Lower uric acid level may be associated with hemorrhagic transformation after intravenous thrombolysis

Association between uric acid and the risk of hemorrhagic transformation in patients with acute ischemic stroke: a systematic review and meta-analysis

Background

The relationship between hemorrhagic transformation (HT) and uric acid (UA) remains controversial. This study aimed to investigate the relationship between UA concentrations and the risk of HT following acute ischemic stroke (AIS).

Methods

Electronic databases were searched for studies on HT and UA from inception to October 31, 2023. Two researchers independently reviewed the studies for inclusion. STATA Software 16.0 was used to compute the standardized mean difference (SMD) and 95% confidence interval (CI) for the pooled and post-outlier outcomes. Heterogeneity was evaluated using the I2 statistic and the Galbraith plot. Additionally, sensitivity analysis was performed. Lastly, Begg's funnel plot and Egger's test were used to assess publication bias.

Results

A total of 11 studies involving 4,608 patients were included in the meta-analysis. The pooled SMD forest plot (SMD = -0.313, 95% CI = -0.586--0.039, p = 0.025) displayed that low UA concentrations were linked to a higher risk of HT in post-AIS patients. However, heterogeneity (I2 = 89.8%, p < 0.001) was high among the studies. Six papers fell outside the Galbraith plot regression line, and there exclusive resulted in the absence of heterogeneity (I2 = 52.1%, p = 0.080). Meanwhile, repeated SMD analysis (SMD = -0.517, 95% CI = -0.748--0.285, p = 0.000) demonstrated that the HT group had lower UA concentrations. Finally, Begg's funnel plot and Egger's test indicated the absence of publication bias in our meta-analysis.

Conclusion

This meta-analysis illustrated a substantial connection between UA concentrations and HT, with lower UA concentrations independently linked with a higher risk of HT post-AIS. These results lay a theoretical reference for future studies.Systematic review registration:https://www.crd.york.ac.uk/PROSPERO/CRD42023485539.

Lower serum uric acid to serum creatinine ratio as a predictor of poor functional outcome after mechanical thrombectomy in acute ischaemic stroke

BACKGROUND AND PURPOSE

The ratio of serum uric acid (SUA) to serum creatinine (SCr), representing normalized SUA for renal function, is associated with functional outcome in acute ischaemic stroke (AIS) patients. However, its effect on AIS patients undergoing mechanical thrombectomy (MT) remains unknown. This study aimed to investigate the influence of the SUA/SCr ratio on clinical outcome in MT-treated AIS patients.

METHODS

Acute ischaemic stroke patients who underwent MT were continuously enrolled from January 2018 to June 2023. Upon admission, SUA and SCr levels were recorded within the initial 24 h. Stroke severity was determined using the National Institutes of Health Stroke Scale (NIHSS) score. Clinical outcome included poor functional outcome (modified Rankin Scale score >2) at 90 days, symptomatic intracranial haemorrhage and death.

RESULTS

Amongst 734 patients, 432 (58.8%) exhibited poor functional outcome at 90 days. The SUA/SCr ratio exhibited a negative correlation with NIHSS score (ρ = -0.095, p = 0.010). Univariate analysis revealed a significant association between SUA/SCr ratio and poor functional outcome. After adjusting for confounders, the SUA/SCr ratio remained an independent predictor of functional outcome (adjusted odds ratio 0.348, 95% confidence interval 0.282-0.428, p < 0.001). Receiver operating characteristic curve analysis highlighted the ability of the SUA/SCr ratio to predict functional outcome, with a cutoff value of 3.62 and an area under the curve of 0.757 (95% confidence interval 0.724-0.788, p < 0.001).

CONCLUSION

The SUA/SCr ratio is correlated with stroke severity and may serve as a predictor of 90-day functional outcome in AIS patients undergoing MT.

Baseline Uric Acid Levels and Intravenous Thrombolysis Outcomes in Patients With Acute Ischemic Stroke: A Prospective Cohort Study

BACKGROUND

The study aimed to investigate the relationship between uric acid (UA) levels and functional outcomes at 3 months in patients with acute ischemic stroke (AIS) who underwent intravenous thrombolysis (IVT).

