Background: Fractional flow reserve (FFR) is correlated with angiographic and intravascular ultrasound assessments of stent placement. Post-stenting FFR has been described as a good predictor of clinical events after 6 months.
Objective: To evaluate the feasibility and clinical impact of targeting an FFR > 0.95 via incremental in-stent inflation pressures.
Methods: In this multicenter prospective study, 100 consecutive patients underwent FFR measurement at baseline, after balloon predilatation, and after stenting with 4-atm inflation pressure increments from 8 to 20 atmospheres. Inflations were stopped when FFR increased above 0.95 and angiographic stenosis was less than 20%.
Results: FFR > 0.95 was achieved in 81% of cases; this FFR target was reached at 8 atm in 47% of patients, 12 atm in 16 %, 16 atm in 15%, and 20 atm in 3%. Fifty percent of patients with adequate angiographic result had an FFR less than 0.95 and needed further higher inflations. FFR was correlated with residual stenosis when the total procedure was evaluated, and this correlation persisted when in-stent inflations alone were considered. Final FFR was significantly correlated with anginal status after 6 months.
Conclusions: Angiography guided PCI does not allow optimization of FFR. Since optimal post stenting FFR is correlated to better anginal status at 6-months, this suggests that FFR guided PCI is required to achieve optimal functional results of PCI.