BACKGROUND: 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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: In our cohorts, the rate of SHT after thrombolysis is equivalent between Chinese and North American stroke patients.