Thrombophilia Testing After Ischemic Stroke: Why, When, and What?

Thrombophilia testing is frequently performed after an ischemic stroke, particularly when cryptogenic. However, there is minimal evidence supporting a significant association between most conditions assessed through thrombophilia testing and ischemic stroke, and the rationale for thrombophilia testing in many clinical situations remains uncertain. In this topical review, we review and contextualize the existing data on the risks, predictors, and outcomes of thrombophilic conditions in patients with ischemic stroke. We report that inherited thrombophilias have an uncertain relationship with ischemic stroke. Conversely, antiphospholipid syndrome, an acquired immune-mediated thrombophilia, seems to be a strong risk factor for arterial thromboembolic events, including ischemic stroke, and especially among young patients. Our findings suggest that certain circumstances may warrant targeted thrombophilia testing, such as stroke in the young, cryptogenic stroke, and high estrogen states. Future prospective studies should investigate the utility and cost effectiveness of thrombophilia testing in various stroke settings, including among patients with patent foramen ovale; as well as the optimal secondary stroke prevention regimen in patients with confirmed thrombophilia, particularly if no other potential stroke mechanism is identified.