Dr. Robert Hart has long-standing interests in stroke, stroke research, and clinical trials. He has directed several randomized clinical trials serving as the principal investigator of the NIH/NINDS-sponsored Stroke Prevention in A trial Fibrillation (SPAF) I, II and III trials (1987-2000) and has participated in many others (NASCET, TASS, CATS, CAPRIE, EC-IC Bypass, Canadian-American Persantine Trial, STAT, SPARCL, MATCH, PRoFESS). He was the coordinator of the Cerebral Embolism Study Group (1981-1984), Cerebral Embolism Task Force (1986-1996) and Stroke Risk in Atrial Fibrillation Working Group (2005-8). Following completion of the SPAF trials, he continues to serve as the co-principal investigator of the NIH/NINDS-sponsored Secondary Prevention of Small Subcortical Strokes (SPS3) trial. Between 2000 and 2008, he was a special consultant to the NINDS/NIH Clinical Trials Group. He was a member of the Operations and Stroke Advisory Committees of the AVERROES trial testing apixaban in atrial fibrillation. Antithrombotic therapies to prevent stroke in atrial fibrillation and especially novel oral anticoagulants a re areas of special research interest.