Incidence and impact on outcomes of acute kidney injury after a stroke: a systematic review and meta-analysis.

BACKGROUND: Patients with chronic kidney disease have worse outcomes after stroke. However, the burden of acute kidney injury after stroke has not been extensively investigated. METHODS: We used MEDLINE and Embase to conduct a systematic review and meta-analysis of published studies that provided data on the risk of AKI and outcomes in adults after ischemic and hemorrhagic stroke. Pooled incidence was examined using the Stuart-Ord method in a DerSimonian-Laird model. Pooled Odds Ratios and 95% confidence intervals were calculated for outcomes using a random effects model. This review was registered with PROSPERO (CRD42017064588). RESULTS: Eight studies were included, five from the United States, representing 99.9% of included patients. Three studies used established acute kidney injury criteria based on creatinine values to define acute kidney injury and five used International Classification of Diseases coding definitions. Overall pooled incidence was 9.61% (95% confidence interval 8.33-10.98). Incidence for studies using creatinine definitions was 19.51% (95% confidence interval 12.75-27.32%) and for studies using coding definitions 4.63% (95% confidence interval 3.65-5.72%). Heterogeneity was high throughout. Mortality in stroke patients who sustained acute kidney injury was increased (Odds Ratio 2.45; 95% confidence interval 1.47-4.10). Three studies reported risk factors for acute kidney injury. There was sparse information on other outcomes. CONCLUSIONS: Mortality in stroke patients who develop acute kidney injury is significantly increased. However the reported incidence of AKI after stroke varies widely and is underestimated using coding definitions. Larger international studies are required to identify potentially preventable factors to reduce acute kidney injury after stroke and improve outcomes.

Serum tryptase concentration and progression to end-stage renal disease.

BACKGROUND: Mast cell activation can lead to nonclassical activation of the Renin-Angiotensin-Aldosterone System. However, the relevance of this to human chronic kidney disease is unknown. We assessed the association between serum tryptase, a product of mast cell activation, and progression to end-stage renal disease or mortality in patients with advanced chronic kidney disease. We stratified patients by use of angiotensin-converting enzyme inhibitors/angiotensin receptor II blockers (ACEi/ARB). MATERIALS AND METHODS: This was a prospective cohort study of 446 participants recruited into the Renal Impairment in Secondary Care study. Serum tryptase was measured at recruitment by sandwich immunoassay. Cox regression analysis was undertaken to determine variables associated with progression to end-stage renal disease or death. RESULTS: Serum tryptase concentration was independently associated with progression to end-stage renal disease but not with death. In patients treated with ACEi or ARB, there was a strong independent association between higher tryptase concentrations and progression to end-stage renal disease; when compared to the lowest tertile, tryptase concentrations in the middle and highest tertiles had hazard ratios [HR] of 5·78 (95% confidence interval [CI] 1·19-28·03, P = 0·029) and 6·19 (95% CI 1·49-25·69, P = 0·012), respectively. The other independent risk factors for progression to end-stage renal disease were lower age, male gender, lower estimated glomerular filtration rate and higher urinary albumin creatinine ratio. CONCLUSION: Elevated serum tryptase concentration is an independent prognostic factor for progression to end-stage renal disease in patients with chronic kidney disease who are receiving treatment with an ACEi or ARB.

What influences patient choice of treatment modality at the pre-dialysis stage?

