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.

Decisions and delays within stroke patients' route to the hospital: a qualitative study.

STUDY OBJECTIVE: We examine acute stroke patients' decisions and delays en route to the hospital after onset of symptoms. METHODS: This was a qualitative study carried out in the West Midlands, United Kingdom. Semistructured interviews were conducted with 30 patients (6 accompanied by partners). Patients were asked about their previous experience of having had a stroke and their initial engagement with health services. "One sheet of paper" and thematic analyses were used. RESULTS: Three potential types of delay were identified from onset of symptoms to accessing stroke care in the hospital: primary delays caused by lack of recognition of symptoms or not dealing with symptoms immediately, secondary delays caused by initial contact with nonemergency services, and tertiary delays in which health service providers did not interpret the patients' presenting symptoms as suggestive of stroke. The main factors determining the speed of action by patients were the presence and influence of a bystander and the perceived seriousness of symptoms. CONCLUSION: Despite campaigns to increase public awareness of stroke symptoms, the behavior of both patients and health service providers apparently led to delays in the recognition of and response to stroke symptoms, potentially reducing access to optimum and timely acute specialist assessment and treatment for acute stroke.

The association between prehospital care and in-hospital treatment decisions in acute stroke: a cohort study.

BACKGROUND: Hospital prealerting in acute stroke improves the timeliness of subsequent treatment, but little is known about the impact of prehospital assessments on in-hospital care. OBJECTIVE: Examine the association between prehospital assessments and notification by emergency medical service staff on the subsequent acute stroke care pathway. METHODS: This was a cohort study of linked patient medical records. Consenting patients with a diagnosis of stroke were recruited from two urban hospitals. Data from patient medical records were extracted and entered into a Cox regression analysis to investigate the association between time to CT request and recording of onset time, stroke recognition (using the Face Arm Speech Test (FAST)) and sending of a prealert message. RESULTS: 151 patients (aged 71±15 years) travelled to hospital via ambulance and were eligible for this analysis. Time of symptom onset was recorded in 61 (40%) cases, the FAST test was positive in 114 (75%) and a prealert message was sent in 65 (44%). Following adjustment for confounding, patients who had time of onset recorded (HR 0.73, 95% CI 0.52 to 1.03), were FAST-positive (HR 0.54, 95% CI 0.37 to 0.80) or were prealerted (HR 0.26, 95% CI 0.18 to 0.38), were more likely to receive a timely CT request in hospital. CONCLUSIONS: This study highlights the importance of hospital prealerting, accurate stroke recognition, and recording of onset time. Those not recognised with stroke in a prehospital setting appear to be excluded from the possibility of rapid treatment in hospital, even before they have been seen by a specialist.

Cost-effectiveness of optimizing acute stroke care services for thrombolysis.

BACKGROUND AND PURPOSE: Thrombolysis in acute stroke is effective up to 4.5 hours after symptom onset but relies on early recognition, prompt arrival in hospital, and timely brain scanning. This study aimed to establish the cost-effectiveness of increasing thrombolysis rates through a series of hypothetical change strategies designed to optimize the acute care pathway for stroke. METHODS: A decision-tree model was constructed, which relates the acute management of patients with suspected stroke from symptom onset to outcome. Current practice was modeled and compared with 7 change strategies designed to facilitate wider eligibility for thrombolysis. The model basecase consisted of data from consenting patients following the acute stroke pathway recruited in participating hospitals with data on effectiveness of treatment and costs from published sources. RESULTS: All change strategies were cost saving while increasing quality-adjusted life years gained. Using realistic estimates of effectiveness, the change strategy with the largest potential benefit was that of better recording of onset time, which resulted in 3.3 additional quality-adjusted life years and a cost saving of US $46,000 per 100,000 population. All strategies increased the number of thrombolysed patients and the number requiring urgent brain imaging (by 9% to 21% dependent on the scenario). Assuming a willingness-to-pay of US $30,000 per quality-adjusted life year gained, the potential budget available to deliver the interventions in each strategy ranged from US $50,000 to US $144,000. CONCLUSIONS: These results suggest that any strategy that increases thrombolysis rates will result in cost savings and improved patient quality of life. Healthcare commissioners could consider this model when planning improvements in stroke care.

Acute kidney injury calculated using admission serum creatinine underestimates 30-day and 1-year mortality after acute stroke.

