Approximately 1.3 million new cases of stroke per year are recorded in Europe – with a rising tendency. There is increasing scientific evidence to support thrombectomy – the mechanical removal of blood clots – as a safe and efficient procedure in acute therapy. Experts at the Congress of the European Academy of Neurolgy in Berlin are discussing which patient groups might profit most from the new procedure and what current insights stroke research provides for other fields.
Berlin, 22 June 2015 – Stroke is among those neurological disorders which are developing into an increasingly widespread disease: A total of more than 8.2 million persons in the EU are affected; around 1.3 million new cases are recorded every year – with a rising tendency due to demographic developments, since the illness is more common in old age. „Medicine is making major advances in the prevention, therapy and rehabilitation of stroke. Nonetheless, this disorder still poses major challenges to us“, EAN Vice President Prof Franz Fazekas, Medical University Graz, stated at the 1st Congress of the European Academy of Neurology (EAN) in Berlin. More than 6,500 experts from all over the world are discussing current trends in their field from 20 to 23 June in the German capital city.
Good efficacy and safety for selected patient groups
„Among the most important developments in acute stroke therapy is the increasing scientific evidence regarding the mechanical removal of thrombi from the brain vessels“, Prof Fazekas reported. Recently published study results not only document the high efficacy and safety of thrombectomy, but for the first time, they also show its superiority to standard thrombolysis therapy in specific patient groups. „The procedure makes sense particularly in large thrombi which cannot be dissolved, or can only be partly dissolved with pharmacological therapy, and which occlude large brain supplying blood vessels“, Prof Fazekas stated. „The advances of the new method are indeed promising, but it is clear that mechanical thrombectomy cannot restore circulation in all affected persons either.
Revascularisation is ineffective if brain tissues have already died. The challange will be to apply the procedure specifically in those patients who can profit from it und to provide the organisational structures and workflows necessary for this complex type of treatment.”
Recommendations by European associations
It is precisely for this purpose that the relevant European medical and scientific associations are preparing a joint recommendation on thrombectomy, which is intended to ensure that this innovative procedure will be utilised with the greatest possible benefit for patients. Discussions so far indicate that thrombolysis remains the main treatment for acute ischaemic strokes. „In occlusions of large brain vessels, however, it should be complemented by thrombectomy. If intravenous thrombolysis is contraindicated, thrombectomy undoubtedly represents the first line treatment option in large vessel occlusions“, Prof Fazekas said. „Old age alone should not be a reason to withhold this procedure from patients. If the brain has already suffered significant previous damage, however, or in the case of large infarcts and severe damage of other organs, its use may not lead to the desired results.”
Regarding technologies, efficacy data is available mainly for stent retrievers. The use of other systems depends on the respective situation and requires case-by-case assessment. „The time factor is important for the outcome. Thrombectomy should be performed within a maximum of three to six hours. However, the earlier the intervention is performed, the better the treatment results“,Prof Fazekas stated.
Multidisciplinary cooperation in acute stroke therapy is a key factor for success. The decision to undertake thrombectomy should always be made by a team which includes at least a clinical and an interventional stroke specialist. In many European countries, the team is coordinated by a neurologist who is responsible for differantial diagnosis and other therapeutic steps. „Not only clinical, interventional or neuroanaesthetic experience are most relevant for successful thrombectomy; imaging also plays an important role, for example in determining the vessel occlusion, the size of the stroke or the penumbra size to identify suitable patients“, Prof Fazekas explained. Aside from multidisciplinarity, specialisation is also an important factor. Thrombectomy should only be performed at specialised stroke centres. In this regard, experts call upon health policy makers to ensure comprehensive coverage with such centres so that stroke patients have timely access to thrombectomy when needed.
Thrombolysis has established itself throughout Europe
Despite the latest developments in the field of mechanical thrombectomy, intravenous thrombolysis (IVT) still remains a central instrument in acute stroke treatment. „An important new trend in this respect is that we are treating more and more patient groups with thrombolysis, and specifically penetrate higher age categories“, Prof Fazekas emphasised. „This development should be undertaken with care and consideration.“
A Portuguese study presented at the EAN Congress shows that therapeutic limits are being pushed in various directions. The results suggest that individual patients may benefit from intravenous thrombolysis even when relative contraindications such as cancer, dementia or a recent myocardial infarction exist.
Intravenous thrombolysis has meanwhile become established throughout Europe – successfully, as shown by a French-Serbian study presented at the EAN Congress: The outcome of IVT was investigated in around 250 stroke patients with atrial fibrillation in Lille and Belgrade. Despite the differing socio-economic prerequisites, the procedure is bringing about comparably good treatment results in both countries and centres. Patients from Belgrade were ten years younger, more likely to be male and more often smokers. Prof Fazekas: „It is good news that treatment quality shows comparable parameters in very different countries – a concern which we at the EAN pursue across all sectors.”
Implanted event recorders discover atrial fibrillation
There are important developments in stroke prevention as well. Atrial fibrillation is among the most common causes of a severe stroke. It is important to identify this condition because patients exposed to this risk factor need to receive anticoagulant treatment where novel oral anticoagulants (NOACs) have also opened extended treatment options. New data indicates that atrial fibrillation may be responsible for strokes far more frequently than previously assumed.
It can be difficult to identify intermittent atrial fibrillation in stroke patients because it may be easily missed with ECG recordings only. New monitoring systems have a lot of potential, as indicated by a US study presented at the EAN Congress. Prof Fazekas: „In fact, ten out of the 58 patients in this investigation suffered from atrial fibrillation after cryptogenic stroke – significantly more than one would generally assume. The use of implantable event recorders is suited to detecting the dangerous cardiac arrhythmias in patients after cryptogenic stroke.“ At the same time, research teams are trying to identify those factors which are associated with atrial fibrillation particularly likely, especially in embolic stroke due to unknown sources (ESUS). A study by French researchers which was also presented at the EAN conference reports special echocardiography findings which may serve to advance this purpose.
Sources: BrainFacts.org, Brain Disease in Europe, November 2013; Olesen et al.: The economic cost of brain disorders in Europe. European Journal of Neurology 2012, 19: 1998;101:515-520; EAN-Abstracts: Padjen et al, Effect of intravenous thrombolysis on stroke patients with atrial fibrillation treated in Lille (France) and Belgrade (Serbia); Alves et al, Intravenous Thrombolysis in “grey areas”; Seiler et al, Surveillance for Atrial Fibrillation in patients with cryptogenic stroke using an implantable loop recorder in a community hospital setting : Real world validation of Crystal AF; Sabben et al, Predictors of new onset atrial fibrillation after an ischemic stroke.
1.) European Stroke Organisation, ESO; European Society of Minimally Invasive Neurological Therapy, ESMINT; European Society of Neuroradiology, ESNR; European Academy of Neurology
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