Thus, it may inhibit fibrino- lysis, binding to the catalytic complex of plasminogen, tis- sue plasminogen activator, and fibrin, thereby contributing Meschia et al Guidelines for the Primary Prevention of Stroke 3793 Some, but not all, population-based epidemiological stud- ies have found that Lp(a) is associated with an increased risk In the Physicians Health Study, which com- prised primarily healthy, white, middle-aged men, there was no association between baseline plasma concentration of Lp(a) and future risk of stroke.804 In the CHS, the risk of stroke was increased 3-fold (RR, 3.00; 95% CI, 1.59 5.65) in older men whose Lp(a) levels were in the highest quintile compared with men with levels in the lowest quintile but not older women.801 In the ARIC study, the incidence of ischemic stroke was sig- nificantly increased in individuals with higher Lp(a) levels after adjustment for age, sex, and CVD risk factors, and this associa- tion was stronger in blacks than in whites. Compared with those with Lp(a) <10 mg/dL, the incidence of ischemic stroke was 2.12-fold greater (RR, 2.12; 95% CI, 1.48 3.03) in blacks with Lp(a) >30 mg/dL. 