Search

Young patients presenting with cryptogenic stroke should be investigated for cardiac and extra-cardiac sources of emboli. We present a patient who was investigated for a cardiac source of emboli, following multiple ischaemic strokes and migraine with aura over a period of 17 years. The events were initially thought to be related to a patent foramen ovale (PFO) on bubble contrast echocardiography, however, due to an unusual flow pattern to the left heart, she underwent a CT angiogram to exclude intrapulmonary shunting. This confirmed the presence of a moderate sized congenital pulmonary arteriovenous fistula in the left lung. Transcatheter occlusion of the vascular malformation has resolution of her symptoms. Bubble contrast echocardiography is routinely used to diagnose a PFO in these cases, but extreme caution is required during the procedure to differentiate the pattern of flow seen in patients with a pulmonary arteriovenous malformation., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: Aspirin achieves its antithrombotic effect through inactivation of cyclo-oxygenase (COX)-1, thereby preventing generation of thromboxane (TX)A2 from arachidonic acid (AA). The reported prevalence of aspirin "resistance" varies significantly and is usually based on platelet function tests (PFTs) that use AA-induced platelet reactivity as a surrogate measure of the effect of aspirin, rather than specific assessment of its effect on its therapeutic target (ie, COX-1 inhibition). The reported rates are not only assay specific but also condition specific, with particularly high rates (up to 70%) previously reported in the stroke population. We investigated whether pharmacological responses to aspirin can be reliably determined from a functional test of AA-induced whole-blood clotting., Methods and Results: A prospective study included 35 patients admitted with ischemic stroke and commenced on 300 mg aspirin. AA-induced whole-blood clotting was measured using short thrombelastography, a previously extensively validated near-patient PFT. Serum TXB2 and inflammatory biomarkers were also measured. The prevalence of apparent aspirin resistance measured using AA was high (range from 49% to 67%). However, serum [TXB2] was consistently low, thereby confirming adequate inhibition of COX-1 by aspirin. Mean inflammatory biomarker levels were elevated throughout., Conclusion: This study demonstrates that although COX-1 activity is adequately and consistently suppressed by aspirin in stroke patients, this effect is not reliably indicated by whole-blood clotting in response to AA. These data help to explain why the reported prevalence of aspirin resistance in stroke from studies employing AA-induced platelet reactivity is high and cast doubt on the veracity of such reports., (Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Many hospitals are still setting up acute stroke thrombolysis services, often delayed by fears over workload. However, there are few data on how many patients require urgent assessment before one is treated. We prospectively studied all referrals to the 24-hour stroke thrombolysis service, February 2009 - January 2010, in Southampton General Hospital. 128 patients were referred to the thrombolysis team and 20 received thrombolysis. The most common reasons for treatment exclusion were: stroke severity (37%), time from onset (26%) or CT findings (15%). Approximately six patients required urgent assessment by the thrombolysis team for every one treated. These data are crucial to inform service planning.

About one-fifth of all ischaemic strokes are cardioembolic. Recent years have seen considerable progress in our understanding of atrial fibrillation, the most important cause of cardioembolism, and evidence-based treatment strategies have emerged. Progress in relation to other cardioembolic disorders has been more limited and here stroke prevention strategies remain less certain and subject to debate. This article briefly reviews the methods currently used to identify and investigate cardioembolic stroke and then provides an update on stroke prevention in relation to atrial fibrillation, valvular heart disease, patent foramen ovale and left ventricular dysfunction (after myocardial infarction and chronic failure).

Objective: To study the workload of and use of acute intervention within an established acute stroke service, the Calgary Stroke Programme (CSP)., Methods: Prospective record of all acute referrals, diagnoses, and management decisions over a 4 month period., Results: The CSP received 572 referrals (median: 32 per week), 88% of which were made between 7 am and midnight. Of the 427 patients seen in person, 29% had not had an acute stroke or transient ischaemic attack (TIA). Fifty percent of patients with suspected acute stroke were referred within 3 h of symptom onset and 11% with acute ischaemic stroke (equating to 35% of those referred within 3 h of onset and seen in person) were treated with thrombolysis., Conclusion: Centralisation of services facilitates the rapid referral of, and use of acute interventions in, patients with acute stroke and TIA. Centralised services are likely to be busy (although less so at night), to attract large numbers of patients with disorders that mimic stroke and TIA, and yet still likely to treat only the minority of acute strokes using thrombolysis. These observations may help those planning similar services and underline the need to develop more widely applicable treatments for acute stroke.

