Abstract WP101: Comparative Effects of Thrombolysed Ischemic Patients With Low Platelet Count

Abstract

Introduction: Platelet count (PC) < 100х10 9 /L is considered a relative contraindication to the use of intravenous alteplase in patients with acute ischemic stroke (AIS). However, this recommendation is based on expert opinion only. We aimed to assess whether low PC modified the comparative effects of low- versus standard-dose alteplase in patients who participated in the alteplase-dose arm of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED). Methods: Data from an international, multi-center, prospective, randomized, open-label, blinded-endpoint trial were used to assess the benefits and risks of low- (0.6mg/kg) versus standard-dose (0.9mg/kg) intravenous alteplase in thrombolysis-eligible AIS patients. A logistic regression model was used for analysis of patient subgroups defined by categorical PC (tertiles, with the lowest third as the reference group) on efficacy and safety outcomes, adjusted for confounding variables. Results: After adjusting for baseline characteristics in 3265 AIS patients, low PC was not associated with poor outcome: whether defined by ordinal modified Rankin scale (mRS) scores (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.69-1.37 [middle vs. low] vs. 1.17 (0.99-1.37) [high vs. low]; P=0.066 for trend) or symptomatic intracerebral hemorrhage (sICH) (1.36 (0.71-2.6) vs. 0.8 (0.38-1.69); P=0.630 for trend). There was no differential effect of low- versus standard-dose alteplase on ordinal shift in mRS scores, mortality, or sICH, by tertiles of PC. Conclusions: Low PC was not an independent predictor of poor outcome in thrombolysis-treated AIS patients and it does not modify the differences in effects of low- versus standard-dose alteplase.