In various embodiments methods are provided for identifying a mammal having an elevated risk for an adverse cardiac event (e.g. an MI) and/or determining the prognosis for the mammal. In certain embodiments the methods comprise determining, or causing to be determined, the presence and/or level of antibodies that bind a malondialdehyde acetaldehyde adduct (MAA adduct) in a biological sample from the mammal, where an elevated level of anti-MAA adduct antibodies, as compared to the level found in a normal healthy mammal is an indicator that that said mammal has one or more atherosclerotic lesions and/or is at elevated risk for a myocardial infarction.