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

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 degrees onan angiogram(n = 58). The vessel wall injuries and ISA were evaluated by OCT. The results were compared with non-angled lesions (<45 degrees, 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 centreofangle(6.59 +/- 6.81, mm(3) x 10(2)) washigher than in the distal sub-segment (2.21 +/- 2.87, mm(3) x 10(2), P < 0.001), in the proximal sub-segment (4.14 +/- 5.34, mm(3) x 10(2), P = 0.02), and in the non-angled group (3.30 +/- 2.81, mm(3) x 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.