The Risk of Hemorrhagic Transformation After Thrombolysis for Acute Ischemic Stroke in Chinese Versus North Americans: A Comparative Study

Abstract

There is a widespread belief that Asians are more susceptible to hemorrhagic transformation (HT) after receiving recombinant tissue-type plasminogen activator (rt-PA) for acute ischemic stroke (AIS). However, this has not been examined in clinical practice. This study aims to compare the incidence of symptomatic hemorrhagic transformation (SHT) among thrombolysis-treated AIS patients in China and in the United States. We compared 212 consecutive patients receiving thrombolysis within 4.5 hours of onset ± endovascular therapy from an American (n = 86) and a Chinese Stroke Center (n = 126). SHT was defined using various definitions based on the National Institute for Neurological Disorders and Stroke Recombinant Tissue Plasminogen Activator (NINDS rt-PA) trials, European-Australian Cooperative Acute Stroke Study 2 (ECASS2), and a modified version of Safe Implementation of Thrombolysis in Stroke-Monitoring Study (mSITS-MOST) study criteria. We used Firth logistic regression to adjust for confounding variables and to identify potential predictors. American patients were older, and had higher prevalence of diabetes, hypertension, cardiac disease, and prestroke use of antithrombotics. They also had higher baseline serum glucose, shorter onset-to-treatment time, and fewer endovascular treatments. The rates of SHT were higher in the American cohort compared to the Chinese cohort: 18.6% versus 14.3% based on NINDS definition of SHT; 15.1% versus 12.7% based on ECASS2; and 11.6% versus 7.2% based on mSITS-MOST. However, none of these differences were significant (unadjusted and adjusted P values > .05). Fatal HT was comparable in Americans versus Chinese (8.1% versus 8.7%). Serum glucose emerged as an independent predictor of SHT (P = .024). In our cohorts, the rate of SHT after thrombolysis is equivalent between Chinese and North American stroke patients.