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

Impaired kidney function, cerebral small vessel disease and cognitive disorders: the Framingham Heart Study

BACKGROUND AND HYPOTHESIS

It remains unclear whether the relation of chronic kidney disease (CKD) with cognitive dysfunction is independent of blood pressure (BP). We evaluated kidney function in relation to premorbid BP measurements, cerebral small vessel disease (CSVD), and incident mild cognitive impairment (MCI) and dementia in Framingham Offspring Cohort participants.

METHODS

We included Framingham Offspring participants free of dementia, attending an examination during midlife (exam cycle 6, baseline) for ascertainment of kidney function status, with brain magnetic resonance imaging late in life (exam cycles 7-9), cognitive outcome data, and available interim hypertension and BP assessments. We related CKD (estimated glomerular filtration rate <60 ml/min/1.73 m2) and albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g) to CSVD markers and cognitive outcomes using multivariable regression analyses.

RESULTS

Among 2604 participants (mean age 67.4 ± 9.2, 64% women, 7% had CKD, and 9% albuminuria), albuminuria was independently associated with covert infarcts [adjusted OR, 1.55 (1.00-2.38); P = 0.049] and incident MCI and dementia [adjusted hazard ratio (HR), 1.68 (1.18-2.41); P = 0.005 and 1.71, (1.11-2.64); P = 0.015, respectively]. CKD was not associated with CSVD markers but was associated with a higher risk of incident dementia [HR, 1.53 (1.02-2.29); P = 0.041]. While albuminuria was predictive of the Alzheimer's disease subtype [adjusted HR = 1.68, (1.03-2.74); P = 0.04), CKD was predictive of vascular dementia [adjusted HR, 2.78 (1.16-6.68); P = 0.023].

CONCLUSIONS

Kidney disease was associated with CSVD and cognitive disorders in asymptomatic community dwelling participants. The relation was independent of premorbid BP, suggesting that the link between kidney and brain disease may involve additional mechanisms beyond BP-related injury.

Triglyceride-glucose index predicts major adverse cardiovascular events in patients with chronic kidney disease

BACKGROUND AND PURPOSE

Triglyceride-glucose (TyG) index has been regarded as a reliable surrogate marker of insulin resistance for predicting cardiovascular outcomes. The current study aimed to explore the associations between TyG index with major adverse cardiovascular events (MACE) in patients with chronic kidney disease (CKD).

METHODS/PATIENTS

13,517 patients with chronic kidney disease (CKD) from the Kailuan study were included. Patients were divided into quartiles according to the TyG index. The outcomes were MACE, including acute myocardial infarction (AMI) and ischemic stroke (IS). The association between TyG index and the risk of MACE was analyzed by Cox regression models.

RESULTS

During 13.87-year follow-up, a total 1356 MACEs occurred. Multivariable Cox proportional-hazards analyses showed that a higher TyG index quartile was associated with an elevated risk of MACE.

CONCLUSIONS

TyG index is significantly related to MACE in patients with CKD. TyG index can be regarded as a novel predictor of MACE for patients with CKD.

The Untargeted Metabolomics Reveals Differences in Energy Metabolism in Patients with Different Subtypes of Ischemic Stroke

AIMS

Ischemic stroke (IS) is the most common subtype of stroke. The risk factors and pathogenesis of IS are complex and varied due to different subtypes. Therefore, we used metabolomics technology to investigate the biomarkers and potential pathophysiological mechanisms of different subtypes of IS.

METHODS

We included 126 IS patients and divided them into two groups based on the TOAST classification: large-artery atherosclerosis (LAA) group (n = 87) and small-vessel occlusion (SVO) group (n = 39). Plasma metabolomics analysis was performed using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to identify metabolic profiles in LAA and SVO subtype IS patients and to determine metabolic differences between patients with the two subtypes of IS.

RESULTS

We identified 26 differential metabolites between LAA and SVO subtype IS. A multiple prediction model based on the plasm metabolites had good predictive ability for IS subtyping (AUC = 0.822, accuracy = 77.8%), with 12,13-DHOME being the most important differential metabolite in the model. The differential metabolic pathways between the two subtypes of IS patients included tricarboxylic acid (TCA) cycle, alanine, aspartate and glutamate metabolism, and pyruvate metabolism, mainly focused on energy metabolism.

CONCLUSION

12,13-DHOME emerged as the primary discriminatory metabolite between LAA and SVO subtypes of IS. In LAA subtype IS patients, energy metabolism, encompassing pyruvate metabolism and the TCA cycle, exhibited lower activity levels when compared to patients with the SVO subtype IS. The utilization of targeted metabolomics holds the potential to improve diagnostic accuracy for distinguishing stroke subtypes.

