Renal function is associated with 1-month and 1-year mortality in patients with ischemic stroke

The Kidney-Immune-Brain Axis: The Role of Inflammation in the Pathogenesis and Treatment of Stroke in Chronic Kidney Disease

Cardiovascular diseases such as stroke are a major cause of morbidity and mortality for patients with chronic kidney disease (CKD). The underlying mechanisms connecting CKD and cardiovascular disease are yet to be fully elucidated, but inflammation is proposed to play an important role based on genetic association studies, studies of inflammatory biomarkers, and clinical trials of anti-inflammatory drug targets. There are multiple sources of both endogenous and exogenous inflammation in CKD, including increased production and decreased clearance of proinflammatory cytokines, oxidative stress, metabolic acidosis, chronic and recurrent infections, dialysis access, changes in adipose tissue metabolism, and disruptions in intestinal microbiota. This review focuses on the mechanisms of inflammation in CKD, dialysis and associated therapies, its proposed impact on stroke pathogenesis and prognosis, and the potential role of anti-inflammatory agents in the prevention and treatment of stroke in patients with CKD.

Multiomics analysis demonstrated a strong correlation between lipid-mediated chronic kidney disease and stroke: Potential benefits of affected patient cohorts

OBJECTIVE

Patients with chronic kidney disease (CKD) exhibit a disproportionately elevated risk of stroke, frequently compounded by renal impairment. Therapeutic strategies for stroke based on Traditional Chinese Medicine's 'kidney-brain axis' theory demonstrate clinical efficacy, indicating that there may be a potential association between chronic kidney disease and stroke, which needs further exploration and verification.

METHODS

In this study, databases such as GEO, NHANES, and GWAS were used to collect data related to CKD and stroke. GEO gene data enrichment analysis was used to explore possible mediating factors between CKD and stroke. NHANES clinical data were used to verify the GEO data analysis results. Mendelian randomization was used to confirm the causal relationship between CKD and stroke and verify the association effect of mediating factors in these two diseases.

RESULTS

Cross-gene analysis and transcription factor analysis of GEO data revealed that lipid-related pathways may have a mediating effect on the relationship between CKD and stroke. Logistic regression analysis based on NHANES data revealed that changes in LDL-C, HDL-C, TC, and TG can affect the occurrence of stroke. Mendelian randomization analysis was used to determine the causal relationship between CKD and stroke and verified the mediating effects of lipid factors, such as LDL-C, HDL-C, TC, and TG, indicating that LDL-C, HDL-C, TC, and TG may be potential mediating factors for these two diseases. Our findings highlight the clinical relevance of lipid pathways in bridging CKD and stroke. By integrating predictive biomarkers and multi-level diagnostics, this study paves the way for AI-driven precision medicine in stroke prevention. Specifically, machine learning approaches could enhance risk stratification of high-risk CKD cohorts, enabling tailored interventions such as lipid-lowering therapies and personalized monitoring protocols. These strategies align with emerging paradigms in healthcare benefits and population-specific management.

CONCLUSION

This study provides new insights into the interactive relationship between CKD and stroke and provides a scientific basis for the process of syndrome differentiation and the treatment of stroke under the guidance of the "kidney-brain correlation". Moreover, the influence of mediating factors related to lipid metabolism on the occurrence of these two diseases was investigated, which deepened researchers' understanding of the potential association mechanism between the two diseases.

NT-proBNP point-of-care testing for predicting mortality in end-stage renal disease: A survival analysis

This study examines the predictive value of elevated N-terminal-pro brain natriuretic peptide (NT-pro BNP) levels for mortality among patients with end-stage renal disease (ESRD). Data from 768 ESRD patients, excluding those with cancer or lost follow-up, were analyzed using Kaplan-Meier curves and Cox proportional hazards models over three years. Results indicated that patients with very high NT-pro BNP levels had shorter average survival times and a significantly higher risk of mortality (hazard ratio 1.43). Advanced age, ICU admission, and comorbidities like cerebrovascular diseases and chronic obstructive pulmonary disease also contributed to increased mortality risks. Thus, elevated NT-pro BNP is an independent risk factor for mortality in ESRD patients.

Relationship between Kidney Dysfunction, Stroke Severity, and Outcomes in a Nigerian Tertiary Hospital: A Prospective Study

BACKGROUND

Stroke is a common neurologic disease associated with fatal outcomes. Kidney dysfunction may be an important predictor of stroke severity and outcome.

AIM

To determine the relationship between kidney dysfunction at admission and stroke severity and 30-day outcome.

MATERIALS AND METHODS

This was a prospective study that involved 150 stroke patients. Stroke severity at admission was assessed using the National Institutes of Health Stroke Scale (NIHSS). Renal dysfunction was assessed by the presence of albuminuria and or reduced glomerular filtration rate (GFR) at admission. Neurological outcome was assessed using mortality, modified Rankin Scale (mRS), and Glasgow Outcome Scale (GCS).

RESULTS

The mean age of the study participants was 61.0 ± 13.2 years. Renal dysfunction was present in 66% of the participants while the case fatality rate of stroke was 26%. Poor neurological outcome at 30 days was found in 44.1% of survivors. Those with albuminuria had lower GCS (P = 0.041), lower GFR (P = 0.004), higher mRS score on day 14 (P = 0.041) and day 30 (P = 0.032), and higher NIHSS score (P = 0.034). Independent predictors of 30-day mortality were albuminuria (Adjusted Odd Ratio (AOR) 3.60, 95%CI: 1.07-12.17) and increasing NIHSS score (AOR = 1.15, 95%CI: 1.04-1.28). Lower GCS (P < 0.001), elevated white blood cells (P = 0.003), serum creatinine (P = 0.048), and NIHSS score (P < 0.001) were associated with poor neurological outcome. NIHSS score was the only significant predictor of neurologic outcome (AOR: 1.25; CI: 1.11-1.41; P ≤ 0.001).

