Medical treatment of intracranial atherosclerosis has been shown to be superior
- Cathy Sila1,2
- 1Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- 2Stroke and Cerebrovascular Center, University Hospitals-Case Medical Center, Cleveland, Ohio, USA
- Correspondence to Dr Cathy Sila, George M Humphrey II Professor of Neurology, Case Western Reserve University School of Medicine, Director, Stroke and Cerebrovascular Center, University Hospitals-Case Medical Center, 11100 Euclid Avenue, HAN 5040, Cleveland, OH 44106, USA;
- Accepted 10 January 2012
Enrollment in the Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis (SAMMPRIS) trial was prematurely terminated in April 2011 when safety concerns arose regarding the periprocedural risk of endovascular therapy in trial participants. The early results, published in September 2011, cited a significant increase in the 30-day risk of stroke or death with percutaneous transluminal angioplasty and stenting (PTAS) with aggressive medical therapy compared with aggressive medical therapy alone (14.7% vs 5.8%, p=0.0002).1 The SAMMPRIS trial results demonstrate that the superiority of aggressive medical therapy alone in patients with recently symptomatic and severe intracranial atherosclerosis was driven more by an excessive periprocedural risk with intervention than the better than expected response to the risk factor management regimen.
Why was the periprocedural stroke and death rate higher than expected? It is well known that event rates are strictly defined and meticulously monitored in the setting of clinical trials and are often higher than those cited in self-reported case series and loosely monitored registries.2 Although the new American Stroke Association definition for ischemic stroke includes an event of any duration accompanied by neuroimaging evidence of infarction and captures minor clinical events with positive MRI diffusion-weighted abnormalities, the definition of ischemic stroke used in the SAMMPRIS trial was more conservative. Ischemic stroke was defined as a neurologic deficit detected by a bedside examination at least 24 h after the onset of symptoms and attributed to cerebral ischemia; hemorrhagic stroke was defined as a symptomatic intracerebral, subarachnoid or intraventricular hemorrhage.
The estimates of the periprocedural risks of PTAS using the Wingspan stent system were derived from case series and aggregate data from 387 patients entered into two phase I trials and two post-marketing registries.3–5 Compared with the phase I trial, the post-marketing registries reported acceptable periprocedural risks of 5.4–6.2% with high …