BACKGROUND: Acute kidney injury (AKI) diagnosis requires ascertainment of change from a known baseline. Although pre-admission serum creatinine (SCr) is recommended, to date, all studies of AKI in acute stroke have used the first SCr on admission. METHODS: All patients admitted with an acute stroke to an emergency hospital were recruited. We compared use of pre-admission SCr with admission SCr to diagnose AKI. Regression analyses were used to identify risk factors for 30-day and 1-year mortality, respectively. RESULTS: A total of 1354 patients were recruited from December 2012 to September 2015. Incidence of AKI was 18.7 and 19.9% using pre-admission SCr and admission SCr, respectively. Diagnosis of AKI was associated with significantly increased 30-day and 1-year mortality. Diagnosis of AKI using pre-admission SCr had a stronger relationship with both 30-day and 1-year mortality. In 443 patients with a pre-admission SCr and at least two SCr during admission, AKI diagnosed using pre-admission SCr had a stronger relationship than AKI diagnosed using admission SCr with 30-day mortality [odds ratio (OR) = 2.64; 95% confidence interval (CI) 1.36-5.12; P = 0.004 versus OR = 2.10; 95% CI 1.09-4.03; P = 0.026] and 1-year mortality [hazard ratio (HR) = 1.90, 95% CI 1.32-2.76; P = 0.001 versus HR = 1.47; 95% CI 1.01-2.15; P = 0.046] in fully adjusted models. CONCLUSIONS: AKI after stroke is common and is associated with increased 30-day and 1-year mortality. Using first SCr on admission gives a comparable AKI incidence to pre-admission SCr, but underestimates 30-day and 1-year mortality risk.

The cost of providing mechanical thrombectomy in the UK NHS: a micro-costing study.

INTRODUCTION: The clinical efficacy and cost-effectiveness of mechanical thrombectomy (MT) for the treatment of large vessel occlusion stroke is well established, but uncertainty remains around the true cost of delivering this treatment within the NHS. The aim of this study was to establish the cost of providing MT within the hyperacute phase of care and to explore differences in resources used and costs across different neuroscience centres in the UK. METHOD: This was a multicentre retrospective study using micro-costing methods to enable a precise assessment of the costs of MT from an NHS perspective. Data on resources used and their costs were collected from five UK neuroscience centres between 2015 and 2018. RESULTS: Data were collected on 310 patients with acute ischaemic stroke treated with MT. The mean total cost of providing MT and inpatient care within 24 hours was £10,846 (95% confidence interval (CI) 10,527-11,165) per patient. The main driver of cost was MT procedure costs, accounting for 73% (£7,943; 95% CI 7,649-8,237) of the total 24-hour cost. Costs were higher for patients treated under general anaesthesia (£11,048; standard deviation (SD) 2,654) than for local anaesthesia (£9,978; SD 2,654), mean difference £1,070 (95% CI 381-1,759; p=0.003); admission to an intensive care unit (ICU; £12,212; SD 3,028) against for admission elsewhere (£10,179; SD 2,415), mean difference £2,032 (95% CI 1,345-2,719; p<0001).The mean cost within 72 hours was £12,440 (95% CI 10,628-14,252). The total costs for the duration of inpatient care before discharge from a thrombectomy centre was £14,362 (95% CI 13,603-15,122). CONCLUSIONS: Major factors contributing to costs of MT for stroke include consumables and staff for intervention, use of general anaesthesia and ICU admissions. These findings can inform the reimbursement, provision and strategic planning of stroke services and aid future economic evaluations.

When has service provision for transient ischaemic attack improved enough? A discrete event simulation economic modelling study.

OBJECTIVES: The aim of this study was to examine the impact of transient ischaemic attack (TIA) service modification in two hospitals on costs and clinical outcomes. DESIGN: Discrete event simulation model using data from routine electronic health records from 2011. PARTICIPANTS: Patients with suspected TIA were followed from symptom onset to presentation, referral to specialist clinics, treatment and subsequent stroke. INTERVENTIONS: Included existing versus previous (less same day clinics) and hypothetical service reconfiguration (7-day service with less availability of clinics per day). OUTCOME MEASURES: The primary outcome of the model was the prevalence of major stroke after TIA. Secondary outcomes included service costs (including those of treating subsequent stroke) and time to treatment and attainment of national targets for service provision (proportion of high-risk patients (according to ABCD2 score) seen within 24 hours). RESULTS: The estimated costs of previous service provision for 490 patients (aged 74±12 years, 48.9% female and 23.6% high risk) per year at each site were £340 000 and £368 000, respectively. This resulted in 31% of high-risk patients seen within 24 hours of referral (47/150) with a median time from referral to clinic attendance/treatment of 1.15 days (IQR 0.93-2.88). The costs associated with the existing and hypothetical services decreased by £5000 at one site and increased £21 000 at the other site. Target attainment was improved to 79% (118/150). However, the median time to clinic attendance was only reduced to 0.85 days (IQR 0.17-0.99) and thus no appreciable impact on the modelled incidence of major stroke was observed (10.7 per year, 99% CI 10.5 to 10.9 (previous service) vs 10.6 per year, 99% CI 10.4 to 10.8 (existing service)). CONCLUSIONS: Reconfiguration of services for TIA is effective at increasing target attainment, but in services which are already working efficiently (treating patients within 1-2 days), it has little estimated impact on clinical outcomes and increased investment may not be worthwhile.

Modulation of stroke risk in chronic kidney disease.

