Is lipoprotein(a) a risk factor for ischemic stroke and venous thromboembolism?

The structural similarity with plasminogen as well as thrombogenic and atherogenic in vitro functions raise the question if lipoprotein(a) (Lp(a)) is a risk factor for venous thromboembolism (VTE) and ischemic stroke. Numerous case-control and prospective studies using different cut-off values to define high Lp(a) generated conflicting evidence for both VTE and ischemic stroke. Several meta-analyses demonstrated independent associations of elevated Lp(a) with a history of VTE or ischemic stroke. However, the evidence of prospective studies for associations of Lp(a) with incident stroke or recurrent VTE remains inconclusive. For ischemic stroke, data suggest that Lp(a) increases the risk of large-artery atherosclerosis stroke, but not cardioembolic or lacunar stroke. Lp(a) may increase the risk of VTE in the presence of additional thrombophilic risk factors. Larger cohort studies are needed to elaborate the importance of higher Lp(a) cut-offs and interactions with other risk factors and subgroups of stroke or VTE. The value of Lp(a) to estimate residual vascular risk after the first thromboembolic event remains to be adequately explored.