P5753Jailed pressure wire to assess the side branch result for bifurcation lesions treated by provisional stenting strategy: iFR as a new index
Authors: Romero M , Hidalgo F , Ojeda S , Segura J , Suarez De Lezo J , Mazuelos F , Luque A , Lostalo A , Fernandez J , Pan M 
Published: October 2019

Abstract

Purpose
To analyze the feasibility and efficacy of the jailed pressure wire technique for bifurcation lesions treated by provisional stenting strategy and to assess the physiological side branch (SB) result using instantaneous wave free ratio (iFR).

Methods
Between June 2017 and December 2018, 50 patients who presented a bifurcation lesion considered appropriate for provisional stenting strategy were included in the study. Pressure wire was passed to side branch before treatment. Main vessel (MV) and side branch (SB) was predilated at the operator criteria. iFR determination was obtained in the SB baseline and after MV stenting (leaving the pressure wire jailed). Afterwards, the wire was removed to MV ostium to discard the possibility of drift. SB postdilation was performed if SB iFR was less than 0,89 (according to vessel thresholds established in clinical trials), evaluating the result by a new iFR determination.

Results
The mean age was 64±10 years. Sixteen patients (32%) had diabetes. Clinical presentation was stable angina in 26 patients (52%), non-STEMI in 19 patients (38%) and STEMI (non culprit lesion) in 5 patients (10%). The most frequent bifurcation type according to Medina classifications was 1,1,0 (21 patients, 42%). Seventeen patients (34%) had a true bifurcation lesion. The MV and SB reference diameter was 3,0±0,5 mm and 2,25±0,5 mm respectively. Most of the bifurcations were located at the left anterior descending artery/diagonal branch (27 bifurcations, 54%). Ten patients (20%) presented a distal left main bifurcation. Baseline SB iFR was 0,78±0,2. Under continuous SB iFR monitoring MV stenting was performed by trapping the pressure wire. After MV stenting, the SB iFR changed to 0,90±0,1. We confirmed the presence of drift in 5 patients (10%). In these cases, recalibration of the wire and SB rewiring was performed in 4 cases. In the remaining patient, rewiring was not possible even using specific coronary wires.
According to SB IFR, postdilation was necessary in 14 patients (28%). Final SB iFR was 0,94±0,03. A second stent was not necessary in any patient because final SB iFR was higher than 0.89 in all cases. We observed discordance between angiographic and physiological result in 17 cases (34%). All the wires could be removed. Forty wires (80%) were microscopically analyzed. Some grade of microscopic damage was found in 32 wires (80%), all of them distal to the pressure sensor. However, only one of these wires (2%) presented severe damage, and no case of fracture was observed.
After a mean follow up time of 10±6 months only one patient (2%) presented a major cardiac adverse event (acute coronary syndrome due to voluntary cessation of dual antiplatelet therapy).

Conclusions
The use of jailed pressure wire to monitor SB results for bifurcations treated by provisional stenting seems to be safe. The iFR index seems to provide new physiological information about the significance of the SB stenosis.