dvanced congestive heart failure (CHF) has been generally believed to be progressive and associated with substantial morbidity and mortality. 1 Cardiac transplantation has been the only curative treatment for end-stage CHF, but the number of heart transplantation is severely limited, especially in Japan. Instead, there has been increasing application of left ventricular assist systems (LVAS) for the treatment of severe CHF. 2 The LVAS consists of an electrically or pneumatically driven pump, installed either extra-or intra-corporeally. The main purpose of the LVAS is a "bridge to transplantation", but recent refinements in the engineering of the devices have enabled long-term use as "destination therapy". 3 The pump transports blood from the left ventricle (LV) to the ascending aorta, thereby restoring the systemic circulation to normal. Moreover, the pump provides potent pressure and volume unloading of the LV. These favorable effects have lead to a new indication for the use of LVAS, because there is increasing evidence that mechanical unloading with the LVAS occasionally reverses the progress of CHF and permits device explantation. [4][5][6][7] This "bridge to recovery" with the LVAS is an attractive strategy for the treatment of patients with severe CHF for whom heart transplantation or permanent LVAS use has been the only treatment option. Interest relates not only to the treatment of severe CHF, 8-10 but also to the study of the mechanisms involved in the remodeling process and its regression (ie, "reverse remodeling"). The pathophysiological mechanisms involved in the reverse remodeling induced by mechanical unloading have become a focus of intense research, with the hope of establishing reliable indicators of sustained recovery and strategies to enhance this process. 8,9 Clinically, there still exist many questions about the application of this strategy. The evaluation of LV function while on the LVAS and the prediction of sustained recovery after device explantation have been the major concerns regarding the use of this strategy for a wider range of patients. 10,11 How to evaluate LV function and decide when LVAS explantation is performed are the focus of studies. 6,10,12 Furthermore, to promote the recovery process, pharmacological, 4,7 surgical 13,14 or cell-based therapies, 15,16 combined with LVAS, are under intense investigation. In Japan, the donor supply is severely limited and almost all patients on LVAS are waiting nearly 3 years for a heart transplant. 2 Therefore, we have been forced to adopt more generous criteria for LVAS weaning compared with those used in studies from other countries. Based on this, we evaluated the factors that predict successful explantation of the LVAS and sustained functional LV recovery to determine if we can expand the population of patients who can benefit from the LVAS as a bridge to recovery. Both the clinical and laboratory findings, including our own of bridge to recovery experience with mechanical circulatory support, are reviewed. Clinical ObservationsAn earl...

Semicrystalline network polymers were obtained by the Diels–Alder (DA) reaction of furyl‐telechelic poly(ε‐caprolactone) and tris(2‐maleimide ethyl)amine. Controlling the rates of crystallization and crosslinking reaction gave materials with various properties. Curing at a temperature much below Tm of poly(ε‐caprolactone), at which crystallization proceeded first followed by DA reaction, gave a hard and stiff material, whereas curing above Tm gave a soft and stretchable one. When crystallization and crosslinking were promoted simultaneously, tough and ductile materials were obtained. Structural analysis of the network polymers showed that the variation in the properties was derived from the difference in the crystallinity, crystallite size, and network structure. Therefore, materials with various mechanical properties, from soft to hard, could be obtained by simple thermal treatment. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

cute cardiogenic shock has a high mortality, irrespective of the original etiology such as myocardial infarction, post-cardiotomy heart failure (HF), acute myocarditis, refractory fatal arrhythmia, and acute decompensation of chronic HF. 1 Rescue with mechanical circulatory support remains the only means of survival in most of these patients. 2 Over the past decade, an increasing number of assist devices have been developed for both temporary and long-term circulatory support. 3 The extended indications, development of better support devices and management strategies, and improved results mandate all cardiology professionals to acquire knowledge of the currently available assist devices. Unfortunately, in Japan only a limited number of devices has been approved for clinical use and limited facilities have a ventricular assist system (VAS) program for long-term use. 4 However, extracorporeal devices for acute HF are readily available for rapid implementation in the most facilities. These first-line devices for acute cardiogenic shock aim at stabilizing the patient's general condition by providing enough systemic circulation and improvement of native heart function to enable eventual removal of the device. If recovery is unlikely, the patients can be transferred to a larger facility with a VAS program for longer term support aiming at either a bridge to transplantation or chronic assistance. 5 Although the number of heart transplantations is severely limited, new modalities for long-term circulatory support, such as permanent therapy using continuous flow implantable VAS, is becoming a reality. 6 Therefore, the short-term support to bridge the patient to these long-term therapies is becoming a more and more important strategy for the treatment of severe HF. Paracorporeal devices were initially developed to support acute HF patients for several weeks to months; 7 however, this type of device has been the only choice as a bridge to transplantation for several years in Japan. 4 Our accumulated experience of chronic support using paracorporeal devices may serve as the foundation data for the more currently utilized devices for long-term use.We review the currently available devices that are placed extracorporeally (non-implantable) for both acute and chronic HF. The indications for use, patient management, and overall results are discussed. Extracorporeal Centrifugal Pump and Membrane OxygenationExtracorporeal life support (ECLS) using a centrifugal pump combined with extracorporeal membrane oxygenation (ECMO) is now considered an important tool for treating acute HF in all age groups, including neonates. 8 In the setting of profound cardiogenic shock or cardiac arrest, ECLS is a viable option for resuscitation and initiating circulatory assist. When venous and arterial cannulas are inserted peripherally, the system is called percutaneous cardiopulmonary support (PCPS). 9 Ready-made systems requiring only few minutes of priming time are commercially available. Various conditions causing cardiogenic shock are indicated ...

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