Network Mapping of Time to Antithrombotic Therapy Among Patients With Ischemic Stroke and Transient Ischemic Attack (TIA)

Abstract

Background: There is emphasis on timely administration of thrombolysis and clot retrieval but not antithrombotic therapy within 48 h for ischemic stroke (frequency of 64% in Australia and 97% in North America). We planned to assess the time metrics and variables associated with delaying antithrombotics (antiplatelet and anticoagulant therapy) administration.Methods: This was a retrospective study at Monash Health over 12 months in 2015. We plotted the cumulative event and mapped the key drivers (dimensionless variable Shapley value/SV) of antithrombotics.Results: There were 42 patients with transient ischemic attack/TIA and 483 with ischemic stroke [mean age was 71.8 ± 15.4; 56.0% male; nil by mouth (NBM) 74.5 and 49.3% of patients received “stat” (immediate and one off) dose antithrombotics]. The median time to imaging for the patients who did not have stroke code activated was 2.3 h (IQR 1.4–3.7), from imaging to dysphagia screen was 14.6 h (IQR 6.2–20.3), and from stopping NBM to antithrombotics was 1.7 h (IQR 0–16.5). TIA patients received antithrombotics earlier than those with ischemic stroke (90.5 vs. 86.5%, p = 0.01). Significant variables in regression analysis for time to antithrombotics were time to dysphagia screen (β 0.20 ± 0.03, SV = 3.2), nasogastric tube (β 19.8 ± 5.9, SV = −0.20), Alteplase (β 8.6 ± 3.6, SV = −1.9), stat dose antithrombotic (β −18.9 ± 2.9, SV = −10.8) and stroke code (β −5.9 ± 2.5, SV = 2.8). The partial correlation network showed that the time to antithrombotics increased with delay in dysphagia screen (coefficient = 0.33) and decreased if “stat” dose of antithrombotics was given (coefficient = −0.32).Conclusion: The proportion of patients receiving antithrombotics within 48 h was higher than previously reported in Australia but remained lower than the standard achieved in North American hospitals. Our process map and network analysis show avenues to shorten the time to antithrombotic.

Time to antithrombotic therapy after transient ischaemic attack and ischaemic stroke

“…Similar to the experiences with TIA, patients with minor ischaemic stroke (National Institute of Health Stroke Scale [NIHSS] < 5) are also kept nil by mouth in 57.4% (27 of 47) of cases. Interestingly, the single patient (one in 47) who developed pneumonia in our study had passed a dysphagia screen on admission before developing pneumonia on day 3 after the stroke 10 . The issue of dysphagia screening and antiplatelet administration may reflect different practices across the world.…”

“…These programs achieve high frequency of early aspirin use (92.2%) 9 . By contrast, the percentage of patients with TIA who were admitted to hospital and received antithrombotic therapy within 24 hours was 80.9% ( n = 34), with 90.5% ( n = 38) receiving this therapy at 48 hours 10 . Among these admitted patients with TIA, 38.1% ( n = 16) were kept nil by mouth.…”

“…9 By contrast, the percentage of patients with TIA who were admitted to hospital and received antithrombotic therapy within 24 hours was 80.9% (n = 34), with 90.5% (n = 38) receiving this therapy at 48 hours. 10 Among these admitted patients with TIA, 38.1% (n = 16) were kept nil by mouth. It is not clear if a dysphagia screen is necessary in patients with TIA as by definition they have had resolution of their neurological deficits and would hence appear to have very low risk of aspiration (0 of 42 patients).…”

“…Interestingly, the single patient (one in 47) who developed pneumonia in our study had passed a dysphagia screen on admission before developing pneumonia on day 3 after the stroke. 10 The issue of dysphagia screening and antiplatelet administration may reflect different practices across the world. In a North American trial comparing oral aspirin and intravenous alteplase in patients with minor stroke, 11 39% of the patients had facial palsy and 28% had dysarthria.…”