Anticoagulation in patients with atrial fibrillation undergoing coronary stent implantation

A new article in the September 2013 issue of Thrombosis and Haemostasis strives to shed light on the optimal antithrombotic strategy in patients suffering from atrial fibrillation who undergo coronary stent implantation. This article shows that oral anticoagulation in patients with atrial fibrillation and high thromboembolic risk after stent implantation indeed lowers the risk of subsequent death, stroke and systemic thromboembolism. Yet when it comes to antithrombotic therapy, apparently guidelines are neglected.

The ideal antithrombotic strategy in patients with atrial fibrillation (AF) undergoing coronary stent implantation is still subject to some debate. Nevertheless, patients at low risk of stroke in general receive dual antiplatelet therapy, obviating the need for regular monitoring, while those at high risk theoretically would be better off with long-term oral anticoagulants. Triple therapy, consisting of oral anticoagulation, aspirin as well as clopidogrel at the initial phase, seemed the best option, but is associated with high bleeding rates. For patients with AF at low to intermediate risk of stroke, a dual antiplatelet therapy regime rather than triple therapy has also been suggested during the first months after placement of an intracoronary stent. In high-risk AF patients, oral anticoagulation is recommended to reduce the risk of stroke and thromboembolism. Recent guidelines have extended indications for oral anticoagulation to AF patients with one or more stroke risk factors.

By gathering observational data from a large cohort, Laurent Fauchier, MD, PhD, Professor of Cardiology, Trousseau University Hospital, Tours, France, and his colleagues wanted to find out whether oral anticoagulation at hospital discharge goes along with benefits in morbidity and mortality. They found that 23% of 417 investigated AF patients who underwent stent implantation received vitamin K antagonists when leaving the clinic. Oral anticoagulants were only used in a minority of patients in spite of their clinical benefit and dual antiplatelet therapy was the most common strategy in these patients (70%). The lack of oral anticoagulation at discharge, however, was independently associated with an increased risk of death, stroke and systemic thromboembolism, with older age, heart failure and a history of stroke. In short, oral anticoagulation lowered the risk of subsequent death or stroke in the afflicted. In turn, the authors concluded that oral anticoagulation should be systematically used in this patient population. He further noted that adherence to recent guidelines about management of oral anticoagulation is low in the afflicted. Thus the author urged that efforts be made to improve adherence to most recent guidelines in this patient subset, in particular since oral anticoagulation did not lead to a significantly higher risk of severe or major bleeding in this group of patients. He also pointed out that today new agents have become available which should facilitate decision-making as they are easier to use and at least as effective as vitamin K antagonists in reducing stroke rate and systemic embolism, but at the same time go along with lower major hemorrhage rates. These molecules may also be promising for AF patients with stent implantation.

In summary, the current paper demonstrates the necessity for a wider use of oral anticoagulation, as proposed in recent guidelines, in these patients because it was independently associated with a decreased risk of subsequent cardiovascular events. More needs to be done to improve outcomes in patients with AF undergoing coronary stenting.