Serial Assessment of Vessel Interactions After Drug-Eluting Stent Implantation in Unprotected Distal Left Main Coronary Artery Disease Using Frequency-Domain Optical Coherence Tomography

Objectives This study sought to assess stent-vessel interactions after drug-eluting stent (DES) implantation in unprotected left main coronary artery (ULM) by frequency-domain optical coherence tomography (FD-OCT). Background Percutaneous coronary intervention using DES in ULM has been increasingly performed in routine practice. Recently, FD-OCT assessments of DES-vessel interactions have been used as surrogates for DES safety; however, there are no FD-OCT studies in ULM. Methods We prospectively enrolled 33 consecutive patients with ULM disease treated with sirolimus- (n = 11) and everolimus-eluting stents (n = 22). FD-OCT assessments were performed post-percutaneous coronary intervention and at 9-month follow-up. Three different segments of ULM were compared: distal (DIS), bifurcation (BIF), and ostial-body (BODY). The primary endpoints were percentages of uncovered and malapposed struts at 9-month follow-up, and the secondary endpoint was neointimal hyperplasia area. Results We analyzed 25,873 stent struts. Significant differences were demonstrated for percentage of uncovered struts (3.4%, 11.7%, and 18.7%, respectively for DIS, BIF, and BODY; p < 0.05 for all the comparisons). Malapposition was also more common in BODY (5.3%) than in DIS (0.6%) and BIF (2.0%) segments (p < 0.05 for BODY vs. DIS, and BODY vs. BIF). Equivalent neointimal hyperplasia areas were demonstrated in all segments. Acute malapposition rates led to different patterns of DES-vessel interactions at 9-month follow-up. Conclusions Distinct patterns of DES-vessel interactions were demonstrated in different segments of ULM. Acute stent strut malapposition affects these findings.