 Coronary artery intervention with stents is a routine procedure with several clinical indications. A stentfailure, ie stentrestenosis andor stentthrombosis will occur in some patients. Several different mechanisms have been suggested. Stentfailure may be caused by mechanical properties of the stent. This may be secondary to suboptimal stentimplantation, ie overundersizing or acquired ie malapposition or stentfracture. These stentproperties may be difficult to identify with conventional coronary angiography due to low image resolution. The hypothesis of the study is that high resolution imaging with optical coherence tomography oct will improve diagnosis and enable a more specific or tailored treatment with a subsequent reduction in later stentfailure. 