Personalised antiplatelet therapy as a secondary prophylaxis of ischemic stroke
What is it about?
Each year, over five million people die worldwide from stroke. One out of four strokes is recurrent placing huge burden on health care system. Despite new evidences on how to best treat patients with ischemic stroke, stroke recurrence remains unacceptably high. Therefore, there is a great need for novel thechnologies and markers to prevent hospital readmissions due to recurrent stroke. A post-stroke care coordination program in the first year after a stroke is vital. Therefore, a personalised clinical pathway ensuring that patients receive personalized treatment and care remotely after discharge is utmost. In our research, we focused on personalised antiplatelet regimens based on genetic information, clinical and platelet characteristics. Post ischemic stroke patients are commonly on antiplatelet therapy (aspirin, clopidogrel monotherapy or dual antiplatelet treatment, DAPT). Despite such interventions, the treatment failure leading to recurrent stroke is often explained by the phenomenon called high-on-treatment platelet reactivity (HTPR). There are many attempts currently being made around the world to make translational research findings usable in clinical settings to achieve individualised antiplatelet therapy. Nevertheless, the recognition of HTPR remained unsolved. Measurement of ex vivo platelet function in patients on antiplatelet therapy would potentially enable physicians to tailor antiplatelet strategies to an individual. As such a new and innovative modification of Electric Impedance Aggregometry measurement was published in Clinical Hemorheology and Microcirculation (Ezer E, et al. A novel approach of platelet function test for prediction of attenuated response to clopidogrel) and in Frontiers in Neurology (Schrick D, et al. Novel predictors of future vascular events in post-stroke patients). The ex vivo platelet aggregation induced by an agonist is expressed by the area under the curve (AUC) detected by Multiplate impedance aggregometer.The measurement was performed not only in the whole blood, but as a novelty from the lower and upper blood fractions separated after 1-hour gravity sedimentation by the analogy with erythrocyte sedimentation rate. Importantly, a greater AUC (≥70 as a cut-off value) from the separated upper blood sample after 1-hour gravity sedimentation emerged as a novel independent predictor of future stroke episodes, while clopidogrel resistance based solely on Multiplate electrode aggregometry from the whole blood was not able to predict recurrent stroke in a prospective, but small study. Based on atomic force microscopy, the more reactive, ascending platelets (presumably detected with greater AUC by Multiplate) were found to be larger in volume, suggesting a link between the function and the size of platelets. In accordance, platelets with a higher mean volume showed an association with high residual platelet reactivity after conventional dual antiplatelet therapy in patients with coronary artery disease reported by others.
Why is it important?
This work highlights that antiplatelet therapy should be guided by novel platelet function test.