Abstract TP28: Combining Clinical with Radiographic Criteria to Select Patients for Endovascular Therapy in Acute Stroke
BACKGROUND: Patient selection is emerging as an important aspect of interventional treatment of acute ischemic stroke. The baseline CT scan and NIHSS can be performed very quickly to identify those patients who will have proximal arterial occlusions (PAOs) amenable to endovascular therapy. Hyperdense arteries (HDAs) identified on thin-slice reconstruction (0.625 mm slice) CT have been shown to predict PAOs on CT Angiography. We sought to determine whether the combination of clinical (NIHSS strata) and radiographic (standard 5mm slice non-contrast head CT) criteria could better identify ideal candidates for endovascular therapy.
METHODS: We reviewed IMS I and II subjects who were treated with IV tPA for an anterior circulation stroke, and had a baseline standard head CT followed by a digital subtraction angiogram (DSA; n = 144 of the 161 patients in IMS I and II). Stroke severity (NIHSS 10-19, or ≥20), presence of a HDA on baseline CT (either in the ICA terminus or M1 branch of the MCA), and the location of arterial occlusions (either partial or complete) on DSA were determined. We calculated sensitivity, specificity and the positive predictive value (PPV) of stroke severity and a HDA for the presence of a PAO (ICA, M1 or M2 branches of MCA).
RESULTS: 64 of 144 patients (44%) had a NIHSS ≥20. 74 of 144 patients (51%) had a HDA on CT (39 patients or 49% with NIHSS 10-19; 35 patients or 55% with NIHSS ≥20). After IV tPA, a PAO was seen on DSA in 105 (73%) of patients. DSA showed distal or no occlusion in 39 patients (13 of whom had a HDA on CT). The PPV of a HDA for a PAO was 82% (95%CI = 72-90%; sens = 58%, spec = 67%), whereas the PPV of NIHSS ≥20 for a PAO was 78% (95%CI = 66-87%; sens = 48%, spec = 64%). In patients with a HDA, consideration of stroke severity (NIHSS ≥20) only improved the PPV for a PAO to 86% (95%CI = 70-95%; sens = 60%, spec = 31%). In those with a HDA and a less severe stroke (NIHSS 10-19), PPV was 79% (95%CI = 63-91%; sens = 56%, spec = 68%).
CONCLUSIONS: In patients with acute anterior circulation ischemic stroke, adding stroke severity does not appear to significantly improve the predictive value of a hyperdense artery on baseline standard CT for the presence of a proximal arterial occlusion after IV t-PA. Further study is needed to identify patients who are candidates for endovascular therapy.
- © 2012 by American Heart Association, Inc.