Elevated plasma concentrations of lipoprotein(a) [Lp(a)] are an independent, and possibly causal, risk factor for atherothrombotic diseases including coronary heart disease. The principal evidence base for this comes from large population studies focusing on first atherothrombotic events. However, inconsistent findings have been reported from studies investigating the impact of elevated Lp(a) on atherothrombotic events in subjects with preexisting cardiovascular disease. This question is very important because the secondary prevention population is recommended for Lp(a) screening by some guidelines and could be an important target group for Lp(a)-lowering therapies that are currently on the horizon. In this review, we survey the secondary prevention literature as it relates to Lp(a) and identify some possible confounding factors that may underlie the inconsistent findings, such as index event bias.