Aspirin and antiplatelet agents.docx

1、Aspirin and antiplatelet agentsAspirin and antiplatelet agentsAspirin has been in and out of the headlines for decades and remains a hugely popular drug 110 years after it was first patented. While its use in the treatment of pain and fever has diminished, due to the availability of non-steroidal an

2、ti-inflammatory drugs (NSAIDs) with better safety profiles, aspirin remains the drug of choice for prevention of cardiovascular disease (CVD). The pharmacological basis for the dual anti-inflammatory and antiplatelet activity of aspirin was established in 1971 by John Vane, and more recent research

3、has identified several other mechanisms of action.Despite the widespread use of aspirin for the prevention of CVD, the UK Medicines and Healthcare Products Regulatory Agency has highlighted that aspirin is not licensed for the prevention of heart attacks and strokes in people without a history of va

4、scular disease (primary prevention),1 as the risk of having a major bleed with aspirin may outweigh any vascular benefit.2 Aspirin is only licensed in the UK for the prevention of thrombotic cerebrovascular and cardiovascular disease in people who already have vascular disease (secondary prevention)

5、.1Most recently, research has focused on a possible role for aspirin in the prevention of cancer. In February 2010, the Journal of Clinical Oncology published a prospective observational study showing that aspirin may reduce the risk of death from breast cancer.3 And a recent meta-analysis of cancer

6、-related deaths in randomised controlled trials of aspirin for prevention of vascular disease found a 21% reduction in the odds of death from cancer in people taking aspirin for almost six years (OR 0.79, 95% CI 0.68 to 0.92; p = 0.003).4 However, the ever-present risk of serious bleeding means that

7、 the risk-benefit ratio remains uncertain.5This special collection on aspirin and other antiplatelet agents brings together over 20 Cochrane Reviews addressing the use of such agents in the prevention and treatment of CVD. The collection also includes Cochrane Reviews on the prevention of cancer, an

8、d the treatment of infertility and recurrent miscarriage, dementia and renal disease. The Cochrane Reviews in this collection have been prepared by a broad range of Cochrane Review Groups and their authors, including the Colorectal Cancer Group, the Dementia and Cognitive Improvement Group, the Mens

9、trual Disorders and Subfertility Group, the Pregnancy and Childbirth Group, the Peripheral Vascular Diseases Group, the Renal Group, the Stroke Group, the Heart Group and the Haematological Malignancies Group.Cancer preventionNon steroidal anti-inflammatory drugs (NSAID) and aspirin for preventing c

10、olorectal adenomas and carcinomasThere is evidence from experimental animal studies and from prospective and retrospective observational studies that NSAIDs may reduce the development of sporadic colorectal adenomas and cancer and may induce the regression of adenomas in familial adenomatous polypos

11、is. This review evaluates the effect of NSAIDs for the prevention or regression of colorectal adenomas and cancer.DementiaAspirin for vascular dementiaAspirin is widely prescribed for patients with a diagnosis of vascular dementia; in one study, completed by geriatricians and psychiatrists in the UK

12、, 80% of patients with clinical diagnoses of vascular dementia were prescribed aspirin. However, a number of queries remain unanswered. Is there convincing evidence that aspirin benefits patients with vascular dementia? Does aspirin affect cognition, behaviour or improve prognosis? In addition, does

13、 the risk of cerebral or gastric haemorrhage outweigh any benefit? This review assesses the evidence of effectiveness of the use of aspirin for vascular dementia.Fertility and pregnancyLow-dose aspirin for in vitro fertilisationLow-dose aspirin is sometimes used to improve outcomes in women undergoi

14、ng in vitro fertilisation, despite inconsistent evidence of efficacy and the potential risk of significant side-effects. The most appropriate time to commence aspirin therapy and the length of treatment required are also still to be determined. This review aims to determine the effectiveness of low-

15、dose aspirin for improving the outcome of in vitro fertilisation and intracytoplasmic sperm injection treatment cycles.Prevention of recurrent miscarriage for women with antiphospholipid antibody or lupus anticoagulantSeveral treatments have been proposed to improve pregnancy outcome in recurrent pr

