Impact of chronic outward force on arterial responses of proximal and distal of long superficial femoral artery stent.

BACKGROUND: Self-expanding nitinol stent (SENS) implantation is commonly oversized in the superficial femoral artery (SFA), and leads to chronic outward force (COF) and in-stent restenosis (ISR). This study aimed to investigate the impact of COF of oversizing SENS on ISR of SFA. METHODS: In patients with implanted SENS in SFA, intimal hyperplasia especially between proximal segment and distal segment was evaluated by quantitative angiography, and the impact of COF on mid-term angiographic outcomes was investigated. In addition, porcine model with implanted SENS was used to evaluate the impact of COF on angiographic and histopathologic outcomes at 1 month. Excised stented arteries were evaluated by histopathologic analysis. RESULTS: We analyzed 65 SENS in 61 patients with follow-up angiography at 6 months to 1 year. The baseline diameter was 6.8 ± 0.71 mm and length were 97.0 ± 33.8 mm for the SENS. The ratio of the diameter of the stent to the reference vessel was 1.3 ± 0.24 at the proximal portion and 1.53 ± 0.27 at the distal portion (P < 0.001). In the long SFA stent, stent-to-vessel ratio was significantly higher in the distal stent than in the proximal stent (1.3 ± 0.2 vs. 1.55 ± 0.25, P = 0.001). ISR incidence was higher at the distal stent (37.3% vs 52.6%, P = 0.029). All 11 pigs survived for 4 weeks after SENS implantation. The vessel diameter was 4.04 ± 0.40 mm (control group) vs 4.45 ± 0.63 mm (oversized group), and the implanted stent diameter was 5.27 ± 0.46 mm vs. 7.18 ± 0.4 mm (P = 0.001). The stent-to-vessel diameter ratio was 1.31 ± 0.12 versus 1.63 ± 0.20 (P < 0.001). After 4 weeks, restenosis % was 29.5 ± 12.9% versus 46.8 ± 21.5% (P = 0.016). The neointimal area was 5.37 ± 1.15 mm2 vs. 8.53 ± 5.18 mm2 (P = 0.05). The restenosis % was 39.34 ± 8.53% versus 63.97 ± 17.1% (P = 0.001). CONCLUSIONS: COF is an important cause of restenosis in the distal portion of the SFA stent. Optimal sizing of the SFA stent is important to reduce the incidence of restenosis. Therefore, COF was an important factor of restenosis following distal SFA stenting.

Three-year major clinical outcomes of phosphorylcholine polymer- vs biolinx polymer-zotarolimus-eluting stents: A propensity score matching study.

There are limited long-term outcome data comparing BioLinx polymer (B)-zotarolimus-eluting stents (ZES) with phosphorylcholine polymer (P)-ZES. The aim of this study was to compare the efficacy and safety of B-ZES with P-ZES in patients who underwent percutaneous coronary intervention (PCI) during a 3-year follow-up period.One thousand two hundred fifty four patients who underwent PCI with P-ZES (Endeavor [ZES-E] or Endeavor sprint [ZES-S], n = 356) or B-ZES (Endeavor resolute [ZES-R] or Resolute Integrity [ZES-I], n = 889) were enrolled. The primary endpoint was major adverse cardiac events (MACE); the composite of total death, non-fatal myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), non-target vessel revascularization (Non-TVR), and the secondary endpoint was stent thrombosis (ST).After PSM, 2 propensity-matched (PSM) groups (275 pairs, n = 550, C-statistic = 0.730) were generated. During the 3-year follow-up period, the cumulative incidence of MACE (hazard ratio [HR], 1.525; 95% confidence interval [CI], 0.920-2.526; P = .101) and ST (HR, 1.248; 95% CI, 0.335-4.4649; P = .741) were similar between P-ZES and B-ZES after PSM. However, TLR rate was significantly higher in ZES-S than ZES-I (11.3% vs 3.8%, log rank P = .029) and TVR rate was higher in ZES-S than ZES-R (14.1% vs 4.8%, log rank P = .025).In this single-center, all-comer registry, despite different polymers, P-ZES, and B-ZES showed comparable safety and efficacy during a 3-year follow-up period after PCI.