METHODS AND RESULTS

This prospective cohort study included 1001 consecutive patients with AIS who underwent IVT. The correlation between UA levels and post-IVT AIS outcomes was examined. Any nonlinear relationship was assessed using a restricted cubic spline function. The nonlinear P value for the association of UA levels with favorable (modified Rankin Scale [mRS] score ≤2) and excellent (mRS score ≤1) outcomes at 3 months post-IVT were <0.001 and 0.001, respectively. However, for patients with and without hyperuricemia, no evident nonlinear relationship was observed between UA levels and favorable 3-month post-IVT outcomes, with nonlinear P values of 0.299 and 0.207, respectively. The corresponding interaction analysis yielded a P value of 0.001, indicating significant heterogeneity. Similar results were obtained for excellent outcomes at 3 months post-IVT. In the hyperuricemia group, increased UA levels by 50 μmol/L reduced the odds of a favorable 3-month post-AIS outcome (odds ratio [OR], 0.75 [95% CI, 0.57-0.97]). Conversely, in the nonhyperuricemia group, a similar UA increase was linked to higher favorable outcome odds (OR, 1.31 [95% CI, 1.15-1.50]).

CONCLUSIONS

An inverted U-shaped nonlinear relationship was observed between UA levels and favorable and excellent outcomes at 3 months in patients with AIS who underwent IVT. Higher UA levels predict favorable outcomes in patients without hyperuricemia but unfavorable outcomes in those with hyperuricemia.

Prognostic Significance of Uric Acid Levels in Intracerebral Hemorrhage Patients

Background and Purpose

The role of serum uric acid (UA) level in patients suffering from stroke remains controversial. Our aim was to investigate the effect of UA level on clinical outcomes in patients with intracerebral hemorrhage (ICH).

Methods

In the retrospective cohort study, we analyzed data from 250 patients with intracerebral hemorrhage (85 women and 165 men) to investigate the difference in UA levels between patients with a good prognosis and those with a poor prognosis. Additionally, we analyzed the impact of UA levels on the risk of short-time prognosis of ICH patients.

Results

Patients with a good prognosis presented with significantly lower levels of UA (348.71 ± 84.97 μmol/L) than those with poor prognosis (393.06 ± 148.46 μmol/L). Furthermore, multivariate logistic regression model demonstrated that a high UA level was a likely risk factor for worse prognosis among patients suffering in ICH (odds ratio [95% confidence interval], 1.006 [1.0012, 1.0108]; P = 0.015). Additionally, UA has a threshold effect value of 363.9 μmol/L and was presented in levels that were in a nonlinear relationship with incidence rate of short-time prognosis outcome of ICH patients.

Conclusion

Our findings indicate that higher UA levels can increase the risk of poor clinical prognosis in patients with ICH and high UA levels are not conductive to the clinical prognosis of patients with ICH. These findings provide a new perspective on the treatment and prevention of ICH.

Serum Uric Acid Levels and Outcome of Acute Ischemic Stroke: a Dose-Response Meta-analysis

Previous meta-analyses have reported conflicting results regarding the relationship between baseline uric acid (UA) levels and acute ischemic stroke (AIS) outcomes. Therefore, we conducted a dose-response meta-analysis to elucidate the association's strength and shape. Studies on the association between baseline UA levels and AIS outcomes in the PubMed and EMBASE databases were searched from their inception to April 17, 2023. Two researchers independently reviewed the studies for inclusion. A total of 23 articles involving 15,733 patients with AIS were included. The analysis revealed a significant inverse correlation between UA levels and AIS outcomes. The linear trend estimation indicated that a 50-μmol/L increment in UA level was associated with a 21.7% lower risk of hemorrhagic transformation (odds ratio [OR]: 0.783; 95% confidence interval [CI]: 0.743, 0.826; I2 = 43.4%; n = 4), 7.0% lower risk of 90-day unfavorable outcome [modified Rankin scale score ≥ 2] (OR: 0.930; 95% CI: 0.875, 0.990; I2 = 0%; n = 3), and 7.5% lower risk of 90-day poor outcome [modified Rankin scale score ≥ 3] (OR: 0.925; 95% CI: 0.863, 0.990; I2 = 74.4%; n = 3) in patients with AIS after accounting for relevant covariates. A linear dose-response relationship exists between baseline UA levels and the outcome of patients with AIS within a certain range, with higher baseline UA levels associated with better outcomes after AIS. Further dose-response meta-analyses, including a larger number of original articles, are required to validate our findings.

Impact of lipid profiles on parenchymal hemorrhage and early outcome after mechanical thrombectomy

OBJECTIVE

We aimed to investigate the association of lipid parameters with parenchymal hemorrhage (PH) and early neurological improvement (ENI) after mechanical thrombectomy (MT) in stroke patients.

