Antithrombotic therapy in patients with combined coronary heart disease and atrial fibrillation

Coronary heart disease (CHD) and atrial fibrillation (AF) commonly occur together. This presents challenges for the clinician treating patients with CHD, who require antiplatelet therapy and patients with AF, who require oral anticoagulant therapy. We have reviewed PubMed and SCOPUS to identify relevant guidelines, randomised clinical trials and registry studies and clinical trials presented at international meetings, and where necessary, clinical trial protocols to identify and critically analyze all relevant trials in which combinations of oral anticoagulants and antiplatelet agents in patients with AF and CHD have been evaluated. The available evidence on the efficacy and safety of combined oral anticoagulants and anti platelet agents was reviewed for the AF patient in three clinical scenarios: 1) after percutaneous coronary intervention (PCI); 2) after an acute coronary syndrome without PCI; and 3) in stable CHD. In each the clinical scenarios evaluated, there is limited clinical trial evidence to guide clinical management. Guidelines to help the clinician choose the right combinations of warfarin, clopidogrel and aspirin and the duration of treatment have been published, but they are based on a limited evidence base. There is even less evidence to guide the use of new oral anticoagulants (NOACs) in combination with the new P2Y12 antiplatelet agents. In each clinical scenario, the risks of coronary artery or stent thrombosis in CHD and risks of stroke in AF need to be carefully balanced against the risks of bleeding. We make recommendations for management based on the evidence which is available at this time and indicate the many gaps which are currently being addressed by randomized clinical trials.