Diagnostic and prognostic value of autoantibodies anti-apolipoprotein A-1 and anti-phosphorylcholine in acute non-ST elevation myocardial infarction

Background: Autoantibodies have been shown to play a critical role in predicting major adverse cardiovascular events in atherosclerotic patients. We aimed to assess the diagnostic accuracy of autoantibodies to apolipoprotein A-1 (anti-apoA-1 IgG) and to phosphorylcholine (anti-PC IgM) for non-ST segment elevation acute myocardial infarction (NSTEMI) and to explore their potential prognostic value. Methods: This prospective multicentre study included 1072 patients presenting to the emergency department for suspected NSTEMI. The final diagnosis was adjudicated by two independent cardiologists. For both antibodies alone or expressed as a ratio (anti-apoA-1 IgG/anti-PC IgM), we determined their (i) diagnostic accuracy for NSTEMI and (ii) prognostic accuracy for major adverse cardiovascular events (MACE) during 1-year follow-up. Results: A total of 154 patients (14%) had a final diagnosis of NSTEMI. Diagnostic accuracy for the diagnosis of NSTEMI as quantified by the area under the receiver operating characteristics curve (AUC) was very low for both autoantibodies separately as well as combined as a ratio: AUC anti-apoA-1 IgG 0·50 (95%CI, 0·47-0·53, P = 0·99), AUC anti-PC IgM 0·53 (95%CI, 0·50-0·56, P = 0·30) and AUC of the ratio 0·52 (95%CI, 0·49-0·55, P = 0·47). Adding the anti-apoA-1 IgG/Anti-PC IgM ratio to hs-cTnT did not provide incremental diagnostic value over hs-cTnT alone. MACE occurred in 221 patients (21%) during follow-up. The autoantibodies, separately or expressed as ratio, also had very low accuracy to predict MACE (p=ns). Conclusions: Anti-apoA-1 IgG and anti-PC IgM autoantibodies did not have diagnostic or prognostic value in patients with NSTEMI.