CONCLUSIONS

Kidney dysfunction was associated with stroke severity and mortality. However, it was not an independent predictor of neurological outcome.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Can chronic kidney disease staging early predict outcome of large-artery ischemic stroke with impaired renal function?

Background

Ischemic stroke poses a major threat to human beings, and a prompt intravenous thrombolytic management remains the gold standard protocol for stroke sufferers. Although the role of thrombolytic therapy (r-tPA) for ischemic stroke patients and those with underlying impaired renal function has been advocated as effective treating strategy, there is still a lack of investigation as to finding out baseline important variables that are capable of early outcome prediction.

Objectives

In this project, we hypothesize that the change of clinical chronic kidney disease (CKD) staging (delta stage = CKD stage after 3-month follow-up - CKD stage at admission) could serve as a crucial predictor of the prognosis of patients.

Design

This is a cohort longitudinal retrospective study.

Sources and Methods

A total of 765 cerebral artery ischemic stroke patients with impaired renal function were recruited and followed up for 1 year. Among them, 116 had received the thrombolytic treatment (r-tPA) after being evaluated at the triage in the emergency department and the rest had not (non-r-tPA). Propensity-matching was applied to compare the mortality between the r-tPA and non-r-tPA groups. Multiple logistic regression (LR) and decision tree (DT) algorithm were used to identify important prediction factors for mortality as well as the improvement in neurological function.

Results

The 1-year mortality rates for r-tPA and non-r-tPA groups were 32.8% and 44.4%, respectively. The propensity-matched odds ratio of mortality for the r-tPA group compared with the non-r-tPA group is 0.469, with p = 0.003. Logistic regressions suggest that age, Hct, diabetes mellitus type 2, coronary artery disease, and delta stage are important factors for mortality for the non-r-tPA group, whereas age, diabetes mellitus type 2, chronic heart failure, hospital day, and delta stage are important factors for the r-tPA group. On the usage of antihypertensive drugs, ACEI/ARB was not associated with mortality (p = 0.198), whereas the diuretic was, with odds ratio at 1.619 (p = 0.025), indicating higher mortality after administration. Both LR and DT analyses indicate that delta stage is the most important predictor. For the r-tPA group, patients with delta stage ⩽0 had a 24% mortality, while that for delta stage >0 the mortality is 75%. For non-r-tPA patients, the corresponding mortalities were 30.9 and 66.3, respectively. Delta stage is also useful for predicting patients' improvement of neurological function, assessed by NIHSS, mRS, and Barthel Index. The areas under the curve for the three assessments are 0.83, 0.835, and 0.663, respectively.

Conclusion

Large-artery ischemic stroke patients who received thrombolytic treatment had significantly lower mortality, even when presenting underlying impaired renal function. The change of CKD staging (delta stage) is capable of acting as a powerful clinical baseline surrogate for both r-tPA and non-r-tPA patients in terms of early outcome prediction. Long-term use of diuretics could be potentially harmful to this group of patients. Moreover, delta stage correlates well with clinical long-term neurological functionality assessment (NIHSS, mRS, and Barthel index), which is helpful in aiding urgent clinical decision-making.

Twenty-eight-day in-hospital mortality prediction for elderly patients with ischemic stroke in the intensive care unit: Interpretable machine learning models

Background

Risk stratification of elderly patients with ischemic stroke (IS) who are admitted to the intensive care unit (ICU) remains a challenging task. This study aims to establish and validate predictive models that are based on novel machine learning (ML) algorithms for 28-day in-hospital mortality in elderly patients with IS who were admitted to the ICU.

Methods

Data of elderly patients with IS were extracted from the electronic intensive care unit (eICU) Collaborative Research Database (eICU-CRD) records of those elderly patients admitted between 2014 and 2015. All selected participants were randomly divided into two sets: a training set and a validation set in the ratio of 8:2. ML algorithms, such as Naïve Bayes (NB), eXtreme Gradient Boosting (xgboost), and logistic regression (LR), were applied for model construction utilizing 10-fold cross-validation. The performance of models was measured by the area under the receiver operating characteristic curve (AUC) analysis and accuracy. The present study uses interpretable ML methods to provide insight into the model's prediction and outcome using the SHapley Additive exPlanations (SHAP) method.

Results

As regards the population demographics and clinical characteristics, the analysis in the present study included 1,236 elderly patients with IS in the ICU, of whom 164 (13.3%) died during hospitalization. As regards feature selection, a total of eight features were selected for model construction. In the training set, both the xgboost and NB models showed specificity values of 0.989 and 0.767, respectively. In the internal validation set, the xgboost model identified patients who died with an AUC value of 0.733 better than the LR model which identified patients who died with an AUC value of 0.627 or the NB model 0.672.

Conclusion

The xgboost model shows the best predictive performance that predicts mortality in elderly patients with IS in the ICU. By making the ML model explainable, physicians would be able to understand better the reasoning behind the outcome.

Renal function is associated with one-month and one-year mortality in patients with intracerebral hemorrhage

OBJECTIVE

This study evaluated short-term (1-month) and long-term (1-year) mortality risks associated with the glomerular filtration rate (eGFR) on admission for patients with intracerebral hemorrhage.

METHODS

From the Taiwan Stroke Registry data from April 2006 to December 2016, we identified and stratified patients with intracerebral hemorrhage into five subgroups by the eGFR level on admission: ≥90, 60-89, 30-59, 15-29, and <15 mL/min/1.73 m2 or on dialysis. Risks for 1-month and 1-year mortality after intracerebral hemorrhage were compared by the eGFR levels.

