Association Between Coagulation Function and Spontaneous Hemorrhagic Transformation in Acute Ischemic Stroke

Background and purpose: Hemorrhagic transformation (HT) has an adverse effect on the prognosis of patients with acute ischemic stroke, and it is currently known associated with coagulation system. But the conclusion is not consistent and remains to be identified. The aim of this study was to investigate the association between coagulation function and spontaneous hemorrhagic transformation.

Methods: Patients within 7 days from the onset of ischemic stroke who did not receive reperfusion therapy (thrombolysis or endovascular treatment) were included between January 2016 and October 2017. Coagulation function indicators, including prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), thrombin time (TT) and fibrinogen (FIB), were tested within 24 h after admission. HT was defined as hemorrhage presented on follow-up magnetic resonance imaging (MRI) or computed tomography (CT) but not on baseline CT. We performed binary logistic regression to examine the association between coagulation function and HT. The coagulation indicators were entered into logistic regression analysis as continuous variables (per 1-unit/L increase) and four-categorized variables (with data collapsed into quartiles), respectively.

Results: A total of 1141 patients were included (mean age, 64 ± 15 years; 63.7% males). 102 patients experienced HT (8.9%), of whom 14 patients experienced symptomatic HT (sHT, 1.2%). After adjustment for confounders, TT in the highest quartile is inversely associated with risk of HT (as continuous variable, odds ratio [OR] 0.85; 95% confidence level [CI] 0.73-0.99, P = 0.042; as four-categorized variable, OR 0.36, 95% CI 0.18 - 0.7, P = 0.003). Whether as continuous variables or four-categorized variables, PT, INR, APTT and FIB had no association with HT.

Conclusion: Not the whole process of coagulation function is associated with spontaneous HT. Prolonged TT, which may indicate an extension of the last step of the coagulation process, is independently and inversely associated with spontaneous HT in patients with acute ischemic stroke.