Stroke is the second most common cause of death and the leading cause of neurological disability worldwide, with huge economic costs and tragic human consequences. Both chronic kidney disease (CKD) and end-stage kidney disease are associated with a significantly increased risk of stroke. However, to date this has generated far less interest compared with the better-recognized links between cardiac and renal disease. Common risk factors for stroke, such as hypertension, hypercholesterolaemia, smoking and atrial fibrillation, are shared with the general population but are more prevalent in renal patients. In addition, factors unique to these patients, such as disorders of mineral and bone metabolism, anaemia and its treatments as well as the process of dialysis itself, are all also postulated to further increase the risk of stroke. In the general population, advances in medical therapies mean that effective primary and secondary prevention therapies are available for many patients. The development of specialist stroke clinics and acute stroke units has also improved outcomes after a stroke. Emerging therapies such as thrombolysis and thrombectomy are showing increasingly beneficial results. However, patients with CKD and on dialysis have different risk profiles that must be taken into account when considering the potential benefits and risks of these treatments. Unfortunately, these patients are either not recruited or formally excluded from major clinical trials. There is still much work to be done to harness effective stroke treatments with an acceptable safety profile for patients with CKD and those on dialysis.

Acute Care QUAliTy in chronic Kidney disease (ACQUATIK): a prospective cohort study exploring outcomes of patients with chronic kidney disease.

INTRODUCTION: Chronic kidney disease (CKD) is common and carries a high risk of morbidity, including hospital admissions and readmissions and mortality. This is largely attributed to an increased risk of cardiovascular disease. Patients with CKD are less likely to receive evidence-based treatments for cardiovascular disease. However, these treatments are based on trials which generally exclude patients with CKD. It is therefore unclear whether this patient group derives the same benefits without an increased risk of adverse effects. METHODS AND ANALYSIS: The Acute Care QUAliTy in chronic Kidney disease (ACQUATIK) study is a prospective, observational, multicentre cohort study. Over 4000 patients will be recruited with an enrolment period of 2 years and a follow-up period of 2-4 years. Patients under follow-up by a renal team will be excluded. Data will be obtained from patient and hospital records during the index admission. Preadmission data will be extracted from general practice records based on the Quality and Outcomes Framework. Diagnosis, comorbidities and procedure data pertaining to the index and subsequent admissions will be extracted from the Hospital Episode Statistics database and long-term mortality data will be tracked using the Office of National Statistics. This information will allow us to examine a complete patient journey through primary and secondary care, providing unequalled levels of information on treatment and outcomes of patients with CKD. The combined data set will be used to compare outcomes and treatments among patients with CKD versus patients without CKD. The primary end point is hospital readmission rates. The relationship between age, sex, ethnicity, socioeconomic status and concurrent comorbidities will be analysed to determine their influence on outcomes and treatments. ETHICS AND DISSEMINATION: The ACQUATIK study has been approved by the NRES Committee West Midlands-South Birmingham-Reference 13/WM/0317. The results from ACQUATIK will be submitted for publication in peer-reviewed journals and presented at primary and secondary care conferences. TRIAL REGISTRATION NUMBER: ISRCTN37237454.

RApid Primary care Initiation of Drug treatment for Transient Ischaemic Attack (RAPID-TIA): study protocol for a pilot randomised controlled trial.

BACKGROUND: People who have a transient ischaemic attack (TIA) or minor stroke are at high risk of a recurrent stroke, particularly in the first week after the event. Early initiation of secondary prevention drugs is associated with an 80% reduction in risk of stroke recurrence. This raises the question as to whether these drugs should be given before being seen by a specialist--that is, in primary care or in the emergency department. The aims of the RAPID-TIA pilot trial are to determine the feasibility of a randomised controlled trial, to analyse cost effectiveness and to ask: Should general practitioners and emergency doctors (primary care physicians) initiate secondary preventative measures in addition to aspirin in people they see with suspected TIA or minor stroke at the time of referral to a specialist? METHODS/DESIGN: This is a pilot randomised controlled trial with a sub-study of accuracy of primary care physician diagnosis of TIA. In the pilot trial, we aim to recruit 100 patients from 30 general practices (including out-of-hours general practice centres) and 1 emergency department whom the primary care physician diagnoses with TIA or minor stroke and randomly assign them to usual care (that is, initiation of aspirin and referral to a TIA clinic) or usual care plus additional early initiation of secondary prevention drugs (a blood-pressure lowering protocol, simvastatin 40 mg and dipyridamole 200 mg m/r bd). The primary outcome of the main study will be the number of strokes at 90 days. The diagnostic accuracy sub-study will include these 100 patients and an additional 70 patients in whom the primary care physician thinks the diagnosis of TIA is possible, rather than probable. For the pilot trial, we will report recruitment rate, follow-up rate, a preliminary estimate of the primary event rate and occurrence of any adverse events. For the diagnostic study, we will calculate sensitivity and specificity of primary care physician diagnosis using the final TIA clinic diagnosis as the reference standard. DISCUSSION: This pilot study will be used to estimate key parameters that are needed to design the main study and to estimate the accuracy of primary care diagnosis of TIA. The planned follow-on trial will have important implications for the initial management of people with suspected TIA. TRIAL REGISTRATION: ISRCTN62019087.