"Optimal Duration of Dual Antiplatelet Therapy after Drug-Eluting Stent Implantation: A Randomized Controlled Trial"  
Circ Oct 4
http://circ.ahajournals.org/content/early/2013/10/04/CIRCULATIONAHA.113.003303.abstract
"Conclusions—Among patients who were on 12-month dual antiplatelet therapy without complications, an additional 24 months of dual antiplatelet therapy versus aspirin alone did not reduce the risk of the composite end point of death from cardiac causes, myocardial infarction or stroke."