BACKGROUND: There is little information on factors influencing patient choice of renal replacement modality (RRM) in the UK. Pre-dialysis education programmes have been associated with increased uptake of peritoneal dialysis (PD) in other countries but their relevance in informing patient choice within UK centres has not been extensively studied. In this study, we examined how patient choice of different treatment modalities [haemodialysis (HD), PD and conservative management (CM)] is influenced by personal and demographic parameters. METHODS: Questionnaires were sent to 242 pre-dialysis patients from a single centre. Patients were asked to rate factors affecting their treatment choice. Demographics, functional status, educational day attendance and Charlson index (CI) scores were also collected. RESULTS: One hundred and eighteen replies were received. Seventy per cent of patients had chosen HD, 20% PD and 10% had opted for CM. There was a clear association between age and modality choice. Mean age of patients choosing PD was 55 years compared to 68 years for HD and 84 years for CM (P<0.001). Similarly, the degree of co-morbidity was linked with treatment choice, with patients choosing PD having a mean CI score of 4.1 compared to 5.8 among HD patients and 7.7 for CM (P<0.001). Factors rated as important by all three groups were: the ability to cope, fitting modality with lifestyle, distance to centre and verbal and written information about modality. Conversely, factors rated as not important by all groups were: use of internet, religious beliefs and friends' views. Using analysis of variance, there was a statistically significant variance between the HD and the PD group responses in the following factors: provision of written information (P=0.048), fitting modality with lifestyle (P=0.025), family/home/work circumstances (P=0.003) and past medical history (P=0.018). Fifty per cent of patients who chose PD attended a formal education day compared to 32.9% that chose HD and 0% that chose CM (P=0.011). The following demographic factors were crucial in predicting RRM choice: being married (PD 95.7%, HD 53.8%, CM 41.7%; P<0.001), being employed (PD 33.3%, HD 11.5%, CM 0%; P=0.015) and having another person living at home (PD 100%, HD 69.5%, CM 50%; P=0.003). Patients who have had a social services assessment in the last 12 months or received private care services or disability allowance were more likely to choose CM. CONCLUSIONS: This study highlights important factors influencing patient choice of end-stage renal disease treatment modality including CM. While some of these are non-modifiable, such as age and degree of co-morbidity, others draw attention to the importance of good information provision and pre-dialysis education in empowering socially able patients to choose self-care therapies. Furthermore, the overwhelming association of having a strong social support network and being functionally able with choosing PD emphasizes the need for assisted PD.

Health-Related Quality of Life Impacts Mortality but Not Progression to End-Stage Renal Disease in Pre-Dialysis Chronic Kidney Disease: A Prospective Observational Study.

BACKGROUND: Chronic kidney disease (CKD) is associated with reduced health-related quality of life (HRQL). However, the relationship between pre-dialysis CKD, HRQL and clinical outcomes, including mortality and progression to end-stage renal disease (ESRD) is unclear. METHODS: All 745 participants recruited into the Renal Impairment In Secondary Care study to end March 2014 were included. Demographic, clinical and laboratory data were collected at baseline including an assessment of HRQL using the Euroqol EQ-5D-3L. Health states were converted into an EQ-5Dindex score using a set of weighted preferences specific to the UK population. Multivariable Cox proportional hazards regression and competing risk analyses were undertaken to evaluate the association of HRQL with progression to ESRD or all-cause mortality. Regression analyses were then performed to identify variables associated with the significant HRQL components. RESULTS: Median eGFR was 25.8 ml/min/1.73 m2 (IQR 19.6-33.7ml/min) and median ACR was 33 mg/mmol (IQR 6.6-130.3 mg/mmol). Five hundred and fifty five participants (75.7%) reported problems with one or more EQ-5D domains. When adjusted for age, gender, comorbidity, eGFR and ACR, both reported problems with self-care [hazard ratio 2.542, 95% confidence interval 1.222-5.286, p = 0.013] and reduced EQ-5Dindex score [hazard ratio 0.283, 95% confidence interval 0.099-0.810, p = 0.019] were significantly associated with an increase in all-cause mortality. Similar findings were observed for competing risk analyses. Reduced HRQL was not a risk factor for progression to ESRD in multivariable analyses. CONCLUSIONS: Impaired HRQL is common in the pre-dialysis CKD population. Reduced HRQL, as demonstrated by problems with self-care or a lower EQ-5Dindex score, is associated with a higher risk for death but not ESRD. Multiple factors influence these aspects of HRQL but renal function, as measured by eGFR and ACR, are not among them.