RESULTS

Both the 1-month and 1-year mortality rates progressively increased with the decrease in eGFR levels. The 1-month mortality rate in patients with eGFR < 15 mL/min/1.73 m2 or on dialysis was approximately 5.5-fold greater than that in patients with eGFR ≥ 90 mL/min/1.73 m2 (8.31 versus 1.50 per 1000 person-days), with an adjusted hazard ratio (HR) of 4.59 [95% confidence interval (CI) = 2.71-7.78]. Similarly, the 1-year mortality in patients with eGFR < 15 mL/min/1.73 m2 or on dialysis was 7.5 times that in patients with eGFR ≥ 90 mL/min/1.73 m2 (2.34 versus 0.31 per 1000 person-days), with an adjusted HR of 4.54 (95% CI 2.95-6.98).

CONCLUSION

Impairment of renal function is an independent risk factor for mortality in patients with intracerebral hemorrhage in a gradual way. The eGFR level is a prognostic indicator for patients with intracerebral hemorrhage.

Association between serum uric acid to serum creatinine ratio and poor functional outcomes in patients with acute ischemic stroke

BACKGROUND

The role of serum uric acid (SUA) in prognosis is controversial because SUA levels largely depend on renal clearance function. This study aimed to investigate the association between renal function-normalized SUA (SUA to serum creatinine ratio, SUA/SCr) and poor functional outcomes in patients with acute ischemic stroke (AIS).

METHODS

All patients were recruited from the Third China National Stroke Registry. Poor functional outcomes were defined by modified Rankin Scale (mRS) scores of 3-6 at 3 months or 2-6 at 1 year.

RESULTS

Among 8169 enrolled patients, the median SUA/SCr was 4.19 (interquartile range, 3.47-5.08). Compared with patients in the fourth quintile group, those in the first quintile group had higher proportions of mRS score 3-6 (odds ratio [OR] 1.55; 95% confidence interval [CI] 1.24-1.93) and mRS score 2-6 (OR 1.28; 95% CI 1.08-1.53) at 3 months. The addition of SUA/SCr to the conventional risk model had a greater incremental value than the addition of SUA or SCr alone. Subgroup analysis showed that the association was only significant in patients with normal kidney function (P for interaction<0.05). Similar results were found for outcomes at 1 year.

CONCLUSIONS

A lower level of SUA/SCr was associated with poor functional outcomes in patients with AIS at 3 months and at 1 year, suggesting the potential use of SUA/SCr in clinical practice as a preferable marker for stroke outcomes.

Intravenous Thrombolysis Improves the Prognosis of Patients with Acute Ischemic Stroke and Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is associated with a higher mortality rate and a poor prognosis among patients with acute ischemic stroke (AIS) who receive intravenous thrombolysis (IVT); however, it is still unclear whether IVT improves the prognosis of patients with AIS and CKD.

OBJECTIVE

We conducted this study to evaluate the impact of IVT in patients with AIS and CKD.

METHODS

We analyzed patients with AIS and CKD in 3 stroke centers who met the indications for IVT between January 2015 and January 2020. The patients were grouped into an IVT group and a non-IVT group according to whether patients received IVT. After propensity score matching at a 1:1 ratio, symptomatic intracranial hemorrhage (sICH) and the modified Rankin Scale (mRS) score at 3 months were compared to assess the safety and efficacy of IVT in patients with AIS with CKD.

RESULTS

A total of 888 patients were enrolled: 763 in the IVT group and 125 in the non-IVT group. After matching, 250 patients were analyzed, and no significant differences were found in sICH between the 2 groups. However, the IVT group had a better 90-day mRS (0-2) score (70.4% vs. 57.6; p = 0.048) than the non-IVT group.

CONCLUSIONS

IVT improved the 3-month prognosis and did not increase the occurrence of sICH among patients with AIS with CKD.

Covert vascular brain injury in chronic kidney disease

Chronic kidney disease (CKD) contributes to the increased risk of stroke and dementia. Accumulating evidence indicates that structural brain abnormalities, such as cerebral small vessel disease, including white matter hyperintensities, lacunes, perivascular spaces, and cerebral microbleeds, as well as brain atrophy, are common in patients with CKD. All of these imaging findings have been implicated in the development of stroke and dementia. The brain and kidney exhibit similar impairments and promote structural brain abnormalities due to shared vascular risk factors and similar anatomical and physiological susceptibility to vascular injury in patients with CKD. This indicates that kidney function has a significant effect on brain aging. However, as most results are derived from cross-sectional observational studies, the exact pathophysiology of structural brain abnormalities in CKD remains unclear. The early detection of structural brain abnormalities in CKD in the asymptomatic or subclinical phase (covert) should enable stroke risk prediction and guide clinicians on more targeted interventions to prevent stroke in patients with CKD. This article summarizes the currently available clinical evidence linking covert vascular brain injuries with CKD.

Frequency of kidney dysfunction in patients with acute stroke and the relationship with the type, severity and outcome

BACKGROUND/AIM

Kidney dysfunction is an established risk factor for cardiovascular diseases including stroke. The study aimed at assessing the frequency of kidney dysfunction in patients with acute stroke and to evaluate the relationship to the type, severity and outcome of stroke. To establish a relationship, which has not been explained in past studies.

MATERIALS AND METHODS

This was a cross-sectional analytical study on acute stroke patients and matched controls, evaluating for kidney dysfunction using both estimated glomerular filtration rate (GFR) and the spot urine protein creatinine ratio. The type of stroke was observed by neuroimaging. The National Institute of Health Stroke Score was used to assess the severity of stroke at presentation and outcome after 7 days. Data analysis was done using Statistical Package for Social Sciences (SPSS) application version 23.0 (SPSS Inc., Chicago, IL, USA).

