Effect of atrial fibrillation on endovascular thrombectomy for acute ischemic stroke. A meta-analysis of individual patient data from six randomised trials: Results from the HERMES collaboration

Background

Atrial fibrillation is an important risk factor for ischemic stroke, and is associated with an increased risk of poor outcome after ischemic stroke. Endovascular thrombectomy is safe and effective in acute ischemic stroke patients with large vessel occlusion of the anterior circulation. This meta-analysis aims to investigate whether there is an interaction between atrial fibrillation and treatment effect of endovascular thrombectomy, and secondarily whether atrial fibrillation is associated with worse outcome in patients with ischemic stroke due to large vessel occlusion.

Methods

Individual patient data were from six of the recent randomised clinical trials (MR CLEAN, EXTEND-IA, REVASCAT, SWIFT PRIME, ESCAPE, PISTE) in which endovascular thrombectomy plus standard care was compared to standard care alone. Primary outcome measure was the shift on the modified Rankin scale (mRS) at 90 days. Secondary outcomes were functional independence (mRS 0–2) at 90 days, National Institutes of Health Stroke Scale score at 24 h, symptomatic intracranial hemorrhage and mortality at 90 days. The primary effect parameter was the adjusted common odds ratio, estimated with ordinal logistic regression (shift analysis); treatment effect modification of atrial fibrillation was assessed with a multiplicative interaction term.

Results

Among 1351 patients, 447 patients had atrial fibrillation, 224 of whom were treated with endovascular thrombectomy. We found no interaction of atrial fibrillation with treatment effect of endovascular thrombectomy for both primary (p-value for interaction: 0.58) and secondary outcomes. Regardless of treatment allocation, we found no difference in primary outcome (mRS at 90 days: aOR 1.11 (95% CI 0.89–1.38) and secondary outcomes between patients with and without atrial fibrillation.

Conclusion

We found no interaction of atrial fibrillation on treatment effect of endovascular thrombectomy, and no difference in outcome between large vessel occlusion stroke patients with and without atrial fibrillation.

Impact of Ischemic Lesion Location on the mRS Score in Patients with Ischemic Stroke: A Voxel-Based Approach

BACKGROUND AND PURPOSE

Previous studies indicated that ischemic lesion volume might be a useful surrogate marker for functional outcome in ischemic stroke but should be considered in the context of lesion location. In contrast to previous studies using the ROI approach, which has several drawbacks, the present study aimed to measure the impact of ischemic lesion location on functional outcome using a more precise voxelwise approach.

MATERIALS AND METHODS

Datasets of patients with acute ischemic strokes from the Multicenter Randomized Clinical Trial of Endovascular Therapy for Acute Ischemic Stroke in the Netherlands (MR CLEAN) were used. Primary outcome was functional outcome as assessed by the modified Rankin Scale 3 months after stroke. Ischemic lesion volume was determined on CT scans 3-9 days after stroke. Voxel-based lesion-symptom mapping techniques, including covariates that are known to be associated with functional outcome, were used to determine the impact of ischemic lesion location for outcome.

RESULTS

Of the 500 patients in the MR CLEAN trial, 216 were included for analysis. The mean age was 63 years. Lesion-symptom mapping with inclusion of covariates revealed that especially left-hemispheric lesions in the deep periventricular white matter and adjacent internal capsule showed a great influence on functional outcome.

CONCLUSIONS

Our study confirms that infarct location has an important impact on functional outcome of patients with stroke and should be considered in prediction models. After we adjusted for covariates, the left-hemispheric corticosubcortical fiber tracts seemed to be of higher functional importance compared with cortical lesions.

Implementation of evidence-based practice: outside the box, throughout the hospital

BACKGROUND

Evidence-based practice (EBP) is a generally accepted means to improve healthcare quality. However, not all healthcare professionals and managers apply EBP in daily practice. We investigated EBP attitudes, knowledge and the perceived barriers and facilitators to practising EBP , to define tailor-made interventions for improving evidence-based behaviour.

METHODS

In this cross-sectional survey, doctors and nurses from five major specialities of a university hospital were invited to complete the McColl and Barriers questionnaires.

