Abstract: The invention provides among other things methods and kits based on assaying for cardiac troponin autoantibodies, either in conjunction with an assay for cardiac troponin and/or as an independent indicator of cardiac pathology, such as myocarditis, cardiomyopathy, and/or ischemic heart disease. Assay methods of the invention can be employed among other things to identify cardiac pathology, or risk thereof, in subjects who have an autoimmune disease or who are related to an individual with an autoimmune disease. In particular embodiments, the invention also provides a method of determining whether a subject having, or at risk for, a cardiac pathology is a candidate for immunosuppressive therapy or immunoabsorption therapy. The invention also provides kits and kit components that are useful for performing the methods of the invention.