Method Study part 1. Patients suffering from premature CAD who have had a percutaneous coronary intervention (PCI) or coronary artery bypass graft operation (CABG) done before the age of 40 years will be selected from the West Denmark Heart Registry (VDHD). Specifically, patients treated at Aarhus University Hospital (AUH) in Skejby for myocardial infarction (MI), stable or unstable angina pectoris in the period of January 1st 2007 - December 31st 2013 will be recruited and the occurrence of registered risk factors be evaluated (sample indicates app. 170 patients per year). After informed consent is obtained, they will participate in this research study. Participants will be interviewed in the cardiac outpatient clinic at the Dep. of Cardiology, AUH, Skejby. The following information about cardiovascular risk factors will be collected; family history of atherosclerosis (a pedigree analysis will be performed and cases of diagnosed CVD will be identified), prior medical history (i.e. hypertension, dyslipidemia, diabetes, chronic kidney disease, vascular disease), smoking status and number of pack years, alcohol consumption and vascular symptoms (i.e. angina pectoris, intermittent claudication). Gathered information will be compared to the registered information in patient records and VDHD. In addition, information about localization of the invasive treatment, the degree of CAD, and the latest estimate of the left ventricular ejection fraction (LVEF) will be collated. All patients will be examined regarding height and weight, abdominal girth and a blood sample is collected. An automated office blood pressure measurement (Bp-TRU device) will be performed. Levels of creatinine (e-GFR), total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and HbA1c will be measured. Further, a blood sample will be saved for prospective DNA analysis (below). The investigators will evaluate to what degree the treatment targets have been met in accordance with national guidelines. Analysis will be corrected to reflect changes in these treatment guidelines, which have occurred in recent years.