Noninvasive ultrasound evaluation of vascular endothelial function and circulating endothelial progenitor cells on restenosis after percutaneous coronary intervention

Abstract

Objective To investigate the changes of vascular endothelium function detected by noninvasive ultrasound and circulating endothelial progenitor cells (EPCs) on in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Methods Totally 220 AMI patients with previous PCI and coronary angiography follow-up (3-147 months) were recruited from medical outpatient and inpatient clinic. All patients were divided into ISR (n=29) and nonISR (n=191) group. Endothelium-dependent flow-mediated dilation (FMD), nitroglycerin mediated dilatation (NMD), intima-media thickness (IMT) and circulating EPCs levels were measured by flow cytometry and echocardiography. IMT, FMD, NMD, CD133/KDR+ EPCs, CD34/KDR+ EPCs, CD34+ EPCs, CD133+ EPCs, KDR+ EPCs were compared using an independent sample t-test between the two groups (ISR and nonISR). To assess which factors were associated with ISR, statistical analysis was performed through single and multiple factors unconditioned logistic regression analysis. Results Compared with nonISR patients, ISR patients had significantly unfavorable results on HbA1c, urea nitrogen and creatinine (t value=-1.769, -3.671 and 2.77 respectively, all P<0.05), and received more intensive treatment of ACEI/ARB, insulin, vasodilator and diuretics (χ2 value=3.832, 6.567, 2.072, 16.540 and 4.949 respectively, all P<0.05). Meanwhile, there were no difference on IMT and FMD between ISR and nonISR groups. However, patients with ISR had lower NMD compared with nonISR patients (t value=-2.338, P<0.05). Patients with ISR had lower circulating CD34/KDR+ EPCs, CD133/KDR+ EPCs and KDR+ EPCs counts compared with nonISR patients (t value=2.298, 3.986, 2.106 respectively, all P<0.05). Logistic regression analysis revealed that HbA1c, NMD, diuretics and glyceryl trinitrate were independent predictors of ISR. Conclusions Cardiovascular risk factors , including poor control of HbA1C , damaged arterial smooth muscle, declined vascular function, and reduced circulating CD34/KDR+ EPCs, CD 133/KDR + EPCs and KDR+ EPCs, promoted the development of ISR after percutaneous coronary intervention in elderly patients with PCI. High-frequency ultrasound technology can be a fast, non-invasive method in measurement of endothelial function indirectly reflecting the damage of coronary artery, and can be used as a perfect tool to monitor the changes of peripheral vascular function and provide important information on risk prediction in patients after PCI. Key words: Ultrasonography; Percutaneous coronary intervention; Acute myocardial infarction; In-stent restenosis; Endothelial function; Endothelial progenitor cells