Nine-month angiographic and two-year clinical follow-up of novel biodegradable-polymer arsenic trioxide-eluting stent versus durable-polymer sirolimus-eluting stent for coronary artery disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Despite great reduction of in-stent restenosis, first-generation drug-eluting stents (DESs) have increased the risk of late stent thrombosis due to delayed endothelialization. Arsenic trioxide, a natural substance that could inhibit cell proliferation and induce cell apoptosis, seems to be a promising surrogate of sirolimus to improve DES performance. This randomized controlled trial was to evaluate the efficacy and safety of a novel arsenic trioxide-eluting stent (AES), compared with traditional sirolimus-eluting stent (SES).</p><p><b>METHODS</b>Patients with symptoms of angina pectoris were enrolled and randomized to AES or SES group. The primary endpoint was target vessel failure (TVF), and the second endpoint includes rates of all-cause death, cardiac death or myocardial infarction, target lesion revascularization (TLR) by telephone visit and late luminal loss (LLL) at 9-month by angiographic follow-up.</p><p><b>RESULTS</b>From July 2007 to 2009, 212 patients were enrolled and randomized 1:1 to receive either AES or SES. At 2 years of follow-up, TVF rate was similar between AES and SES group (6.67% vs. 5.83%, P = 0.980). Frequency of all-cause death was significantly lower in AES group (0 vs. 4.85%, P = 0.028). There was no significant difference between AES and SES in frequency of TLR and in-stent restenosis, but greater in-stent LLL was observed for AES group (0.29 ± 0.52 mm vs. 0.10 ± 0.25 mm, P = 0.008).</p><p><b>CONCLUSIONS</b>After 2 years of follow-up, AES demonstrated comparable efficacy and safety to SES for the treatment of de novo coronary artery lesions.</p>

Short-term safety and efficiency of cryoablation for renal sympathetic denervation in a swine model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Renal sympathetic nerves are involved in the reflective activation of the sympathetic nervous system in circulatory control. Catheter-based renal denervation (RDN) ameliorated treatment-resistant hypertension safely, but 10%-20% of treated patients are nonresponders to radiofrequency denervation. The purpose of this study was to investigate the safety and efficiency of cryoablation for sympathetic denervation in a swine model and to explore a new way of RDN.</p><p><b>METHODS</b>Seven swines randomly assigned to two groups: Renal cryoablation (CR) group and control group. The control group underwent renal angiogram only. The CR group underwent renal angiogram plus bilateral renal cryoablation. Renal angiograms via femoral were performed before denervation, after denervation and prior to the sacrifice to access the diameter of renal arterial and the pressure of aorta abdominalis. Euthanasia of the swine was performed on 28-day to access norepinephrine (NE) changes of the renal cortex and the changes of renal nerves.</p><p><b>RESULTS</b>Cryoablation did not induce severe complications at any time point. There was no significant change in diameter of renal artery. CR reduced systolic blood pressure (BP) from 145.50 ± 9.95 mmHg at baseline to 119.00 ± 14.09 mmHg. There was a slight but insignificant decrease in diastolic BP. The main nerve changes at 28-day consisted of necrosis with perineurial fibrosis at the site of CR exposure in conjunction with the nerve vacuolation. Compared with the control group, renal tissue NE of CR group decreased by 89.85%.</p><p><b>CONCLUSIONS</b>Percutaneous catheter-based cryoablation of the renal artery is safe. CR could effectively reduce NE storing in the renal cortex, and the efficiency could be maintained 28-day at least.</p>

Intravascular ultrasound assessment of chitosan/heparin layer-by-layer self assembly coating stent on late stent malapposition and vessel remodeling in porcine model / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate late stent malapposition or vessel remodeling post chitosan/heparin layer-by-layer self assembly coating stent (LBL) implantation in porcine.</p><p><b>METHODS</b>A total of 32 stents [bare metal stent (BMS, n = 9), sirolimus-eluting stent (SES, n = 11) and LBL (n = 12)] were implanted into coronary arteries of 16 porcine. Intravascular ultrasound (IVUS) was performed immediately after stenting and at 1 month after stenting to measure vessel area (VA), stent area (SA) and lumen area (LA). Neointima area (NA) was measured at 1 month post stenting by IVUS to detect signs of stent malapposition and to determine remodeling index (RI). Histopathology was performed at 1 month post stenting to observe vessel wall structure and stent malapposition status.</p><p><b>RESULTS</b>No sign of stent malapposition was detected, VA and SA/LA were similar among groups immediately after stent implantation. At 1 month follow-up, none of three groups showed stent malapposition. VA, SA, NA and LA were (7.30 ± 0.77), (6.83 ± 0.76), (1.40 ± 0.96) and (5.43 ± 0.88) mm(2) in LBL group, (7.13 ± 0.69), (6.63 ± 0.71), (0.28 ± 0.35) and (6.34 ± 0.89) mm(2) in SES group, (7.48 ± 0.70), (7.00 ± 0.52), (2.69 ± 1.58) and (4.31 ± 1.28) mm(2) in BMS group. VA and SA were similar among groups (all P > 0.05). LA in LBL group was smaller than SES group (P < 0.01) and significantly larger than in BMS group (P < 0.05).NA in LBL group was larger than SES group (P < 0.01) and significantly smaller than in BMS group (P < 0.05).RI in LBL, SES and BMS groups was 0.95 ± 0.07, 1.02 ± 0.04 and 0.98 ± 0.04 (P > 0.05).</p><p><b>CONCLUSIONS</b>There is no late stent malapposition or abnormal remodeling post LBL, SES and BMS implantation up to 1 month in this porcine model. LA in LBL group is smaller than SES group and larger than BMS group at 1 month after implantation in this porcine model.</p>

Safety and efficacy of cobalt chromium alloy based sirolimus-eluting stent with bioabsorbable polymer in porcine model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>First generation drug-eluting stents (DESs) were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice.</p><p><b>METHODS</b>Cobalt chromium based DES with bioabsorbable polymer (Simrex stent) as well as control stents (Polymer stent and EXCEL(TM) stent) were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography (QCA) analysis, histomorphometry, and electron-microscopical follow-up were performed.</p><p><b>RESULTS</b>A total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis (%DS), late loss (LL), and percent area stenosis (%AS) of Simrex was (12.9 ± 0.4)%, (0.35 ± 0.02) mm, and (24.5 ± 4.2)%, respectively, without significant difference in comparison to commercialized EXCEL(TM) stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4 - 12 weeks for Simrex to complete its re-endothelialization process.</p><p><b>CONCLUSIONS</b>Cobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.</p>