Long-term prognostic value of IgM antibodies against phosphorylcholine for adverse cardiovascular events in patients with stable coronary heart disease.

BACKGROUND

Low concentrations of IgM-phosphorylcholine autoantibodies (IgM-anti-PC) have been shown to be associated with increased risk of incident cardiovascular disease (CVD) events and total mortality in patients suffering from an acute coronary syndrome. We assessed whether IgM-anti-PC concentrations add prognostic information for cardiovascular risk in patients with known stable coronary artery disease (CAD).

METHODS

IgM-anti-PC concentrations were measured in serum obtained from 1062 patients with clinically manifest stable CAD at baseline. The relation of IgM-anti PC concentrations with CVD events during long-term follow-up was assessed by the Kaplan-Meier and life table method and quantified by means of the log-rank test. Then, Cox proportional hazards regression analysis was performed to assess the independent association of IgM anti-PC concentration with risk of secondary CVD events after adjustment for established and emerging risk factors.

RESULTS

In n = 1062 patients with stable CAD only very low IgM anti-PC serum concentrations were associated with increased risk for future fatal and non-fatal coronary events (n = 201 during median of 10 years of follow-up). Among patients with IgM anti-PC concentrations in the lowest decile, the partly adjusted hazard ratio for fatal and non-fatal coronary events was 1.60 (95% confidence interval (CI) 1.01-2.55) compared to the top quartile and 1.94 (95%-CI 1.18-3.18) after adjustment for multiple covariates.

CONCLUSION

In patients with stable CAD, very low concentrations of IgM anti-PC are associated with increased risk for fatal and non-fatal future coronary events and thus may add prognostic information to traditional cardiovascular risk factors among these patients.