Adam de Havenon, MD

Siddiq F, Adil MM, Norby K, and Qureshi AI. Intracranial Stent Placement for Symptomatic Intracranial Stenosis asPart of a Clinical Trial Versus Outside a Clinical Trial. Stroke. 2013

In 2011 the Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis (SAMMPRIS) trial was halted early by their Safety Monitoring Board because of an increase in the 30-day stroke and death rate from 5.8% in the medical management group to 14.7% in the endovascular treatment group. This dramatic result almost immediately changed clinical management for thousands of patients with severe intracranial atherosclerosis. Many, though, were quick to criticize the SAMMPRIS results for a variety of familiar reasons (operator experience, type of stent, case volume, etc.).

This study by Farhan Siddiq et al. looks at 3,447 patients from 2008-2010 in the Nationwide Inpatient Sample with cerebral ischemic events treated with intracranial stenting as part of a clinical trial (CT) or outside a clinical trial (OCT). The 223/3,447 (6.5%) patients in a CT had a composite endpoint (post-operative stroke, cardiac complications and mortality) of 4.5% versus 14.2% for OCT patients. 76.8% of the CT patients were discharged home while only 49.6% of the OCT patients were.

Assuming that the ICD coding that the study used to identify patients is reliable, the results suggest several conclusions. The first is that the CT patients were probably “cherry-picked” to some degree, a phenomenon that is evident in many clinical trials, including the seminal ones addressing carotid stenting. The second is that the results of SAMMPRIS appear even more robust based on this data and a major advance in stent technology or endovascular technique would be required before re-addressing the utility of intracranial stenting.