Abstract TMP21: Intravenous Thrombolysis with Alteplase for Acute Ischemic Stroke in Patients with Thrombocytopenia

Abstract

Objective: To evaluate the rate of symptomatic intracranial hemorrhage (sICH) in patients who received Intravenous tPA(IVT) for acute ischemic stroke(AIS) and were later found to have platelets less than 100,000 /mm 3 . Background: With increasing use of IVT for AIS and more studies on its risk and benefits, many of the initial exclusion criteria which were part of the pivotal NINDS trial have been challenged with well-designed case series and reports. Based on the latest scientific statement from the AHA/ASA on the exclusion and inclusion criteria for IVT in AIS published in February 2016, the safety and efficacy of IVT in AIS is unknown for the patients with platelet count <100,000(Class III, Level of evidence C). The platelet threshold of 100,000 /mm 3 was derived from expert consensus in the NINDS trial and since many of the exclusion criteria have been challenged, this value also comes into question. Methods: We retrospectively reviewed the charts of all patients who received IVT for AIS from the beginning of 2006 till the end of August 2015 at our large volume comprehensive stroke center (SUNY Buffalo). Those with platelets <100,000/mm 3 were identified. Head CT done in 24 to 36 hours Post-thrombolysis was reviewed to evaluate the rate of sICH. sICH was defined as ICH with an increase in National Institute of Health Stroke Scale of at least 4 points. Results: A total of 835 patients received IV rtPA for AIS in our center during a 9·6-year period. Fifty one patients (6.1 %) were found to have sICH. A total of 5 patients (0.6 %) were identified to have platelet count <100,000 /mm 3 . One of them (20%) developed sICH post IV tPA administration .The mean platelet count of those 5 patients was 63,000 ± 19,000 /mm 3 (Range: 38,000 - 85,000 /mm 3 ) . To the best of our knowledge, only 21 thrombocytopenic patients have been reported to receive IV rtPA for AIS in the medical literature. Combining our 5 cases with 21 patients previously reported, we have 26 AIS patients who had platelet count <100,000 /mm 3 and received IV rtPA, with 2 of them developed sICH (7.7 %). Comparing the rate of sICH among this group with the patients with normal platelet count in our cohort, there was no statistically significant difference (7.7% versus 6.04%, p-value = 0.73). Conclusion: Although our extremely low number of cases precludes any solid conclusion, IV rtPA for AIS might be safe in patients with platelet count <100,000/ mm 3 and it is reasonable not to delay IV rtPA administration while waiting for the platelet count result, unless there is strong suspicion for abnormal platelet count.