Prof. Dr. med.
Head Acute Stroke Unit
Head Neurovascular Outpatient Clinic
University Hospital Basel
+41 61 556 54 42
Research Group Leo Bonati
Area of Research
Prevention of stroke and vascular dementia in patients with atherosclerosis and atrial fibrillation in randomised trials and large prospective registries. Use of vascular and cerebral imaging and biomarker analysis for personalized treatment. Coordination of the nationwide acute stroke registry (Swiss Stroke Registry). Ageing brain.
Approved Research Projects
- Main applicant research grant, Foundation for Clinical Research and Medical Image Analysis, Basel (Stiftung zur Förderung der gastroenterologischen und allgemeinen klinischen Forschung sowie der medizinischen Bildauswertung): “Mechanisms of Cognitive Impairment and Neurodegeneration (COIN)”
- Co-applicant SNF longitudinal study grant (33CS30_177520): “Swiss Atrial Fibrillation Cohort Study”
- Co-applicant SNF project grant (32003B_169975): “Safety of Early versus Late initiation of direct oral anti-coagulants in post-ischaemic stroke patients with Non-valvular atrial fibrillation (ELAN safety)”
- Main applicant SNF project grant (32003B_156658): “BIO-PLAQUE: The role of carotid plaque imaging and biomarkers for plaque instability in selecting patients with carotid artery stenosis for endarterectomy or stenting – a translational randomised multi-centre study”
- Main applicant Swiss Heart Foundation research grant: “Cerebral infarction associated with stent treatment versus endarterectomy for asymptomatic carotid artery stenosis – the Magnetic Resonance Imaging Substudy of the Second Asymptomatic Carotid Surgery Trial”
- Main applicant AstraZeneca Externally Sponsored Research grant (ESR-14-10473): “Prevention of Cerebral Ischaemia in Stent Treatment for Carotid Artery Stenosis - A randomised multi-centre phase II trial comparing Ticagrelor versus Clopidogrel with outcome assessment on MRI (PRECISE-MRI)”
All Stroke Centers
- Prof. Emanuel Carrera, Geneva;
- Prof. Patrik Michel, Lausanne;
- Prof. Marcel Arnold and Urs Fischer, Berne;
- Prof. Andreas Luft, Zurich; PD Dr. Carlo Cereda, Lugano,
- Prof. Krassen Nedeltchev, Aarau;
- Dr. Georg Kägi, St. Gallen
all Stroke Units in Switzerland
- UCL Institute of Neurology, London (Proff. Martin Brown and David Werring)
- Nuffield Department of Vascular Surgery (Prof. Alison Haliday) and Clinical Trial Service Unit (Prof. Richard Peto), University of Oxford
- Department of Neurology, Mayo Clinic Jacksonville FL (Prof. Thomas Brott)
Ongoing Research Projects
Atherosclerosis and stroke prevention
Safety and efficacy of carotid endarterectomy, stenting, and optimised medical therapy for primary and secondary prevention of stroke in patients with asymptomatic and symptomatic carotid stenosis are evaluated in several investigator-initiated international randomised controlled trials (RCTs):
• Prevention of Cerebral Ischaemia in Stent Treatment for Carotid Artery Stenosis - A randomised multi-centre phase II trial comparing Ticagrelor versus Clopidogrel with outcome assessment on MRI (PRECISE-MRI; personal role: Principal Investigator, status: ongoing, 96 of 370 planned patients recruited).
• The Second European Carotid Surgery Trial (ECST-2; Principal Investigator: Martin Brown, University College London, UK; personal role: Co-Principal Investigator of main trial, Principal Investigator of plaque and brain imaging and biomarker substudies; status: ongoing, 416 of 1200 planned patients recruited).
• The Asymptomatic Carotid Surgery Trial 2 (ACST-2; Principal Investigator: Alison Halliday, University of Oxford, UK; personal role: Neurological Co-Principal Investigator of main trial, Principal Investigator of plaque and brain imaging and biomarker substudy; status: ongoing, 3399 of 3600 planned patients recruited).
• The Carotid Stenosis Trialists Collaboration (CSTC; personal role: Chairman, status: ongoing).
• The Cochrane Systematic Review on stenting versus endarterectomy for symptomatic and asymptomatic carotid stenosis (personal role: Corresponding Author, status: 2019 update accepted).
• The International Carotid Stenting Study (ICSS, Principal Investigator: Martin Brown, London; personal role: Member of the main trial team, Principal Investigator of the brain imaging substudy; status: recruitment and follow-up of 1710 patients completed).
Atrial fibrillation and oral anticoagulation
Safety and efficacy of oral anticoagulation, the occurrence of vascular brain lesions and other neurological sequelae are evaluated in a randomised clinical trial as well as in large prospective observational registries of patients with atrial fibrillation (AF), with or without prior history of cerebrovascular disease.
• Safety of Early versus Late initiation of direct oral Anticoagulants in post-ischaemic stroke patients with Non-valvular atrial fibrillation (ELAN safety; Principal Investigator: Urs Fischer, University of Berne; personal role: member of the steering committee of the main trial, Co-Principal Investigator of the brain imaging substudy; status: ongoing, 381 of 2000 planned patients recruited).
• Swiss Atrial Fibrillation Cohort Study (SWISS-AF; Principal Investigator: Stefan Osswald, University of Basel; personal role: member of the steering committee responsible for coordinating neurological outcome studies; status: recruitment completed, follow-up ongoing).
• Direct oral anticoagulants in stroke patients (DOAC-ISP) and in long-term prevention (DOAC-longterm; Principal Investigator: Stefan Engelter, University of Basel; personal role: Co-Principal Investigator; status: ongoing).
• The Swiss Stroke Registry (SSR; personal role: Coordinator, status: ongoing).
Spontaneous dissection of cervico-cerebral arteries
Spontaneous dissections of cervico-cerebral arteries (CeAD) are among the most frequent causes for ischemic stroke in the young. We investigate pathophysiologic mechanisms, diagnosis, treatment and prognosis of CeAD in large observational registries, as well as in an investigator-initiated RCT.
• Treatment of cervico-cerebral artery dissection (Treat-CAD; Principal Investigator: Stefan Engelter, University of Basel; personal role: member of the steering committee; status: recruitment of 194 patients completed in June 2019).
• Clinical course and genetics of CeAD are evaluated in local and international prospective registries.
The study of physiological and pathological changes in the ageing brain provides important reference data against which disease cohorts can be compared. In addition, longitudinal studies of a normal ageing cohort may lead to novel insights into early disease mechanisms and prevention strategies.
• Mechanisms of Cognitive Impairment and Neurodegeneration (COIN; personal role: Principal Investigator, status: funding secured - initiation).