Cystatin C-based estimated glomerular filtration rate and risk of stroke in the general population: a prospective cohort study

Background

Previous results on the association between the estimated glomerular filtration rate (eGFR) and stroke are mixed. Most studies derived the eGFR from serum creatinine, which is affected by non-kidney determinants and thus has possibly biased the association with stroke risk.

Methods

In this cohort study, we included 429 566 UK Biobank participants (94.5% white, 54% women, age 56 ± 8 years) free of stroke at enrollment. The eGFRcys and eGFRcr were calculated with serum cystatin C and creatinine, respectively. Outcomes of interest were risk of total stroke and subtypes. We investigated the linear and nonlinear associations using Cox proportional hazards models and restricted cubic splines, corrected for regression dilution bias.

Results

During an average follow-up of 10.11 years, 4427 incident strokes occurred, among which 3447 were ischemic and 1163 were hemorrhagic. After adjustment for confounders, the regression dilution-corrected hazard ratios (95% confidence intervals) for every 10 mL/min/1.73 m2 decrement in eGFRcys were 1.10 (1.05-1.14) for total stroke and 1.11 (1.08-1.15) for ischemic stroke. A similar pattern was observed with eGFRcr, although the association was weaker. When either type of eGFR was below 75 mL/min/1.73 m2, the risks of total and ischemic stroke increased exponentially as eGFR decreased. A U-shaped relationship was witnessed if eGFRcr was used instead. There was a null association between eGFR and hemorrhagic stroke.

Conclusions

The risks of total stroke and ischemic stroke increased exponentially when the eGFRcys fell below 75 mL/min/1.73 m2.

Stroke Subtype Among Individuals With Chronic Kidney Disease

Background

It is widely accepted that there is a stepwise increase in the risk of acute ischemic stroke with chronic kidney disease (CKD). However, whether the risk of specific ischemic stroke subtypes varies with CKD remains unclear.

Objective

To assess the association between ischemic stroke subtypes (cardioembolic, arterial, lacunar, and other) classified using the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and CKD stage.

Design

retrospective cohort study.

Setting

Ontario, Canada.

Patients

A total of 17 434 adults with an acute ischemic stroke in Ontario, Canada between April 1, 2002 and March 31, 2013, with an estimated glomerular filtration rate (eGFR) measurement or receipt of maintenance dialysis captured in a stroke registry were included.

Measurements

Kidney function categorized as an eGFR of ≥60, 30-59, <30 mL/min/1.73 m2, or maintenance dialysis. Ischemic stroke classified by TOAST included arterial, cardioembolic, lacunar, and other (dissection, prothrombotic state, cortical vein/sinus thrombosis, and vasculitis) types of strokes.

Methods

Adjusted regression models.

Results

In our cohort, 58.9% had an eGFR of ≥60, 34.7% an eGFR of 30-59, 6.0% an eGFR of <30 and 0.5% were on maintenance dialysis (mean age of 73 years; 48% women). Cardioembolic stroke was more common in patients with non-dialysis-dependant CKD (eGFR 30-59: 50.4%, adjusted odds ratio [OR] 1.20, 95% confidence interval [CI]: 1.02, 1.44; eGFR<30: 50.6%, OR 1.21, 95% CI: 1.02, 1.44), whereas lacunar stroke was less common (eGFR 30-59: 22.7% OR 0.85, 95% CI: 0.77, 0.93; eGFR <30: 0.73, 95% CI: 0.61, 0.88) compared with those with an eGFR ≥60. In stratified analyses by age and CKD, lacunar strokes were more frequent in those aged less than 65 years, whereas cardioembolic was higher in those aged 65 years and above.

Limitations

TOAST classification was not captured for all patients.

Conclusion

Non-dialysis CKD was associated with a higher risk of cardioembolic stroke, whereas an eGFR ≥60 mL/min/1.73 m2 was associated with a higher risk of lacunar stroke. Detailed stroke subtyping in CKD may therefore provide mechanistic insights and refocus treatment strategies in this high-risk population.

Characteristics of stroke after liver and kidney transplantation

Background

The mechanism and characteristics of a post-transplantation stroke may differ between liver (LT) and kidney transplantation (KT), as the associated comorbidities and peri-surgical conditions are different. Herein, we investigated the characteristics and etiologies of stroke occurring after LT and KT.

Methods

Consecutive patients who received LT or KT between January 2005 to December 2020 who were diagnosed with ischemic or hemorrhagic stroke after transplantation were enrolled. Ischemic strokes were further classified according to the etiologies. The characteristics of stroke, including in-hospital stroke, perioperative stroke, stroke etiology, and timing of stroke, were compared between the LT and KT groups.

