Lack of association of plasma factor XI with incident stroke and coronary heart disease: The Atherosclerosis Risk in Communities (ARIC) Study

Background and aims: An elevated plasma concentration of intrinsic coagulation factor XI is a risk factor for venous thromboembolism, but its role in the etiology of atherothrombotic outcomes is uncertain. We examined the association of factor XI with incident stroke and coronary heart disease in the prospective Atherosclerosis Risk in Communities (ARIC) Study. Methods: We measured factor XI on plasma samples collected in 1993-1995 from middle-aged adults (n = 11,439), who were followed through 2012 for incident cardiovascular events. Results: Over a median of 18 years of follow-up (max = 20 years), 722 participants had incident stroke events (631 ischemic and 91 hemorrhagic) and 1776 had incident coronary events. Although there were weak positive associations between factor XI and total, ischemic, cardioembolic, and nonlacunar stroke, when adjusted for demographics, further adjustment for other stroke risk factors eliminated the associations. Similarly, there was no independent association of factor XI with incident coronary heart disease events. Conclusion: A higher basal factor XI concentration in the general population was not a risk marker for stroke or coronary heart disease.