16、egnancy loss associated with antiphospholipid antibody. Small studies have not resolved uncertainty about benefits and risks. This review examines the outcomes of all treatments given to maintain pregnancy in women with prior miscarriage and antiphospholipid antibody.Aspirin or anticoagulants for tr

17、eating recurrent miscarriage in women without antiphospholipid syndromeSince hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained recurrent m

18、iscarriage. In this review, the efficacy and safety of anticoagulant agents, such as aspirin and heparin, are evaluated in women with a history of at least two miscarriages without apparent causes other than inherited thrombophilia.Antiplatelet agents for preventing pre-eclampsia and its complicatio

19、nsPre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypothesis that antiplatelet agents, low-dose aspirin in particular, m

20、ight prevent or delay development of pre-eclampsia. This review aims to assess the effectiveness and safety of antiplatelet agents for women at risk of developing pre-eclampsia.Renal diseaseMedical adjuvant treatment to increase patency of arteriovenous fistulae and graftsEnd-stage renal disease (ES

21、RD) patients often require the formation of an arteriovenous (A-V) fistula or an A-V interposition prosthetic shunt for haemodialysis. This review assesses the effects of adjuvant drug treatment on the patency of fistulae and grafts in patients with ESRD who are undergoing haemodialysis by assessing

22、 the number of thrombotic episodes.Interventions for preventing and treating kidney disease in Henoch-Schnlein Purpura (HSP)Henoch-Schnlein purpura (HSP) is a primary small-vessel vasculitis. Glomerulonephritis is one of the major complications of HSP. This review evaluates the benefits and harms of

23、 various agents (used singularly or in combination) used for the prevention or treatment of kidney disease in patients with HSP.Interventions for haemolytic uraemic syndrome and thrombotic thrombocytopenic purpuraHaemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) are rel

24、ated conditions with similar clinical features of variable severity. Survival of patients with HUS and TTP has improved greatly over the past two decades with improved supportive care for patients with HUS and by the use of plasma exchange with fresh frozen plasma for patients with TTP. Separate pat

25、hogenesis of these two disorders has become more evident, but management overlaps. This review evaluates the benefits and harms of different interventions for HUS and TTP separately, in patients of all ages.Stroke and CVD preventionPrimary prevention in high-risk groupsAntiplatelet therapy for preve

26、nting stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacksNon-valvular atrial fibrillation (AF) carries an increased risk of stroke mediated by embolism of stasis-precipitated thrombi originating in the left atrial appendage. The va

27、lue of antiplatelet therapy for primary stroke prevention in patients with non-valvular AF merits consideration because of the suspected cardioembolic mechanism of most strokes in AF patients. This review assesses the efficacy and safety of long-term antiplatelet therapy for primary prevention of st

28、roke in patients with chronic non-valvular AF.Oral anticoagulants versus antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no history of stroke or transient ischemic attacksNon-valvular atrial fibrillation (AF) carries an increased risk of stroke. Prima

29、ry stroke prevention in patients with non-valvular AF potentially merits consideration because of the suspected cardio-embolic mechanism of most strokes in AF patients. The aim of this review is to characterise the relative effect of long-term oral anticoagulant treatment compared with antiplatelet

30、therapy on major vascular events in patients with non-valvular AF and no history of stroke or transient ischaemic attack.Antiplatelet agents and anticoagulants for hypertensionAlthough elevated systemic blood pressure results in high intravascular pressure, the main complications (coronary heart dis

31、ease, ischaemic strokes, peripheral vascular disease) are related to thrombosis rather than haemorrhage. Some complications related to elevated blood pressure, heart failure and atrial fibrillation, are themselves associated with stroke and thromboembolism. Use of antithrombotic therapy may be parti

32、cularly useful in preventing thrombosis-related complications of elevated blood pressure. This review evaluates the role of antiplatelet therapy and anticoagulation in patients with high blood pressure.Antiplatelet agents versus control or anticoagulation for heart failure in sinus rhythmMorbidity a

33、nd mortality in patients with symptomatic chronic heart failure are high, and the condition predisposes to stroke and thromboembolism, which in turn contribute to high mortality in heart failure. This review determines the effect of antiplatelet agents when compared with placebo or anticoagulant therapy on de