Impacts of lesion angle on incidence and distribution of acute vessel wall injuries and strut malapposition after drug-eluting stent implantation assessed by optical coherence tomography

Abstract

Aims: To investigate the impact of lesion angle on the incidence and distribution of acute vessel wall injuries and incomplete stent apposition (ISA) following second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Several ex vivo studies demonstrated that angled arterial walls are exposed to imbalanced mechanical stress from deployed stents.

Methods and results: We included 243 lesions treated with a single DES (148 everolimus-eluting stent and 95 zotarolimus-eluting stent). Angled lesions were defined as lesions with angle ≥45° on an angiogram (n = 58). The vessel wall injuries and ISA were evaluated by OCT. The results were compared with non-angled lesions (<45°, n = 185). The incidence of instent dissection, thrombus, and ISA was significantly higher in the angled group than in the non-angled group (84.5 vs. 63.2%, P < 0.01; 55.2 vs. 35.1%, P < 0.01; 75.9 vs. 44.9%, P < 0.001, respectively). In the angled group, the normalized tissue protrusion volume around the centre of angle (6.59 ± 6.81, mm(3) × 10(2)) was higher than in the distal sub-segment (2.21 ± 2.87, mm3 × 10(2), P < 0.001), in the proximal sub-segment (4.14 ± 5.34, mm3 × 10(2), P = 0.02), and in the non-angled group (3.30 ± 2.81, mm3 × 10(2), P < 0.001). The incidence of major adverse cardiac events within 12 months was similar between the groups.

Conclusions: Angled coronary lesions had a higher incidence rate of OCT-detected vessel wall injuries and ISA compared with non-angled lesions following second-generation DES implantation. Further studies are needed to understand the long-term clinical significance of these findings.

Keywords: Drug-eluting stent; Optical coherence tomography; Post-stent complication.