Abstract TP113: Advanced Imaging is Associated With Longer Door to Needle Time in Candidates for Thrombolytic Treatment With No Benefit Regarding Clinical Decisions

Abstract

Introduction: Growing availability of advanced imaging studies (AdIS) has resulted in increasing use of studies other than non-contrast CT (NCCT) in the evaluation of acute ischemic stroke (AIS) patients. The diagnosis of AIS is mainly clinical, and thrombolysis in patients with stroke mimics is generally considered to be safe. However, the need for diagnostic certainty and timely detection of large vessel occlusion (LVO) may incline physicians to perform more AdIS. Hypothesis: Performing pre-treatment AdIS in all patients with AIS will prolong DNT without conferring clear benefits regarding treatment decisions. Methods: We reviewed a prospective registry of AIS patients arriving at the Neurologic Emergency Department. We obtained additional information from the patients’ clinical records, and all pertinent imaging studies were reviewed to confirm diagnosis and site of arterial occlusion. Results: We analyzed 128 AIS patients treated with IV thrombolysis. Mean Door to-Needle-Time (DNT) was 83 min. Only 46% of patients were thrombolysed in the first 60 minutes after arrival. AdIS were performed in 60 patients (48%) They were equally performed among patients with NIHSS scores below and above 10 points, a possible cutoff for the presence of LVO. They also were performed equally in patients with clinically mild, and severe strokes, when the clinical diagnosis of AIS was not in doubt. On bivariate analysis, factors associated with DNT<60 minutes were: female sex, posterior circulation stroke and whether only NCCT was performed. Exclusive use of NCCT was associated with a higher percentage of DNT<60 minutes (59 vs 34%, p=0.005). On multivariable analysis, NCCT use was independently associated with DNT<60 min (OR= 2.92, p<0.007) Regarding different imaging studies, DNT means were as follows: NCCT: 69 min, CTA:79 min, CTP: 125 min, MRI 108 min (Difference between groups p=0.007). No patients were excluded from thrombolytic treatment based on AdIS results. Conclusions: The pre-thrombolysis performance of AdIS carries the risk of prolonging DNT and lowering the possibility of benefit for AIS patients. Selection of patients for specific studies and deferring AdIS until after initiating alteplase should be pursued.