RESULTS

Response rates were 70% (305÷435) for doctors and 74% (396÷537) for nurses. They were welcoming towards EBP, but considered time constraints, knowledge gaps and poor availability of evidence as major barriers to implement EBP . They also mentioned contradicting results (75%) and flawed methodology (69%), while nurses frequently mentioned unawareness of (75%), or difficulty in reading and interpreting research papers (70%). Regarding EBP knowledge, 6/8 common EBP terms could be explained by 54% of doctors but by only 15% of nurses. Facilitating factors among doctors concerned the availability and accessibility of high-level evidence and communication of evidence during various clinical meetings and handovers for clinical decision making. Among nurses, promoting factors involved more teaching and instances to incorporate EBP in clinical practice. Both groups desired more managerial support in terms of motivation and opportunities.

CONCLUSIONS

Doctors and nurses have embraced the EBP paradigm as an important means to improve quality of clinical patient care, but its application is still cumbersome. This paper offers a tailored programme for implementation and managerial role-models.sustainment of EBP, corroborated by professional and managerial role-models.

Beta-cell dysfunction and insulin resistance after subarachnoid haemorrhage

BACKGROUND

Hyperglycaemia is a common finding and an independent risk factor for increased morbidity and mortality in aneurysmal subarachnoid haemorrhage (SAH). Although in these patients hyperglycaemia is commonly ascribed to insulin resistance, there is little understanding of underlying mechanisms.

AIMS

To prospectively study temporal disturbances of glucose metabolism after aneurysmal SAH in patients without known abnormalities of glucose metabolism and to explore possible correlations with markers of stress.

METHODS

In consecutive aneurysmal SAH patients not subjected to insulin therapy, in-hospital and follow-up oral glucose tolerance tests (OGTTs) and assessments of insulin resistance, pancreatic β-cell function, free fatty acids (FFA) and cortisol were performed and compared with reference values.

RESULTS

We included 13 patients. In the first 2 weeks of admission, median fasting glucose and FFA levels were elevated while insulin levels were not. OGTTs were indicative of glucose intolerance in all patients at days 3 and 7, while on follow-up 1 patient had glucose intolerance and all patients had normal fasting glucose levels. Pancreatic β-cell function was impaired throughout the first week and insulin resistance from day 4 to 10. Levels of cortisol correlated with higher fasting glucose and increased FFA. FFA in turn correlated with pancreatic β-cell dysfunction.

CONCLUSIONS

Aneurysmal SAH patients have transient abnormalities of glucose metabolism. During the first week, it appears to result predominantly from transient pancreatic β-cell dysfunction, in combination with insulin resistance.

A randomised controlled trial of antiplatelet therapy in combination with Rt-PA thrombolysis in ischemic stroke: rationale and design of the ARTIS-Trial

Background

Thrombolysis with intravenous rt-PA is currently the only approved acute therapy for ischemic stroke. Re-occlusion after initial recanalization occurs in up to 34% in patients treated with rt-PA, probably caused by platelet activation. In acute myocardial infarction, the combination of thrombolysis and antiplatelet therapy leads to a greater reduction of mortality compared to thrombolysis alone. In patients with acute ischemic stroke, several studies showed that patients already on antiplatelet treatment prior to thrombolysis had an equal or even better outcome compared to patients without prior antiplatelet treatment, despite an increased risk of intracerebral bleeding. Based on the fear of intracerebral haemorrhage, current international guidelines recommend postponing antiplatelet therapy until 24 hours after thrombolysis. Remarkably, prior use of antiplatelet therapy is not a contra-indication for thrombolysis. We hypothesize that antiplatelet therapy in combination with rt-PA thrombolysis will improve outcome by enhancing fibrinolysis and preventing re-occlusion.

Methods/Design

ARTIS is a randomised multi-center controlled trial with blind endpoint assessment. Our objective is to investigate whether immediate addition of aspirin to rt-PA thrombolysis improves functional outcome in ischemic stroke. Patients with acute ischemic stroke eligible for rt-PA thrombolysis are randomised to receive 300 mg aspirin within 1.5 hours after start of thrombolysis or standard care, consisting of antiplatelet therapy after 24 hours. Primary outcome is poor functional health at 3 months follow-up (modified Rankin Scale 3 - 6).

Discussion

This is the first clinical trial investigating the combination of rt-PA and acute aspirin by means of a simple and cheap adjustment of current antiplatelet regimen. We expect the net benefit of improved functional outcome will overcome the possible slightly increased risk of intracerebral haemorrhage.

Trial registration

The Netherlands National Trial Register NTR822. The condensed rationale of the ARTIS-Trial has already been published in Cerebrovascular Diseases.

Efficacy and safety of two 5 day insulin dosing regimens to achieve strict glycaemic control in patients with acute ischaemic stroke

BACKGROUND

In patients with acute ischaemic stroke and hyperglycaemia, prolonged strict glycaemic control may improve clinical outcome. The question is how to achieve this prolonged strict glycaemic control. In this study, the efficacy and safety of two regimens with different basal to meal related insulin ratio are described.

