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.

Inclusion Criteria:

• All patient regardless of sex, or age were eligible for the study if they were scheduled for an elective coronary angiography using a femoral approach, and were agreeable to participate in the study after signing informed consent, and had a coronary stenosis in any major native epicardial coronary artery between 50-70% determined by quantitative angiography that was an adequate target for FFR at the discretion of the operator.

Exclusion Criteria:

• Exclusion criteria included patients requiring mandatory DAT, patient undergoing radial access due to concomitant anticoagulation, patients with contra-indications or intolerant to DAT, patients with severe left ventricular hypertrophy defined as a wall thickness greater than 14 mm by echocardiography in the septal or lateral wall, patients with hypertrophic cardiomyopathy, left ventricular function less than 30%, severe aortic valvular stenosis defined as an aortic valve area of less than 1 cm2, presenting with an acute coronary syndrome in the past two weeks, hemodynamic instability, cardiogenic shock, reported allergy to clopidogrel, aspirin or bivalirudin, planned to be anticoagulated during or previous to the time of the coronary angiography, using Prasugrel or Ticagrelor, patients with coronary arteries unsuitable for FFR calculation due to severe tortuousity and/or calcification, lesions supplied by a bypass conduit, any mental condition rendering the subject incapable to understand the nature, scope, and possible consequences of the study such that the patient is unable to give appropriate informed consent or refusal or inability to sign an informed consent .