Platelets are circulating cell fragments known to clump up and form blood clots that stop bleeding in injured vessels. Cardiologists have long known that platelets can become "hyperreactive" to cause abnormal clotting that blocks arteries and contributes to heart attack, stroke, and poor blood flow (peripheral artery disease) in the legs of millions of Americans. Despite this major contribution to , routine measurement of whether each patient's clump (aggregate) too much has been infeasible to date.

This is because results delivered by the method typically used to determine platelet activity, called platelet aggregometry, vary too much from lab to lab. To address this challenge, a new study led by researchers at NYU Grossman School of Medicine has precisely identified a group of patients with platelet hyperreactivity, and then surveyed them to reveal 451 genes, the activity of which differed significantly in those with hyperreactive platelets versus those without. Publishing in , the research team then used bioinformatics to assign a weight to each genetic difference and generate each patient's Platelet Reactivity ExpresSion Score (PRESS).

"Our results demonstrate that our new platelet-centric scoring system can, for the first time and across populations, circumvent aggregometry to reliably predict platelet hyperreactivity and the related risk of cardiovascular events," said corresponding study author Jeffrey Berger, MD, director of the Center for the Prevention of Cardiovasc.