What do you do with the antiplatelet agents in patients with drug eluting stents who then receive a mechanical valve?

Dual antiplatelet therapy (DAT) with aspirin and clopidogrel is a cornerstone of treatment during and after percutaneous coronary interventions with drug-eluting stent (DES) implantation. Oral anticoagulation (OAC) is the recommended treatment for patients with mechanical heart valves. When patients with DES need a mechanical heart valve or vice versa, we face the difficult choice of their antithrombotic therapy. Different institutions empirically follow a combination of OAC and single or DAT, the so-called triple antithrombotic therapy (TT) aiming to find the best balance between the thrombotic and bleeding risk for this subset of patients. A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether there is an optimal antithrombotic management for patients with DES undergoing mechanical heart valve or vice versa. Altogether, more than 148 papers were found using the reported search, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that DES implantation in patients who could potentially need valve surgery in the future should be discouraged and bare-metal stent or an aortic bioprosthesis preferred. However, in high-risk patients with DES, the recommendation is to postpone elective surgery for 1 year and, if surgery cannot be deferred, continue aspirin during the perioperative period. Moreover, when OAC is given in combination with clopidogrel and/or low-dose aspirin, the target INR should be 2.0-2.5 (Class IIb, level of evidence C). As per the long-term management, antithrombotic management with DAT alone in mechanical aortic valve replacement might be possible, but there is not enough evidence to support it. The available evidence suggests that triple anticoagulation (OAC + DAT) is associated with the best clinical outcome compared with all the other possible strategies. The duration of TT should be 3 months after sirolimus DES implantation, and 6 months after paclitaxel DES implantation, followed by long-term therapy with OAC plus clopidogrel or aspirin with either PPIs, or H2-receptor antagonists (Class IIa Level of Evidence C).