Objectives: To provide valid predictions of outcome, the variables included in a prognostic model must be capable of reliable collection. The authors have recently reported a set of simple but rigorously developed models that predict outcome after stroke. The aim of this study was to establish the inter-rater reliability of the variables included in the models., Methods: Inter-rater agreement was measured prospectively (between two clinicians; 92 patients) and retrospectively (between two auditors; 200 patients) and the validity of the data collected retrospectively was estimated by comparing them with data collected prospectively (195 patients). In the prospective study inter-rater agreement for urinary incontinence and for the variables of three other previously published models was also measured. The median difference (md) between ages and kappa statistics for other variables was calculated., Results: For the model variables, prospective agreement ranged from good to excellent (age: md 0 years; living alone before the stroke kappa 0.84; pre-stroke functional independence kappa 0.67; normal verbal Glasgow Coma Scale score kappa 0.79; ability to lift both arms against gravity kappa 0.97; ability to walk unaided kappa 0.91) while retrospective agreement (age: md 0 years; kappa 0.55-0.92) and agreement between prospective and retrospective observers (age: md 0 years; kappa 0.49-0.78) was acceptable but less good. Prospective agreement was excellent for urinary incontinence (kappa 0.87) and variable for the other models (kappa 0.23-0.81), Conclusion: The variables included in these new simple models of outcome after stroke are capable of reliable collection, comparable to or better than that of the other predictive variables considered. When collected retrospectively, the model variables are likely to remain reliable and reasonably valid.

Background and Purpose: We sought to evaluate a system for monitoring the quality of hospital-based stroke services that uses routinely collected case fatality data, adjusted for case mix, as well as simple measures of the process of stroke care., Methods: We compared the process of care and case fatality after stroke between 5 Scottish hospitals (A through E) during 1995-1997. We retrospectively identified 2724 patients with acute stroke using routine discharge data and obtained case mix and process of care data from the medical record. We ascertained case fatality by record linkage and adjusted for case mix using a simple, externally validated regression model., Results: Crude case fatality varied by 21 deaths per 100 admissions between the 5 hospitals. After adjustment, case fatality still differed significantly (P=0.047), with 5 to 7 more deaths per 100 admissions at Hospital A than at Hospitals B through E. There were major shortcomings in the specialization and organization of care, the use of CT scanning, and the completeness of documentation at Hospital A compared with the other hospitals. There were smaller, but clinically important, differences in care between Hospitals B through E but no significant differences in adjusted case fatality., Conclusions: Once adjusted for important prognostic variables, routinely collected case fatality data might identify hospitals with major shortcomings in the processes of stroke care. More moderate, but still clinically important, variations in stroke care can only be identified by monitoring the process of care directly.

Background and Purpose: This study describes the large variations in outcome after stroke between countries that participated in the International Stroke Trial and seeks to define whether they could be explained by variations in case mix or by other factors., Methods: We analyzed data from the 15 116 patients recruited in Argentina, Australia, Italy, the Netherlands, Norway, Poland, Sweden, Switzerland, and the United Kingdom: We compared crude case fatality and the proportion of patients dead or dependent at 6 months; we used logistic regression to adjust for age, sex, atrial fibrillation, systolic blood pressure, level of consciousness, and number of neurological deficits. We used the frequency of prerandomization head CT scan and prescription of aspirin at discharge to indicate quality of care., Results: The differences in outcome (all treatment groups combined) between the "best" and "worst" countries were very large for death (171 cases per 1000 patients) and for death or dependency (375 cases per 1000 patients). The differences were somewhat smaller after adjustment for case mix (160 and 311 cases per 1000 patients, respectively). Process of care may have accounted for some but not all of the residual variation in outcome., Conclusions: Adjustment for case mix explained only some of the variation in outcome between countries. The residual differences in outcome were too large to be explained by variations in care and most likely reflect differences in unmeasured baseline factors. These findings demonstrate the need to achieve balance of treatment and control within each country in multinational randomized controlled stroke trials and the need for caution in the interpretation of nonrandomized comparisons of outcome after stroke between countries.

Objective: To determine how far the difference in published stroke case fatality between the Western General Hospital (WGH), Edinburgh and the Falkirk and District Royal Infirmary (FDRI) for the period 1990-93 can be explained by adjusting more fully for casemix., Design: The cases were ascertained and followed prospectively at the WGH and retrospectively at the FDRI; casemix correction was performed using a validated logistic regression model., Setting: The WGH is a teaching hospital and the FDRI a district general hospital., Subjects: Four hundred and thirty seven patients with a verified acute stroke at the WGH; 471 patients assigned a cerebrovascular disease discharge diagnostic code at the FDRI., Outcome Measure: Thirty day case fatality., Results: About half of the difference in the two hospitals' published stroke case fatality could be accounted for by variation in measured casemix. The residual difference in adjusted case fatality might have been due to differences in the structure of stroke care or simply to remaining differences in casemix. Full investigation of the cause was prevented by the destruction of the deceased patients records., Conclusions: Comparisons of routinely collected stroke outcomes will remain difficult to interpret unless casemix is properly accounted for and deceased patients' records stored for several years.