METHODS

33 patients with ischaemic stroke and hyperglycaemia at admission were randomised in an open design to receive: (1) conventional glucose lowering therapy, (2) strict glucose control with predominantly basal insulin using intravenous insulin or (3) strict glucose control with predominantly meal related insulin using subcutaneous insulin in the first 5 days after stroke. The target range of glucose control for the last two groups was 4.4-6.1 mmol/l. 16 consecutive patients without hyperglycaemia at admission were included to serve as normoglycaemic controls.

RESULTS

The median area under the curve (AUC) in the meal related insulin group was 386 mmol/l x 58 h (range 286-662) for days 2-5, and did not differ from the hyperglycaemic control group (median AUC 444 mmol/l x 58 h; range 388-620). There was also no difference in median AUC of the basal insulin group (453 mmol/l x 58 h, range 347-629) and the hyperglycaemic control group on days 2-5. In the first 12 hours, glucose profiles were lower in the groups treated with strict glucose control; median AUC was 90 mmol/l x 12 h (range 77-189) for the hyperglycaemic control group versus 81 mmol/l x 12 h (range 60-118) for the meal related insulin group (p = 0.03) and 74 mmol/l x 12 h (range 52-97) for the basal insulin group (p = 0.008).

CONCLUSION

In intermittently fed ischaemic stroke patients, strict glycaemic control between day 2 and day 5 with two different basal bolus regimens did not result in lower glucose profiles due to postprandial hyperglycaemia. Continuous enteral feeding may therefore be needed to achieve prolonged strict glycaemic control in acute stroke patients.

What should be defined as good outcome in stroke trials; a modified Rankin score of 0-1 or 0-2?

BACKGROUND AND PURPOSE

Good outcome in stroke trials has been defined as a modified Rankin scale (mRs) score of 0-1 or 0-2. The aim of this study was to investigate the clinical meaning of these two dichotomies.

METHODS

We studied 152 patients six months post stroke using the mRs and a new disability measure the AMC Linear Disability Scale (ALDS) item bank. Descriptive statistics were used to show the ALDS scores by the levels of the mRs. To investigate the clinical meaning of the different definitions of good outcome, the mean probability to perform activities of daily life (ADL) of all mRs grades and these two dichotomies was calculated.

RESULTS

The ability to perform difficult ALDS items declined gradually with increasing mRs grade. When favourable outcome is defined as mRs 0-1, 15 % of the cohort has a good outcome; of these patients 84 % were likely to perform outdoor activities. If good outcome is defined as mRs 0-2, the percentage of patients with good outcome increased to 37 %, whereas 66 % of these patients were likely to perform outdoor activities.

CONCLUSION

If good outcome is defined as the ability to perform outdoor activities mRs 0-1 should be chosen. If complex ADL are considered as good outcome mRs 0-2 is the outcome measure of choice. Independent of which outcome measure is chosen, the treatment effect in clinical trials must be large before good outcome is achieved. Therefore, it is likely that clinically important treatment effects can be missed in clinical trials with both these mRs endpoints.

Nimodipine increases fibrinolytic activity in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The purpose of this study was first, to investigate which factor in the fibrinolytic cascade is responsible for the recently observed increase of fibrinolytic activity in patients with aneurysmal subarachnoid hemorrhage (SAH), and second, the cause of this increase.

METHODS

Fibrinolytic activity and the main regulators of endogenous fibrinolytic activity, tissue plasminogen activator, and plasminogen activator inhibitor 1 (PAI-1) were measured in patients treated with and without nimodipine.

RESULTS

In patients with aneurysmal SAH, fibrinolytic activity significantly increases from 2.7 IU/mL on admission to 4.2 IU/mL in week 3 (P<0.01, paired-sample t test), caused by a 1.6-fold decrease in plasma levels of PAI-1. The results also show that increased fibrinolytic activity is seen only in patients treated with nimodipine and that plasminogen activity and PAI-1 returned to baseline levels after treatment with nimodipine had been discontinued.

CONCLUSIONS

The mechanism of increased fibrinolytic activity in patients with aneurysmal SAH is a decrease in the level of PAI-1, which is most likely caused by treatment with nimodipine.

