Lipoprotein-associated phospholipase A2 and its association with cardiovascular outcomes in patients with acute coronary syndromes in the PROVE IT-TIMI 22 (PRavastatin or atorVastatin evaluation and infection therapy-thrombolysis in myocardial infarction) trial

Background-Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is associated with the risk of cardiovascular (CV) events in population-based studies. The prognostic value of Lp-PLA(2) in patients with acute coronary syndromes (ACS) has not been established. Methods and Results-Plasma levels of Lp-PLA(2) activity were measured at baseline (n=3648) and 30 days (n=3265) in patients randomized to atorvastatin 80 mg/d or pravastatin 40 mg/d after ACS in the PROVE IT-TIMI 22 (PRavastatin Or atorVastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction) trial. The primary end point was death, myocardial infarction, unstable angina, revascularization, or stroke (mean follow-up 24 months). At baseline after ACS, the risk of recurrent CV events was similar across all quintiles of Lp-PLA(2) activity (P-trend=0.88). Overall, mean levels of Lp-PLA(2) were lower at 30 days of follow-up than at baseline (35.7 versus 40.9 nmol.min(-1).mL(-1), P<0.001). In particular, treatment with atorvastatin 80 mg/d was associated with a 20% reduction in Lp-PLA(2) activity (P<0.001), whereas Lp-PLA(2) rose 3.6% with pravastatin 40 mg/d (P<0.001). Patients with 30-day Lp-PLA(2) activity in the highest quintile were at significantly increased risk of recurrent CV events compared with those in the lowest quintile (26.4% versus 17.6%, P-trend=0.002). After adjustment for cardiac risk factors, treatments, achieved low-density lipoprotein (LDL), and C-reactive protein, Lp-PLA(2) activity in the highest quintile remained independently associated with a higher risk of recurrent CV events (adjusted hazard ratio 1.33, 95% confidence interval [CI] 1.01 to 1.74). Conclusions-Lp-PLA(2) is not useful for risk stratification when measured early after ACS. At 30 days, Lp-PLA(2) activity is significantly lowered with high-dose statin therapy and is associated with an increased risk of CV events independent of C-reactive protein and LDL cholesterol levels.