were 21%, 19% and 17%, respectively. In patients of LVDD with PH, higher UA level was independently correlated with adverse outcomes. Furthermore, NLR partially mediated the effect of UA on the risk of all-cause mortality, cardiac death and HF hospitalization.

Electrocardiogram Parameters Associated With the Diagnosis of Pulmonary Hypertension in High-Altitude Tibetan Populations: A Retrospective Single-Centre Study

BACKGROUND

Electrocardiogram (ECG) is a commonly used diagnostic method for pulmonary hypertension (PH) in Tibetan areas, but its sensitivity and specificity are not good enough. This study aimed to investigate the ECG parameters associated with the diagnosis of PH in Tibetan areas.

METHODS

Ninety-four PH patients of Tibetan ethnicity who were treated at the hospital between March 2019 and October 2020, and 52 Tibetan individuals as controls, were included. The ECG parameters were compared between groups. Multivariate logistic analysis was performed to identify the ECG parameters that can be used for the diagnosis of PH. The univariate significances of ECG parameters were included in the multivariate analyses, whereas those exhibiting opposite trends between different PH subtypes were excluded.

RESULTS

Two ECG parameters were significant in multivariate analysis. The final model included S wave amplitude in lead V3 (OR 5.81; 95% CI 2.79-12.11; p<0.001) and a negative T wave in leads V1-V3 (OR 0.05; 95% CI 0.01-0.41; p=0.005). The ROC curve analysis on the final model yielded an AUC of 0.830 (95% CI 0.766-0.894; p<0.001), indicating good diagnostic performance. A nomogram for diagnosis of PH was also established using S wave amplitude in lead V3 and a negative T wave in leads V1-V3.

CONCLUSION

The ECG parameters S wave amplitude in lead V3 and a negative T wave in leads V1-V3 were independent factors associated with the diagnosis of PH in high-altitude Tibetan populations.

The Relationship between Hyperuricemia and Echocardiographic Parameters in Patients with Chronic Atrial Fibrillation

Purpose Uric acid serves as a marker for cardiovascular risk and is often linked to inflammation and oxidative stress. There is evidence suggesting an association between uric acid and atrial fibrillation (AF), including its severity and occurrence of crises, as well as its involvement in cardiovascular mechanisms. The objective of this study was to assess the correlation between hyperuricemia and echocardiographic features in patients with chronic AF lasting for more than 5 years. Methods This case-control study involved 107 patients diagnosed with chronic non-valvular AF. Uric acid levels were measured in all patients, and they were divided into two groups: the first group consisted of 66 patients with hyperuricemia (>7.2 mg/dL), while the second group included 41 patients with normal uric acid levels. Echocardiography (TTE) was performed to evaluate each patient. Various clinical and echocardiographic parameters, such as left ventricle telediastolic (LVTDD) and telesystolic (LVTSD) diameters, left atrial diameter (LAD), aortic diameter (AoD), ejection fraction (EF), and pulmonary artery pressure (PAP), were analyzed. Results Binary logistic regression analysis revealed a statistically significant relationship between uric acid levels (>7.2 mg/dL) and LAD. For each unit increase in LAD, the probability of having hyperuricemia increased by 9% [odds ratio (OD): 0.91, 95% confidence interval (CI): 0.84-0.99]. A significant relationship was found between uric acid levels (>8 mg/dL) and LVESD (p = 0.045) as well as PAP (p = 0.006). For every unit increase in LVESD, the likelihood of having uric acid levels greater than 8 mg/dL increased by 22% [OD: 0.82, 95% CI: 0.67-0.99, b = -0.2]. Likewise, for each unit increase in PAP, the probability of having uric acid levels greater than 8 mg/dL was 9.4% [OD: 0.91, 95% CI: 0.86-0.97, b = -0.09]. Conclusions This study demonstrates that hyperuricemia has a significant relationship with the development of atrial remodeling, with an important association observed between hyperuricemia and an increase in left atrial diameter. Hyperuricemia is also correlated with an enlargement of the left ventricle end-systolic diameter and pulmonary artery pressure, showing a possible influence that hyperuricemia might have also left ventricle morphology and right ventricle function.

