Analysis of risk factors for in-stent restenosis and reocclusion after coronary stent implantation in advanced-age patients

Objective To investigate risk factors for in-stent restenosis and reocclusion after coronary stent implantation in aged patients. Methods 131 patients diagnosed with chronic total occlusion and old myocardial infarction due to coronary stenosis were recruited in this retrospective study from Mar 2004 to May 2015. Patients were divided into 50 to 59 years old group (n=51), 60 to 69 years old group (n=43), and 70 to 80 years old group (n=37) to study coronary lesion characteristics. In-stent restenosis and reocclusion were detected at 6, 12, 18, and 24 months after coronary stent implantation. Results Before coronary stent implantation, the incidence rate of type 2 diabetes was significantly increased with three increasing age groups: 9.8% at ages 50-59 group (n=5), 18.6% at ages 60-69 group (n=8), and 27.0% at ages 70-80 group (n=10) (all P 20 mm), eccentric coronary lesions, serious angle of coronary lesions, irregular coronary lesions, proximal coronary curvature, moderate to severe calcified coronary lesions, coronary restenosis (90%-99% or 100%), and complex bifurcation lesions were significantly elevated with three increasing age groups (P <0.01 or P <0.05). The ratios of patients with in-stent restenosis at 24 months after coronary stent implantation were significantly elevated with three increasing age groups: at 9.8% (n=5), 18.6% (n=8), and 27.0%(n=10) for 90%-99% restenosis sub-group, and at 5.9% (n=3), 14.0% (n=6) and 24.3% (n=9) for 100% restenosis sub-group, respectively (all P<0.05 or P<0.01). Conclusions Type 2 diabetes is an independent risk factor for complex coronary lesions in aged patients. Complex coronary lesions, three or more stents, and long coronary stents may lead to in-stent restenosis and reocclusion after coronary stent implantation in aged patients. Key words: Coronary artery disease; Angioplasty, transluminal, percutaneous coronary; Coronary stenosis