AIMS This study was performed to evaluate the functional outcomes of fractional flow reserve (FFR)-guided jailed side-branch (SB) intervention strategy.

METHODS AND RESULTS One hundred and ten patients treated by provisional strategy were consecutively enrolled and SB FFR was measured in 91 patients. SB intervention was allowed when FFR was <0.75. FFR measurement was repeated after SB intervention and at 6-month follow-up angiography. In 26 of 28 SB lesions with FFR <0.75, balloon angioplasty (SB balloon/artery ratio = 0.84 +/- 0.14) was performed and FFR >or=0.75 was achieved in 92% of the lesions although the mean residual stenosis was 69 +/- 10%. During follow-up, there were no changes in SB FFR in lesions with (0.86 +/- 0.05 to 0.84 +/- 0.01, P = 0.4) and without SB angioplasty (0.87 +/- 0.06 to 0.89 +/- 0.07, P = 0.1). Functional restenosis (FFR <0.75) rate was only 8% (5/65). When clinical outcomes of these patients were compared with 110 patients with similar bifurcation lesions treated without FFR-guidance, there was no difference in 9-month cardiac event rates (4.6 vs. 3.7%, P = 0.7) between the two groups.

CONCLUSION In conclusion, FFR-guided SB intervention strategy resulted in good functional outcomes.