Mid- to Long-term Clinical Outcomes of Hancock II Bioprosthesis in Chinese Population

Background： Compared to the Western countries, Chinese patients present a special primary disease spectrum, diverse valvular pathogenesis, and different postoperational anticoagulation strategy. This research aimed to evaluate the mid- to long-term clinical performance of Hancock II bioprosthesis in the Chinese population. Methods： This study retrospectively reviewed all patients who received surgical treatments with at least one Hancock II bioprosthesis implantation from January 2004 to December 2013 at a single center in China. Totally 647 patients were included in the clinical evaluation, and 629 patients were successfully discharge, among whom 605 patients were completely fbllowed-up. The follow-up rate was 96.2%. The mean and median follow-up time was 62.0 ± 59.0 and 56.0 months, respectively, Postoperative outcomes of survival rates, reoperations and valve related morbidities were assessed. Continuous and categorical variables were compared using the t -test and Chi-square test, respectively. Survival and freedom from adverse events were calculated by using a Kaplan-Meier method. Results： The overall in-hospital mortality was 2.8% （18/647） while there were 34 deaths （5.6%, 34/605） in the tbllow-up stage after discharge. The overall survival rate was 94.6% and 82.7% at 5 years and 10 years, respectively. The cumulative survival rate of 10 years was 82.8% in AVR group, 84.4% in MVR group, and 78.4% in DVR group. The overall rate of freedom from reoperations was 95.5% at 5 years and 86.8% at 10 years. The freedom from reoperation at 10 years was 87.0%, 88.1%, and 84.0% in AVR, MVR, and DVR group, respectively. The freedom from morbidities at 10 years was： 90.3% for thromboembolism, 95.2% for hemorrhage, 97.5% for prosthesis endocarditis, 95.9% for paravalvular leak, and 94.6% for structural valve deterioration, respectively. Conclusions： Hancock II bioprosthesis exhibited a satisfactory mid- to long-term durability and promising clinical performance in the Chinese popt, lation. The occurrence rates of death and other adverse events in this single-center study were overall coincident and quite acceptable when compared with existing data.

A novel case of transcatheter mitral valve-in-valve replacement using Mi-thos^TM system

Transcatheter mitral valve replacement(TMVR)has become an alternative to surgical mitral valve replacement for the treatment of patients with severe mitral insufficiency(MI)who are at very high or prohibitive surgical risk.[1]Because of impaired left ventricular dysfunction and previous cardiac surgery,some aged patients with degenerated bioprosthetic mitral valve and mitral regurgitation were refused to redo surgery.[2]Increasing demand are required for minimally invasive treatment of these patients.Hundreds of patients worldwide have been treated with a transcatheter mitral valve-in-ring or valve-in-valve procedure using transcatheter aortic valve.[3]However,rare case of transcatheter mitral valve-in-valve/ring replacement using transcatheter mitral valve system was reported.Here,we reported a successfully case of transcatheter mitral“valve-in-valve”replacement for the treatment of bioprosthetic mitral valve degeneration and severe regurgitation with domestic Mithos^TM valve.

Experimental Study on Modified Treatment andEndothelialization of Bovine Pericardial Valves

The purpose of this study were to confirm whether the modified treatment with L-glutamic acid could attenuate the calcification of the GA-fixed valves and improve its biocompatibility. Pericardial valves were routinely treated with GA and valves were treated with GA and 8% L-glutamic acid. The valves treated with these methods were implanted subcutaneously in rats. Calcium deposits of the valves collected at the 7th, 21st, 60th, 90th day were assessed by atomic absorption spectroscopy, and the pathologic changes were examined by light and electron microscopy. Cultured endothelial cells (ECs ) were seeded onto the valves. The cell counts were determined at the 1st. 4th, 7th, 10th day after seeding. PGI2 in culture medium was tested at the 10th day. Transmission and scanning electron microscopy were used to observe the growth of ECs on the valves.Results showed that subsequent treatment with L-glutamic acid could significantly mitigate calcification of bovine pericardial valves as compared with simple GAfixed valves (P<0. 01). ECs seeded on the GA treated valves died within 4 days.On the valves treated by modified method, ECs could proliferate and release PGI2. It is concluded that treatment with L- glutamic acid can markedly inhibit the calcification and improve the biocompatibility of bioprosthetical valves.

Percutaneous aortic valve replacement using a W-model valved stent： a preliminary feasibility study in sheep

Background Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. However, the clinical experience is still limited. We developed a W-model valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the native aortic valve position.Methods A self expanding nitinol stent with W-model, containing porcine pericardium valves in its proximal part, was implanted in six sheep by means of a 14 French catheter through the right common iliac artery under guidance of fluoroscopy. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. These sheep were followed up shortly after procedure with supra-aortic angiogram and left ventriculography. Additionally, one sheep was sacrificed after the procedure for anatomic evaluation.Results It was possible to replace the aortic valve in the beating heart in four sheep. The procedure failed in two sheep due to coronary orifice occlusion in one case and severe aortic valve regurgitation in the other case. One sheep was killed one hour after percutaneous aortic valve replacement for anatomic evaluation. There were no signs of damage of the aortic JntJma, or of obstruction of the coronary orifice,Conclusions Percutaneous aortic valve replacement with a W-model valved stent in the beating heart is possible. Further studies are mandatory to assess safety and efficacy of this kind of valved stent in larger sample size and by longer follow-up period.

Mitigated calcification of glutaraldehyde-fixed bovine pericardium by tannic acid in rats

Background Bioprosthetic heart valves derived from glutaraldehyde （Glut）-fixed xenografts have been widely used to replace diseased cardiac valves. However, calcification and degeneration are common following their implantation. Inflammation is closely associated with calcification of Glut-fixed xenografts via macrophage infiltration. Tannic acid （TA） possesses anti-inflammatory effects. This study was designed to investigate the anti-calcification of TA treatment on the Glut-fixed bovine pericardium （BP） in a rat subdermal model. Methods Fresh BP was divided into two groups （10 in each group） and separately subjected to different fixation procedures as follows： （1） Glut group： fixation with 0.6% Glut alone; （2） Glut/TA group： fixation with 0.6% Glut and subsequent 0.3% TA. Then the BP samples were subdermally implanted in juvenile male Sprague-Dawley rats and explanted 21 days after implantation. Each explanted BP sample was divided into three parts for calcium content analysis von Kossa＇s staining and immunohistochemical staining, and reverse transcription-polymerase chain reaction study. Results The data from quantitative calcium analysis and von Kossa＇s staining showed that Glut-fixed BP developed significantly more calcification than Glut/TA-fixed BP （（90.3＋32.5） mg/g dry weight vs （6.4_＋1.3） mg/g dry tissue, P 〈0.01）. Immunostaining demonstrated lower matrix metalloproteinase-9 and tenascin-C expression as well as macrophage infiltration into Glut/TA-fixed BP than in its Glut-fixed counterpart （P 〈0.01 for all）. Additionally, the reverse transcription-polymerase chain reaction study showed that higher levels of expression of matrix metalloproteinase-9 and tenascin-C mRNA occurred within Glut-fixed BP than within the Glut/TA-fixed ones （P 〈0.01 for all）. Conclusion TA exerts excellent anti-calcification effects on Glut-fixed BP via inhibiting macrophage infiltration and expression of matrix metalloproteinase-9 and tenascin-C.