Real-world experience of drug-eluting stents in saphenous vein grafts compared to native coronary arteries: results from the prospective multicenter German DES.DE registry - Akın, Ibrahim; Wiemer, Marcus; Schneider, Steffen; Senges, Jochen; Hochadel, Matthias; Richardt, Gert; Abdel-Wahab, Mohamed S.; Kuck, Karl-Heinz; Nienaber, Christoph (Clinical research in cardiology, 2012)