RESULTS

: Ninety-eight patients and 100 controls were recruited, with a mean age of 64.7 ± 15.5 and 64.8 ± 15.1 years, respectively. The patients with stroke had a statistically significant higher frequency of kidney dysfunction compared to the controls (85.9% vs. 62.0%, P ≤ 0.001). Patients with haemorrhagic stroke had a higher frequency of kidney dysfunction compared with those with ischaemic stroke (93.8% vs. 77.3%, P = 0.048). The proportion of patients with kidney dysfunction was seen to increase from those with mild to those with severe stroke symptoms, both at presentation and after 7 days. Estimated GFR was seen to be an independent predictor of poor outcome in patients with stroke (odds ratio 0.955, 95% confidence interval 0.924 - 0.986, P = 0.005).

CONCLUSION

The study demonstrated that in patients with acute stroke there is a high frequency of kidney dysfunction. Haemorrhagic stroke, increasing stroke severity and poor outcome were seen to be associated with kidney dysfunction. Thus, recommending the need for kidney care as an important part of stroke management.

Etiology and Outcome of Ischemic Stroke in Patients With Renal Impairment Including Chronic Kidney Disease: Japan Stroke Data Bank

Background and Objectives

Chronic kidney disease is a worldwide public health problem that is recognized as an established risk factor for stroke. It remains unclear whether its distribution and clinical impact are consistent across ischemic stroke subtypes in patients with renal impairment. We examined whether renal impairment was associated with the proportion of each stroke subtype vs ischemic stroke overall and with functional outcomes after each stroke subtype.

Methods

Study participants were 10,392 adult patients with an acute stroke from the register of the Japan Stroke Data Bank, a hospital-based multicenter stroke registration database, between October 2016 and December 2019, whose baseline serum creatinine levels or a dipstick proteinuria result were available. All ischemic strokes were classified according to the Trial of Org 10172 in Acute Stroke Treatment criteria. Unfavorable functional outcome was defined as modified Rankin Scale (mRS) score 3–6 at discharge. Mixed effect logistic regression was used to determine the relationship between the outcomes and the estimated glomerular filtration rate (eGFR), eGFR strata (<45, 45–59, ≥60 mL/min/1.73 m²), or dipstick proteinuria ≥1 adjusted for covariates.

Results

Overall, 2,419 (23%) patients had eGFR 45–59 mL/min/1.73 m² and 1,976 (19%) had eGFR <45 mL/min/1.73 m², including 185 patients (1.8%) receiving hemodialysis. Both eGFR 45–59 and eGFR <45 mL/min/1.73 m² were associated with a higher proportion of cardioembolic stroke (odds ratio [OR], 1.21 [95% CI, 1.05–1.39] and 1.55 [1.34–1.79], respectively) and a lower proportion of small vessel occlusion (0.79 [0.69–0.90] and 0.68 [0.59–0.79], respectively). A similar association with the proportion of these 2 subtypes was proven in the analyses using decreased eGFR as continuous values. Both eGFR <45 mL/min/1.73 m² and proteinuria were associated with unfavorable functional outcomes in patients with cardioembolic stroke (OR, 1.30 [95% CI, 1.01–1.69] and 3.18 [2.03–4.98], respectively) and small vessel occlusion (OR, 1.44 [1.01–2.07] and 2.08 [1.08–3.98], respectively).

Discussion

Renal impairment contributes to the different distributions and clinical effects across specific stroke subtypes, particularly evident in cardioembolic stroke and small vessel occlusion. This possibly indicates shared mechanisms of susceptibility and potentially enhancing pathways.

Low-Density Lipoprotein Cholesterol and Mortality in Patients With Intracerebral Hemorrhage in Taiwan

Objective: Lower serum low-density lipoprotein cholesterol (LDL-C) levels are associated with increased intracerebral hemorrhage (ICH) risk. However, reverse causality and residual confounding has not attracted public attention. Therefore, we assessed whether people with LDL-C have increased risk of mortality adjusting for potential confounders using two large Taiwan cohorts.

Methods: The Mei-Jhao (MJ) cohort has 414,372 adults participating in a medical screening program with 378 ICH deaths within 15 years of follow-up (1994–2008). Cox proportional hazards regressions estimated hazard death ratios according to LDL-C levels. We identified 4,606 ICH patients from the Taiwan Stroke Registry (TSR) and analyzed the impact of LDL-C on 3-month mortality.

Results: Low cholesterol (LDL-C <100 mg/dL), found in 1/4 of the MJ cohort, was highly prevalent (36%) among young adults (age 20–39). There was a graded relationship between cholesterol and mortality for ICH [Hazard ratio, 1.56; 95% confidence interval (CI), 1.13–2.16]. Compared with patients with an LDL-C of 110–129 mg/dL in TSR, the risk for mortality was 1.84 (95% CI, 1.28–2.63) with an LDL-C of <100 mg/dL.

Conclusion: Lower serum LDL-C level independently predicts higher mortality after acute ICH. While its causative role may vary, low cholesterol may pose potential harms in Taiwan.

Intravenous tissue plasminogen activator for acute ischemic stroke in patients with renal dysfunction

OBJECTIVE

This study used the Taiwan Stroke Registry data to evaluate the efficacy and safety of intravenous tissue plasminogen activator (tPA) in treating acute ischemic stroke in patients with renal dysfunction.

DESIGN

We identified 3525 ischemic stroke patients and classified them into two groups according to the estimated glomerular filtration rate (eGFR) at the emergency department: ≥60, and <60 ml/min/1.73 m2 or on dialysis and by the propensity score from August 2006 to May 2015. The odds ratio of poor functional outcome (modified Rankin Scale ≥2) was calculated for patients with tPA treatment (N = 705), compared to those without tPA treatment (N = 2820), by eGFR levels, at 1, 3 and 6 months after ischemic stroke. We also evaluated the risks of intracerebral hemorrhage, upper gastrointestinal bleeding, mortality, between the two groups by eGFR levels.

