 Despite the routine use of procedural anti-coagulation and anti-platelet therapy for FFR calculation, no study has evaluated the optimal anti-thrombotic regimen in patients undergoing FFR. Therefore, the aim of the Evaluation of Simplified Anti-Thrombotic Therapy for Coronary Fractional Flow Reserve SMART-FFR study was to evaluate the safety of using a simplified anti-thrombotic regimen with only upstream dual anti-platelet therapy DAT with aspirin and clopidogrel, compared with anticoagulation plus single- or- DAT therapy in patients with intermediate coronary artery stenosis undergoing FFR calculation during elective coronary angiography. 