Hemorrhagic transformation of ischemic stroke

Abstract

The better understanding of the diverse mechanisms leading to the hemorrhagic transformation of an ischemic stroke is the crucial point in the prevention of this altogether common phenomenon. The different individual risk factors include the anatomical variability of collateral blood supply, age, genetics, body weight, etiology of the occlusion, side of the occluded vessel, renal status, stroke severity, history of high serum glucose or hypertension and hypertension or hyperglycemia at the onset of the stroke, ferritin level, INR, antiplatelet usage or the platelet count etc. All these might contribute to the process of hemorrhagic transformation. These risk factors have been identified by retrospective epidemiological studies and are useful to identify patients who are at high risk for hemorrhagic conversion and help the decision between conservative, thrombolytic or more advanced treatments such as thrombectomy. The modulations of potential molecular targets participating in the process seem to be promising in animal models, but human trials are lacking the breakthrough success so far, both in extending the time frame of the thrombolysis and in replacing the recombinant tissue plasminogen activator (rtPA) as thrombolytic agent.So far, the careful preselection of patients eligible for thrombolytic therapy is the best way to prevent hemorrhagic transformation. The intensive research in the field revealing small but important molecular details are continuously contributing to the better understanding of hemorrhagic transformation with the intention of finding new agents that co-administrated to the rtPA or completely replacing that could decrease the risk of secondary bleeding.The aim of this review is to give comprehensive insight into the process of hemorrhagic transformation of ischemic stroke, starting with basic overview of the penumbra concept and the collateral supply followed by discussion of the recanalisation-reperfusion-hemorrhagic transformation process after vessel occlusion also highlighting the importance of timing and ratio of recanalisation spontaneously and in case of thrombolytic agent administration. We overview the risk factors of hemorrhagic transformation, which may be helpful to physicians to identify high risk patients before rtPA administration. The last part of the work is dealing with future therapeutic possibilities based on the so far revealed molecular mechanisms of hemorrhagic transformation. With the aim to assess the rate and influencing factors on the recanalisation and reperfusion rate 381 patients with large-vessel occlusion was investigated. The patient group involved ones treated with rtPA or treated conservatively. Partial or complete recanalisation was achieved in 121 out of 210 (58%) patients after intravenous rtPA administration. The recanalisation success was more likely if the patient had atrial fibrillation [4] -maybe because cardioembolic clots consists more fibrin and are more likely to reopen by plasmin proteolysis than thrombosis of an atherosclerotic plaq...

Hemorrhagic Transformation After Ischemic Stroke: Mechanisms and Management

“…With recent advances in intravenous (9) or endovascular (10) reperfusion therapies for acute ischemic stroke (11), stroke physicians need to deepen their understanding of cerebral hemorrhagic complications. Although the overall risks of complications have been well-documented in various (8).…”

Aflibercept, a VEGF (Vascular Endothelial Growth Factor)-Trap, Reduces Vascular Permeability and Stroke-Induced Brain Swelling in Obese Mice

“…The hemorrhagic transformation included parenchymal hematoma and hemorrhagic infarction in either the penumbra or infarct core. 37 Histological analyses revealed increased infarct volume and edema in obese mice (Figure 1C). In lean mice, infarct size significantly correlated with edema ( r 2 =0.3913, P <0.05) but not in obese mice ( r 2 =0.0073, ns; Figure 1C).…”

Anticoagulation Resumption in a Patient With Mechanical Heart Valves, Antithrombin Deficiency, and Hemorrhagic Transformation Following Thrombectomy After Ischemic Stroke

“…The risk of HT deterioration with an indication for anticoagulation after acute ischemic stroke is multifactorial (Marsh et al, 2013;László and Hortobágyi, 2017). Endovascular therapy for these stroke patients could also make them suffer from hemorrhage, particularly in patients with atrial fibrillation (Sussman and Connolly, 2013;Nogueira et al, 2015), and HT after thrombectomy was of comparatively high rate in patients taking anticoagulants (Kaesmacher et al, 2017;Purrucher et al, 2016).…”