This study will investigate the short term angiographic and long term clinical outcome of after implantation of an improved drug eluting coronary artery stent (Everolimus-eluting Platinum Chromium Stent with Abluminal Bioabsorbable Polymer) with shorter post interventional dual antiplatelet therapy (DAPT) in comparison to a conventional drug eluting stent with a permanent Polymer followed by 12 months DAPT for treatment of unprotected left main coronary artery disease