Complications and outcome in patients with aneurysmal subarachnoid haemorrhage: a prospective hospital based cohort study in the Netherlands

OBJECTIVE

The aim of this study was to investigate prospectively in an unselected series of patients with an aneurysmal subarachnoid haemorrhage what at present the complications are, what the outcome is, how many of these patients have "modern treatment"-that is, early obliteration of the aneurysm and treatment with calcium antagonists-what factors cause a delay in surgical or endovascular treatment, and what the estimated effect on outcome will be of improved treatment.

METHODS

A prospective, observational cohort study of all patients with aneurysmal subarachnoid haemorrhage in the hospitals of a specified region in The Netherlands. The condition on admission, diagnostic procedures, and treatments were recorded. If a patient had a clinical deterioration, the change in Glasgow coma score (GCS), the presence of focal neurological signs, the results of additional investigations, and the final diagnosed cause of the deterioration were recorded. Clinical outcome was assessed with the Glasgow outcome scale (GOS) at 3 month follow up. In patients with poor outcome at follow up, the cause was diagnosed.

RESULTS

Of the 110 patients, 47 (43%) had a poor outcome. Cerebral ischaemia, 31 patients (28%), was the most often occurring complication. Major causes of poor outcome were the effects of the initial haemorrhage and rebleeding in 34% and 30% of the patients with poor outcome respectively. Of all patients 102 (93%) were treated with calcium antagonists and 45 (41%) patients had early treatment to obliterate the aneurysm. The major causes of delay of treatment were a poor condition on admission or deterioration shortly after admission, in 31% and 23% respectively.

CONCLUSIONS

In two thirds of the patients with poor outcome the causes of poor outcome are the effects of the initial bleeding and rebleeding. Improved treatment of delayed or postoperative ischaemia will have only minor effects on the outcome of patients with subarachnoid haemorrhage.

Timing of surgery in patients with aneurysmal subarachnoid haemorrhage: rebleeding is still the major cause of poor outcome in neurosurgical units that aim at early surgery

OBJECTIVE

To investigate prospectively the proportion of patients actually operated on early in units that aim at surgery in the acute phase of aneurysmal subarachnoid haemorrhage (SAH) and what is the main current determinant of poor outcome.

METHODS

A prospective analysis of all SAH patients admitted during a one year period at three neurosurgical units that aim at early surgery. The following clinical details were recorded: age, sex, date of SAH, date of admission to the neurosurgical centre, whether a patient was referred by a regional hospital or a general practitioner, Glasgow coma scale and grade of SAH (World Federation of Neurological Surgeons (WFNS) score) on admission at the neurosurgical unit, results of CT and CSF examination, the presence of an aneurysm on angiography, details of treatment with nimodipine or antifibrinolytic agents, and the date of surgery to clip the aneurysm. At follow up at three months, the patients' clinical outcome was determined with the Glasgow outcome scale and in cases of poor outcome the cause for this was recorded.

RESULTS

The proportion of patients that was operated on early--that is, within three days after SAH--was 55%. Thirty seven of all 102 admitted patients had a poor outcome. Rebleeding and the initial bleeding were the main causes of this in 35% and 32% respectively of all patients with poor outcome.

CONCLUSIONS

In neurosurgical units with what has been termed "modern management" including early surgery, about half of the patients are operated on early. Rebleeding is still the major cause of poor outcome.

Outcome in patients with large intraventricular haemorrhages: a volumetric study

Patients with large amounts of intraventricular blood have a poor prognosis. The question is whether the quantity of ventricular blood or other factors related to the origin of the intraventricular bleeding cause poor outcome. The association between ventricular blood volume and outcome was analysed in patients with a primary intraventricular haemorrhage (PIVH) and in patients with an aneurysmal subarachnoid haemorrhage (SAH). The medical records of 24 patients with PIVH were reviewed and these patients were compared with 59 patients selected from a prospectively studied series of patients with aneurysmal SAH who had intraventricular blood without an intraparenchymal haematoma. Glasgow coma score on admission and outcome at three months expressed on the Glasgow outcome scale were available for all patients. Volumetric analysis on CT was carried out if there was at least a moderate amount of blood measured with a semi-quantitative scale (SAH n = 30, PIVH n = 22). In patients with SAH more than 20 ml intraventricular blood was lethal, as previously shown for patients with intraparenchymal haemorrhage. Patients with a PIVH can, however, survive such large volumes of intraventricular blood without impaired consciousness immediately after the bleeding, without developing hydrocephalus, and without any disability after three months. It is concluded that the cause of an intraventricular haemorrhage is more important for outcome than the amount of intraventricular blood, and large intraventricular haemorrhages are not always associated with hydrocephalus.