Dr Gregory Hundley:       Welcome everyone to the June 18th edition of Circulation on the Run. I am Dr Greg Hundley, Professor of Internal Medicine and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia.                                                 In today's issue we're deviating from our common format due to some scheduling difficulties. So, rather than our traditional coffee chat in this program I'm going to have a large gulp of coffee and present results from several exciting papers. Then we'll turn over the second half of our program to Dr Carolyn Lam for our feature discussion.                                                 Now, I promise this is a one-time deviation and we will return to our common chat format in early July. But, before I launch into my presentations I did want to introduce what will transpire with Carolyn. She will be discussing an exciting paper from the Adelaide Medical School at the University of Adelaide in Australia.                                                 Some have wondered whether the persistence of a patent arterial venous fistula post-kidney transplant may contribute to ongoing maladaptive cardiovascular remodeling. To address this issue Carolyn will be discussing with authors whether ligation of this AV fistula may reverse this maladaptive remodeling. And like you, I'm excited to listen to that discussion. But before that let me review several of the other distinctive papers on this issue.                                                 The first one is entitled “Individual Treatment Effect Estimation of Two Doses of Dabigatran on Stroke and Major Bleeding in Atrial Fibrillation.” They are the results from the RE-LY trial. The corresponding author is Professor Frank Visseren from the University Medical Center of Utrecht in Utrecht University.                                                 The study emanates from the randomized evaluation of long-term anticoagulation therapy or the RE-LY trial. In which high dose dabigatran, that's 150 milligrams twice daily, was found more effective in prevention of ischemic stroke and systemic embolism than low dose dabigatran which is 110 milligrams twice daily.                                                 But this occurred at that expense of an increased risk of gastrointestinal bleeds. Importantly however, the absolute treatment effect of dabigatran in both doses, likely differs between individuals. And therefore, individual treatment effect estimation has the potential to identify patients who have a favorable trade off and absolute benefit and harm from dabigatran compared with no treatment, and to select the optimal dose for each individual patient.                                                 So in this study, the investigative team derived and validated a prediction model for ischemic stroke and systemic embolism and major bleeding in patients with atrial fibrillation from three treatment arms of the RE-LY study. They had 11,955 individuals in the derivation cohort and 6,158 in the validation cohort. And they evaluated the patient characteristics of sex, age, smoking, anti-platelet drugs, prior vascular disease, diabetes, blood pressure, estimated glomerular filtration rate, and hemoglobin. Dr Gregory Hundley:       Well, what were the results? Well the five-year absolute risk reduction, for ischemic stroke and systemic embolus minus the five-year absolute risk increase for major bleeding, when comparing the high to the low dose of dabigatran yielded a net benefit in 46% of patients. And therefore, the authors conclude that the absolute treatment benefits and harms of dabigatran in atrial fibrillation can be estimated based on readily available patient characteristics.                                                 And perhaps down the road such treatment effect estimations can be used for shared decision making before starting dabigatran treatment and to determine its optimal dose of administration. W