Hemorrhagic transformation of cerebral infarction: risk factors, diagnosis, and new approaches to treatment

Background. Hemorrhagic transformation (HT) is a frequent complication of acute cerebral infarction, which is unfavo­rable for the treatment and prognosis of patients. It can be divided into two main subtypes, hemorrhagic infarction, and parenchymal hematoma, depending on the type of hemorrhage. Although the pathophysiological mechanism of HT is still unclear, hypotheses have been proposed about the loss of microvascular integrity and impaired neurovascular homeostasis. The purpose of the study was to analyze the current scientific literature on risk factors, diagnosis, and new approaches to the treatment of hemorrhagic transformation of cerebral infarction. Materials and methods. A literature search using keywords was conducted in Web of Science, Scopus, PubMed, and Elsevier databases. Results. Ischemic tissues have a natural tendency to bleed. In addition, the first trials of recanalization using intravenous thrombolysis showed an increase in the incidence of mild to severe intracranial hemorrhages. Symptomatic intracerebral hemorrhage is closely associated with poor outcomes and is an important factor in recanalization decisions. The development of HT after stroke involves numerous interrelated pathological processes from peripheral blood cells to neurovascular units such as hyperactive ischemic cascades with increased levels of matrix metalloproteinases, excessive reactive oxygen species, coagulopathy, blood-brain barrier breakdown, and reperfusion injury. A number of risk factors or prognostic factors for HT after cerebral infarction have been identified, namely the use of antiplatelet agents or anticoagulants, infarct size, atrial fibrillation, hypertension, age, gender, heart failure, coronary artery disease, diabetes mellitus, lipid profile, reperfusion therapy, and white matter hyperintensity load. The incidence of HT is reported mainly in clinical studies using brain imaging techniques such as computed tomography or magnetic resonance imaging, diffusion weighted imaging, and perfusion weighted imaging. Recombinant tissue plasminogen activator therapy and mechanical thrombectomy are currently the main treatments for ischemic stroke, but reperfusion injury due to revascula­rization increases the risk of cerebral hemorrhage. Understanding the risk factors and in-depth evaluation of predictors can significantly help physicians develop strategies to reduce the occurrence of HT, as well as provide insight into the pathophysiological mechanism of the disease. Conclusions. Patients at risk of hemorrhagic transformation require invasive and non-invasive neuromonitoring to help make decisions in decompressive neurosurgery for large cerebellar infarction, specific cardiorespiratory treatment, nutrition, blood pressure control, biochemical parameters, and the choice of an individual management strategy.