RESULTS

Among patients with eGFR levels of <60 ml/min/1.73 m2, tPA therapy reduced the odds ratio of poor functional outcome to 0.60 (95% confidence interval = 0.42-0.87) at 6 months after ischemic stroke. The tPA therapy was not associated with increased overall risk of upper gastrointestinal bleeding, but with increased risk of intracerebral hemorrhage. The low eGFR was not a significant risk factor of intracerebral hemorrhage among ischemic stroke patients receiving tPA treatment.

CONCLUSIONS

tPA for acute ischemic stroke could improve functional outcomes without increasing the risks of upper gastrointestinal bleeding for patients with or without renal dysfunction. The low eGFR was not a significant risk factor for intracerebral hemorrhage among patients receiving tPA treatment.

Effect of renal impairment on the efficacy and safety of intra-arterial treatment: A post-hoc analysis of DIRECT-MT study

OBJECTIVE

To determine the influence of renal impairment on clinical outcomes in patients presenting emergent anterior circulation occlusion treated with mechanical thrombectomy.

METHODS

Consecutive patients with anterior circulation stroke treated with mechanical thrombectomy at 41 academic tertiary care centers were included. renal impairment was defined as glomerular filtration rate <60 mL/min/1.73 m² at the time of admission. The primary outcome was the distribution of scores on the modified Rankin scale, and safety outcomes were mortality within 90 days and hemorrhagic complications. Binary and ordinal logistic regression was used to evaluate the associations between renal impairment and categorical outcomes. Linear regression was used to assess continuous outcomes.

RESULTS

A total of 607 patients (47 renal impairment and 600 non-renal impairment) who underwent mechanical thrombectomy were included in this study. Multivariate regression analysis showed that renal impairment was independently associated with the increase of the modified Rankin scale at 90 days. The proportion of patients with successful reperfusion was 71.7% in the renal impairment group and 83.3% in the non-renal impairment group. Renal impairment was an independent predictor of 90-day mortality. No significant treatment for the ordinal modified Rankin scale or 90-day mortality was observed by renal impairment interaction. The risk of asymptomatic intracranial hemorrhage was higher in the mechanical thrombectomy plus IVT group (53.6%) than in the mechanical thrombectomy alone group (15.8%) for renal impairment, but was similar between the mechanical thrombectomy plus IVT group (34.6%) and the mechanical thrombectomy alone group (36.4%) for non-renal impairment (p = 0.01).

CONCLUSION

These results demonstrated that the outcomes of mechanical thrombectomy alone and mechanical thrombectomy plus IVT group did not differ significantly in acute stroke patients with and without renal impairment. Also, renal impairment was an independent predictor of worse functional independence and higher mortality at 90 days.

Smoking Status and Functional Outcomes in Young Stroke

Objective: Stroke in young adults is uncommon, and the etiologies and risk factors of stroke in young adults differ from those in older populations. Smoker's paradox is an unexpected favorable outcome, and age difference is used to explain the association between smoking and the favorable functional outcome. This study aimed to investigate the existence of this phenomenon in young stroke patients. Methods: We analyzed a total of 9,087 young stroke cases registered in the nationwide stroke registry system of Taiwan between 2006 and 2016. Smoking criteria included having a current history of smoking more than one cigarette per day for more than 6 months. After matching for sex and age, a Cox model was used to compare mortality and function outcomes between smokers and non-smokers. Results: Compared with the non-smoker group, smoking was associated with older age, higher comorbidities, and higher alcohol consumption. Patients who report smoking with National Institutes of Health Stroke Scale scores of 11-15 had a worse functional outcome (adjusted odds ratio, 0.81; 95% confidence interval, 0.76 - 0.87). Conclusion: Smokers had a higher risk of unfavorable functional outcomes at 3 months after stroke, and therefore, we continue to strongly advocate the importance of smoking cessation.

Protein energy wasting-based nutritional assessment predicts outcomes of acute ischemic stroke and solves the epidemiologic paradox

OBJECTIVE

Overweight and hyperlipidemia, the two established risk factors for acute ischemic stroke, are paradoxically associated with favorable outcomes. The paradox may be resolved by the concept of protein energy wasting (PEW), in which total cholesterol level and body mass index are used as nutritional indexes for predicting outcomes of chronic kidney disease.

METHODS

Among 12 271 people with acute ischemic stroke and chronic kidney disease, 2086 were defined as being at risk of PEW-with a body mass index <22 kg/m² plus either a serum albumin level <38 g/L or a total cholesterol level <4.14 mmol/L (160 mg/dL) without the use of lipid-lowering drugs-and all the others were a control group. The hazards of PEW for mortality and functional outcomes were evaluated using propensity score matching and multivariate Cox regression analysis.

RESULTS

Based on the propensity score, 2081 PEW participants were matched to the same number of non-PEW control participants. PEW was associated with a higher mortality risk at 3 mo (adjusted hazard ratio, 1.19; 95% confidence interval [CI], 1.02-1.42) and 1 y (adjusted hazard ratio, 1.33; 95% CI1.13-1.52). PEW was also associated with poor functional outcomes (modified Rankin Scale score >2) at 1 mo (adjusted odds ratio, 1.32; 95% CI, 1.08-1.61) and 3 mo (adjusted odds ratio, 1.27; 95% CI, 1.03-1.56).

CONCLUSIONS

According to the PEW-based assessment system, a modest decrease in body mass index and total cholesterol levels suggests malnutrition and is associated with adverse outcomes of acute ischemic stroke.

Renal dysfunction is associated with lower odds of home discharge for patients with stroke

OBJECTIVES

Studies on the association of estimated glomerular filtration rate (eGFR) levels with hospital discharge disposition after stroke are limited with inconsistent results. This study investigated the odds of home discharge with eGFR levels at admission for patients with stroke using the Taiwan Stroke Registry (TSR) data.

METHODS

From the TSR database, a total of 51,338 stroke patients from 2006 to 2015 were categorized into five groups based on eGFR levels at admission. The proportion of home discharge by the eGFR levels was calculated and logistic regression analysis was used to estimate the related odds ratio (OR) and 95% confidence interval.