Results

There were 105 (1.8%) and 58 (1.3%) post-transplantation stroke patients in 5,950 LT and 4,475 KT recipients, respectively. Diabetes, hypertension, and coronary arterial disease were less frequent in the LT than the KT group. In-hospital and perioperative strokes were more common in LT than in the KT group (LT, 57.9%; KT, 39.7%; p = 0.03, and LT, 43.9%; KT, 27.6%; p = 0.04, respectively). Hemorrhagic strokes were also more common in the LT group (LT, 25.2%; KT, 8.6%; p = 0.01). Analysis of ischemic stroke etiology did not reveal significant difference between the two groups; undetermined etiology was the most common, followed by small vessel occlusion and cardioembolism. The 3-month mortality was similar between the two groups (both LT and KT, 10.3%) and was independently associated with in-hospital stroke and elevated C-reactive protein.

Conclusions

In-hospital, perioperative, and hemorrhagic strokes were more common in the LT group than in the KT group. Ischemic stroke subtypes did not differ significantly between the two groups and undetermined etiology was the most common cause of ischemic stroke in both groups. High mortality after stroke was noted in transplantation patients and was associated with in-hospital stroke.

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.

Levels and Dynamics of estimated Glomerular Filtration Rate and Recurrent Vascular Events and Death in Patients with Minor Stroke or TIA

BACKGROUND

Impaired kidney function is associated with an increased risk of vascular events in acute stroke patients, when assessed by single measurements of estimated glomerular filtration rate (eGFR). It is unknown whether repeated measurements provide additional information for risk prediction.

METHODS

The Systematic Monitoring for Detection of Atrial Fibrillation in Patients with Acute Ischemic Stroke (MonDAFIS) study randomly assigned 3,465 acute ischemic-stroke patients to either standard procedures or an additive Holter-ECG. Baseline eGFR (CKD-epi formula) were dichotomized into values <vs.≥60ml/min/1.73m² . eGFR dynamics were classified based on two in-hospital values: "stable normal" (≥60ml/min/1.73m² ), "increasing" (by at least 15% from baseline, 2nd value ≥60ml/min/1.73m² ), "decreasing" (by at least 15% from baseline ≥60ml/min/1.73m² ), and "stable decreased" (<60ml/min/1.73m² ). The composite endpoint (stroke, major-bleeding, myocardial-infarction, all-cause death) was assessed after 24 months. We estimated hazard ratios in confounder adjusted models.

RESULTS

eGFR at baseline was available in 2,947 and a 2nd value in 1,623 patients. After adjusting for age, stroke severity, cardiovascular risk factors, and randomization, eGFR <60ml/min/1.73m² at baseline (HR 2.2; 95%CI 1.40-3.54) as well as "decreasing" (HR 1.79; 95%CI: 1.07-2.99) and "stable decreased" eGFR (HR 1.64; 95%CI: 1.20-2.24) were independently associated with the composite endpoint. In addition, eGFR<60ml/min/1.73² at baseline (HR 3.02; 95%CI: 1.51-6.10) and "decreasing" eGFR were associated with all-cause death (HR 3.12; 95%CI: 1.63-5.98).

CONCLUSIONS

In addition to patients with low eGFR levels at baseline also those with decreasing eGFR have an increased risk for vascular events and death, hence, repeated estimates of eGFR might add relevant information to risk prediction. Trial registration number Clinicaltrials.gov NCT02204267.

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.

Interactions Between Kidney Function and Cerebrovascular Disease: Vessel Pathology That Fires Together Wires Together

The kidney and the brain, as high-flow end organs relying on autoregulatory mechanisms, have unique anatomic and physiological hemodynamic properties. Similarly, the two organs share a common pattern of microvascular dysfunction as a result of aging and exposure to vascular risk factors (e.g., hypertension, diabetes and smoking) and therefore progress in parallel into a systemic condition known as small vessel disease (SVD). Many epidemiological studies have shown that even mild renal dysfunction is robustly associated with acute and chronic forms of cerebrovascular disease. Beyond ischemic SVD, kidney impairment increases the risk of acute cerebrovascular events related to different underlying pathologies, notably large artery stroke and intracerebral hemorrhage. Other chronic cerebral manifestations of SVD are variably associated with kidney disease. Observational data have suggested the hypothesis that kidney function influences cerebrovascular disease independently and adjunctively to the effect of known vascular risk factors, which affect both renal and cerebral microvasculature. In addition to confirming this independent association, recent large-scale human genetic studies have contributed to disentangling potentially causal associations from shared genetic predisposition and resolving the uncertainty around the direction of causality between kidney and cerebrovascular disease. Accelerated atherosclerosis, impaired cerebral autoregulation, remodeling of the cerebral vasculature, chronic inflammation and endothelial dysfunction can be proposed to explain the additive mechanisms through which renal dysfunction leads to cerebral SVD and other cerebrovascular events. Genetic epidemiology also can help identify new pathological pathways which wire kidney dysfunction and cerebral vascular pathology together. The need for identifying additional pathological mechanisms underlying kidney and cerebrovascular disease is attested to by the limited effect of current therapeutic options in preventing cerebrovascular disease in patients with kidney impairment.

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.

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.