The outcome after percutaneous coronary intervention (PCI) has improved considerably thanks to more effective antithrombotic treatment strategies and improved coronary stents. Stent thrombosis (ST) is a rare complication to PCI associated with considerable mortality and morbidity. The general aim of this thesis was to add real-world evidence for antithrombotic and technical strategies in invasive treatment of coronary artery disease. Five observational studies were performed on a large, unselected, real-world population undergoing PCI. All studies were based on data from the national registry SWEDEHEART. In 31,258 patients undergoing PCI for ST-elevation myocardial infarction (STEMI), the rate of definite early ST was low (0.84%, n=265) but ST was associated with very high mortality (21%, n=51) at one year. Among 20,600 patients with STEMI, we compared the outcomes for those treated with heparin and those treated with bivalirudin during PCI. Rates of ST were low and similar with heparin and bivalirudin but all-cause mortality at 30 days and one year was significantly higher with heparin. We found no differences in rates of major bleeding, re-infarction and stroke. A novel bioresorbable scaffold (Absorb), used in patients undergoing PCI for all indications, was associated with a four- to eightfold higher adjusted rate of definite ST over two years, compared with conventional modern drug-eluting stents (DES). One in four ST events occurred later than one year after PCI. Rates of in-stent restenosis were comparable with Absorb and DES. Suboptimal implantation technique and non-adherence to antiplatelet therapy guidelines was common among patients with bioresorbable scaffold thrombosis. The novel parenteral and potent platelet inhibitor cangrelor was used nearly exclusively in STEMI (n=899), in early presenters with high-risk, often with cardiac arrest (18%) but was associated with low ST rates and no major bleeding events. In an unselected population of 65,000 patients undergoing PCI for all indications, the Xience permanent polymer everolimus eluting stent (n=36,600) appears to be safe and effective with low event rates of ST and in-stent restenosis. Compared with a control group of other modern DES (n=167,000) including a high proportion of thinner struts and absorbable polymers, Xience exhibits similar results in all important endpoints. All studies of this thesis provided important real-world evidence on antithrombotic and technical treatment strategies in invasive management of coronary artery disease.