RESULTS

Near 85% of stroke patients were discharged to home. The proportion of home discharges decreased as the eGFR level declined. Compared to patients with eGFR ≥90 mL/min/1.73 m², the adjusted ORs of home discharge were 0.91, 0.85, 0.63, 0.56 for patients with eGFR 60-89, eGFR 30-59, eGFR 15-29, and eGFR < 15 mL/min/1.73 m² or on dialysis, respectively, in a graded relationship. The trends were consistent in the ischemic stroke and hemorrhagic stroke patients. The areas under the receiver operating characteristic curve for all stroke patients, ischemic stroke patients, and hemorrhagic stroke patients were 0.801, 0799, 0.815, respectively.

CONCLUSION

The odds of home discharge for stroke patients decreased with a significant independent graded association with declining eGFR levels. Renal function could predict home discharge after stroke.

Chronic Kidney Disease and Cerebrovascular Disease: Consensus and Guidance From a KDIGO Controversies Conference

The global health burden of chronic kidney disease is rapidly rising, and chronic kidney disease is an important risk factor for cerebrovascular disease. Proposed underlying mechanisms for this relationship include shared traditional risk factors such as hypertension and diabetes, uremia-related nontraditional risk factors, such as oxidative stress and abnormal calcium-phosphorus metabolism, and dialysis-specific factors such as cerebral hypoperfusion and changes in cardiac structure. Chronic kidney disease frequently complicates routine stroke risk prediction, diagnosis, management, and prevention. It is also associated with worse stroke severity, outcomes and a high burden of silent cerebrovascular disease, and vascular cognitive impairment. Here, we present a summary of the epidemiology, pathophysiology, diagnosis, and treatment of cerebrovascular disease in chronic kidney disease from the Kidney Disease: Improving Global Outcomes Controversies Conference on central and peripheral arterial disease with a focus on knowledge gaps, areas of controversy, and priorities for research.

Prognostic impact of renal dysfunction on embolic stroke of undetermined source-Role beyond CHA2 DS2 -VASc score: Results from Taiwan Stroke Registry

BACKGROUND AND PURPOSE

The CHA₂ DS₂ -VASc score has immense prognostic value in patients with embolic stroke of undetermined source (ESUS). We aimed to determine the usefulness of advanced renal dysfunction and its addition to the CHA₂ DS₂ -VASc score in improving predictive accuracy.

METHODS

In total, 3775 ESUS patients were enrolled from a nationwide hospital-based prospective study. Advanced renal dysfunction was defined as estimated glomerular filtration rate <30 ml/min per 1.73 m² or patients under dialysis. Clinical outcomes included recurrent stroke and 1-year all-cause mortality. Poor functional outcome was defined as a modified Rankin Scale >2 at first-, third-, and sixth-month post-stroke. The renal (R)-CHA₂ DS₂ -VASc score was derived by including advanced renal dysfunction in the CHA₂ DS₂ -VASc score. Risk stratification improvement after including advanced renal dysfunction was assessed using C statistic, integrated discrimination improvement (IDI), and category-free net reclassification index (NRI).

RESULTS

After adjusting for confounding factors and CHA₂ DS₂ -VASc score, advanced renal dysfunction showed significant associations with all-cause mortality (HR: 2.88, 95% CI: 1.92-4.34) and poor functional outcome at third- (OR: 2.69, 95% CI: 1.47-4.94) and sixth-month post-stroke (OR: 2.67, 95% CI: 1.47-4.83). IDI and NRI showed that incorporating advanced renal dysfunction significantly improved risk discrimination over the original CHA₂ DS₂ -VASc score. R-CHA₂ DS₂ -VASc score ≥2 increased risk by 1.94-fold (95% CI: 1.15-3.27) for all-cause mortality, and ≥4 increased risk by 1.62-fold (95% CI: 1.05-2.50) of poor functional outcome at third-month post-stroke and by 1.81-fold (95% CI: 1.19-2.75) at sixth-month post-stroke.

CONCLUSIONS

Advanced renal dysfunction was significantly associated with clinical and functional outcomes in ESUS patients and may improve prognostic impact of the CHA₂ DS₂ -VASc score.

Impact of multimorbidity on risk and outcome of stroke: Lessons from chronic kidney disease

With both an aging population and greater post-stroke survival, multimorbidity is a growing healthcare challenge, affecting over 40% of stroke patients, and rising rapidly and predictably with increasing age. Commonly defined as the co-occurrence of two or more chronic conditions, multimorbidity burden is a strong adverse prognostic factor, associated with greater short- and long-term stroke mortality, worse rehabilitation outcomes, and reduced use of secondary prevention. Chronic kidney disease can be considered as the archetypal comorbidity, being age-dependent and also affecting about 40% of stroke patients. Chronic kidney disease and stroke share very similar traditional cardiovascular risk factor profiles such as hypertension and diabetes, though novel chronic kidney disease-specific risk factors such as inflammation and oxidative stress have also been proposed. Using chronic kidney disease as an exemplar condition, we explore the mechanisms of risk in multimorbidity, implications for management, impact on stroke severity, and downstream consequences such as post-stroke cognitive impairment and dementia.

Machine learning to predict mortality after rehabilitation among patients with severe stroke

Stroke is among the leading causes of death and disability worldwide. Approximately 20–25% of stroke survivors present severe disability, which is associated with increased mortality risk. Prognostication is inherent in the process of clinical decision-making. Machine learning (ML) methods have gained increasing popularity in the setting of biomedical research. The aim of this study was twofold: assessing the performance of ML tree-based algorithms for predicting three-year mortality model in 1207 stroke patients with severe disability who completed rehabilitation and comparing the performance of ML algorithms to that of a standard logistic regression. The logistic regression model achieved an area under the Receiver Operating Characteristics curve (AUC) of 0.745 and was well calibrated. At the optimal risk threshold, the model had an accuracy of 75.7%, a positive predictive value (PPV) of 33.9%, and a negative predictive value (NPV) of 91.0%. The ML algorithm outperformed the logistic regression model through the implementation of synthetic minority oversampling technique and the Random Forests, achieving an AUC of 0.928 and an accuracy of 86.3%. The PPV was 84.6% and the NPV 87.5%. This study introduced a step forward in the creation of standardisable tools for predicting health outcomes in individuals affected by stroke.