METHODS

We retrospectively analyzed consecutive patients who underwent MT between January 2019 and February 2022 at a tertiary stroke center. PH was diagnosed and classified as PH-1 and PH-2 according to the European Cooperative Acute Stroke Study definition. ENI was defined as a decrease in the National Institutes of Health Stroke Scale (NIHSS) score by ≥8 or an NIHSS score of ≤1 at 24 h after MT.

RESULTS

Among 155 patients, PH occurred in 41 (26.5%) patients, and 34 (21.9%) patients achieved ENI. In multivariate analysis, lower triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) value (OR = 0.51; 95% CI 0.30-0.89; p = 0.017) and higher HDL-C level (OR = 5.83; 95% CI 1.26-26.99; p = 0.024) were independently associated with PH. The combination of TG <0.77 mmol/L and HDL-C ≥ 0.85 mmol/L was the strongest predictor of PH (OR = 10.73; 95% CI 2.89-39.87; p < 0.001). A low HDL-C level was an independent predictor of ENI (OR 0.13; 95% CI 0.02-0.95; p = 0.045), and PH partially accounts for the failure of ENI in patients with higher HDL-C levels (estimate: -0.05; 95% CI: -0.11 to -0.01; p = 0.016).

INTERPRETATION

The combination of lower TG level and higher HDL-C level can predict PH after MT. Postprocedural PH partially accounts for the failure of ENI in patients with higher HDL-C levels. Further studies into the pathophysiological mechanisms underlying this observation are of interest.

Serum uric acid and prognosis in acute ischemic stroke: a dose-response meta-analysis of cohort studies

Background

There have been contradictory findings regarding the relationship between serum uric acid levels and prognosis in acute ischemic stroke. Whether this association is nonlinear due to uric acid's paradoxical properties (antioxidant and prooxidant) is unclear.

Methods

We searched PubMed, Web of Science, and Embase databases until December 2022. Cohort studies reporting serum uric acid levels and functional outcome, mortality, or neurological complications in patients with acute ischemic stroke were included. Summary effect estimates were calculated using a random-effect model. Moreover, dose-response relationships were assessed by the generalized least squares trend estimation.

Results

Altogether, 13 cohort studies were identified in this study. Compared to the lowest baseline serum uric acid levels, the highest levels were associated with decreased risk of poor functional outcome (OR = 0.70, 95% CI 0.54-0.91, I2 = 29%), hemorrhagic transformation (OR = 0.15, 95% CI 0.05-0.42, I2 = 79%), and post-stroke depression (OR = 0.04, 95% CI 0.00-0.95, I2 = 89%), but not associated with mortality and symptomatic intracerebral hemorrhage. A nonlinear relationship was observed in poor functional outcome (U-shaped, P for nonlinearity = 0.042), hemorrhagic transformation (inverse, P for nonlinearity = 0.001), and post-stroke depression (inverse, P for nonlinearity = 0.002). In addition, there was a single study reporting a U-shaped association in post-stroke epilepsy (P for nonlinearity <0.001). Furthermore, another study reported a positive curvilinear association in stroke recurrence (P for nonlinearity <0.05). The insufficient number of original articles for some prognostic indicators should be considered when interpreting the results of this meta-analysis.

Conclusion

In patients with acute ischemic stroke, serum uric acid levels are nonlinearly associated with the risk of poor functional outcome (U-shaped). More evidence is needed to confirm the association between serum uric acid levels and neurological complications following acute ischemic stroke.

A novel nomogram to predict hemorrhagic transformation in ischemic stroke patients after intravenous thrombolysis

Background

Hemorrhagic transformation (HT) is the most serious complication of ischemic stroke patients after intravenous thrombolysis and leads to a poor clinical prognosis. This study aimed to determine the independent predictors associated with HT in stroke patients with intravenous thrombolysis and to establish and validate a nomogram that combines with predictors to predict the probability of HT after intravenous thrombolysis in patients with ischemic stroke.

Method

This study enrolled ischemic stroke patients with intravenous thrombolysis from December 2016 to June 2022. All the patients were divided into training and validation cohorts. The nomogram was composed of the significant predictors for HT in the training cohort as obtained by the multivariate logistic regression analysis. The area under the receiver operating characteristic curve was used to assess the discriminative performance of the nomogram. The calibration performance of the nomogram was assessed by the Hosmer–Lemeshow goodness-of-fit test and calibration plots. Decision curve analysis was used to test the clinical validity of the nomogram.

