Neurovascular
Aspirin Resistance in Acute Stroke Study. Phase 2
Supervisor: Dr Bernard Yan
Location: Department of Neurology, Royal Melbourne Hospital
Contact: Dr. Bernard Yan, Consultant Neurologist and Neurointerventionist,
Neurovascular Research Group, Department of Neurology, Royal Melbourne Hospital. T: +61 3 9349 2477 / F: +61 3 9349 4489
Email: bernard.yan@mh.org.au
Background:
Ischaemic stroke is the third most common cause of morbidity and mortality in the western world and on the rise in developing countries. The prevention of recurrent ischaemic events is an important strategy in reducing the global health and economic burden of stroke. Anti-platelet agents, such as aspirin and clopidogrel, have been shown in multiple studies to be moderately efficacious in the secondary prevention of stroke and are currently the mainstay of therapy. However, there is emerging evidence for a differing response to anti-platelets in patients with cardiac diseases and that the prevalence of aspirin resistance is as high as 30%. Given that anti-platelets are also widely used in the stroke patient population, there is growing concern that a similar proportion of patients harbour anti-platelet resistance and therefore, are at higher risk of recurrent stroke due to unrecognised ineffectiveness of anti-platelet therapy. This has never been investigated and it is imperative that this group of stroke patients with anti-platelet resistance are identified in order for an alternative secondary stroke preventive strategy to be implemented. The purpose of this observational pilot study is to recruit, prospectively and retrospectively, patients who present with acute stroke and to test their aspirin and clopidogrel resistance status. The hypothesis is that patients with anti-platelet resistance will be at higher risk of recurrent stroke.
Hypothesis: Subjects with anti-platelet resistance have a higher incidence of recurrent ischaemic strokes compared to subjects without.
Inclusion criteria: All patients presenting with acute ischaemic stroke to the Stroke Care Unit, Royal Melbourne Hospital.
Exclusion criteria: Intracranial haemorrhage. Patients who are unable to give consent.
Sample size: N = 50.
For all queries, please contact:
Dr. Bernard Yan
Consultant Neurologist and Neurointerventionist
Neurovascular Research Group
Department of Neurology, Royal Melbourne Hospital
Tel: +61 3 9349 2477 / Fax: +61 3 9349 4489 /
Email: bernard.yan@mh.org.au
Intraarterial clot burden: a predictor of recanalization post intravenous tissue plasminogen activator?
Supervisors: Dr Bernard Yan, A/Professor Peter Mitchell, Dr Richard Dowling
Location: Department of Neurology, Royal Melbourne Hospital
Contact: Dr. Bernard Yan, Consultant Neurologist and Neurointerventionist,
Neurovascular Research Group, Department of Neurology, Royal Melbourne Hospital. T: +61 3 9349 2477 / F: +61 3 9349 4489
Email: bernard.yan@mh.org.au
Background:
The treatment goal of acute ischaemic stroke is to recanalize the occluded artery in order to revascularise the ischaemic penumbra, tissue surrounding the core region of infarction which is potentially salvageable. Tissue plasminogen activator (tPA) has been shown to recanalize occluded arteries in acute strokes. Moreover, multiple studies have proven that treatment with tPA in acute stroke decreases morbidity and mortality. However, the recanalization and clinical benefis are not uniform and there is emerging evidence that a proportion of patients with “larger clot burden” in the occluded artery fails to recanalize. This has not been systemically proven. We aim to correlate clot burden and clot location with recanalization in acute stroke patients who were treated with intravenous tPA.
Hypothesis: In acute ischaemic stroke, the likelihood of arterial recanalization post intravenous tissue plasminogen activator decreases with large clot burden.
Inclusion criteria: All patients presenting with acute ischaemic stroke to the Stroke Care Unit, Royal Melbourne Hospital.
Exclusion criteria: Intracranial haemorrhage.
Sample size: N = 150
For all queries, please contact:
Dr. Bernard Yan
Consultant Neurologist and Neurointerventionist
Neurovascular Research Group
Department of Neurology, Royal Melbourne Hospital
Tel: +61 3 9349 2477 / Fax: +61 3 9349 4489 /
Email: bernard.yan@mh.org.au
Treatment of Arteriovenous Malformation by Onyx embolization: factors determining treatment success
Supervisors: Dr Bernard Yan, A/Professor Peter Mitchell, Dr Richard Dowling
Location: Department of Neurology, Royal Melbourne Hospital
Contact: Dr. Bernard Yan, Consultant Neurologist and Neurointerventionist,
Neurovascular Research Group, Department of Neurology, Royal Melbourne Hospital. T: +61 3 9349 2477 / F: +61 3 9349 4489
Email: bernard.yan@mh.org.au
Background:
Arteriovenous Malformation (AVM) is an important cause of intracerebral haemorrhage. With the advent of microcatheter techniques, AVM’s are now increasingly amenable to treatment by microcatheter guided embolization with Onyx, an embolic material. However, the determinants of treatment success have not been clearly defined. It has been postulated that higher number of arterial feeders and high arterial flow are associated with treatment failure.
Hypothesis: That number of arterial feeders and arterial flow pattern are strong predictors of embolization success for Arteriovenous Malformation
Inclusion criteria: All patients treated with Onyx embolization for Arteriovenous Malformation at Royal Melbourne Hospital.
For all queries, please contact:
Dr. Bernard Yan
Consultant Neurologist and Neurointerventionist
Neurovascular Research Group
Department of Neurology, Royal Melbourne Hospital
Tel: +61 3 9349 2477 / Fax: +61 3 9349 4489 /
Email: bernard.yan@mh.org.au