Prognostic Value of Cystatin C in Acute Ischemic Stroke Patients with Intravenous Thrombolysis

BACKGROUND

Less is known about the prognostic value of serum cystatin C in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT). The aim of the present study was to examine the association between serum cystatin C levels and prognosis of AIS patients after IVT.

METHODS

Serum cystatin C was measured within 24 hours after recombinant tissue plasminogen activator (rt-PA) treatment in 280 consecutively recruited patients with AIS. The main outcomes included combination of death and major disability, death, major disability (modified Rankin Scale score 3-5) and vascular events at 3-month follow-up.

RESULTS

During the 3-month follow-up, 94 patients (33.6%) experienced death or major disability (28 deaths and 66 major disability) and 49 patients (17.5%) experienced vascular events. After multivariate adjustment, serum cystatin C was significantly associated with an increased risk of the combined outcome of death and major disability (OR=4.51, P = 0.006). Adding serum cystatin C quartiles to a model containing conventional risk factors improved the predictive power for the combined outcome of death and major disability (continuous net reclassification index 43.88%, P < 0.001; categorical net reclassification index 9.15%, P = 0.013; integrated discrimination improvement 2.31%, P = 0.025). Similar phenomena were also observed in major disability and vascular events.

CONCLUSION

Higher levels of serum cystatin C in AIS patients after IVT were independently associated with increased risks of poor functional outcomes and vascular events, especially combining conventional risk factors, suggesting that serum cystatin C might improve risk prediction for poor prognosis in AIS patients receiving rt-PA treatment.

Etiological Subtypes of Transient Ischemic Attack and Ischemic Stroke in Chronic Kidney Disease: Population-Based Study

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD) is strongly associated with stroke risk, but the mechanisms underlying this association are unclear and might be informed by subtype-specific analyses. However, few studies have reported stroke subtypes in CKD according to established classification systems, such as the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria. We, therefore, aimed to determine which transient ischemic attack and ischemic stroke subtypes using the TOAST classification occur most frequently in patients with CKD.

METHODS

In a population-based study of all transient ischemic attack and stroke (OXVASC [Oxford Vascular Study]; 2002-2017), all ischemic events were classified by TOAST subtypes (cardioembolism, large artery disease, small vessel disease, undetermined, multiple, other etiology, or incompletely investigated). Logistic regression was used to determine the relationship between CKD (defined as an estimated glomerular filtration rate <60 mL/min per 1.73 m2) and transient ischemic attack/stroke subtypes adjusted for age, sex, and hypertension and then stratified by age and estimated glomerular filtration rate category.

RESULTS

Among 3178 patients with transient ischemic attack (n=1167), ischemic stroke (n=1802), and intracerebral hemorrhage (n=209), 1267 (40%) had CKD. Although there was a greater prevalence of cardioembolic events (31.8% versus 21.2%; P<0.001) in patients with CKD, this association was lost after adjustment for age, sex, and hypertension (adjusted odds ratio=1.20 [95% CI, 0.99-1.45]; P=0.07). Similarly, although patients with CKD had a lower prevalence of small vessel disease (8.8% versus 13.6%; P<0.001), undetermined (26.1% versus 39.4%; P<0.001), and other etiology (1.0% versus 3.6%; P<0.001) subtypes, these associations were also lost after adjustment (adjusted odds ratio=0.86 [0.65-1.13]; P=0.27 and 0.73 [0.36-1.43]; P=0.37 for small vessel disease and other defined etiology, respectively) for all but undetermined (adjusted odds ratio=0.81 [0.67-0.98]; P=0.03).

CONCLUSIONS

There were no independent positive associations between CKD and specific TOAST subtypes, which suggest that renal-specific risk factors are unlikely to play an important role in the etiology of particular subtypes. Future studies of stroke and CKD should report subtype-specific analyses to gain further insights into potential mechanisms.

Effect of renal function on association between uric acid and prognosis in acute ischemic stroke patients with elevated systolic blood pressure

BACKGROUND AND AIMS

The prognostic value of uric acid in ischemic stroke remains controversial, and it is unclear whether renal function status modifies the prognostic value of uric acid in ischemic stroke patients.

METHODS

A total of 3284 acute ischemic stroke patients from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS) with creatinine and uric acid measurements were included in this analysis. The primary outcome was a composite of death and major disability (modified Rankin Scale score ≥3) at 1 year after stroke.

RESULTS

The prognostic value of uric acid in ischemic stroke was appreciably modified by patients' renal function status (p for interaction <0.05). After multivariate adjustment, higher uric acid level was significantly associated with a better prognosis in patients with normal renal function (odds ratio, 0.61; 95% confidence interval, 0.45-0.83), but not in those with abnormal renal function (odds ratio, 0.87; 95% confidence interval, 0.48-1.55), when two extreme quartiles were compared. Linear association between uric acid and primary outcome was observed among patients with normal renal function (p for linearity = 0.023).

CONCLUSION

The present study suggests that high serum uric acid concentration is associated with better prognosis in ischemic stroke patients with normal renal function, but not in those with abnormal renal function. The establishment of causality between increased uric acid levels and better stroke prognosis needs more suitably designed randomized clinical trials.

