<qa>  What is the main study of the UMPIRE clinical trial?PESCA is a substudy of the UMPIRE clinical trial which is evaluating a polypill treatment strategy for subjects with established cardiovascular disease or at high risk. All PESCA subjects will have already been recruited to UMPIRE and randomised to taking either a single polypill comprising low dose aspirin, a cholesterol-lowering statin, and one of two blood pressure lowering medicines or their usual treatment consisting of similar medication in more than one separate tablets. 