Vasomotor function and molecular responses following drug-eluting stent in a porcine coronary model

Saint Joseph's Translational Research Institute, Saint Joseph's Hospital of Atlanta, Atlanta, GA, United States.
International journal of cardiology (Impact Factor: 4.04). 06/2012; 160(3):210-2. DOI: 10.1016/j.ijcard.2012.06.018
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Available from: Takamitsu Nakamura
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    • "However, those responses are observed within 15-28 days, and the precise mechanisms of endothelial dysfunction remain unknown. The findings can have implications for the development of more appropriate prostheses, minimizing smooth-muscle cell proliferation34. In the present study, HRV analysis was performed concomitantly with stent implantation, when those biological responses would not have been triggered. "
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    ABSTRACT: Background: The autonomic nervous system plays a central role in cardiovascular regulation; sympathetic activation occurs during myocardial ischemia. Objective: To assess the spectral analysis of heart rate variability during stent implantation, comparing the types of stent. Methods: This study assessed 61 patients (mean age, 64.0 years; 35 men) with ischemic heart disease and indication for stenting. Stent implantation was performed under Holter monitoring to record the spectral analysis of heart rate variability (Fourier transform), measuring the low-frequency (LF) and high-frequency (HF) components, and the LF/HF ratio before and during the procedure. Results: Bare-metal stent was implanted in 34 patients, while the others received drug-eluting stents. The right coronary artery was approached in 21 patients, the left anterior descending, in 28, and the circumflex, in 9. As compared with the pre-stenting period, all patients showed an increase in LF and HF during stent implantation (658 versus 185 ms2, p = 0.00; 322 versus 121, p = 0.00, respectively), with no change in LF/HF. During stent implantation, LF was 864 ms2 in patients with bare-metal stents, and 398 ms2 in those with drug-eluting stents (p = 0.00). The spectral analysis of heart rate variability showed no association with diabetes mellitus, family history, clinical presentation, beta-blockers, age, and vessel or its segment. Conclusions: Stent implantation resulted in concomitant sympathetic and vagal activations. Diabetes mellitus, use of beta-blockers, and the vessel approached showed no influence on the spectral analysis of heart rate variability. Sympathetic activation was lower during the implantation of drug-eluting stents.
    Full-text · Article · Jul 2014 · Arquivos Brasileiros de Cardiologia
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    ABSTRACT: Stents have become a standard of care for the treatment of coronary artery disease. A series of cellular and molecular processes contribute to the vascular response following stent placement. For the purpose of local gene expression studies, metallic stent struts are usually removed from the vessel wall with forceps under a dissection microscope prior to RNA extraction. Main drawbacks of the manual dissection are that it may cause additional tissue damage and compromise the quality of RNA through prolonged tissue handling. In this technical note, we report the recovery of high-quality RNA from atherosclerotic vessels with stent struts left in situ.
    No preview · Article · Jun 2013 · Microvascular Research
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    ABSTRACT: Objectives To assess the late postinterventional response to iliac stenting in atheromatous rabbits using the Xience V everolimus-eluting stent (Xience V EES; Abbott Vascular) and the Resolute zotarolimus-eluting stent (Resolute ZES; Medtronic Vascular) with the MultiLink Vision bare metal stent (BMS; Abbott Vascular) as a reference.Background Xience V EES and Resolute ZES were developed to overcome shortcomings of first-generation DES.Methods Functional and microscopic changes were assessed by organ bath experiments and histopathologic examination. Gene expression was investigated using RT-PCR.ResultsAfter 91 days, re-endothelialization was nearly complete (BMS: 93 ± 3%; Resolute ZES: 92 ± 2%; Xience V EES: 94 ± 3%; P = 0.10). Neointima thickness was similar in Resolute ZES (0.17 ± 0.08 mm) and BMS (0.17 ± 0.09 mm), and reduced in Xience V EES (0.03 ± 0.01 mm; P < 0.0001). Xience V EES had less peri-strut inflammation compared with BMS (P = 0.001) and Resolute ZES (P = 0.0001), while arterial segments distal to Xience V EES were more sensitive to acetylcholine than those distal to BMS and Resolute ZES (P = 0.02). Lectin-like oxidized receptor-1 was overexpressed in stented arteries (P < 0.001), whereas thrombomodulin was downregulated in Resolute ZES (P = 0.01) and BMS (P = 0.02) compared to unstented arteries of rabbits on regular chow. No significant changes were seen for vascular cell adhesion molecule-1, nitric oxide synthase 3, or endothelin-1.Conclusions At 3-month follow-up, nearly complete re-endothelialization was achieved for all stent groups. Xience V EES induced greater suppression of neointimal growth and peri-strut inflammation, higher vasorelaxation to acetylcholine, and expression of thrombomodulin at the level of unstented controls.
    No preview · Article · May 2014 · Journal of Interventional Cardiology
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