Impact of Pulmonary Hypertension on Renal Functions in Obstructive Sleep Apnea Syndrome

OBJECTIVES

Pulmonary hypertension (PH) is common in obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the effect of PH on kidney functions in patients with OSAS.

METHODS

The data of patients who were diagnosed as having OSAS after referral to the sleep center in the Gaziantep University Medical Faculty between January 2005 and June 2017 were evaluated. The estimated glomerular filtration rate was calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal functions of the subjects who had data after 5 years were included for long-term analysis.

RESULTS

A total of 2152 patients with OSAS (n = 1540), PH (n = 49), OSAS and PH coexistence (n = 359), and the control group (n = 204) were included in the study. Pulmonary arterial pressure (PAP) was 44.51 ± 23.73 in the PH group; it was 37.1 ± 13.14 in the group with OSAS + PH (P = 0.001) Urea and uric acid were found to be higher in the association of OSAS + PH. CKD-EPI was lower in the presence of PH or OSAS + PH than in the presence of OSAS. PH was present in 16.06% of males and 25.10% of females (P = 0.000), and PAP was detected as 35.80 ± 13.23 and 40.96 ± 16.65, respectively (P = 0.001). PH was present in 15.99% of males and 25.84% of females with OSAS (P = 0.000). The PAP of males with OSAS was 36.03 ± 13.46, and the PAP of females was 38.68 ± 12.55 (P = 0062). Urea, creatinine, and uric acid were higher and CKD-EPI was lower in male subjects in the presence of OSAS and PH, whereas the same scenario also was present in the presence of PH alone in female subjects. Long-term comparisons (n = 343) revealed significant decreases in the CKD-EPI in those with OSAS and OSAS + PH and these decrease were more pronounced in the presence of OSAS and PH. The regression analysis revealed that female patients had lower CKD-EPI in the presence of PH, although the presence of PH had no effect on CKD-EPI in males.

CONCLUSIONS

PH is a risk factor for the deterioration of renal function in OSAS and more prominent in the long term.

The role of tolvaptan in pulmonary hypertension: A retrospective study

Pulmonary hypertension (PH) is a severe form of pulmonary vascular disease that can lead to right heart failure (RHF). Nearly 2-thirds of patients with PH die within 5 years. Studies suggest that a new diuretic medication, called tolvaptan (TLV), can be used to treat PH. However, there is still insufficient evidence to confirm its effectiveness. Therefore, we investigated the role of TLV in patients with PH. This retrospective study included 73 patients with PH hospitalized in Shanghai Pulmonary Hospital between November 2019 and March 2022. All patients received 7.5 to 15.0 mg of TLV for 3 to 21 days starting at admission, in addition to targeted drugs and traditional diuretic therapy. The outcomes included the blood pressure, urine and water intake volumes, electrolyte concentrations, and renal, liver, and cardiac function indexes before and after TLV treatment. In addition, we assessed the clinical symptoms and adverse reactions during the treatment. After TLV treatment, the water intake and urine volumes significantly increased, and body weight, diastolic blood pressure (DBP) and mean arterial pressure significantly decreased. Total bilirubin, direct bilirubin, N-terminal pro-brain natriuretic peptide, and serum uric acid (UA) levels after TLV treatment were significantly lower than before treatment. After TLV treatment, dyspnea significantly improved in 71 of 73 patients, and lower limb edema disappeared in 42 of 53 patients. No obvious adverse reactions occurred during the TLV treatment period. These results suggest that adding TLV to targeted drug and traditional diuretic therapies is effective for patients with PH. However, more data are required to support these findings.

