Antiplatelet agents and anticoagulants for hypertension

Anti-platelet therapy with ASA in patients with elevated blood pressure reduces the incidence of myocardial infarction. For primary prevention, the benefit is negated by an increase in major haemorrhage, but for secondary prevention antiplatelet therapy is recommended because the absolute benefit is much greater.

A Cochrane review (abstract , review ) included 4 studies with a total of 44 012 subjects. 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. Based on one large trial (HOT trial), ASA taken for 5 years reduced myocardial infarction (ARR, 0.5%, NNT 200 for 5 years), increased major haemorrhage (ARI, 0.7%, NNT 154), and did not reduce all cause mortality or cardiovascular mortality. There was no significant difference between ASA and clopidogrel for the composite endpoint of stroke, myocardial infarction or vascular death in one trial. In two small trials warfarin alone or in combination with ASA did not reduce stroke or coronary events.

The ATC (Antiplatelet Trialists' Collaboration) 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.

Ədəbiyyat

1. Lip GY, Felmeden DC, Dwivedi G. Antiplatelet agents and anticoagulants for hypertension. Cochrane Database Syst Rev 2011;(12):CD003186. .