Lipoprotein-associated phospholipase A2 and prognosis after myocardial infarction in the community

Objective - We evaluated the role of lipoprotein-associated phospholipase A(2) ( Lp- PLA(2)), an inflammatory biomarker, in defining risk after myocardial infarction ( MI). Methods and Results - Olmsted County, Minn, residents who experienced an MI meeting standardized criteria between 2003 and 2005 ( n = 271) were prospectively identified and followed. Lp- PLA2 levels were measured at baseline and evaluated along with traditional risk indicators. Lp- PLA2 was modestly associated with total and low-density lipoprotein cholesterol, smoking, and age ( inversely) but not with MI characteristics or severity, comorbidities, C- reactive protein, or the time from symptom onset to blood sampling. During the first year of follow- up, 42 deaths occurred. The survival estimates ( 95% confidence intervals [ CI]) at 1 year were 92% ( 86% to 98%), 85% ( 78% to 93%), and 74% ( 65% to 84%) in the lowest, middle, and upper Lp- PLA(2) tertiles, respectively ( P = 0.007). After adjustment for age and sex, the hazard ratios for death in the middle and upper Lp- PLA(2) tertiles were 2.20 ( 95% CI: 0.88 to 5.54) and 4.93 ( 95% CI: 2.10 to 11.60), compared with the lowest tertile, respectively ( P-trend < 0.001). Further adjustment for other risk indicators resulted in even stronger associations. Lp- PLA(2) also contributed to risk discrimination as indicated by the increases in the area under the receiver operating characteristic curves obtained in each of the models examined ( all P <= 0.05). Conclusions - Among community subjects presenting with MI, increased Lp- PLA(2) levels measured early after MI are strongly and independently associated with mortality and provide incremental value in risk discrimination over traditional predictors.