The Prognostic Impact of Serum Uric Acid on Disease Severity and 5-Year Mortality in Patients With Idiopathic Pulmonary Artery Hypertension

Background

Serum uric acid (UA) has long been identified as a prognostic factor of adverse outcomes in pulmonary hypertension. However, there remains a paucity of evidence on patients with idiopathic pulmonary artery hypertension (IPAH) in the era of targeted drug therapy. This study aims to explore the impact of serum UA levels on the disease severity and mortality in patients with IPAH.

Methods

Consecutive patients diagnosed with IPAH were enrolled, from which UA levels at baseline and the first follow-up were collected. Patients were divided into groups of “hyperuricemia,” which is defined as serum UA level ≥357 μmol/L in women and ≥420 μmol/L in men, and otherwise “normouricemia.” The potential relationship between UA and hemodynamics at right heart catheterization was investigated. Associations between UA and survival were evaluated by Kaplan-Meier analysis and Cox proportional hazard modeling.

Results

Of 207 patients with IPAH, 121 (58.5%) had hyperuricemia. Higher serum UA levels were associated with lower cardiac index (r = 0.47, p < 0.001) and higher pulmonary vascular resistance (r = 0.36, p < 0.001). During a median follow-up of 34 months, there were 32 deaths recorded, accounting for a 15.5% mortality rate. Patients with hyperuricemia had a significantly lower survival rate than those with normouricemia (log-rank test, p = 0.002). Hyperuricemia at baseline was independently associated with a 2.6-fold increased risk of 5-year death, which was consistent across different subgroups, especially in females and those aged ≥30 years (each p < 0.05). Individuals with higher variability in UA had a higher mortality than those with stable UA (log-rank test, p = 0.024).

Conclusions

Baseline hyperuricemia and high variability in serum UA at first follow-up were related to a higher rate of 5-year mortality in patients with IPAH. Closely detecting the UA levels may aid in the early recognition of IPAH patients at higher mortality risk.

U-shaped association of uric acid to overall-cause mortality and its impact on clinical management of hyperuricemia

Serum uric acid (SUA) is significantly elevated in obesity, gout, type 2 diabetes mellitus, and the metabolic syndrome and appears to contribute to the renal, cardiovascular and pulmonary comorbidities that are associated with these disorders. Most previous studies have focused on the pathophysiologic effects of high levels of uric acid (hyperuricemia). More recently, research has also shifted to the impact of hypouricemia, with multiple studies showing the potentially damaging effects that can be caused by abnormally low levels of SUA. Along with these observations, recent inconclusive data from human studies evaluating the treatment of hyperuricemia with xanthine oxidoreductase (XOR) inhibitors have added to the debate about the causal role of UA in human disease processes. SUA, which is largely derived from hepatic degradation of purines, appears to exert both systemic pro-inflammatory effects that contribute to disease and protective antioxidant properties. XOR, which catalyzes the terminal two steps of purine degradation, is the major source of both reactive oxygen species (O2^.-, H₂O₂) and UA. This review will summarize the evidence that both elevated and low SUA may be risk factors for renal, cardiovascular and pulmonary comorbidities. It will also discuss the mechanisms through which modulation of either XOR activity or SUA may contribute to vascular redox hemostasis. We will address future research studies to better account for the differential effects of high versus low SUA in the hope that this will identify new evidence-based approaches for the management of hyperuricemia.

Innovative Anti-Inflammatory and Pro-resolving Strategies for Pulmonary Hypertension: High Blood Pressure Research Council of Australia Award 2019

Pulmonary hypertension is a rare, ostensibly incurable, and etiologically diverse disease with an unacceptably high 5-year mortality rate (≈50%), worse than many cancers. Irrespective of pathogenic origin, dysregulated immune processes underlie pulmonary hypertension pathobiology, particularly pertaining to pulmonary vascular remodeling. As such, a variety of proinflammatory pathways have been mooted as novel therapeutic targets. One such pathway involves the family of innate immune regulators known as inflammasomes. In addition, a new and emerging concept is differentiating between anti-inflammatory approaches versus those that promote pro-resolving pathways. This review will briefly introduce inflammasomes and examine recent literature concerning their role in pulmonary hypertension. Moreover, it will explore the difference between inflammation-suppressing and pro-resolution approaches and how this links to inflammasomes. Finally, we will investigate new avenues for targeting inflammation in pulmonary hypertension via more targeted anti-inflammatory or inflammation resolving strategies.

