Treatment Of Ischemic Complications Research Articles

The Role of Cortical Spreading Depolarizations in Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is the leading potentiallytreatable cause of mortality and disability in patients with aneurysmal subarachnoid hemorrhage (SAH). However, to date there is no effective treatment for this entity. The recently demonstrated lack of clinical response to pharmacologic reversal of arterial spasm as a result of SAH has spurred a reassessment of the pathophysiological concepts on DCI that follows SAH. DCI was long believed the consequence of the angiographically visible arterial spasm observed in patients with SAH. Since the measurement of cortical spreading depolarizations (CSD) in patients with SAH, increasing evidence has suggested a role for these phenomena in the pathophysiology of DCI. When inducedin a healthy brain, CSDs are associated with an increasein regional cerebral blood flow that facilitates the delivery ofthe necessary energy substrates for cellular repolarization. In a brain that has been injured, however, CSDs can induce microvascular constriction, or cortical spreading ischemia. This inverse hemodynamic response to CSD was first discovered in an animal model replicating the conditions following SAH, and later demonstrated in patients with SAH. The spreading ischemia leads to energy substrates shortage and hypoxia, resulting in cortical lesions, and may explain similar lesion patterns which occur in SAH patients. This review describes the salient characteristics of CSD and its potential relevance in the pathophysiology, monitoring, and treatment of ischemic complications following SAH.

Chemotherapeutic Agents and the Risk of Ischemia and Arterial Thrombosis.

Numerous chemotherapeutic agents have been associated with the development of ischemia and arterial thrombosis. As newer therapies have been developed to treat cancer, some of these chemotherapy drugs have been implicated in the development of vascular disease. In this review, we will summarize the most common chemotherapeutic drug classes that may play a role in the development of ischemic heart disease. Angiogenesis inhibitors, alkylating agents, antimetabolites, antimicrotubules, and proteasome inhibitors have a number of cardiovascular toxicities. The possible mechanisms of action of these drugs leading to ischemic complications are varied but include endothelial dysfunction, platelet aggregation, reduced levels of nitrous oxide (NO), and elevated levels of reactive oxygen species (ROS), and vasospasm. While some drugs act through multiple pathways that result in the development of ischemic heart disease, others such as the antimetabolites and antimicrotubules appear to primarily cause vasospasm. Furthermore, while aromatase inhibitors increase the risk of heart disease in comparison to tamoxifen in large studies, this finding likely occurs because of a protective role of tamoxifen on cardiovascular risk factors rather than a direct effect of aromatase inhibitors. Angiogenesis inhibitors, alkylating agents, antimetabolites, antimicrotubules, and proteasome inhibitors can lead to ischemic complications in patients with cancer. Many of these drugs have proven to be effective in improving cancer prognosis, but their possible cardiovascular effects have to be carefully monitored and treated. Treatment of ischemic complications in the setting of cancer therapy should focus on the optimal medical management of known cardiovascular risk factors and follow an evidence-based approach.

The Utility of Platelet and Coagulation Testing of Antithrombotics: Fusing Science with Patient Care

Strategy, Management and Health PolicyEnabling Technology, Genomics, ProteomicsPreclinical ResearchPreclinical Development Toxicology, Formulation Drug Delivery, PharmacokineticsClinical Development Phases I-III Regulatory, Quality, ManufacturingPostmarketing Phase IV There is an increasing need for the standardization of platelet function and coagulation testing for the assessment of antithrombotic therapies. Investigators continue to strive to identify ideal laboratory testing and monitoring procedures for acquired and inherited platelet function defects as well as for evaluating patient status when treated with existing or emerging antithrombotics. These therapies are used primarily in the treatment of ischemic complications. In patients receiving antithrombotic therapy, the balance between hemostasis and thrombosis is a challenge as there is an ongoing risk for bleeding when patients are receiving antiplatelet agents or anticoagulants to lessen their risk for secondary thrombotic events. There are several diverse tests for monitoring anticoagulant therapy; however, as new agents are developed, more specific tests will be required to directly assess these agents in relationship to overall coagulation status. Research in the platelet biology field is ongoing to provide point-of-care methodologies for the assessment of platelet reactivity in terms of both bleeding and thrombosis risk. Currently there are no instruments that reliably assess the risk of bleeding. The challenges that routinely faced are the complexity of physiology, the need for standardization of platelet testing methodology, and the necessity for appropriate interpretation of the test results.