P. Loewen et al., THE EFFICACY AND SAFETY OF COMBINATION WARFARIN AND ASA THERAPY - A SYSTEMATIC REVIEW OF THE LITERATURE AND UPDATE OF GUIDELINES, Canadian journal of cardiology, 14(5), 1998, pp. 717-726
The English-language literature was systematically reviewed to clarify
the role of combination antithrombotic therapy with warfarin and acet
ylsalicylic acid (ASA) versus monotherapy with either agent, including
data from several recently published trials. Sixteen published studie
s with evaluable efficacy and/or safety data were identified. For pati
ents with prosthetic heart valves at high risk of thromboembolism, com
bined warfarin and ASA therapy may be beneficial compared with warfari
n alone. Combination therapy may also be used for primary prevention i
n patients at high risk for ischemic heart disease, although the expec
ted benefits are small. Evidence does not support the use of combined
antithrombotic therapy in patients with established ischemic heart dis
ease, ischemic stroke, coronary artery bypass grafts or atrial fibrill
ation. Combination therapy is associated with an increased risk of min
or and major bleeding. The highest dose of ASA that can be recommended
in combination with warfarin is 100 mg daily.