Abstract Objective: To evaluate the changes of the mitral valve geometrics and the degrees of moderate mitral regurgitation (MR) in patients undergoing aortic valve replacement (AVR) for aortic stenosis (AS). Methods: A retrospective analysis study of intraoperative transesophageal echocardiography (TEE) and postoperative transthoracic echocardiography (TTE) was performed in 49 patients diagnosed with pure AS combined with moderate MR, who underwent AVR from January 2013 to December 2017. TEE was used to evaluate the direct geometric changes of the mechanical effects on mitral annulus after AVR. TTE was used to evaluate the changes of MR after operation. All patients underwent TTE during the midterm follow-up. The mean follow-up time was 40.21 months. Results: All of the 49 patients had moderate MR. Anterolateral-posteromedial diameter, anterior-posterior diameter, and mitral annular area were significantly reduced after AVR, while no significant changes were found in the intraoperative left ventricular loading conditions before and after AVR. The degree of mitral valve regurgitation, left ventricular size, left atrial size, left ventricular end-diastolic volume, and left ventricular to aortic pressure gradient were significantly reduced before discharge, and midterm follow-up showed good results. Conclusion: This study supports the belief that aortic outflow tract obstruction and an actual mechanical compression of the anterior mitral annulus after AVR would cause reduction in MR. Ventricular remodeling would also cause reduction in MR with time going on. Patients with AS, especially young patients with moderate MR, were most likely to benefit from AVR in early time.

Abstract Objective: To investigate whether low bleeding influences the early outcomes after off-pump coronary artery bypass grafting (CABG). Methods: Retrospective analysis of ischemic heart disease patients who underwent off-pump CABG from January 2013 to December 2017. Patients were divided into low-bleeding group (n=659) and bleeding group (n=270), according to total drainage from chest tube during the first postoperative 12 hours. Clinical material and early outcomes were compared between the groups. Results: Baseline was similar in the two groups. Operation time was 270±51 min in the low-bleeding group and 235±46 min in the bleeding group (P<0.0001). The low-bleeding group presented smaller drainage during the first 12 h (237±47 ml) and shorter mechanical ventilation time (6.86±3.78 h) than the bleeding group (557±169 ml and 10.66±5.19 h, respectively) (P<0.0001). Hemodynamic status was more stable in the low-bleeding group (P<0.0001) and usage rate of more than two vasoactive agents in this group was lower than in the bleeding group (P<0.0001). Number of distal anastomosis, reoperation for bleeding, suddenly increase in chest tube output, intensive care unit (ICU) stay, hospital stay, and other early outcomes had no statistical significance between the groups (P>0.05). Conclusion: Postoperative bleeding < 300 ml/12 h in off-pump CABG patients did not require blood product transfusion and reoperation and that would contribute to reduction in mechanical ventilation time and maintaining hemodynamic stability. Bleeding < 800 ml during the first postoperative 12 h did not increase infection rates and ICU length of stay.

Abstract Objective: This study aims to compare the early and medium outcomes of on-pump beating-heart (OPBH) coronary artery bypass grafting (CABG) and off-pump CABG (OPCABG) in patients with left ventricular ejection fraction (LVEF) between 30% and 40%. Methods: This is a retrospective study of ischemic heart disease patients with LVEF between 30% and 40% who underwent surgical revascularization from January 2013 to December 2017. Patients were divided into OPBH group (n=44) and OPCABG group (n=68), according to the surgical method. Clinical material with early and medium outcomes were investigated and compared between these groups. Results: The two groups had similar baseline. Two OPBH patients and 3 OPCABG patients died in the hospital, which had no statistical significance (P>0.05). OPBH patients received a greater number of grafts (3.74±0.84) and presented more improved LVEF (45.92±7.11%) than OPCABG patients (3.36±0.80) and (42.81±9.29%), respectively, which had statistical significance (P<0.05). An increased amount of drainage during the first 12 hours was found in the OPBH group (P<0.05). Reoperation for bleeding, duration of mechanic ventilation, and other early outcomes had no statistical significance between the two groups. During the medium-time follow-up, OPBH patients showed significantly lower major adverse cardiovascular events (MACE)-free survival time (P=0.049) than OPCABG patients. Conclusion: The OPBH technique was a safe and an acceptable alternative for surgical revascularization in patients with moderate left ventricular dysfunction which provided better mid-term MACE-free survival compared with OPCABG.

RESUMEN El desarrollo del gas de lutita en el mundo ha significado una revolución en el campo de la energía; en China, durante los útlimos años se ha convertido en un tema importante. Las lutitas, ricas organicamente, están ampliamente distribuidas en China y la comercilización inicial de gas de lutita ha sido lograda; sin embargo, la investigación, exploración y desarrollo de este producto permanence en etapas prematuras. Los problemas se presentan en las tecnologías clave, la innovación, los mecanismos institucionales, la protección ambiental y otros aspectos de la industria. La exploración del gas de lutita y el desarrollo industrial en China se pueden mejorar a partir de las experiencias de otros países y con su fortalecimiento en el mercado, acompañado del apoyo de políticas gubernamentales. Gracias a sus condiciones geológicas únicas, China puede acelerar la introducción de innovación técnica y establecer sus sistemas y métodos únicos para la exploración y desarrollo del gas de lutita.

ABSTRACT Shale gas development throughout the world has resulted in a revolution in the field of global energy and has also become an important topic in China in recent years. While organic-rich shale is widely distributed in China and the initial commercialization of shale gas has been achieved, the research, exploration, and development of shale gas remain at an early stage. Problems exist with crucial technologies, innovation, institutional mechanisms, environmental protection, and other aspects of the industry. The shale gas exploration and development industry in China can learn from the experiences of other countries and strengthen its position in the market, with the support of new government policy. Given its unique geological conditions, China should speed up the introduction of technical innovation and establish its unique systems and methods for shale gas exploration and development.