International Stroke Conference
February 19–21, 2020
Parneet Grewal, MD
Moderators: Dr. Ashutosh Jadhav and Dr. Robin Novakovic
This session at the International Stroke Conference 2020 in Los Angeles included extensive discussion about various imaging modalities that are being used to select patients as candidates for endovascular treatment (EVT) in the real world, along with their pitfalls. The discussion was led by Dr. Albert J. Yoo, Dr. Achala Vagal, and Dr. Bernard Yan. There were also case scenarios presented by Dr. Richard Aviv of challenging CT angiography (CTA) cases.
Early time, late time, large core, small core: Non-con CT is all you need (Dr. Albert J. Yoo)
In his presentation, Dr. Yoo discussed the importance of non-contrast CT head in selecting patients for EVT and urged the clinicians to consider CT head and CTA as the only imaging modalities that are needed prior to making decisions for EVT. The EVT candidate patients are broadly divided into early window (0-6 hours) and late window (> 6-24 hours) based on their time of presentation, as well as into small core and large core based on the size of ischemic infarct. All the major landmark trials in the early window, such as MR CLEAN, ESCAPE, EXTEND IA, SWIFT PRIME and REVASCAT, utilized CT head/CTA for patient selection with EXTEND IA and SWIFT PRIME also using CT perfusion (CTP) imaging. All the trials demonstrated improved perfusion and functional outcome for patients with large vessel occlusion who underwent EVT but had different criteria for patient selection. A study by Tawil et al. on comparing eligibility for different trial protocols to estimate the number of patients eligible for treatment showed that 53% of the patient population met criteria for MR CLEAN, which decreased to only 17% for EXTEND IA. Secondary analysis of the MR CLEAN trial has also shown that the patients who were ineligible per EXTEND IA criterion also benefitted from the EVT, which means that excluding patients in the early window using CTP might lead us to miss a subset of the population which can still benefit from thrombectomy.