We will also determine if there are associations between any preoperative or postoperative medications and major perioperative vascular events. We will also determine if there are associations between any medications started after a major perioperative vascular event and vascular mortality 1 year after surgery. We will evaluate the 1 year risk of stroke in patients who do and do not develop atrial fibrillation after surgery and if there is an association with antiplatelet or warfarin therapy. We will measure N-terminal prohormone brain natriuretic peptide (NT-proBNP) in 8,000 - 10,000 patients prior to surgery and determine if NT-proBNP is an independent predictor of major perioperative vascular events. We will determine the incidence of perioperative new acute renal failure requiring dialysis and pneumonia and develop models to predict these events.