Sex Differences in Long-Term Mortality and Functional Outcome After Rehabilitation in Patients With Severe Stroke

Objective: We sought to determine sex differences in outcomes in patients with severe stroke who had been admitted to inpatient rehabilitation. Methods: We studied 1,316 patients aged 18 to 99 (mean 72) classified as case-mix groups 0108, 0109, and 0110 of the Medicare case-mix classification system. These groups encompass the most severe strokes. Three outcomes were analyzed: (1) 3-year mortality from admission to rehabilitation; (2) combined outcome of transfer to acute care or death within 90 days from admission to rehabilitation; (3) functional outcome, including proportional recovery in motor functioning and good functional outcome as defined by achievement of a Functional Independence Measure (FIM)-motor score ≥65 points at discharge. Multivariable regression analyses were used to assess sex-difference in each outcome between women and men. The covariates examined included age, marital status, comorbidities, time from stroke onset to rehabilitation admission <30 days, ischemic stroke, dysphagia, neglect, motor FIM score at admission, and cognitive FIM score at admission. Results: Kaplan-Meier estimated 3-year mortality rate was 20.7% in women and 22.0% in men. The crude hazard ratio (HR) of death for women compared with men was 0.94 (95% CI 0.74-1.20). After adjustment for significant covariates, the HR of 3-year mortality was 0.73 (95% CIs 0.56-0.96; p = 0.025). Comorbidity, including diabetes, anemia, coronary artery disease, atrial fibrillation, and chronic obstructive pulmonary disease, significantly increased mortality risk by 49-88%. The incidence of the combined outcome was 8.3% in women and 8.4% in men. The crude HR of the combined end-point for women compared with men was 1.05 (95% CI 0.72-1.53). After adjustment for significant covariates, the HR was 0.95 (95% CIs 0.65-1.40; p = 0.810). Likewise, no significant difference in proportional recovery or in the rate of achievement of a good functional outcome between women and men was observed. Conclusion: Among patients admitted to inpatient rehabilitation after severe stroke, women and men had comparable crude mortality rates at 3 years. After multivariable adjustment, however, women had lower mortality risk. No sex-differences in the risk of being transferred to acute care or dying within 90 days from admission to rehabilitation or in responsiveness to rehabilitation were observed.

Brain-kidney interaction: Renal dysfunction following ischemic stroke

Stroke is a leading cause of mortality and morbidity, with long-term debilitating effects. Accumulating evidence from experimental studies as well as observational studies in patients suggests a cross talk between the brain and kidney after stroke. Stroke may lead to kidney dysfunction which can adversely impact patient outcome. In this review article, we discuss the epidemiology and mechanisms of brain–kidney interaction following ischemic stroke. Specifically, we discuss the role of the central autonomic network, autoregulation, inflammatory and immune responses, the role of extracellular vesicles and their cargo microRNA, in mediating brain–kidney interaction following stroke. Understanding the bidirectional nature of interaction between the brain and kidney after cerebral injury would have clinical implications for the treatment of stroke and overall patient outcome.

Temporal Trends in the Outcomes of Dialysis Patients Admitted With Acute Ischemic Stroke

BACKGROUND

There is a paucity of contemporary data on the characteristics and outcomes of acute ischemic stroke (AIS) in patients on maintenance dialysis.

METHODS AND RESULTS

We used the nationwide inpatient sample to examine contemporary trends in the incidence, management patterns, and outcomes of AIS in dialysis patients. A total of 930 010 patients were admitted with AIS between 2003 and 2014, of whom 13 642 (1.5%) were on dialysis. Overall, the incidence of AIS among dialysis patients decreased significantly (Ptrend<0.001), while it remained stable in non-dialysis patients (Ptrend=0.78). Compared with non-dialysis patients, those on dialysis were younger (67±13 years versus 71±15 years, P<0.001), and had higher prevalence of major comorbidities. Black patients constituted 35.2% of dialysis patients admitted with AIS compared with 16.7% of patients in the non-dialysis group (P<0.001). After propensity score matching, in-hospital mortality was higher in the dialysis group (7.6% versus 5.2%, P<0.001), but this mortality gap narrowed overtime (Ptrend<0.001). Hemorrhagic conversion and gastrointestinal bleeding rates were similar, but blood transfusion was more common in the dialysis group. Rates of severe disability surrogates (tracheostomy, gastrostomy, mechanical ventilation and non-home discharge) were also similar in both groups. However, dialysis patients had longer hospitalizations, and accrued a 25% higher total cost of acute care.

CONCLUSIONS

Dialysis patients have 8-folds higher incidence of AIS compared withnon-dialysis patients. They also have higher risk-adjusted in-hospital mortality, sepsis and blood transfusion, longer hospitalizations, and higher cost. There is a need to identify preventative strategies to reduce the risk of AIS in the dialysis population.

Registry-based stroke research in Taiwan: past and future

Stroke registries are observational databases focusing on the clinical information and outcomes of stroke patients. They play an important role in the cycle of quality improvement. Registry data are collected from real-world experiences of stroke care and are suitable for measuring quality of care. By exposing inadequacies in performance measures of stroke care, research from stroke registries has changed how we manage stroke patients in Taiwan. With the success of various quality improvement campaigns, mortality from stroke and recurrence of stroke have decreased in the past decade. After the implementation of a nationwide stroke registry, researchers have been creatively expanding how they use and collect registry data for research. Through the use of the nationwide stroke registry as a common data model, researchers from many hospitals have built their own stroke registries with extended data elements to meet the needs of research. In collaboration with information technology professionals, stroke registry systems have changed from web-based, manual submission systems to automated fill-in systems in some hospitals. Furthermore, record linkage between stroke registries and administrative claims databases or other existing databases has widened the utility of registry data in research. Using stroke registry data as the reference standard, researchers have validated several algorithms for ascertaining the diagnosis of stroke and its risk factors from claims data, and have also developed a claims-based index to estimate stroke severity. By making better use of registry data, we believe that we will provide better care to patients with stroke.