Can antiplatelet agent be considered as an alternative to OAC in SPAF?
In terms of stroke prevention in AF, the bottom line is effective stroke prevention means oral anticoagulation therapy and these days it can either mean a NOAC (non vit. K oral anticoagulant) or Vit.K antagonist (VKA) e.g. Warfarin because that is where the evidence is clearly there which shows that OAC harpy prevents stroke. Aspirin or anti-platelet therapy had been tested in SPAF (stroke prevention in Atrial fibrillation), and the evidence suggests no significant benefits, there is however evidence of harm i.e. increase in the risk of both major and intracranial bleeding. NICE guidelines in UK, in 2014 which also undertakes a cost effectiveness analysis stated that not only is aspirin ineffective but it is actually not safe and certainly not cost effective. In net clinical benefits for aspirin in SPAF is essentially neutral or trending towards harm. In short, aspirin mono-therapy should be used as Mono-therapy in SPAF.
Can we combine the Oral anticoagulants with anti-platelets in SPAF?
Anti-platelet therapy can be combined with oral anticoagulant therapy essentially in a situation of the patient with AF possesses ACS or undergoes coronary intervention including coronary stenting. In patient with stable vascular disease essentially in majority of patients with AF there is no demonstrated benefit to add anti-platelet therapy to oral anticoagulant therapy because the available data shows that there is no benefit in terms of stroke reduction, morality or myocardial infarction, however, what you do see is a significant increase in major bleeding as well as significant increase in intracranial bleeding when anti platelet therapy is combined with oral anticoagulation.
So in short do not combine anti-platelet therapy and oral anticoagulant therapy in majority of patients of AF as there is little evidence of benefit, there is certainly strong evidence of harm in these patients.
This combination therapy should be reserved when there is a necessity to have associated anti-platelet therapy most commonly after an ACS or a coronary stent intervention.