Introduction: Five randomized trials proving the efficacy and safety of mechanical embolectomy for ischemic stroke patients used differing radiological methods to select patients for treatment.
Hypothesis: The percentage of patients evaluated in a non-clinical trial setting that would meet radiological criteria to be included in the five trials will differ substantially.
Methods: Retrospective study of consecutive ischemic stroke patients who were considered for endovascular stroke therapy based on confirmed intracranial large vessel occlusion (M1, M2, or carotid terminus) at an academic medical center from April 2010 - November 2014. All patients underwent CT perfusion and CT angiogram.
Results: The table shows baseline characteristics of 119 patients. Median age was 69 years (IQR 57-79) and median NIHSS 18 (IQR 14-21). Most patients had ASPECTS score ≥ 6 (n=105, 88.2%). The M1 segment of MCA was the most common vessel occluded (n=81, 68%). All 119 patients (100%) met radiological criteria for MR CLEAN while 105 (88.2%) met criteria for SWIFT-PRIME, 96 (80.7%) for REVASCAT, 80/116 (69.0%) for EXTEND IA, and 74 (62.2%) for ESCAPE. IV TPA was given to 58 patients (48.7%) and acute endovascular stroke therapy attempted in 66 (55.5%). Any intracranial hemorrhage was more common in the patients treated with endovascular therapy than in those who were not (36% vs. 17%, p=0.025). The frequency of symptomatic ICH did not significantly differ between these two groups (6.1% vs 3.8%, p=0.691).
Conclusions: The percentage of patients with acute stroke and large vessel occlusion that would qualify for endovascular stroke trials based on radiological criteria varies considerably (62%-100%) in a non-clinical trial cohort from an academic comprehensive stroke center. Additional individual patient characteristics influence treatment decisions in non-clinical trial settings.