Abstract WP342: Antithrombotics Within 24 Hours After Recanalization Treatment: Is it Safe?

Abstract

Background: Majority of hemorrhagic transformation (HTf) occurs within 24 hours after IV or IA treatment, and earlier antithrombotics may be useful in preventing early reocclusions or ischemic neurologic deteriorations. However, the safety of early antithrombotics ≤24-hour after recanalization treatment is not sufficiently evaluated. Methods: From a total of 6777 stroke cases who admitted to Seoul National University Bundang Hospital between July 2007 and March 2015, the authors collected eligible cases with the following inclusion criteria; (1) Lesion-documented ischemic strokes (N=5451); (2) received recanalization treatments (N=792). We excluded 72 cases with (1) missing in the time information (N=19), (2) ultraearly bleeding complications (N=41), (3) extremely grave prognosis (N=5), and (4) surgical treatment (N=7). We systemically gathered the exact timing of antithrombotics use from a database of electronic bar-code medication administration system. Results: Of the 720 analyzable cases, male was 57% (n=407), mean age was 68.9 ± 12.8, and median NIHSS score was 12 [7 - 19] point. Recanalization treatment was consisted of 34% (n=243) of IV-only, 32% (=231) of IA-only, and 34% (n=246) of combined IV-IA strategies. Outcomes after stroke was as following; 218 (30%) any HTf, 31 (4%) symptomatic HTf, and 266 (37%) mRS score 0 - 1 at 3 months. In this population, antithrombotics were initiated within 24 hours after recanalization treatment in 64% (n=458) of cases and within 12 hours in 24% (n=170) of patients. Multivariable analyses revealed that early initiation of antithrombotics within 24 hours after recanalization treatment was significantly associated with lower odds of having any HTf (adjusted OR, 0.69; 95% CI, 0.48 - 0.98). Early initiation was not significantly associated with symptomatic HTf (0.71; 0.34 - 1.46) and mRS score 0 - 1 at 3 months after stroke (1.41; 0.97 - 2.06). Conclusions: Earlier initiation of antithrombotics within 24 hours after recanalization treatment may not increase hemorrhagic complications after stroke. Further clinical research is warranted to clarify which subgroup of stroke patients will benefit of earlier antithrombotics.