Influence of dual antiplatelet therapy duration on neointimal condition after second-generation drug-eluting stent implantation

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 mm(3)/mm; longer DAPT group, 0.19 +/- 0.27 mm(3)/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.