Abstract 4032: Lipoprotein-Associated Phospholipase A2 and Prognosis After Myocardial Infarction in a Geographically Defined Cohort
Background- Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a useful inflammatory marker of cardiovascular disease risk in healthy individuals, yet its role in defining risk after myocardial infarction (MI) is not clear.
Methods and Results- Olmsted County (Minnesota) residents who experienced an MI meeting standardized criteria between 2003 and 2005 (n=271, mean age±SD 69±15 years) were prospectively identified and followed. Lp-PLA2 levels were measured at baseline (mean±SD 43±39 hours post-MI), and evaluated along with traditional risk factors, comorbidities, C-reactive protein (CRP), and MI characteristics. Lp-PLA2 was modestly associated with total and LDL cholesterol, smoking, and age (inversely), but not with MI characteristics or severity, comorbidities, CRP, or the time from symptom onset to blood sampling. During the first year of follow-up, 42 deaths occurred. The Kaplan-Meier survival estimates (95% CI) at one year were 84% (79– 88%) overall, and 92% (86–98%), 85% (78–93%), and 74% (65– 84%) in the lowest, middle, and upper Lp-PLA2 tertiles, respectively (P=0.007 for equality of survival distributions). After adjustment for age and sex, the hazard ratios (HR) for death in the middle and upper Lp-PLA2 tertiles were 2.20 (95% CI: 0.88–5.54) and 4.93 (95% CI: 2.10–11.60), compared with the lowest tertile, respectively (Ptrend<0.001). Further adjustment for other risk indicators resulted in even stronger associations (Table⇓).Lp-PLA2 also contributed to risk discrimination as indicated by the increases in the area under the ROC curves obtained in each of the models examined (Table⇓).
Conclusions- Among community subjects presenting with MI, increased Lp-PLA2 levels measured early after MI are strongly and independently associated with mortality, and provide incremental value in risk discrimination over traditional predictors.