Some complications related to elevated blood pressure, heart failure or atrial fibrillation, are themselves associated with stroke and thromboembolism. Therefore it is important to investigate if antithrombotic

therapy may be useful in preventing thrombosis-related complications in patients with elevated blood pressure.\n\nObjectives\n\nTo conduct a systematic review of the role of antiplatelet therapy and anticoagulation in patients with high blood pressure, including those with elevations in both systolic and diastolic blood pressure, isolated elevations of either systolic or diastolic blood pressure, to address the following hypotheses: (i) antiplatelet agents reduce total deaths and/or major thrombotic events when compared to placebo

or other active treatment; and (ii) oral anticoagulants reduce total deaths and/or major click here thromboembolic events when compared to placebo or other active treatment.\n\nSearch methods\n\nElectronic databases (MEDLINE, EMBASE, DARE, CENTRAL, Hypertension Group specialised register) were searched up to January 2011. The reference lists of papers resulting from the electronic searches and abstracts from national and international cardiovascular meetings were hand-searched to identify missed or unpublished studies. Relevant authors of studies were contacted to obtain further data.\n\nSelection criteria\n\nRandomised controlled trials (RCTs) in patients with elevated blood pressure were included if they were of at least 3 months in duration and compared antithrombotic therapy with control selleck compound or other active treatment.\n\nData collection and analysis\n\nData were independently collected and verified by two reviewers. Data from different trials were pooled where appropriate.\n\nMain results\n\nFour trials with a combined total of 44,012 patients met the inclusion criteria and are included in this review. Acetylsalicylic acid (ASA) did not reduce stroke or ‘all cardiovascular events’ compared to placebo in primary prevention

patients with elevated blood pressure and no prior cardiovascular disease. In one large trial ASA taken for 5 years reduced myocardial infarction (ARR 0.5%, NNT 200), this website increased major haemorrhage (ARI 0.7%, NNT 154), and did not reduce all cause mortality or cardiovascular mortality. In one trial there was no significant difference between ASA and clopidogrel for the composite endpoint of stroke, myocardial infarction or vascular death.\n\nIn two small trials warfarin alone or in combination with ASA did not reduce stroke or coronary events.\n\nThe ATC meta-analysis of antiplatelet therapy for secondary prevention in patients with elevated blood pressure reported an absolute reduction in vascular events of 4.1% as compared to placebo. Data on the 10,600 patients with elevated blood pressure from the 29 individual trials included in the ATC meta-analysis was requested but could not be obtained.