Results

A total of 394 patients with intravenous thrombolysis were enrolled in the study. In the training cohort (n = 257), 45 patients had HT after intravenous thrombolysis. Multivariate logistic regression analysis demonstrated early infarct signs (OR, 7.954; 95% CI, 3.553-17.803; P < 0.001), NIHSS scores (OR, 1.110; 95% CI, 1.054-1.168; P < 0.001), uric acid (OR, 0.993; 95% CI, 0.989–0.997; P = 0.001), and albumin-to-globulin ratio (OR, 0.109; 95% CI, 0.023–0.508; P = 0.005) were independent predictors for HT and constructed the nomogram. In the training and validation cohorts, the AUC of the nomogram was 0.859 and 0.839, respectively. The Hosmer–Lemeshow goodness-of-fit test and calibration plot showed good concordance between predicted and observed probability in the training and validation cohorts. Decision curve analysis indicated that the nomogram was significantly useful for predicting HT in the training and further confirmed in the validation cohort.

Conclusion

This study proposes a novel and practical nomogram based on early infarct signs, NIHSS scores, uric acid, and albumin-to-globulin ratio that can well predict the probability of HT after intravenous thrombolysis in patients with ischemic stroke.

U-Shaped Association Between Serum Uric Acid and Hemorrhagic Transformation After Intravenous Thrombolysis

BACKGROUND

Uric acid (UA) has both antioxidative and pro-oxidative properties. The study aimed to investigate the relationship between serum UA and hemorrhagic transformation (HT) after intravenous thrombolysis in patients with acute ischemic stroke.

METHODS

The patients undergoing intravenous thrombolysis from two hospitals in China were retrospectively analyzed. HT was evaluated using computed tomography images reviewed within 24- 36h after thrombolysis. Symptomatic intracranial hemorrhage (sICH) was defined as HT accompanied by worsening neurological function. Multivariate logistic regression and spline regression models were performed to explore the relationship between serum UA levels and the risk of HT and sICH.

RESULTS

Among 503 included patients, 60 (11.9%) were diagnosed with HT and 22 (4.4%) developed sICH. Patients with HT had significant lower serum UA levels than those without HT (245 [214-325 vs. 312 [256-370] μmol/L, p < 0.001). Multivariable logistic regression analysis indicated that patients with higher serum UA levels had a lower risk of HT (OR per 10-μmol/L increase 0.96, 95%CI 0.92-0.99, p = 0.015). Furthermore, multiple-adjusted spline regression models showed a Ushaped association between serum UA levels and HT (p < 0.001 for non-linearity). Similar results were present between serum UA and sICH. Restricted cubic spline models predicted the lowest risk of HT and sICH when the serum UA levels were 386μmol/L.

CONCLUSION

The data show the U-shaped relationship between serum UA levels and the risk of HT and sICH after intravenous thrombolysis.

Uric Acid and Clinical Outcomes in Young Patients with Ischemic Stroke

BACKGROUND AND PURPOSE

There is limited available evidence for the relationship between uric acid (UA) levels and ischemic stroke in young adults. We aimed to explore the association between UA levels and acute ischemic stroke (AIS) in young patients.

MATERIALS AND METHODS

This was a prospective and observational study. We recruited young patients aged 18-45 years with AIS at our tertiary hospital. Patients were categorized into four groups according to quartiles of UA levels. The primary outcome was functional outcome at 3 months. The secondary outcomes included stroke severity, in-hospital complications, and functional outcome at discharge. Modified Rankin Scale (mRS) scores were used to assess functional outcome as poor (mRS=2-6) or favorable(mRS=0-1).

RESULTS

A total of 636 patients were enrolled in the current analysis. The four groups were defined as follows: Q1≤289.8 µmol/L, 289.8 µmol/ L<Q2≤349.0 µmol/L, 349.0 µmol/L<Q3≤421 µmol/L, and Q4>421 µmol/L. Multiple logistic regression analysis showed that UA levels were not significantly predictive of functional outcome either at discharge or at 3 months after AIS. However, compared to Q1, higher UA levels were significantly negatively associated with the rate of moderate-severe stroke (NIHSS≥5) at admission (p for trend =0.016). Furthermore, a reduction in the risk for in-hospital pneumonia was significantly associated with higher UA levels compared to Q1 (P for trend < 0.0001).

CONCLUSION

Serum UA was a protective factor for stroke severity and in-hospital pneumonia after AIS in young patients. However, we were unable to identify the predictive significance of UA for functional outcome either at discharge or at 3 months after AIS.