Serial optical frequency domain imaging in STEMI patients: the follow-up report of TROFI study.
AIMS
To investigate the incidence of incomplete stent apposition and to explore the impact of the presence of thrombus and protruding plaque after stent implantation on neointima formation at follow-up in ST-segment elevation myocardial infarction (STEMI) patients with serial optical frequency domain imaging (OFDI) investigations.


METHODS AND RESULTS
In a multi-centre study, 141 patients with ST elevation myocardial infarction <12 h from onset were randomized to either PPCI with thrombectomy (TB) using an Eliminate catheter (TB: n = 71) or without TB (non-TB: n = 70). OFDI after drug-eluting stenting was performed using TERUMO OFDI system. Per protocol, at follow-up 49 patients segments were reimaged. At post-procedure and follow-up, there were no differences in stent and lumen areas between the two groups. At follow-up, per strut-level analysis, percentage of incompletely apposed struts was 0.42 ± 0.94 vs. 0.38 ± 0.77% (P = 0.76), and percentage of covered struts was 92.7 ± 7.2 vs. 94.4 ± 9.2% (P = 0.47) in the TB and non-TB groups, respectively. There was a positive correlation between intra-stent structure (ISS) volume at post-procedure and the neointima volume at 6-month follow-up (Pearson's r = 0.409, P = 0.04). Up to 12 months, there have been two and four patients having target vessel failure in the TB and in the non-TB groups, respectively.


CONCLUSIONS
In patients with STEMI, there were no significant differences in OFDI parameters between TB and non-TB groups at both post-procedure and 6-month follow-up. However, ISS volume at post-procedure was positively associated with neointimal volume at 6-month follow-up.