IgM antibodies against phosphorylcholine measured early after acute ST-elevation myocardial infarction in relation to atherosclerotic disease burden and long-term clinical outcome

by Eva Cecilie Knudsen, Ingebjørg Seljeflot, Tonje Amb Aksnes, Jan Eritsland, Harald Arnesen, Geir Øystein Andersen

Purpose

Studies have reported an association between low levels of natural immunoglobulin M antibodies against phosphorylcholine(IgM anti-PC) and worse prognosis in patients with coronary artery disease (CAD). The aims of the present study were, in patients with ST-elevation myocardial infarction (STEMI); 1) to compare serum levels of IgM anti-PC measured acutely and after 3 months; 2) to study an association between levels of IgM anti-PC and the severity ofCAD, and; 3) to investigate whether IgM anti-PC levels are associated with long-term clinical outcome.

Methods

A total of 213 patients without known diabetes (median age 59 years) with a PCI treated STEMI were enrolled. IgM anti-PC was measured in-hospital and after 3 months. Median follow-up time was 6.5 years (all-cause mortality, non-fatal myocardial re-infarction, recurrent ischemia causing hospital admission, heart failure and stroke). The severity of CAD was evaluated by coronary angiograms and patients were classified as having single- or multi-vessel disease and by SYNTAX score (SXscore).

Results

IgM anti-PC levels were stable over time when measured acutely and after 3 months. Patients with multi-vessel disease and high SXscore had significantly lower levels of IgM anti-PC in the acute phase of STEMI. Low levels of IgM anti-PC (the 25 percentile) measured acutely were associated with a 2-fold increase in the odds of having multi-vessel disease (adjusted OR 2.28 (95% CI 1.17, 4.44), p = 0.016), but not with high SXscore (Crude OR 2.20 (95% CI 0.96, 5.07), p = 0.06). Fifty-three patients experienced a new clinical event during long-term follow-up. Low levels of IgM anti PC were not associated with worse prognosis, (crude HR 1.54 (0.87–2.76), p = 0.14).

Conclusion

STEMI patients with multi-vessel disease or high SXscore had significantly lower levels of IgM anti-PC in the acute phase and low levels were associated with multi-vessel disease, but not with worse clinical outcome during long-term follow-up.