Feasibility of coronary fractional flow reserve with dual anti-platelet therapy in low risk coronary lesions without systemic anticoagulation-results of the SMART-FFR study.

BACKGROUND: Fractional flow reserve (FFR) is used to assess the functional significance of coronary artery stenoses. The optimal anti-thrombotic regimen for FFR has not been studied.

PURPOSE: The goal of this study was to determine whether FFR could be safely performed in Type A coronary lesions, using only upstream dual anti-platelet therapy (DAT) with aspirin and clopidogrel, compared with DAT plus anticoagulation in low risk coronary lesions.

METHODS/MATERIALS: Two hundred patients undergoing FFR for Type A intermediate coronary lesions were blindly randomized into two groups of 100 patients each. Group 1: Upstream DAT, without intra-procedural anti-coagulation and Group 2: Upstream DAT plus intra-procedural bivalirudin. The primary end-points were any coronary thrombotic complications during the index hospital stay, and a composite end-point of any major adverse cardiovascular events (MACE) at 30-days. Secondary end-points included post-procedure troponin levels and TIMI major and minor bleeding scores.

RESULTS: There were no thrombotic complications reported. At 30-days, two MACE occurred in Group 1, and three in Group 2 (p=0.83). No difference was seen in the post-procedure troponin levels (p=0.72), or TIMI bleeding scores study between groups (p=093).

CONCLUSIONS: This initial study evaluating a simplified anti-thrombotic regimen for FFR, suggests that FFR can be performed in low risk coronary lesions using DAT without the need for intra-procedural anticoagulation, with similar results as DAT plus anticoagulation with bivalirudin. Further research in this area is needed to determine the optimal and most cost-effective anti-thrombotic regimen for FFR calculation.