Guidelines recommend shorter duration (1-12 months) for dual antiplatelet
therapy (
DAPT) in the second-generation
drug-eluting stent (DES) era. However, whether shorter
DAPT duration affects
stent strut conditions and neointimal characteristics at mid-term follow-up remains uncertain. Therefore, we studied the relation between
DAPT duration and vascular healing response as assessed by optical coherence tomography (OCT). This study was retrospective observational study. Participants comprised 64 patients who underwent serial OCT at both 9 and 18 months after DES implantation. All patients received
DAPT until the 9-month follow-up then were divided into two groups: 49 patients who continued
DAPT (longer
DAPT group); and 15 patients who stopped taking the P2Y12 inhibitor and were treated with
aspirin alone (shorter
DAPT group) at the 18-month follow-up. Using OCT, we evaluated and compared
stent strut conditions and neointimal characteristics between groups at both 9 and 18 months after
stent implantation. Baseline clinical and procedural parameters were mostly similar between groups. At the 18-month follow-up, no in-
stent thrombus assessed by OCT was observed in either group. No significant differences in OCT characteristics or measurements of
neointima were seen between groups at 9- or 18-month follow-ups. Neointimal volume increased from 9 to 18 months in both groups, with a similar degree of neointimal proliferation in both groups (shorter
DAPT group, 0.23 ± 0.29 mm3/mm; longer
DAPT group, 0.19 ± 0.27 mm3/mm; P = 0.56). In conclusion, interrupting
DAPT 9 months after second-generation DES implantation did not affect the development of in-
stent thrombus, neointimal proliferation or
stent strut coverage at 18-month follow-up compared with continuing
DAPT.