In patients with ischemic heart disease, prophylactic low dose aspirin prevents arterial thrombosis by irreversible inactivation of platelet aggregation.[1][2][3][4]
Aspirin induces an irreversible functional defect in platelets by inhibiting cyclo oxygenase (COX-1) and subsequently suppressing the activation of thromboxane A2 that is responsible for platelet aggregation.[5]
In patients with chronic stable angina, prior MI and unstable angina, aspirin improves survival and prevents infarction.[4]
Aspirin has shown to improve endothelial function and at high doses reduce acute phase reactants.
Use of warfarin in conjunction with aspirin and/or clopidogrel is associated with an increased risk of bleeding and therefore, close monitoring is required.
Meta-analysis (2002) of 140,000 patients from the Antiplatelet Trialists’ Collaboration showed that aspirin (75-325 mg/day) reduced the rate of subsequent myocardial infarction, stroke, and death in patients with history of angina pectoris, myocardial infarction, CABG, and stroke.[4]
Meta-analysis (2000) of 24 randomized controlled trials involving 66,000 patients showed significant increase in the incidence of gastrointestinal hemorrhage associated with long term aspirin therapy. There was no supportive evidence of lower dose or modified release formulations reducing the incidence of GI bleed.[8]
In the Swedish Angina Pectoris Aspirin Trial (SAPAT) (1992), aspirin (75 mg/day) in conjunction with the beta blocker sotalol conferred an additional 34% reduction in acute myocardial infarction and sudden cardiac death among men and women with chronic stable angina.[9]
2012 Chronic Angina Guidelines for the Management of Patients With Chronic Stable Angina (DO NOT EDIT)[10][11][12]
"1. Treatment with aspirin 75 to 162 mg daily should be continued indefinitely in the absence of contraindications in patients with SIHD. (Level of Evidence: A) "
"1. Treatment with aspirin 75 to 162 mg daily and clopidogrel 75 mg daily might be reasonable in certain high-risk patients with SIHD (Level of Evidence: B) "
ESC Guidelines- Pharmacological Therapy to Improve Prognosis in Patients with Stable Angina (DO NOT EDIT) [13]
"1.Aspirin 75 mg daily in all patients without specific contraindications (i.e. active GI bleeding, aspirin allergy, or previous aspirin intolerance). (Level of Evidence: B) "