Serum and pulmonary uric acid in pulmonary arterial hypertension

Previous studies have suggested an association between uric acid (UA) and the severity of pulmonary arterial hypertension (PAH), but it is unknown whether UA contributes to disease pathogenesis.The aim of this study was to determine the prognostic value of circulating UA in the era of current management of PAH and to investigate the role of UA in pulmonary vascular remodelling.Serum UA levels were determined in idiopathic, heritable or anorexigen PAH at baseline and first re-evaluation in the French Pulmonary Hypertension Network. We studied protein levels of xanthine oxidase (XO) and the voltage-driven urate transporter 1 (URATv1) in lungs of control and PAH patients and of monocrotaline (MCT) and Sugen/hypoxia (SuHx) rats. Functional studies were performed using human pulmonary artery smooth muscle cells (PA-SMCs) and two animal models of pulmonary hypertension (PH).High serum UA levels at first follow-up, but not at baseline, were associated with a poor prognosis. Both the generating enzyme XO and URATv1 were upregulated in the wall of remodelled pulmonary arteries in idiopathic PAH patients and MCT and SuHx rats. High UA concentrations promoted a mild increase in cell growth in idiopathic PAH PA-SMCs, but not in control PA-SMCs. Consistent with these observations, oxonic acid-induced hyperuricaemia did not aggravate MCT-induced PH in rats. Finally, chronic treatment of MCT and SuHx rats with benzbromarone mildly attenuated pulmonary vascular remodelling.UA levels in idiopathic PAH patients were associated with an impaired clinical and haemodynamic profile and might be used as a non-invasive indicator of clinical prognosis during follow-up. Our findings also indicate that UA metabolism is disturbed in remodelled pulmonary vascular walls in both experimental and human PAH.

Association of Disease Subtype and Duration with Echocardiographic Evidence of Pulmonary Hypertension in Myeloproliferative Neoplasm

BACKGROUND

Pulmonary hypertension (PH) can complicate the course of myeloproliferative neoplasms (MPNs). Echocardiography is a useful noninvasive screening test for PH in populations at risk. We aimed to investigate the echocardiographic evidence of PH and clinical characteristics of patients with MPNs.

METHODS

This study included 197 patients with MPNs (mean age, 59 ± 14 years; females, 53%; mean disease duration, 3.4 ± 2.8 years). Clinical and laboratory characteristics, including JAK2V617F mutation status, were obtained. All participants underwent a comprehensive transthoracic echocardiographic examination. The echocardiographic evidence of PH was defined as systolic pulmonary artery pressure (SPAP) ≥40 mm Hg.

RESULTS

Overall, 11 patients (5.5%) with SPAP ≥40 mm Hg had echocardiographic evidence of PH. Patients with myelofibrosis had echocardiographic evidence of PH more often than patients with other MPNs (p < 0.001). Disease duration since the diagnosis of MPNs was 6.7 ± 4.6 years in the PH group and 3.1 ± 2.5 years in the non-PH group (p < 0.001). There was a weak positive correlation between SPAP values and time since diagnosis (r = 0.236, p =0.001). JAK2V617F mutation was not associated with PH. In multivariate logistic regression analysis, the presence of myelofibrosis (odds ratio [OR]: 22.177, 95% CI: 4.480-109.790, p < 0.001), long disease duration (OR: 1.217, 95% CI: 1.024-1.447, p = 0.026), and high uric acid levels (OR: 1.868, 95% CI: 1.049-3.328, p = 0.034) were found to be related with the echocardiographic evidence of PH. Survival was worse in the PH group (p = 0.0001).

CONCLUSION

Our results suggest that patients with myelofibrosis are more likely to develop PH than other MPNs patients. Disease duration may predict the development of PH in MPN patients.