Risk Factors and Mechanism of Hemorrhagic Transformation of Acute Ischemic Cerebral Infarction

A feared complication of ischemic cerebrovascular accident (CVA) is hemorrhagic transformation and it increases the length of hospital admissions, results in poor clinical outcomes and increases mortality. This study aims to identify risk factors of hemorrhagic transformation, discuss the pathogenesis of transformation and prognosis of the condition from original studies conducted within the past 10 years. PubMed and EMBASE are the major databases used. Eight articles met the inclusion criteria and are a mixture of retrospective and prospective studies. The sample size ranges from 32 to 1484 patients. Generally, the mechanism of hemorrhagic transformation identified involves the release of reactive oxygen species and metalloproteinase as a result of cerebral ischemia. Metalloproteinase further causes a breakdown of the extracellular matrix, thereby giving rise to the extravasation of cellular components. Some identified risk factors include: age, use of antithrombotic, the subtype of ischemic stroke, the severity of stroke and hypertension. Prognosis is linked to the type of hemorrhagic infarctions according to the European Cooperative Acute Stroke Study II (ECASS II) with patients with either hemorrhagic infarct type 2 (HI2) and parenchymal hematoma type 2 (PH2) having the worst functional outcome.