Combining oral anticoagulation and antiplatelet therapies: appropriate patient selection

Anticoagulant therapy and antiplatelet therapy are used regularly for prevention of arterial and venous thrombosis, and combinations of the two drug classes are seen with relative frequency in clinical practice. While co-prescribing is as high as 39-55% in some real-world cohort studies, the number of patients that meet criteria for combination therapy based on the overall body of evidence is likely much lower. This may not always be realized by prescribers, and many patients may be continued on long term combination therapies that provide little additional benefit, and carry significant risk for harm. Given the heightened bleeding risk with combination therapies, prescribers should readily reassess the risk: benefit ratio in all patients on combination therapies. Combined antiplatelet and anticoagulant therapy should be used only in those with a low risk of bleeding who have a higher risk of thromboembolic disease events. Most patients with coronary artery disease, atrial fibrillation, peripheral arterial disease, or bioprosthetic cardiac valves will not benefit from combining antiplatelet and anticoagulant therapies. Conversely, patient populations more likely to derive benefit from antiplatelet-anticoagulant combinations include those with mechanical cardiac valves, patients undergoing percutaneous cardiac intervention who have another indication for anticoagulant therapy, and patients with recurrent thrombotic events while being treated with a single agent. This article will attempt to provide readers with a framework to assess which patient populations are likely to derive the greatest benefit with combination anticoagulant-antiplatelet therapies relative to the weighted risk for bleeding.